JP2019098234A - Biological deodorization method - Google Patents

Abstract

To make it possible to exhibit stable deodorization performance at a low cost and during an extended period even for a malodorous gas of composite odor with variation of an odor concentration and an odor quality.SOLUTION: A biological filter 21, which digests a malodorous gas g by biological treatment, is configured in such a manner that a wood chip 21A is filled at a bulk density within a range of 150 to 500 kg/m, AND a moisture content of the wood chip 21A is so maintained as to be 150% or more and 300% or less by sprinkling performed from above the biological filter 21 by sprinkling means 30. Further, an excess water, which passed the biological filter 21 by circulation means 40, is recovered and is fed to the sprinkling means 30, thereby circulating water to be sprinkled by the sprinkling means 30.SELECTED DRAWING: Figure 2

Description

  The present invention is a biological deodorizing process that deodorizes odorous gases generated when fermenting and decomposing organic wastes such as food waste and food processing residues, and organic matter such as livestock manure and sludge of sewage and sewage treatment using a biological deodorizing system. In particular, the present invention relates to a biological deodorizing method which can exhibit stable deodorizing performance at low cost for a long period of time, even for an odor gas having a complex odor accompanied by fluctuations in odor concentration and odor quality.

  Waste disposal facilities for composting organic wastes such as raw vegetables, fruits, meats, food processing residues, etc. and poultry farming for raising livestock and treating livestock excrement · As a measure against odors and odors in livestock facilities and wastewater and sewage treatment facilities where organic sludge etc. are generated, combustion deodorization method in which odorous substances are oxidatively decomposed and deodorized by combustion, odorous substances are adsorbed by adsorbents such as activated carbon There are known adsorption deodorization methods to deodorize, cleaning deodorization methods (chemical treatment methods) to deodorize chemical substances by contacting chemical substances with chemical substances and biological deodorization methods to decompose odorous substances by microorganisms and deodorize, etc. There is.

Above all, according to the biological deodorization method that causes microorganisms to decompose odorous substances, it is necessary to post-process adsorbents (waste activated carbon etc.), chemical sludge, waste liquid, etc. like combustion deodorization method, adsorption deodorization method, cleaning deodorization method without also generate a residue, odor components are carbon dioxide (CO _2), and water (H ₂ O) harmless substances or SO _4, such as ^- and NO ₃ ^- can be decomposed into inorganic ions such. Also, as the combustion process, dust, dioxins and, since there is no possible to discharge a large amount of CO ₂ and NO _x, a gentle deodorization method environment. Furthermore, since expensive materials such as chemicals are not used, and frequent replacement is required as in the case of adsorbents, no fuel is required, and operating costs can be reduced.

In particular, in recent years there has been a high level of interest in Japan's environmental problems, and with regard to waste disposal, efforts have been made to reduce the amount of incineration by reusing organic waste as a resource from the viewpoint of environmental impact. The method of fermenting and aging waste, composting it, and using it as an organic fertilizer is actively carried out. For this reason, the need for odor control of gas containing odor emitted from such composting facilities is increasing.
In addition, in the livestock industry, about 90% of livestock excrement is composted, but it is difficult to add cost to odor control that does not lead to productivity. Therefore, the deodorization technology whose installation cost and operating cost are cheap is desired for the odor control.

  And, in the composting treatment of organic wastes and livestock manure such as garbage, since it is mainly aerobic fermentation treatment (organic matter decomposition by aerobic microorganisms), the odor generated in the decomposition process (fermentation process) of the organic matter Is a complex odor that has a relatively low concentration and a large air volume, and also contains various odor components, compared to odors generated in chemical factories etc. and odors in livestock night processing facilities and anaerobic fermentation processing facilities Ingredients, concentrations may also vary. For this reason, there is a demand for a deodorizing technique that achieves a deodorizing performance reliably and continuously even with a low concentration and multi-volume odor which is a combined odor containing various odorous components and in which the odorous components and the concentration can also vary.

Here, the soil deodorization method, the rock wool deodorization method, etc. are mainly known as conventional biological deodorization methods.
In the soil deodorization method, the odorous components of the odorous gas sent from under the soil layer dissolve in the water on the surface of the soil particles or adsorb on the surface of the soil particles while passing through the soil layer, and further by soil microorganisms Although it is a deodorizing system by being decomposed, it requires a large site area because the ventilation resistance of the soil layer is high. Therefore, rock wool deodorization has been developed to compensate for the defects, and the use of rock wool can improve the air flow resistance. And, in the rock wool deodorization method, the installation area can be reduced as compared with the soil deodorization method. However, since rock wool is an inorganic substance, it lacks the ability to adsorb odorous components and the activity of microorganisms. For this reason, the device which raises the activity of the microorganism which mixes with organic matter and contributes to deodorization is required.

  For example, Patent Document 1 mainly uses a mixture of inorganic fiber-made granular cotton such as rock wool granular cotton in which particles having a particle size of 1 mm or more and 40 mm or less are mixed, and woody chip; There is disclosed a deodorizing material in which a microbial activity substance consisting of compost manure and excess sludge alone or a mixture of two or more is mixed. In this patent document 1, a wood-based chip is introduced as an organic substance that serves as a carbon source for maintaining the activity of microorganisms that inhabit the rock wool layer, and exhibits an initial adsorption effect.

WO2011 / 024507 Japanese Patent Application Publication No. 2004-024353 Patent document 1: JP-A-2005-246106 Japanese Patent Application Publication No. 2006-035028

However, in the conventional biological deodorizing apparatus using rock wool as a microorganism carrier including the patent document 1, although the initial aeration resistance is improved by the soil deodorizing method, the water management and the microorganism management are difficult, and the pressure by the use The loss was likely to be large. For this reason, it is necessary to apply a high pressure or to increase the volume of the deodorizing material in order to increase and maintain the treatment capacity and treatment efficiency, and it is difficult to reduce the cost. Rock wool materials are also expensive.
In addition, the biological deodorizing device using conventional rock wool as a microorganism carrier is effective for fixed odor gas, but is poor in response to fluctuation of odor concentration and fluctuation of odor quality, and maintains stable deodorizing effect The sex was low. In particular, due to the prior art emphasis on deodorizing efficiency with respect to fixed odorous gases, microorganisms effective for specific odorous components may be infested or seeded, or microbial active substances may be added. In addition to the cost of technological development for adopting microorganisms suitable for odor sources, when a specific microorganism is inoculated, inoculated or inoculated with a microorganism active substance, it is vulnerable to fluctuations in odor concentration and odor quality, and There was a case that a load exceeding the activity was applied. In such a case, although measures to control the odor to be introduced may be considered, the operation management cost becomes expensive.

  Further, in the technology of Patent Document 1, the packing property is also high due to the combination of the inorganic fiber-made granular cotton and the woody chip, and furthermore, the size of the air passage becomes nonuniform. Instead, a large amount of offensive odor is likely to pass through a specific air passage, and the air passage may be easily closed there. For this reason, pressure loss is likely to increase with the introduction of odor, and it is also difficult to maintain high deodorizing efficiency. Naturally, the facility operating cost (power cost) also increases as the pressure loss increases. Furthermore, since the action of biological deodorization is difficult to be obtained unless microbial active substances such as livestock manure, compost manure and surplus sludge are mixed, the management of the microbes is complicated and the price of the material is also expensive.

By the way, in this kind of biological deodorizing apparatus, watering is performed to prevent the drying of the microorganism carrier and maintain the microbial activity. Therefore, in order to reduce the cost, for example, Patent Literatures 2 to 4 disclose a technique that adopts a circulating water sprinkling method in which water of sprinkled water is circulated.
In Patent Document 2, a treated water and an odorous gas introduced from an odorous gas inlet are mutually passed in a countercurrent direction to a countercurrent packed bed filled with a carrier carrying a microorganism, and the countercurrent packed bed is The treated water having passed through and deodorized treated gas is discharged from the treated gas outlet, while the treated water which has passed through the countercurrent packed bed is provided in the downstream direction of the treated water flow, and is filled with a carrier carrying a microorganism. In the deodorizing method for treating the odorous gas by passing the single flow packed bed, the treated water having passed the countercurrent packed bed is allowed to pass through the single flow packed bed, and subsequently, the downstream direction of the treated water flow After being stored in the water storage section provided in the water storage section, circularly passing from the water storage section to the water storage section via the countercurrent packed bed and the single flow packed bed, and passing the single flow packed bed Between before and before reaching the countercurrent packed bed By adding an alkali to serial processing water, discloses a technique for maintaining the pH value of the treated water immediately after passing through the single-flow packed bed 6.5.

  Further, in Patent Document 3, a container into which an offensive odor gas is introduced, a filling carrier which is filled in the container and carries a deodorizing microorganism or an enzyme derived therefrom, and water in the container is sprayed to the filling carrier. A biological water treatment dewatering device of the circulation watering operation type, comprising: a water sprinkler; and a water sprinkler pipe for recovering water in the container as water for water irrigation and circulatingly supplying the water to the water sprinkler, wherein the odorous gas is biologically deodorized. The technique which arrange | positioned the odor substance reduction member which can reduce the at least 1 type or more of odor substance contained in the said water for irrigation in the middle of a water spray piping is disclosed.

  Furthermore, Patent Document 4 is provided separately from a biological deodorizing apparatus of a circulating watering operation type that converts ammonia into nitric acid and / or nitrous acid to deodorize ammonia by microorganisms having a nitrifying action, and the biological deodorizing apparatus, A denitrifying apparatus for converting nitric acid and / or nitrous acid into nitrogen by a microorganism having an action, and an organic matter supplying apparatus for supplying an organic matter serving as a nutrient of the microorganism having the denitrifying action to the denitrifying apparatus In a biological deodorizing method using a biological deodorizing apparatus configured to circulate circulating water between an apparatus and the denitrifying apparatus, nitric acid and / or nitrous acid is reduced by a microorganism having a denitrifying action in the denitrifying apparatus. A technology is disclosed that performs control to maintain the concentration of nitrate nitrogen and nitrite nitrogen contained in the circulating water at a value of 2500 ppm or less by changing to nitrogen.

In the case of a circulating watering system in which water used for watering is circulated, decomposition products produced by decomposition of odorous substances by odorous substances or microorganisms are gradually accumulated in circulating water and become high in concentration, and such odorous substances or decomposition products It is difficult to maintain the deodorizing effect because the activity of the microorganisms is inhibited by the sprinkling of the circulating water concentrated.
Therefore, in Patent Documents 2 to 4, the pH of circulating water is adjusted, odor substances and decomposition products are adsorbed by an odor substance reducing member such as an ion adsorbent, and a denitrification step is provided in a circulating water channel. Technology is used.
However, on the other hand, there is a problem that equipment and control become complicated, and new costs such as material cost, equipment cost, and running cost are required.

  Then, this invention makes it a subject to provide the biological deodorizing method which can exhibit the deodorizing performance stable for a long time at low cost also with respect to odor gas of the complex odor accompanied by the fluctuation | variation of odor concentration or odor quality.

According to the biological deodorizing method of the first aspect of the present invention, a biofilter formed by packing wood chips in a bulk density range of 150 to 500 kg / m ³ is sprayed with water from above, and the surplus passed through the biofilter Water is circulated as the water spray, the moisture content of the wood chip is maintained at 150% or more and 300% or less, and the odor gas introduced from below is digested by the biological treatment with the biofilter. It is digested by treatment.

The biofilter is made by packing wood chips at a bulk density of 150 to 500 kg / m ³ , and digests odor gas introduced from the bottom by biological treatment.
Here, the term "digestion by biological treatment" means that the odorous components in the odorous gas are decomposed and deodorized by the enzyme action or the like of the microorganism.
In addition, the wood chips are raw wood (stems, whole trees, shrubs, end trees, branches, pruning branches, rootstocks, etc.), lumbers (backboards, scraps, peeled cores, etc.), building demolition materials, building materials, packaging materials Plywood, laminated wood, particle board, waste pallets and the like are cut or crushed by a chipper, shredder, mill, crusher, hammer, punching or the like to obtain a wood piece, which is sieved and a predetermined size is selected.

The present inventors have repeatedly conducted intensive research on biofilters that can stably exhibit long-term deodorizing performance and can be configured at low cost stably even for odorous gases with a complex odor accompanied by fluctuations in odor concentration and odor quality. As a result, it has been found that, by constructing the biofilter with wood chips, the ability to follow odor gas of complex odor accompanied by fluctuation of odor concentration and odor quality is high, and high deodorizing effect can be stably maintained for a long time The
In particular, it has been found that biofilters formed by depositing wood chips are less likely to clog and have less increase in pressure loss due to use if they have a predetermined bulk density, and that high deodorizing effect over a long period of time is maintained. According to the experiments of the present inventors, the bulk density for depositing wood chips is specified to be in the range of 150 kg / m ³ or more and 500 kg / m ³ or less.
In addition, this bulk density (Kg / m ³ ) is a value of the initial setting, and the volume of the wood chip of the predetermined size is determined from the integration of the packing height filled with wood chips and the cross sectional area of the biofilter. It is calculated by dividing the total weight of the wood chips of the predetermined size by the calculated volume value.

Further, the watering is performed on the biofilter from above on the side opposite to the side on which the odor gas is introduced. The water spray wets the biofilter to maintain the wood chips at a predetermined moisture content. Watering may be intermittent or continuous.
And the said watering is circulated. That is, water sprayed from above the biofilter to pass through the biofilter from below, that is, excess water flowing down without being retained in the biofilter is recovered and used again as water spray. The water for sprinkling may be configured to be supplemented with water from the outside in addition to the excess water that has passed through the biofilter.

  In the biological deodorizing method of the invention according to claim 2, a biofilter for digesting odor gas by biological treatment is constituted by wood chips, and a large number of biofilters are disposed in a housing below having an inlet through which the odor gas is introduced. A floor material having vents is accommodated, and the wood chips are filled thereon, and the water content of the wood chips is maintained at 150% or more and 300% or less by water sprinkling made from above the biofilter by water sprinkling means It is Further, the surplus water having passed through the biofilter is recovered by a circulating means and supplied to the water sprinkling means, whereby the water sprinkled by the water sprinkling means is circulated.

The above-mentioned biofilter is made by filling wood chips and digests odorous gas by biological treatment.
Here, the term "digestion by biological treatment" means that the odorous components in the odorous gas are decomposed and deodorized by the enzyme action or the like of the microorganism.
In addition, the wood chips are raw wood (stems, whole trees, shrubs, end trees, branches, pruning branches, rootstocks, etc.), lumbers (backboards, scraps, peeled cores, etc.), building demolition materials, building materials, packaging materials Plywood, laminated wood, particle board, waste pallets and the like are cut or crushed by a chipper, shredder, mill, crusher, hammer, punching or the like to obtain a wood piece, which is sieved and a predetermined size is selected.

The present inventors have repeatedly conducted intensive research on biofilters that can stably exhibit long-term deodorizing performance and can be configured at low cost stably even for odorous gases with a complex odor accompanied by fluctuations in odor concentration and odor quality. As a result, it has been found that, by constructing the biofilter with wood chips, the ability to follow odor gas of complex odor accompanied by fluctuation of odor concentration and odor quality is high, and high deodorizing effect can be stably maintained for a long time The
In particular, the biofilter formed by depositing wood chips has high ability to follow odor gas of complex odor accompanied with fluctuation of odor concentration and odor quality by control of predetermined moisture content, and it is stable and high for a long time It was determined that the deodorizing effect was maintained, and it was specified by the experiments of the present inventors that the water content was maintained at 150% or more and 300% or less by watering. That is, by maintaining the water content of the wood chips at 150% or more and 300% or less by watering, high treatment capacity can be obtained due to the high water retention property of the wood chips, and the odor of the complex odor accompanied by the fluctuation of odor concentration and odor quality Even for gas, the high water retention property of wood chips can stably exhibit a long-term high deodorizing effect.
The moisture content of the wood chip represents the ratio of the water weight to the weight (total dry weight, dry basis) of the wood chip not containing water, and is calculated by the following equation (A).
Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100 (A)
The total dry weight is 105.degree. C., which is a value in a dry state until the change in weight disappears.

The housing is formed of at least three surfaces of a lower surface and left and right side surfaces, and accommodates a floor material and a biofilter thereon. There is provided an inlet below which the odorous gas is introduced, so that the odorous gas introduced does not leak to the outside. On the other hand, the odorous gas introduced from the lower inlet rises, passes through the floor material and the biofilter disposed thereon, and is released from the upper surface of the biofilter, so the upper side of the biofilter Is released. The air released from the biofilter may be released to the atmosphere without forming the upper surface of the housing, or the air opening may be provided even if the upper surface is formed, and the air is discharged from the biofilter from the air opening. Air may be released to the atmosphere.
In addition, since the water of the sprinkling water is circulated, the surplus water of the sprinkling water is usually below the housing in order to recover the water which has passed through the biofilter and the floor material and reached the bottom of the housing and is circulated to the sprinkling means A drainage outlet is also provided.

  Further, the floor material is accommodated in the housing together with the biofilter, and defines a space of a predetermined volume between the bottom of the biofilter and the bottom of the housing, ie, It is disposed in the housing at a predetermined distance from the bottom of the housing. Therefore, the wood chips are loaded on the floor in the housing. The floor material is a space defining a space of a predetermined volume communicating with the introduction port of the housing into which the odor gas is introduced, and the floor material is provided with a large number of vent holes penetrating vertically. Therefore, the odorous gas introduced from the inlet below the housing is circulated in the entire bottom surface direction of the biofilter by a space of a predetermined volume, and is input to the biofilter through the air vents of the floor material. It will be.

And as for the said flooring, it is preferable that the opening of the said ventilating hole is in the range of 20 mm-100 mm, and an opening ratio is in the range of 5% or more and 95% or less.
According to the experiments of the present inventors, according to the floor material disposed in the lower part of the biofilter filled with wood chips of the above-mentioned predetermined size, the fluid loss generated there by the control of the size and density of the vents. The structure of such floor material is specified by the opening ratio and the opening ratio, since it is possible to set the minimum of the floor material and to prevent the load from being applied by the predetermined fluid resistance even if the introduced amount of odorous gas fluctuates. It is
Here, the openings and the opening ratio represent the size and density of the vents of the floor material. The above-mentioned openings also indicate, for example, the top-bottom width or the left-right width at the opening (space) per eye formed by crossing a vertical line and a horizontal line such as mesh, etc. If it is a square, it corresponds to one side of a square. The air holes do not specify the shape of the circular eye or square, but the air resistance is small and the surface area is large. Therefore, a circular hole with a circular cross section or a square with a square cross section Holes are preferred.
The opening of the floor material and the opening ratio are measured in accordance with the standard of sieve wire mesh, and the plane area of the floor material is S, the number of floor materials is M, and the diameter of the vertical and horizontal lines is d. When it is assumed, the opening is calculated by the following equation (B), and the aperture ratio is calculated by the following equation (C).
Opening A (mm) = S / M-d (B)
Opening ratio ε (%) = (A / A + d) ² × 100 (C)

  The water sprinkling means supplies water to the biofilter contained in the housing by water sprinkling from the upper side opposite to the odor gas introduction side. The water spray makes the biofilter wet and maintains the moisture content of the wood chips at 150% or more and 300% or less. Watering may be intermittent or continuous.

The circulating means is water that has been sprayed from above the biofilter and passed from above to below the biofilter, ie, flows down through the vents of the floor material down the housing without being retained in the biofilter. Surplus water is collected and supplied to the water sprinkling means to circulate the water of the water sprinkling. The excess water that has passed through the biofilter may be collected at the lower portion in the housing and stored there, or a separate water receiving portion may be provided outside the housing and stored there.
Further, the water for sprinkling may be configured to be replenished with water from the outside in addition to the surplus water that has passed through the biofilter.

According to the biological deodorization method of the invention of claim 3, when water sprayed to the biofilter is 100 vol% of water sprayed per unit time, the water passed through the bio filter is 36 vol% or more, from the outside The amount of water to be replenished is 64% by volume or less.
Here, 36% by volume or more of water passed through the biofilter and 64% by volume or less of externally replenished water means that the water for sprinkling water sprayed from the sprinkling means to the biofilter is newly taken from the outside The excess water of the watering collected by the circulation means may be used, that is, only the circulation water may be used, or even when the water is newly replenished from the outside, 100% of the total volume of water for watering, The proportion of water to be replenished is 64% or less, meaning that the excess water recovered by the circulating means, that is, 36% by volume or more of the circulating water, is included.

According to the biological deodorizing method of the first aspect of the present invention, it is constituted by filling wood chips within a bulk density of 150 to 500 kg / m ³ , and the water sprinkled on the biofilter is circulated by the circulating means. I am doing it. As a result, low-cost and long-term stable deodorizing performance is exhibited even for an odor gas having a complex odor accompanied by a change in odor concentration or odor quality.

  As a result of intensive research and research, the present inventors constructed a biofilter with wood chips as a microorganism carrier and circulated water sprinkling water to the biofilter by circulation means. Function as a biofilter that digests odorous components by biological treatment with microorganisms at an early start-up, even if the microorganisms do not feed or breed microorganisms, or do not add microbial active substances for imparting microbial activity, etc. In addition, it has been found that the deodorizing effect can be sustained over a long period of time, and there is little increase in pressure loss with time, and the ability to follow fluctuations in odor concentration and odor quality is high. The present invention has been completed on the basis of this.

That is, the air flow resistance is suppressed to a low level by filling the wood chips in a volume density of 150 to 500 kg / m ^{3 to form} the biofilter, and the water is sprayed to the wood chips by the circulation means. By recycling the water which has passed through, the decomposition products (metabolites) produced by the decomposition of the odorous components by the microorganisms or the microorganisms are distributed evenly in the biofilter.
Therefore, the narrowing, clogging, and clogging of the air passage of the biofilter are unlikely to occur, and an increase in pressure loss over time can be suppressed.

In particular, due to the water retention characteristics of wood chips by watering, microbial species that can cope with the decomposition of various odors are also easily propagated. And, in the biofilter in which wood chips are packed in a bulk density range of 150 to 500 kg / m ³ , the flow path is wide, water is uniformly distributed throughout the biofilter, and the high water retention of wood chips , The effect of alleviating concentration fluctuation and pH fluctuation is high. For this reason, it is hard to produce the fall of pH one by one, and can maintain pH of a neutral region.
Therefore, even for various odors, a microorganism species that can cope with its decomposition is likely to be active, and its activity can be sustained. In particular, even if the water that has passed through the biofilter by recycling means is reused as water sprinkling, the activity of the microorganism and the decrease in the activity of the microorganism hardly occur. In addition, in biofilters composed of such wood chips, the odorous gas is easily dissolved in the liquid phase around the wood chips due to the water retention characteristics and high surface area of the wood chips, and the amount of contact between the wood chips and the odor gas Processing capacity is high.
Therefore, even if the odor concentration or odor quality to be introduced fluctuates, stable deodorizing performance can be maintained for a long time.

Furthermore, air resistance can be suppressed by filling wood chips within a bulk density of 150 to 500 kg / m ^{3 to form} a biofilter, and clogging is less likely to occur, and pressure loss increases with time. Also, the running cost for blowing off the odorous gas can be reduced.
Also, wood chips can be obtained inexpensively. Moreover, since the biofilter configured as described above has high processing capacity and can suppress pressure loss, a predetermined high throughput can be ensured even with a small volume. And, even if the water that has passed through the biofilter by recycling means is reused as water sprinkling, the buffer effect of pH fluctuation is high due to the high water retentivity of the biofilter. It is not necessary to provide means to control the amount of odor gas introduced or to control the amount of odor gas introduced.
Therefore, the material cost, the equipment cost, and the running cost can be suppressed and the cost can be reduced.

  According to the biological deodorizing method of the second aspect of the present invention, the biofilter comprising wood chips is provided, the water content of the wood chips is maintained at 150% or more and 300% or less by watering, and the biofilter is used. Water to be sprayed is circulated by circulation means. As a result, low-cost and long-term stable deodorizing performance is exhibited even for an odor gas having a complex odor accompanied by a change in odor concentration or odor quality.

  As a result of the intensive research conducted by the present inventors, the present inventors constructed the biofilter with wood chips as a microorganism carrier, and circulated the water sprinkling water to the biofilter by the circulating means, and the water content of the wood chips was By maintaining the microorganism at 150% or more and 300% or less, it is possible to quickly start up the odorous component of the microorganism by using the microorganism, even if it does not feed or breed microorganisms or add a microorganism active substance or the like for imparting microbial activity. It can function as a biofilter that digests by chemical treatment, and the increase in pressure loss over time is also small, and the odor concentration fluctuation and odor quality fluctuation are highly responsive, and the deodorizing effect can be long over a long period of time It has been found that it can be sustained, and the present invention has been completed based on this finding.

That is, by configuring the biofilter with wood chips, the air flow resistance can be suppressed to a low level by selecting the size of the wood chips, the air flow resistance can be suppressed to a low level, and watering for maintaining the water content of the wood chips at a predetermined level. In addition, by recycling the water that has passed through the biofilter by the circulation means, decomposition products (metabolites) generated by the decomposition of the odor by the microorganism and the microorganism are distributed without bias in the biofilter.
Therefore, the narrowing, clogging, and clogging of the air passage of the biofilter are unlikely to occur, and an increase in pressure loss over time can be suppressed.

In particular, due to the characteristics of wood maintained at a moisture content of 150% or more and 300% or less, microbial species that can cope with the decomposition of various odors are also easily propagated. And, in the biofilter composed of wood chips, the flow path can be broadened by selecting the size thereof, and water is uniformly distributed throughout the biofilter, and the wood chip maintaining the moisture content at 150% or more and 300% or less Has a high effect of alleviating pH fluctuations. For this reason, it is hard to produce the fall of pH one by one, and can maintain pH of a neutral region.
Therefore, even if it is many odors, the microbial species which can respond to the decomposition are easy to be active, and the activity can be sustained. In particular, even if the water that has passed through the biofilter by the circulation means is reused as water sprinkling, it is difficult to cause a reduction in the activity of microorganisms and a decrease in the activity of microorganisms. Also, in a biofilter consisting of wood chips whose water content is maintained at 150% or more and 300% or less, the odorous gas is easily dissolved in the liquid phase around the wood chips due to the water retention characteristics and high surface area of the wood chips. In addition, since the amount of contact between the wood chips and the odorous gas is large, the processing capacity is high. Furthermore, pressure loss can be mitigated also by the rectification effect by the many vents of the floor material disposed under the biofilter, and processing efficiency can be enhanced.
Therefore, even if the odor concentration or odor quality to be introduced fluctuates, stable deodorizing performance can be maintained for a long time.

Furthermore, by configuring the biofilter with wood chips, the air flow resistance can be suppressed by selecting the size of the wood chips, and clogging is less likely to occur, so there is little increase in pressure loss with time, so odor gas blowing Running costs can be reduced.
Also, wood chips can be obtained inexpensively. Moreover, a biofilter consisting of wood chips maintained at a water content of 150% or more and 300% or less has high processing capacity and can suppress pressure loss, so the biofilter has a predetermined high throughput even with a small volume. Can be secured. And, even if water that has passed through the biofilter by cyclic means is reused as water spray, the buffer effect of pH fluctuation is high due to the high water retentivity of the biofilter, so the decomposition products generated by the decomposition of pH and odor of circulating water It is not necessary to provide means to control the amount of odor gas introduced or to control the amount of odor gas introduced.
Therefore, the material cost, the equipment cost, and the running cost can be suppressed and the cost can be reduced.

  According to the biological deodorizing method according to the invention of claim 3, the water sprayed to the biofilter is 36 vol% or more of the water passing through the biofilter when the amount of water sprayed per unit time is 100 vol%. By making the externally replenished water 64% by volume or less, the cost can be low and the high deodorizing ability can be maintained.

  The inventors of the present invention accumulated the earnest experimental research, and as a result, in a biological deodorizing apparatus using wood chips of a predetermined size as a microbe carrier of a biofilter, surplus water having passed through the biofilter is recovered by circulation means for watering The water may be externally replenished when it is circulated in water, but it has been found that the deodorizing ability decreases when the ratio of the replenishment water in the water for sprinkling increases, and the present invention is completed.

  That is, if the ratio of replenishing water in the water for sprinkling is 64% by volume or less and the excess water having passed through the biofilter, that is, the ratio of circulating water to be circulated is 36% by volume or more, Or in addition to the effect of Claim 2, it is low cost and can maintain high deodorizing ability.

FIG. 1 is a conceptual diagram for explaining the flow until the odor gas is introduced into the biological deodorizing apparatus according to the embodiment of the present invention. FIG. 2 is an explanatory view showing the entire configuration of the biological deodorizing apparatus according to the embodiment of the present invention. FIG. 3 (a) is an explanatory view showing a floor material of the biological deodorizing apparatus according to the embodiment of the present invention and the configuration around it, and FIG. 3 (b) is a biological deodorizing apparatus according to the embodiment of the present invention 3 (c) is a cross-sectional view taken along line X-X of FIG. 3 (b). FIG. 4: is a principal part enlarged view explaining the structure in the housing of the biological deodorizing apparatus based on embodiment of this invention. FIG. 5 is a graph showing changes in pressure loss over time in the biological deodorizing apparatus of the example according to the embodiment of the present invention. FIG. 6 is a graph showing the time-dependent temperature change of the biofilter in the biological deodorizing apparatus of the example according to the embodiment of the present invention. Fig.7 (a) is the elements on larger scale explaining an example of the protruding wall provided in the housing of the biological deodorizing apparatus based on embodiment of this invention, FIG.7 (b) is biological organisms based on embodiment of this invention It is the elements on larger scale explaining another example of the protruding wall provided in the deodorizing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that, in the embodiment, the same symbols and symbols in the drawings are the same or corresponding functional parts, and thus the description thereof will not be repeated.

First, the flow until the odor gas G is introduced into the biological deodorizing apparatus 10 according to the embodiment of the present invention will be described with reference to FIG.
The odor gas G targeted by the biological deodorizing apparatus 10 according to the present embodiment is, for example, a waste processing facility that composts (composts) food waste such as raw vegetables, fruits, meats and food processing residues, and livestock. Are odors that arise from poultry and livestock facilities that produce livestock and composting livestock excrement, sewage and sewage treatment facilities where agricultural sludge etc. occur, agricultural settlement drainage treatment facilities, food factory drainage treatment facilities, etc. And the odor generated during aerobic fermentation and decomposition of organic matter. The odor gas G produced during the aerobic fermentation and decomposition of such organic substances is, for example, ammonia, trimethylamine, dimethyl sulfide (DMS), hydrogen sulfide, methyl sulfide, methyl disulfide, methyl mercaptan, volatile fatty acid ( VFA), an aldehyde component such as acetaldehyde and the like, and an odor component such as terpenes, and it is a combined odor containing a plurality of odor components and various odors. In addition, the odor from the facility that aerobically ferments and decomposes organic matter is lower than the odor of the livestock's human waste treatment facility and anaerobic treatment and fermentation facility, and has a large air volume, and the odor quality, odor concentration, air volume, etc. Greatly fluctuate.

That is, in FIG. 1, in the composting device 2, aerobic fermentation / decomposition treatment of organic waste or livestock manure is performed, and an odor gas G is generated. In this composting apparatus 2, for example, the bacteria-retaining chip having aerobic bacteria attached to organic waste such as collected food residue, pruned branches or composting material such as livestock manure or sewage sludge is put, temperature, oxygen, humidity Aerobic fermentation and decomposition treatment is carried out by controlling the surrounding annular conditions such as in a predetermined manner. A wide variety of devices have been proposed for composting by aerobic fermentation. For example, there is a device for composting in a closed concrete housing called a biocell system. In particular, in recent years, the composting method in a closed container or in a building has become mainstream due to the influence on the surrounding environment, the problem of odor and the like.
And odor gas G which arose in the aerobic fermentation and decomposition process process in this composting device 2 is collected suitably using a blower, a fan, etc., and it is made as pressure wind to biological deodorizing device 10 concerning this embodiment. It will be sent.

In addition, before the odor gas G discharged | emitted from the composting apparatus 2 is sent to the biological deodorizing apparatus 10, the odor concentration is reduced by the chemical deodorizing apparatus 3 as needed.
Furthermore, the scrubber device 4 removes harmful substances and dust contained in the odor gas G discharged from the composting device 2 as necessary. The scrubber device 4 uses, for example, a washing and collecting device (dust removing device, gas washing device) to collect and separate particles in the odor gas G with a washing solution or a liquid film.

In particular, when the acid scrubber treatment is performed by the scrubber device 4 at the stage before the biological deodorizing device 10, the biological deodorizing device 10 is clogged with an odor containing sulfur compounds and ammonia generated from sludge of a sewage treatment plant ( Constriction, obstruction) can be prevented and the load can be reduced.
It should be noted that if there is a wet scrubber 4 that captures and removes dust by spraying water, the odor gas G is humidified before introducing the odor gas G to the biological deodorizing device 10, so that the odor is high in humidity. Gas G can be introduced into the biofilter 21. If the humidity of the odorous gas G introduced into the biofilter 21 can be increased, it is also effective in suppressing the temperature fluctuation of the biofilter 21 as described later.

  The odor gas G discharged from the composting device 2 and appropriately through the chemical deodorizing device 3 and the scrubber device 4 is sucked and pressurized by the blower 5 and blown to the biological deodorizing device 10. In addition, the blower 5 which guides odor gas G to the biological deodorizing apparatus 10 is inverter-controlled so that rotation speed control can be performed as needed. Therefore, for example, when the treated amount of the odorous gas G discharged from the composting device 2 and the odor concentration are extremely small, the energy saving operation can be performed by reducing the rotational speed. However, the blower 5 is operated at all times to send an air flow to the biological deodorizing device 10, thereby preventing clogging (constriction, blockage) of the biofilter 21 of the biological deodorizing device 10. The capacity of the blower 5 is determined by the processing amount of the odor gas G, the volume, size, etc. of the biofilter 21. According to the biological deodorizing apparatus 10 of the present embodiment, the pressure loss is small as described later. In addition, since an increase in pressure loss over time is also suppressed, a high throughput can be ensured even with a low-performance, small-sized fan, without using an expensive one with high blowing capacity.

  Next, the whole structure which implements the biological deodorizing apparatus 10 which concerns on embodiment of this invention is demonstrated with reference to FIG.

  The biological deodorizing apparatus 10 of the present embodiment includes a deodorizing unit 20 in which a biofilter 21 for digesting odor gas G by biological treatment and a floor material 22 provided under the biofilter 21 are accommodated in a housing H, The water sprinkling means 30 sprinkling water from the upper part of the biofilter 21 constituting the deodorizing processing portion 20, the water receiving portion 41 collecting and storing the water sprinkling water from the water sprinkling means 30, and the water receiving portion 41 are supplied to the water sprinkling means 30 The supply path 42 to be circulated is configured, and the surplus water that has passed through the biofilter 21 and the floor material 22 is recovered and circulated to the water sprinkling means 30.

  In the deodorization processing unit 20 of the present embodiment, the floor material 22 is opened via the support legs 23 in a box-like housing H formed of reinforced concrete, and the lower surface and the left and right side surfaces are opened upward. It arrange | positions and the wood chip | tip 21A is filled on it, and the biofilter 21 is formed.

  The size of the housing H is designed in accordance with the amount of odor gas G to be treated, the desired rate of deodorization, and the like. For example, the volume is set to about 1.5 to 4 times the tunnel volume of the composting facility, and in terms of pressure loss, the height h of the biofilter 21 is 1.5 m or more and 3.5 m or less as described later preferable. The housing H is not limited to reinforced concrete, and may be made of a material that is resistant to corrosion, and a heat insulator may be used on the outside. It is also possible to maintain the growth environment of microorganisms favorably by the heat insulating material and to stabilize the deodorizing efficiency. However, in the present embodiment, as described later, since the deodorizing efficiency can be stably maintained regardless of the seasonal variation, there is no problem even if the heat insulating material is not used.

  At the bottom of the housing H, an introduction port 24 for introducing the odorous gas G pressure-fed by the blower 5 is provided, and an introduction consisting of a duct or the like connecting the output of the blower 5 to the introduction port 24 at the bottom of the housing H The odor gas G pressure-fed from the blower 5 is introduced from the inlet 24 through the passage 24 a. The inlet 24 and the inlet 24a have such a size that pressure loss does not occur therein. For example, the inlet 24 is provided below any one of the four side surfaces of the housing H.

  Then, in the housing H of the space partitioned by concrete, as shown in FIG. 3, a plurality of support legs 23 for maintaining the floor material 22 at a predetermined height are erected on the bottom surface of the housing H, The floor material 22 is placed on the support legs 23. The support leg 23 is made of, for example, concrete formed in a columnar or cylindrical shape, and is designed and arranged to withstand the pressure of the floor material 22 and the pressure of the biofilter 21 which is made wet by watering. In this manner, after the support legs 23 are erected on the floor surface of the housing H, the floor material 22 is disposed thereon, and the floor material 22 is held at a predetermined height, so that the bottom and the floor of the housing H A predetermined space S communicating with the inlet 24 a of the housing H is defined between the members 22. That is, the bottom of the housing H and the floor material 22 are spaced apart by the support leg 23, and a predetermined space S is formed between the bottom of the housing H and the floor material 22. By providing the predetermined space S communicating with the inlet 24 a of the housing H, the odor gas G introduced from the inlet 24 a of the housing H can be distributed to the entire bottom of the housing H.

The floor material 22 is thus placed on the support legs 23 erected at the bottom of the housing H, and is spread over the entire cross section in the housing H, and the wood chips 21A are loaded thereon.
For example, as shown in FIG. 3, the floor material 22 is provided with a plurality of through holes 22a of a predetermined shape which penetrates the wall thickness, and a predetermined thickness which is provided with a plurality of grooves 22b which penetrate the wall thickness on the side surface A plurality of concrete parts are combined and laid in concrete H.

  Thus, the floor material 22 is provided with, for example, a vent hole 22A formed by a combination of a vent hole 22A which is a through hole 22a having a cylindrical shape (circular cross section) and a groove 22b provided around the part. The odor gas G introduced from the inlet 24a of the housing H and circulated through the entire bottom of the housing H is introduced into the wood chip 21A laid on the floor 22 through the vents 22A of the floor 22. It will be done. Note that the vent holes 22A are distributed over the entire floor material 22, thereby enabling uniform supply of the odorous gas G to the entire area of the biofilter 21.

Here, according to experiments of the present inventors, the floor material 22 disposed under the biofilter 21 filled with the wood chips 21A of the predetermined size is controlled by controlling the size and density of the air holes 22A. Since the fluid loss generated there can be set to the minimum, and even if the introduced amount of odorous gas fluctuates, the load can not be applied by a predetermined fluid resistance. About the open and specified by the aperture ratio.
That is, if the opening area and the opening ratio of the vents 22A provided in the floor material 22 are too large, the mechanical strength is weak, and a tough material is required, resulting in a cost increase. On the other hand, even if the opening area and the opening ratio are too low, the pressure loss is high, and a strong air flow is required, resulting in an increase in running cost.
Therefore, the floor material 22 preferably has an opening of the vent holes 22A in the range of 20 mm to 100 mm, and an opening ratio in the range of 5% to 95%.

In addition, the said opening and the aperture ratio represent the magnitude | size and air density of ventilation hole 22A of the flooring 22. As shown in FIG. The above-mentioned openings also indicate, for example, the top-bottom width or the left-right width at the opening (space) per eye formed by crossing a vertical line and a horizontal line such as mesh, etc. If it is a square, it corresponds to one side of a square. The air holes do not specify the shape of the circular eye or square, but the air resistance is small and the surface area is large. Therefore, a circular hole with a circular cross section or a square with a square cross section Holes are preferred.
In addition, the opening of the floor material 22 and the open area ratio are measured according to the standard of sieve wire mesh, the plane area of the floor material is S, the number of floor material floors is M, and the wire diameter of vertical and horizontal lines is d. When this is done, the opening is calculated by the following equation (B), and the aperture ratio is calculated by the following equation (C).
Opening A (mm) = S / M-d (B)
Opening ratio ε (%) = (A / A + d) ² × 100 (C)

  As described above, in the floor material 22 on which the wood chips 21A having a predetermined diameter are laid, the pressure drop is within the range of 20 mm to 100 mm, and the opening ratio is within the range of 5% to 95%. The load is reduced by a predetermined fluid resistance even if there are fluctuations or variations in the amount of introduced odor gas. More preferably, the opening is in the range of 30 mm to 90 mm, and the aperture ratio is 10% to 90%.

  Further, in FIG. 3, in order to enhance the rectification effect and to reduce the influence of pressure fluctuation due to the flow velocity of the odor gas G, the diameters of the plurality of vents 22A are directed upward, ie, the biofilter 21. The diameter is gradually reduced toward the side. Furthermore, according to Bernoulli's theorem, the odor gas G from the blower 5 may be adjusted to reduce the change in flow rate by adjusting the size, shape and aperture ratio of the vents 22a.

In addition, in FIG. 3, the plurality of air holes 22A of the floor material 22 are formed in a circular cross-sectional shape, that is, a circle when viewed from the front, but in the case of practicing the present invention, the cross-sectional oval It may be oval, triangular in cross section, rectangular in cross section, hexagonal in cross section or the like. A shape with small fluid resistance is preferable, for example, a cross section having a circular shape, an oval shape, an oval shape, a square shape, etc. is preferable. Further, the configuration of the housing H, the support leg 23 and the floor material 22 is made of concrete. In the case of practicing the present invention, another material may be used as long as the material is resistant to corrosion and the predetermined strength can be ensured.

Thus, in the present embodiment, the floor material 22 is installed on the support legs 23 erected at the bottom of the housing H, and the wood chip 21A forming the biofilter 21 is filled on the floor material 22.
At this time, as shown in FIG. 4, a plate-like projecting wall 28 is installed on the floor material 22 so as to surround along the side wall of the housing H, and wood is provided in the space surrounded by the plate-like projecting wall 28. The chip 21A may be filled. Thus, the installation area (bottom area) of the biofilter 21 filled with the wood chips 21A is reduced by the amount of protrusion of the projecting wall 28 with respect to the laying area of the floor material 22. That is, the bottom area of the biofilter 21 disposed on the floor material 22 is smaller than the top area of the floor material 22 on which the biofilter 21 is placed. That is, the floor area (plane area) on the input side of the lower end portion of the biofilter 21 is smaller than the plane area on the output side of the floor material 22 without the side surface of the biofilter 21 and the side surface of the floor material 22 coinciding .

  Thus, the plate-like projecting wall 28 is provided on the floor material 22 so as to surround along the side wall of the housing H, and the area ratio of the input side area where the odor gas G is input to the biofilter 21 is By making the area smaller than the area of the upper surface of the floor material 22, the rectification effect can be enhanced, the odor leakage along the side wall of the housing H can be suppressed, and the odor gas more uniformly over the entire area of the biofilter 21 G can be supplied to increase the processing efficiency with respect to the volume of the biofilter 21. Furthermore, the increase in pressure change at the boundary between the floor material 22 and the biofilter 21 makes it easy to eliminate the clogging on the input side where the odor gas G is introduced into the biofilter 21. However, if the installation area of the biofilter 21 is too small relative to the installation area of the floor material 22 having the vent holes 22A of a predetermined cross-sectional area at a predetermined aperture ratio, the plate-like protruding wall 28 When the flow velocity of the odorous gas G passing through the floor material 22 at the entrance is greatly restricted, the pressure loss becomes large to secure a predetermined throughput, and the cost increase due to the increase of the sending pressure of the blower 5 Become. Therefore, in consideration of pressure loss, for example, the protruding length of the protruding wall 28 is set in the range of 150 mm to 1000 mm, more preferably in the range of 250 mm to 600 mm.

Here, although it has been described that the projecting wall 28 is provided between the biofilter 21 and the housing H on the floor material 22, the inner side wall of the biofilter 21 itself is located inside from above the position of the floor material 22 (biofilter 21) may be formed so as to protrude toward the side 21).
Further, the projecting wall 28 does not have to be provided up to the position of the filling height h of the biofilter 21 as shown in FIG. 4A, and as shown in FIG. For example, the height position may be 10 cm to 20 cm. In any case, the leakage of the odor gas G rising along the wall surface of the housing H may be prevented.

  Furthermore, when implementing this invention, as shown in FIG.7 (b), the range of 150 mm-1000 mm below from the surface opposite to the mounting surface of the flooring 22 in which wood chip 21A is loaded, for example There may be provided a plate-like projecting wall 28 projecting inward from the side wall of the housing H with an inner projecting length, more preferably within a range of 250 mm to 600 mm. Also by this, it is possible to rectify the odor gas G input to the biofilter 21 and to suppress the odor leakage along the side wall of the housing H. In the case of practicing the present invention, as shown in FIG. 7B, the projecting wall 28 may be provided with a thickness (length in the vertical direction) of 10 cm to 20 cm from below the floor material 22, Alternatively, the volume of the space S may be reduced by providing a plate-like protruding wall 28 or a plurality of support legs 23 along the side wall of the housing H in the lower space S of the floor material 22 or the inner side wall of the biofilter 21 itself. May be formed to project toward the inside of the housing H. Even in this case, it is possible to prevent the leakage of the odorous gas G rising along the wall surface of the housing H.

Furthermore, in the present embodiment, as shown in FIG. 2, the bottom of the housing H is water that has been sprinkled from the water sprinkling means 30 above the biofilter 21 and has passed through (flowing down) the biofilter 21 and the floor material 22. A drainage port 42 is provided to allow the water to flow out to the water receiving portion 41. Here, reaches the water in the bottom of the housing H through the biofilter 21 and flooring 22 (hereinafter sometimes referred to excess water W ₁₎ from the drain port 42 without accumulating a predetermined amount or more to the bottom of the housing H The drainage port 42 is designed to be in a predetermined position so as to flow out to the water receiving portion 41. When the amount of water stored in the bottom of the housing H is large, there is also reproduction of an organism such as an insect and the deodorizing performance is lowered.
However, in the space S below the floor material 22, the water passing through the biofilter 21 and the floor material 22 is collected at the bottom of the housing H, so the humidity is high, and the odor introduced from the inlet 24 below the housing H It is also possible to increase the humidity of the gas G. If the humidity of the odorous gas G introduced into the biofilter 21 can be increased, it is also effective in suppressing the temperature fluctuation of the biofilter 21 as described later.
In the case of carrying out the present invention, the outflow of water reaching the bottom of the housing H is sloped on the bottom surface of the lower part of the housing Hn to collect water from the water receiving portion 41 and the drainage port 42 without stopping water retention. It may be done. A plurality of drains 42 may be provided

Excess water W ₁ flowing out of the drain outlet 42 of the housing H through the drain passage 42a consisting of conduits or the like that connects the drain outlet 42 to the water receiving portion 41, is recovered is collected in the water receiving portion 41.
From the water receiving portion 41, a water sprinkling supply path 43 formed of a pipe or the like is disposed up to the upper side of the housing H, and above the housing H, a water sprinkling pipe constituting the water sprinkling means 30 connected to the water sprinkling supply path 43 31 are arranged. In the middle of the water sprinkling supply path 43, a pump and a valve are provided.
The water sprinkling pipe 31 has a required number of water sprinkling nozzles 32 for sprinkling water, and has a structure capable of sprinkling water substantially uniformly on the upper surface of the biofilter 21 in the housing H. Water spray is usually sprayed as water droplets. 1 and 2, the direction of the water spray nozzle 32 is directed downward on the biofilter 21 side, but the direction of the water spray nozzle 32 is not limited thereto, and the water spray nozzle 31 is directed upward. You may do so. In any case, by sprinkling water from above the housing H toward the biofilter 21, the sprayed water falls to the biofilter 21 by gravity, and the water is supplied to the wood chip 21A constituting the biofilter 21. Do.

Thus, the surplus water W ₁ collected in the water receiving portion 41 is supplied to the water sprinkling pipe 31 as the water sprinkling means 30 for sprinkling water from above the housing H to the biofilter 21 by the water sprinkling supply path 43. Used for humidifying water spray. That is, in the present embodiment, the surplus water W ₁ which has passed through the biofilter 21 is used as water to be sprayed to the biofilter 21, and the water is circulated.

Furthermore, in the water receiving unit 41 of the present embodiment, the water conveyance unit 44 for introducing industrial water (industrial water etc.) as a replenishment means for replenishing water from the outside to the circulation means 40 and supplying water to the circulation means 40 is also connected. In addition to the waste water W ₁ (surplus water W ₁ ), new water W ₂ can be newly taken in from the water conveyance unit 44 through a valve as needed. That can be summarized in the water receiving unit 41, a replenishing water W ₂ from the drainage W ₁ (excess water W ₁₎ water conduit 44 as required from the housing H.
Therefore, the surplus water W ₁ used for sprinkling in the water receiving section 41 and the supplementary water ₂ supplied from the outside as needed are put together and pumped up, and supplied to the sprinkling pipe 31 through the sprinkling supply passage 43. Be done. Then, the water supplied to the water sprinkling pipe 31 is supplied to the biofilter 21 by the water sprinkling from the water sprinkling nozzle 31 directed to the upper surface of the biofilter 21. At this time, water sprinkling may be intermittent or may be performed continuously.
In addition, in the water conveyance part 44 which introduce water, such as industrial water, the filter for filtering refuse, sand, and microparticles | fine-particles and the scrubber apparatus 4 are installed as needed. As a result, clogging of the biofilter 21 can be prevented without the inclusion of dust, sand and fine particles in the watering.

Thus, in the biological deodorizing apparatus 10 of the present embodiment, surplus water W ₁ sprinkled from the water sprinkling means 30 and passed through the biofilter 21 is used mainly for moisture adjustment and humidification of the biofilter 21, and further, if necessary Since the replenishing water W ₂ is supplemented from the external industrial water etc., the waste water is completely eliminated. That is, the water spray is circulated without draining to the outside.

Here, the configuration of the biofilter 21 of the present embodiment will be described in detail.
The biofilter 21 according to the present embodiment is, for example, raw wood (trunk, whole wood, shrubs, end trees, branches, pruning branches, rootstocks, etc.), lumber (backboard, end material, peeled core, etc.), building demolition material, construction The material, packing material, plywood, laminated wood, particle board, waste pallet and the like are cut or crushed by a chipper, shredder, mill, crusher, hammer, punching or the like to deposit wood chips 21A in the form of wood chips. Not limited to raw wood chips obtained by cutting and crushing raw wood (including harvested wood, thinned wood, and small diameter wood), factory residual wood chips, forest residual wood chips, dismantling wood chips, etc. may be used. That is, the wood chips 21A are not limited to solid wood chips, and may include laminated wood chips, MDF chips, and particle board chips. However, since wood fiber chips, MDF chips, particle board chips, etc. are attached with impurities such as adhesives and paints, their content is preferably 40% by weight or less in consideration of the influence on the microbial environment. More preferably, it is 30 wt% or less, more preferably 20 wt% or less. Wood chips 21 mainly consist of wood xylem and pulp only, but bark chips and bark chips are mixed (preferably 20% by weight or less of the whole, more preferably 5% by weight of the whole) Or less).
The wood chip 21A may be a cutting chip obtained by cutting a raw wood, a lumber, a waste material or the like with a cutter using a wood chipper (a disc-type chipper or the like), a shredder, a mill, a hammer, a crusher or the like. It may be a crushed chip (pin chip, crusher chip or the like) obtained by crushing raw wood, lumber, waste material or the like by using it.

  In addition, wood used for wood chip 21A is cedar, cypress, red pine, tsuga, pine, yew, nezuko, fir, fir, sawara, asunaro, hiba, inuigaya, spruce, spruce, eastern white pine, western larch, western fur Or coniferous trees such as Western Hemlock or Tamarac, or birch, birch, linden, birch, beech, china, poplar, eucalyptus, acacia, narcissus, maple, birch, elm, persimmon, persimmon, willow, sen, persimmon, oak It may also be a broadleaf tree such as kunugi, horsetail, zelkova, mizume, mizuki, aodamo, or blueberry.

  In addition, the present inventors are changing the material type of wood chip 21A used as the microbial carrier of the biofilter 21 to be used, and are carrying out the evaluation test of the deodorizing effect by the biological deodorizing apparatus 10. The results at that time are shown in Table 1.

  As shown in Table 1, as lumber chips 21A, shredded lumber and lumber scraps of softwood (mixture of cedar and cypress), lumber of lumber lumber (blend of birch and leek) lumber and lumber of lumber Using five types of crushed products, crushed materials of lumber and lumber scraps of crushed wood, perforated hardwood with porous wood (Mizunara), crushed products of construction waste, and crushed products of pruned branches, the biological deodorizing apparatus 10 shown in Table 1 The deodorizing effect of the odor gas G was tested under the specifications and test conditions.

Here, the numerical values shown in Table 1 are the results of sensory evaluation of odor by a monitor for evaluating the deodorizing effect.
For evaluation of the deodorizing effect, 12 people (hereinafter referred to as monitors) collected from the general public smell the odor gas G of the source odor and the processing air after passing through the biofilter 21 five times each at 1 hour intervals. Received, the smell intensity is shown in the lower table 1 Table 6 (0: no odor, 1: I do not know what smell is in the haze, 2: I do not mind, 3: I do not care, 4: strong odor, 5: Very smelly, intense smell) received sensory evaluation. The 12 monitors were divided into two groups of six each, and in one group they smelled in the order of odor gas G of source odor and treated air, and in the other group smell in the order of treated air and odor gas G Have a sense of smell and perform a sensory evaluation. The numerical values shown in Table 1 above are average values of odor evaluations by 12 monitors. However, when calculating the average value, it is an integer of the average value of 10 people excluding the highest value and the lowest value. Further, the odor evaluation here is performed three times, one month, three months, and one year after the introduction of the odor gas G to the biological deodorizing apparatus 10.

  As shown in Table 1, even if wood chips 21A are of any material type, no odor is known even one year after the start of the introduction of the odor gas G (1) or It is an evaluation that the odor does not become (2), and a high deodorizing effect was maintained. That is, it is possible that the high deodorizing effect continues for a long time regardless of whether the wood chips 21 are crushed products from thinnings and lumber scraps, crushed products from construction wastes or broken products from pruned branches. I understand.

  In particular, according to the experimental research of the present inventors, the wood chip 21A made of conifers such as pine, cedar and cypress etc. contains a large amount of resin, so the deodorizing effect for a longer period is sustained and It has been confirmed that the life is increased. On the other hand, in the hardwood wood chip 21A, compared with the softwood wood chip 21A, the acclimatization of microorganisms effective for the decomposition of the odor gas G and the formation of the microflora (biofilm) are quickened, showing a quick start-up. It has been confirmed that the deodorizing ability of the biofilter 21 is high.

In addition, when recycling waste materials, such as a factory residual material and a demolition residual material, as wood chip 21A, processing of foreign substance removal is usually performed before and after cutting or crushing processing.
Then, in the wood chip 21A of the present embodiment, after cutting or crushing of wood, for example, wood chips classified (sorted) to a predetermined size (grain size) with a vibrating screen, a roll classifier or the like are used. .
Such wood chips 21A have resistance to acidity and alkalinity, are less likely to deteriorate or lose their shape, and have high shape retention. Therefore, it is possible to suppress an increase in pressure loss over time and a decrease in deodorizing efficiency due to use.

  The size of the wood chip 21 is, for example, that the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of wood is It is in the range of 4 mm to 10 mm.

Here, when the length of the wood chip in the fiber direction of the wood chip is in the range of 10 mm to 300 mm, the length of the wood chip is 10 mm or more and 300 mm or less when the length direction of wood grain is the wood chip length. Indicates that it is within the range of
In addition, when the width of the wood chip in the tangential direction is 5 mm to 30 mm, the width of the wood chip is in the range of 5 mm to 30 mm when the tangential direction in contact with the annual ring circle of wood is the width of the wood chip. Indicates that it is within.
Furthermore, when the radial thickness of the wood chip is in the range of 4 mm to 10 mm, the thickness of the wood chip is in the range of 4 mm or more and 10 mm or less when the radial direction of the wood annual ring is the thickness of the wood chip. Indicates that.
However, for example, when it is difficult to determine the direction of the wood, such as MDF chip, PB chip, etc., the long side direction of the wood chip is the length of the wood chip, and the direction perpendicular to the long side direction is the width of the wood chip Let the direction perpendicular to the length and width be the thickness of the wood chip.

  For cutting chips and crushing chips, the longest width in the fiber direction of wood is the length of wood chip 21A, the longest width in the tangential direction of wood is the width of wood chip 21A, the longest width in the radial direction of wood is the thickness of wood chip 21A and Do. In addition, for MDF chips, PB chips, etc., in which the fiber direction, tangential direction, and radial direction can not be determined, the longest side of the wood chip 21A is the length, the longest width in the direction perpendicular to the long side is the width, and the long side And let the longest width in the direction perpendicular to the width be the thickness of the wood chip 21.

Depending on the size of the wood chips 21 as described above, filling can be performed in the range of bulk density 150 to 500 kg / m ³ . However, due to differences in the wood raw materials, wood species, processing means or mechanism of crushing or cutting, the shape of the wood chip is not a fixed shape, but has variations and a complicated shape. It is a rough value including an error due to the above, and it does not deny several errors.

  Here, the present inventors are changing the size of the wood chip 21A group which comprises the biofilter 21 variously, and are carrying out the evaluation test of the deodorizing effect. The results at that time are shown in Table 2. Wood chips 21A shown in Table 2 are expressed by the length dimension (the fiber direction of wood) of the wood chips 21a.

  Here too, the deodorizing effect of the odor gas G is tested in the same manner as described above under the specifications of the biological deodorizing apparatus 10 shown in Table 2 and the test conditions, and the numerical values shown in Table 2 are obtained by the above-mentioned 12 monitors It is a result of sensory evaluation (average value) of odor. The odor evaluation was performed four times, one month, three months, one year, and three years after the introduction of the odor gas G to the biological deodorizing apparatus 10.

  As shown in Table 2, in the wood chip group where the length of the wood is 10 mm or more and 100 mm or less, the odor one month after the start of the introduction of the odor gas G does not matter (2), 3 months after The evaluation of (1) does not know what kind of smell, Furthermore, the evaluation after one year also does not understand what kind of smell (1), and the high deodorizing effect continued for a long time. In addition, in the wood chip group where the length of wood is 150 mm or more and 300 mm or less, the odor one month after the start of the introduction of the odor gas G does not mind the smell (2), three months, one year later and The evaluation three years later also shows no smell (1) and a higher deodorizing effect has been sustained for a long time. Here, for such wood chips having a length of 10 mm or more and 300 mm or less, for example, the width is 5 mm to 30 mm, and the thickness is 4 mm to 10 mm.

  On the other hand, in the wood chip group where the length of wood is less than 10 mm, the evaluation one month and three months after the introduction of the odor gas G starts is the unnoticeable odor (2), but one year The evaluation after 3 years was anxious odor (3) or strong odor (4), and the deodorizing effect clearly decreased one year after the introduction of the odor gas G was started. Such a wood chip having a length of less than 10 mm has, for example, a width of about 1 to 10 mm, a thickness of about 1 mm to 5 mm, and a so-called chip dust called wood chip It was included.

  This is because the flow path of the odor gas G is small due to the small size (particle diameter) of the wood chip 21A, and therefore the deposition of decomposition products (metabolites) produced by the decomposition of the odor component by the microorganism film (biofilm) or microorganisms It is considered that clogging (constriction, obstruction) is likely to occur due to the like. When the wood chip 21A is partially clogged, a partial flow which the passage of the odor gas G is limited occurs, the contact amount with the wood chip 21A necessary for the decomposition of the odor component of the odor gas G decreases, and the entire biofilter 21 It seems that it will not be used uniformly and uniformly.

  On the other hand, wood chips with a length of 400 mm or more and 700 mm or less have an odor (3) that is anxious one year after the start of the introduction of odor gas G, and the deodorizing effect of odor gas G is low It was a thing. In addition, the width | variety was about 20 mm-50 mm, for example, and the thickness of the wood chip whose length of such a wood is 400 mm or more was about 5 mm-20 mm.

  This is because the size of the wood chip group is large, the flow path of the odor gas G becomes large, the contact ratio between the odor component in the odor gas G and the wood chip 21A decreases, or the wood chip 21A in the entire biofilter 21 This is considered to be because the water holding amount and the amount of microorganisms effective for the decomposition of the odor component are small due to the small surface area of

  In addition, even if wood chips with a length of 150 mm or more and 300 mm or less are used, the volume is 80% of the entire biofilter 21 and the remaining 20% volume is mixed with wood chips less than 10 mm in length. If you do, the evaluation one month and three months after the start of the introduction of the odor gas G is a smell that you do not mind (2), but the evaluation after one year is a scent that you care about (3) Yes, the sustainability of the deodorizing effect was low.

  This is due to the combination of small-diameter wood chips (wood length less than 10 mm) and large-diameter wood chips (wood length 150 mm or more, 300 mm or less), the packing density is increased, and odor gas G flows Smaller channels tend to cause clogging and uneven flow of odor gas G, and the amount of contact with wood chips 21A necessary for decomposition of odor components of odor gas G decreases, and the entire biofilter 21 is effectively uniform. It is considered to be because it is not used.

Thus, with regard to wood chips 21, clumps are less likely to occur in a community where the size is too small, such as chip dust, particles, etc., while biofilters 21 are predetermined even in communities where the size is too large. It does not become bulk density and can not exhibit an effective deodorizing effect.
Therefore, for example, the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of wood is in the range of 4 mm to 10 mm If there is a certain group of wood chips 21A, clogging is unlikely to occur, and odor gas G can pass through the entire biofilter 21 evenly, and the high surface area ensures good water retention and retention of microorganisms, and deodorizing effect Sustainability is improved. That is, regardless of the difference in the raw material of wood, it is difficult to cause narrowing, clogging, clogging, increase in pressure loss and formation of an optimal flow path size, and the sustainability of high deodorizing effect can be ensured.

  More preferably, the size of the wood chip 21 is such that the length in the fiber direction of the wood is in the range of 150 mm to 300 mm, the width in the tangential direction of the wood is in the range of 5 mm to 25 mm, and the radial direction of the wood The thickness of 4 mm to 10 mm in the range of 80% by mass or more of wood chips of this size makes it easy to obtain the optimum conditions for forming a passage that is hard to clog. That is, when the size distribution of the wood chip group is seen, the length of the fiber direction of the wood is 150 mm to 300 mm even though the difference between the wood raw material and tree species and the processing means or mechanism of crushing or cutting is reflected in the size distribution. 80% by weight or more of wood chips of wood chip size in which the tangential width of the wood is in the range of 5 mm to 25 mm and the radial thickness of the wood is in the range of 4 mm to 10 mm If it is, it is possible to obtain stable characteristics as a wood chip which constitutes a biofilter having a high durability of deodorizing effect.

The wood chips 21A group of such a predetermined size can be obtained, for example, by sieving wood chips after cutting or crushing. Usually, sieving of wood chips is classified using a screen, shaking the sieve.
And about wood chip 21A group of the above-mentioned predetermined size, for example, a sieve of 60 mm of openings passes (pass), and it is available as a size of a wood chip group which does not pass of a sieve of 10 mm of openings. For example, an undersized wood chip having a sieve opening of 60 mm is obtained, and then the undersize wood chip having a mesh opening of 60 mm is further passed through a sieve having a mesh size of 10 mm. Obtain an oversized wood chip that does not pass the opening 10 mm. In this way, it is possible to obtain an oversized wood chip which is an undersize having a mesh size of 60 mm and which does not pass through a mesh size of 5 mm to obtain a wood chip 21 having a predetermined size. In addition, sieving may be classified with a sieve shaker in which sieves are designed in a stacked structure. In addition, the opening indicates the width or the width in the opening (space) of one eye formed by crossing the vertical line and the horizontal line, but here, circular eyes (round holes) or square eyes ( A square hole) sieve was used. In the case of a sieve having an opening of 60 mm, in the case of a circular eye, the diameter of the circular hole is 60 mm, and in the case of a square, one side of the square is 60 mm. In the case of a sieve having a mesh size of 10 mm, in the case of a circular mesh, the diameter of the circular hole is 10 mm, and in the case of a square grid, one side of the square is 10 mm. However, the shape of wood chips is not a fixed shape but has a dispersion and a complicated shape due to the difference between the raw materials of wood, the species of wood, and the processing means / mechanism of crushing or cutting. It is not always possible to obtain a wood chip 21A group having a size and a size. More preferably, it is a wood chip which passes through a sieve having an opening of 40 mm by sieving and does not pass through a sieve having an opening of 20 mm.

  By the way, such a wood chip 21A is filled on the floor material 22 to constitute the biofilter 21 with a predetermined bulk density, but depending on the size of the vents 22a of the floor material 22, the wood chip 21A may be used. May fill the vents 22a of the floor material 22.

Therefore, in the case of carrying out the present invention, as shown in FIG. 4 (b), after laying the wood chips 21b of coarse size on the floor surface of the floor material 22, for example, the fibers of wood as described above The length of the direction is in the range of 10 mm to 300 mm, the width of the tangential direction of the wood is in the range of 5 mm to 30 mm, and the thickness of the wood in the radial direction is in the range of 4 mm to 10 mm It is also possible to fill.
For example, as coarse size wood chips 21b, the length in the fiber direction of wood is in the range of 350 mm to 700 mm, the width in the tangential direction of wood is in the range of 10 mm to 40 mm, and the thickness in the radial direction of wood Is in the range of 5 mm to 20 mm, more preferably, the length in the fiber direction of wood is in the range of 400 mm to 500 mm, the width in the tangential direction of wood is in the range of 10 mm to 80 mm, the radial thickness of wood Can be used in the range of 5 mm to 50 mm.

In this manner, by laying coarse-sized wood chips 21b so that fine-sized wood chips 21a do not fall into the vents 22A of the floor material 22 and then filling the fine-sized wood chips 21a. Also, the pressure loss can be alleviated, and the narrowing of the air passage due to the consolidation under the biofilter 21 can be alleviated, and the deodorizing efficiency can also be improved. In addition, since the strong ventilation is not required for ventilation of odor gas G by the reduction effect of pressure loss, it is also possible to reduce the running cost of the blower 5.
Such coarse wood chips 21b are filled with 5% or less of the volume of the fine wood chips 21a.

  Thus, the drying of the wood chips 21A is performed on the biofilter 21 configured of the wood chips 21A (hereinafter, the wood chips 21a and the wood chips 21b may be collectively referred to as the wood chips 21A unless otherwise distinguished). In order to prevent it and maintain the activity of the biological treatment by the biofilter 21, the water is sprayed from the water spray means 30 to humidify the biofilter 21. That is, when the moisture of the wood chip 21A is small, the growth of microorganisms is suppressed, and the deodorizing action is reduced because the wood chip 21A can not catch the odor component in the odor gas G. The biofilter 21 maintains the wet state by water sprinkling from the water sprinkling means 30.

  Here, the inventors further investigated the conditions for optimizing the dissolution, adsorption, and microbial environment of the odor component in water, and the amount of water sprinkling of the biofilter 21 composed of the wood chip 21A serving as a microorganism carrier. It has been found that when the moisture content of the wood chips 21a is controlled by adjustment, a high deodorizing effect is obtained and the effect is sustained. Table 3 shows the results when an evaluation test was conducted on the relationship between the moisture content of the wood chip 21 a and the deodorizing effect.

Here, the wood chip 21a is adjusted to each moisture content to 20% to 220% by adjusting the amount of watering and maintained, and the deodorization of odor gas G in the test conditions and the specifications of the biological deodorizing apparatus 10 shown in Table 3 The effect was tested.
The numerical values shown in Table 3 are also the results of sensory evaluation (average value) of the odor by the above-mentioned 12 monitors. The odor evaluation was performed four times, one month, three months, one year, and three years after the introduction of the odor gas G into the biological deodorizing apparatus 10.

With regard to the moisture content of the wood chips 21a, the moisture content was measured periodically whether or not the wood chips 21a were maintained at each moisture content, and the amount of water spray was adjusted and managed so as to be maintained at each moisture content.
At the time of measurement, a predetermined amount of wood chips 21a is collected from the biofilter 21, and the weight is measured before and after drying to determine the moisture content.
The moisture content of the wood chips 21a at this time represents the ratio of the water weight to the weight (total dry weight, dry basis) of the wood chips 21A in a state not containing water, and the water content is obtained by the following formula (A) The rate is being sought.
Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100 (A)
The total dry weight was 105 ° C., and the value in the dried state was used until there was no change in weight.

  As shown in Table 3, when the moisture content of the wood chip 21a is 150% or more, the evaluation one month after the start of the introduction of the odorous gas G is annoyed odor (3) or does not care Smell (2), but the evaluation after 3 months was (1) which I do not know what smell of garnet. In addition, even in the evaluation one year later, it does not know what smell is present (1), and even after three years, it does not mind (2), and a high deodorizing effect is maintained for a long time. The

On the other hand, it was inferior to the deodorizing effect as the moisture content of the wood chip 21a is less than 150%. That is, when the moisture content of the wood chip 21 is 120%, the evaluation has a strong smell (4) even one month after the start of the introduction of the odor gas G, and it is anxious even in the evaluation after three months It was odor (3), and the evaluation one year later was a strong odor (4).
In addition, when the moisture content of the wood chips 21a is 80% or less, the evaluation has a strong odor (4) or a very strong odor, even one month after the start of the introduction of the odor gas G (5), 3 months after, 1 year later, 1 year later, 3 years after evaluation also annoyed in the evaluation (3), strong smell (4) or very strong smell, intense smell (5) Deodorizing effect was not obtained.

Therefore, the high deodorizing effect can be maintained for 3 years or more by maintaining the moisture content of the wood chips 21a at 150% or more. According to the experiments of the present inventors, it is more preferably 160% or more, still more preferably 180% or more.
And in the experimental research of the present inventors, there is an upper limit to the moisture content of the wood chip 21a from the characteristic of the wood, and the upper limit is determined by the characteristics of the wood species of the wood chip etc. is there.

  The water content of the wood chips 21a is maintained at 150% or more and 300% or less by water sprinkling from the water spray means 30, and the high deodorizing effect is sustained by the water retention of the wood chips 21a to the moisture of the odor component. It is speculated that the dissolution, adsorption, and microbial environment are optimized. In particular, in the case of wood chips 21a having a moisture content of 150% or more and 300% or less, a thick water film is formed around them, which can increase the microbial activity and gas is easily dissolved in the liquid phase and easily adsorbed. It may have become. Furthermore, it is speculated that such a thick water film has high pH buffering action against the concentration fluctuation of the odor component and also against the production of decomposition products generated by the decomposition of the odor component, and the fluctuation of pH is suppressed. Be done. And, by thus suppressing the fluctuation of pH and maintaining the pH in the neutral range, it is difficult for the microbial activity to be inactivated, and the activities of a plurality of types of microbial groups are maintained to cope with various odors. It seems to be possible. That is, it is thought that it can maintain in the optimal environment for the growth of the microbe group which can respond to various odors.

Thus, in the present embodiment, the water content of the wood chips 21 a is maintained at 150% or more and 300% or less by watering from the watering means 30.
The amount of water spray is such that the water content of the wood chips 21a is maintained at 150% or more and 300% or less. However, regardless of the upper and lower layers of the biofilter 21, the wood chips 21a, It is assumed that the moisture content of the wood chip 21b is maintained at 150% or more and 300% or less.

Here, the inventors further investigated the conditions for maintaining a high deodorizing effect, and in the present embodiment, the excess water W ₁ used for watering in the water receiving portion 41 and the outside as needed The replenishment water W ₂ supplied from the pump is put together, pumped up, and supplied to the water pipe 31 via the water supply path 43 and watered. Depending on the conditions of the water used for watering at this time, the deodorizing performance Was found to fluctuate.
That is, for the water to be sprinkled with water spray means 30, as shown in Table 4, is recovered is drained as excess water W ₁ from the housing H by in the water receiving portion 41, the water to be used as a water spray the circulating water W ₁ again , difference in deodorizing performance when water is replenished from the water conduit 44 and the replenishing water W _2, the ratio of the circulating water W ₁ and replenishing water W ₂ of water used as a watering for certain watering amount per unit time It was seen. Table 4 shows the results of an evaluation test on the relationship between the condition of water used for watering and the deodorizing effect.

Here, the water to be sprinkled with water spray means 30, the specification of biological deodorization apparatus 10 shown by adjusting the ratio of the circulating water W ₁ and replenishing water W ₂ in Table 4, the test of deodorizing effects of odorous gas G test conditions Did.
The numerical values shown in Table 4 are also the results of the sensory evaluation (average value) of the odor by the 12 monitors described above. The odor evaluation is performed four times, one month, three months, one year, and three years after the introduction of the odor gas G into the deodorizing apparatus 10.

As shown in Table 4, the water for sprinkling consists of 100% by volume of circulating water W ₁ when a fixed amount of water discharge per unit time is 100% by volume, or it is assumed that replenishment water W ₂ is taken from the outside Even if the water for sprinkling is circulating water W ₁ / supplemented water W ₂ 7 7/12 by volume ratio, the odor after one month after the start of the introduction of the odorous gas G is annoyed (3) Or, I do not mind (2), and the evaluation after 3 months was (1) which I do not know what smell of garnet. In addition, in the evaluation one year later, it does not know what smell is present (1) or odor (2), and even after three years, it does not know what odor does occur. (1) or odor that does not bother (2), and high deodorizing effect was maintained for a long time.

On the other hand, water for sprinkling is not circulated (circulating water W ₁ : replenishing water W ₂ = 0: 10), water for sprinkling in volume ratio is circulating water W ₁ / replenishing water W ₂ <7 / When it was 12, it was inferior to the deodorizing effect. That is, at 0/10 ≦ circulating water W ₁ / replenished water W ₂ <7/12, the evaluation has a strong smell (4) even one month after the start of the introduction of the odor gas G, and 3 months The later evaluation also showed a strong odor (4).

Therefore, when the constant water discharge amount per unit time is 100% by volume, the water W sprinkled by the water spray means 30 has the circulating water W ₁ of about 36% by volume or more and the replenishment water W ₂ of 64% by volume or less. High deodorizing effect can be sustained for over 3 years.
The reason is that the water that has passed through the biofilter 21 contains microorganisms effective for odor decomposition, and the circulating water W ₁ containing such microorganisms is reused as watering without being discharged to the outside (waste water) Therefore, the amount of microbes in the biofilter 21 is maintained by the fact that the water sprayed to the biofilter 21 contains effective microorganisms, and the bias of the microbiota is prevented, and the microflora in the entire biofilter 21 is It is considered that they are uniformly distributed, and the entire biofilter 21 is effectively used. In addition, it is considered that the followability and responsiveness to the odor gas G of the complex odor accompanied by the fluctuation of the odor concentration and the odor quality are also enhanced. In particular, by reducing the dilution with replenishment water W _{2 with} respect to circulating water W ₁ , that is, when the ratio of circulating water W ₁ to water used for sprinkling is high, microorganisms having high concentration are effective biofilter 21 Since the water is sprayed, the high microbial load of the biofilter 21 and the microbial activity are maintained, and it is possible to continuously maintain a high deodorizing effect even on the odor gas G having a complex odor accompanied with the fluctuation of odor concentration and odor quality. . In addition, odor components (such as ammonia ions) that cause a rise in pH and decomposition products (such as nitrate ions) of an odor component that cause a decrease in pH are balanced by the circulation of such water spray, and the neutral range of pH is It is assumed that it has been maintained and has maintained a high deodorizing effect.

Thus, in the present embodiment, assuming that the fixed water discharge amount per unit time is 100% by volume, the volume ratio of water sprayed by the water spray means 30: 0/10 ≦ replenished water W ₂ / circulating water W ₁ It is assumed that ≦ 12/7. That is, the water receiving portion in 41 using the watering surplus water W ₁ was passed through the biofilter 21 (circulating water W _1), the replenishing water from the outside not exceed 64% by volume of water used for watering as needed W ₂ Is supplied from the water spray means 30 to the biofilter 21 as water spray.

In such organisms deodorizing device 10, including the drainage 42a and the water receiving unit 41 introduction path 24a and the surplus water W ₁ is discharged odor gas G is introduced from the blower 5, at the bottom of the housing H is While the odor gas G is a closed system that does not leak to the outside, the upper part of the housing H from which the deodorized air is discharged through the biofilter 21 is generally opened. In the housing H provided with a ceiling, an opening is provided so that deodorized air can be released to the atmosphere. In this case, the water spray pipe 31 and the like may be embedded in the ceiling, and the water spray nozzle 31 may be disposed in the ceiling.
Installation of such a biological deodorizing apparatus 10 may be indoors or outdoors, and when installed outdoors, it prevents the penetration of rain or the irradiation of direct sunlight to the biofilter 21 in the housing H as necessary. In order to cover the housing H, a roof such as a tent for covering the housing H may be provided above the water spray pipe 31. Also, the housing H may be of the underground type.

In addition, as for the biological deodorizing apparatus 10 of this Embodiment, computer control is desirable.
Taking up only the main information management, for example, the information of the sending amount and sending pressure of the blower 5 is detected and input to the computer COMP. Further, in the computer COMP, information on the pressure on the air discharge side above the biofilter 21 and the internal temperature of the biofilter 21 is detected by a sensor and is input. Further, information on the moisture content of the wood chip 21 artificially measured is input to the computer COMP and managed, and based on that, the amount of water sprayed by the water spray means 30 is determined. Further, the amount of water in the water receiving portion 41 is also detected, and the amount of water from the water guiding portion 44 is determined based on the amount of water sprayed by the water sprinkling means 30, and is used as the input of the computer COMP. The computer COMP controls the drive of the pump, valve, flow meter, and valve disposed in the water conveyance unit 44 for taking in water from the outside, for pumping the water stored in the water receiving unit 41 to the sprinkling means 30. Control of the amount of water spouted from the water sprinkling means 30. Usually, the pump for watering is timer-controlled. Further, the odor concentration is detected by the sensor above the biofilter 21 and is input to the computer COMP. The pressure, temperature, odor concentration and the like of the odor gas G may be detected at the inlet where the odor gas G is introduced into the biological deodorizing apparatus 10 and may be input to the computer COMP.

Thus, the information on the moisture content of the wood chip 21A is mainly used for the amount of water sprinkling of the water sprinkling means 30, that is, the drive control of the pump and the valve. Further, the information on the pressure on the air discharge side on the biofilter 21 and the sending amount of the blower 5 and the sending pressure are mainly used for control of the blower 5. These information, including the odor concentration information, can be controlled and managed as schedule management information by the monitor, and can be used for proof of compliance with local government regulations by keeping a processing record. The chemical deodorizing device 3 and the scrubber device 4 in FIG. 1 are also monitored and operated independently.
Further, by visual monitoring with respect to the filling height h of the wood chips 21A, when it falls below a predetermined amount, new predetermined wood chips 21A are replenished.
Furthermore, the pressure loss calculated from the sending pressure of the blower 5 and the ejection pressure on the biofilter 21 is managed, and when the pressure loss exceeds a predetermined amount, the sending amount of the blower 5 and the sending pressure are controlled. Further, when the size of the wood chips 21A is visually monitored, fine grains are increased and the pressure loss is large, screening is performed to eliminate the fine grains and replenish the new wood chips 21A. Do.

Hereinafter, the Example which materialized the biological deodorizing apparatus 10 of this Embodiment is described.
In the present embodiment, odor gas G generated at a composting facility such as household waste and urban waste is targeted, and supporting legs 23 are erected as shown in FIG. 3 at the bottom of a concrete housing H. The floor material 22 with an opening in the range of 20 mm to 100 mm and an opening ratio in the range of 5 to 95% is placed thereon, and, for example, a fiber of wood is placed on the floor material 22. The length of the direction is in the range of 350 mm to 700 mm, the width of the tangential direction of the wood is in the range of 10 mm to 80 mm, and the thickness in the radial direction of the wood is in the range of 5 mm to 50 mm Then, for example, the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of wood is 4 mm to 10 mm Within range The biofilter 21 is formed by filling the timber chip 21a, to constitute a deodorization treatment unit 20.
At this time, the separation distance between the bottom of the housing H and the bottom of the floor material 22 is set to, for example, 10 cm to 50 cm, preferably 20 cm to 40 cm, and the coarse wood chips 21b are filled with 10% or less of the volume of the fine wood chips 21a. Be done.
In addition, in composting facilities such as household waste and urban waste, the wastes processed there are not always a fixed property, and various miscellaneous raw materials that are different each time are fermented and decomposed, so the odor gas G generated there is a complex It is an odor, and furthermore, its odor concentration and odor quality fluctuate. In addition, in composting facilities that perform compost turning, concentration fluctuations due to compost turning also increase.

  At this time, in the present embodiment, as shown in FIG. 7A, a plate-like member having a projection length in the range of 150 mm to 1000 mm, preferably in the range of 250 mm to 600 mm is provided on the floor material 22. Protruding wall 28 is installed along the four side walls of housing H at a predetermined height from the upper surface of floor material 28, and in a space in housing H provided with such a projecting wall 28, a wood chip 21A of a predetermined size is provided. It was filled. That is, on the floor material 22, a side wall on the housing H side protrudes toward the biofilter 21 by the protruding wall 28.

As shown in FIG. 2, at the bottom of the housing H, an inlet 24 for the odor gas G connected to the blower 5 via the introduction passage 24 a is provided, and a water receiving portion via the drainage passage 42 a outlet 42 which excess water W ₁ which has passed through the biofilter 21 and flooring 22 connected is drained is provided 41.
The water receiving portion 41 is connected with a water sprinkling supply path 43 formed of a pipe line connected to a water sprinkling pipe 31 having a water sprinkling nozzle 32 disposed above the housing H, and industrial water (industrial water etc. as necessary). The water conveyance part 44 for introduce | transducing water of 2.) is connected. The water sprinkling supply passage 43 is provided with a valve and a pump, and the water conduit 44 is also provided with a valve.
The specifications and design of the biological deodorizing apparatus 10 according to the present embodiment are as shown in Table 5. In the present embodiment, the water sprinkling means 30 is operated intermittently, and water sprinkling is intermittently performed by a timer-controlled water distribution pump.

At the time of design of the biological deodorization device 10, the processing air volume (m ³ / min) and the processing speed (mm / sec) desired from the amount of odor gas G (source odor) generated in composting facilities such as urban waste The installation area (cross-sectional area) of the biofilter 21 that secures a predetermined processing capacity that does not exceed the load is set based on the processing air volume (m ³ / min) and the processing speed (mm / sec). For example, the cross-sectional area, volume, etc. of the biofilter 21 are determined such that the odor gas G has an apparent wind speed of 15 to 30 mm / sec, more preferably 20 to 25 mm / sec. The apparent velocity is obtained by dividing the flow rate (mm ³ / sec) of the odorous gas G to be processed by the cross-sectional area (mm ² ) of the biofilter 21.
Here, in order to ensure low cost and long-term stable deodorizing performance, the present inventors further thickness of the layer of the biofilter 21 formed by filling the wood chip 21A (wood chip 21a, wood chip 21b) That is, the filling height (loading height) h of the wood chips 21A was investigated. About the filling height h of the biofilter 21, it experimented by setting an initial setting to 1.0 m-3.5 m, and the evaluation test of the deodorizing effect was done. The results at that time are shown in Table 6.

  The numerical values shown in Table 6 are also the results of the sensory evaluation (average value) of the odor by the 12 monitors described above. The odor evaluation was performed four times, one month, three months, one year, and three years after the introduction of the odor gas G into the biological deodorizing apparatus 10.

As shown in Table 6, when the filling height h of the wood chips 21A is 1.5 m or more and 3.0 m or less, the odor after one month after the start of introducing the odor gas G does not mind It is (2), and a high deodorizing effect has been maintained for a long time, such as an odor (2) which does not matter in an evaluation after three months, one year, and three years, or (2) which smell does not know.
In particular, when the filling height of the wood chips 21A was 2.0 m or more and 2.5 m or less, the sustainability of the high deodorizing effect was high.

On the other hand, when the filling height of the wood chips 21A is 1.4 m or less, after one year, it is an evaluation of offending odor (3) or strong odor (4), particularly in 1.0 m or less Evaluation of a strong odor (4) or a very strong odor (5) always resulted in no deodorizing effect.
This is because the contact amount between the odor component of the odor gas G and the wood chip 21A can not be obtained sufficiently.

In addition, even if the filling height h of the wood chips 21A is 3.5 m or more, it is an evaluation of offensive odor (3) after 3 months, and the sustainability of the deodorizing effect is reduced.
This is because the packing height h of the wood chip 21A is too high, and the consolidation is high at the lower part of the biofilter 21, and the drift of the odor gas G is easily generated. It is considered that the amount of contact with the chip 21A is reduced, and the entire biofilter 21 can not be effectively used uniformly.

  Therefore, if the filling height h of the wood chips 21A constituting the biofilter 21 is a height within the range of 1.5 m to 3.0 m, a high deodorizing effect is maintained for a long time. More preferably, the filling height h of the wood chips 21A is in the range of 2.0 m to 2.5 m.

And, in the present embodiment, the bulk density when filled with the wood chips 21A is preferably in the range of 150 to 500 kg / m ³ . As a result, clogging of the flow path (air passage) is unlikely to occur, and the increase in pressure loss over time is also small.

That is, if the bulk density is too high, the pressure loss is large, and the cost of blowing the odor gas G also becomes high. In addition, clogging easily occurs, and uneven flow of the odor gas G is caused, so that the durability of the deodorizing effect is reduced. On the other hand, even if the bulk density is too low, the amount of contact between the odor component and the wood chip 21A decreases, so the deodorizing effect decreases. If the bulk density of the wood chips 21A is in the range of 150 to 500 kg / m ³ , the pressure loss can be suppressed to suppress the cost, and high durability of the deodorizing effect can be obtained. A more preferred bulk density is in the range of 200 to 400 kg / m ³ .

Therefore, in the present embodiment, the initial filling height h of the wood chips 21A (the wood chips 21a and the wood chips 21b) constituting the biofilter 21 is set to 2.0 m.
In the experimental research of the present inventors, the wood chip 21A is shredded and shrunk due to the consumption, metabolism, and deterioration of the wood chip 21A by microorganisms over time, and the volume of the biofilter 21 decreases. . For example, when the filling height h of the initial setting falls below 1.7 m due to use, the length in the fiber direction of the wood is, for example, 10 mm to 300 mm, and the wood tangential direction The deodorizing effect is achieved by replenishing the wood chips 21a whose width is in the range of 5 mm to 30 mm and the thickness in the radial direction of the wood is in the range of 4 mm to 10 mm and recovering the filling height h to 2 m. It has been confirmed that a long-term high deodorizing effect can be maintained for three years or more without reduction.

Then, in the present embodiment, the water content of the wood chips 21 a is maintained at 150% or more and 300% or less by watering from the water sprinkling means 30.
The moisture content of the wood chips 21a is changed periodically due to changes in the humidity conditions of the surrounding (ambient environment), and also because the water holding amount changes due to the fragmentation and shrinkage of the wood chips 21a. The water content is measured, and the amount of watering is adjusted so that the water content of the wood chips 21a is maintained at 150% or more and 300% or less.

  In the biological deodorizing apparatus 10 configured as described above, the odor gas G from the composting apparatus 2 is diffused from the introduction port 42 to the space S of a predetermined volume at the bottom of the housing through the introduction path 42a by driving the blower 5; As it flows, it rises up into the biofilter 21 through the vents 22A of the floor material 22. Since the air passes through the ventilation holes 22A of a predetermined diameter of the floor material 22 before being input to the biofilter 21, the odor gas G introduced from the inlet 42 is rectified and is input to the biofilter 21, and the odor The air flow resistance of the gas G can be relaxed to suppress the pressure loss.

At this time, the water content of the wood chips 21a of the biofilter 21 is maintained at 150% or more and 300% or less by water sprinkling from the water sprinkling means 30, and the inside of the biofilter 21 is maintained in a wet state. In the initial stage of startup of the apparatus, fresh water is taken from the water conveyance unit 44 to the water reception unit 41, and the water in the water reception unit 41 is pumped up to the water injection pipe 31 through the water supply passage 43 by the pump. Water to the biofilter 21. Then, the excess water W _{1 which} has passed through the air holes 22 a of the biofilter 21 and the floor material 22 and reached the bottom portion of the housing H does not accumulate in the space S of a predetermined volume or more. Are collected by the water receiving unit 41 through the drainage channel 42a. The water collected and stored by the water receiving portion 41 is pumped up from the water sprinkling supply path 43 to the water sprinkling pipe 31 by a pump at the timing of water sprinkling without being discharged to the outside, and used again as water sprinkling. The moisture content of the wood chips 21a 0.99% or more, at the timing of the watering to maintain 300% or less, but surplus water W ₁ recovered in the water receiving portion 41 is sprinkled pumped up sprinkler pipe 31, the water receiving portion When the amount of recovery at 41 is small, water is replenished from the water conveyance unit 44 as necessary. In particular, in the present embodiment, the water used for water sprinkling is adjusted to 0/10 ≦: replenishment water W2 / circulation water W1 ≦ 12/7.

In the biofilter 21 maintained in a wet state by water sprinkling from the water sprinkling means 30, appropriate moisture is held in the wood chip 21A, whereby the microorganisms propagate and the activity is maintained.
In particular, wood chip 21A, which is a natural resource, is an organic substance and is excellent in water retention function, so that it can inoculate and plant a specific fungus by leaving it under appropriate moisture and temperature environment, or a microbial active substance When the odor gas G is allowed to pass through, the microorganisms involved in the decomposition of the odor component propagate immediately, and the deodorizing function can be exhibited as the biofilter 21 even if the odor gas G is not added. And in such a wood chip 21A, it is in the environment where many kinds of microbes are possessed from the beginning, or various kinds of microbes which are directly or indirectly involved in the decomposition of a plurality of odor components are easily inhabited In the biofilter 21 composed of wood chips 21A, both an aerobic environment and an anaerobic environment are present, and microorganisms directly or indirectly involved in deodorization are not limited to aerobic microorganisms, either. It is presumed that sexual microorganisms also contribute. In such a biofilter 21, the microorganism uses the component of the wood chip 21A (polysaccharide etc.) and the odor component as nutrient source and energy source (utilization), and the microorganism propagates to form a biofilm. There is. For example, nitrite bacteria, nitrifying bacteria, denitrifying bacteria, sulfur oxidizing bacteria, other aerobic microorganisms, anaerobic microorganisms, etc. live on the wood chip 21A.

  Therefore, when the odor gas G is introduced from below to the biofilter 21 in which the wet state is maintained, the odor gas G flows through the biofilter 21 in upward flow. At this time, the water-soluble compound or the like of the odor component contained in the odor gas G dissolves in the water held by the wood chip 21A constituting the biofilter 21 or the water around the wood chip 21A. The odor components are decomposed by the microorganisms which are adsorbed, collected and held on the wood chips 21A and which inhabit and adhere to the wood chips 21A and the surrounding water. Thus, the odorous gas G is deodorized (cleansed) by digestion by biological treatment while rising the biofilter 21 and emitted from above the biofilter 21.

Odor components contained in the case odorous gas G, for example carbon dioxide (CO _2), water (H ₂ O) such harmless materials and SO ₄ ^- or NO ₃ ^- inorganic ions, sulfuric acid or nitric acid, such as Etc. are decomposed into inorganic substances.
For example, focusing on ammonia, which is a typical odor component in the odor gas G, ammonia (NH ₃ ) is NO ₂ (nitrite form), NO due to the nitrification of aerobic microorganisms such as nitrite bacteria and nitrifying bacteria. ₃ Decomposed to nitrogen oxides (NOx) such as (nitrate) and deodorized. Furthermore, it may be degraded to N ₂ (nitrogen) or the like by denitrifying bacteria or an anmox reaction.
Also, the odor component of sulfur compounds (sulfides) such as hydrogen sulfide (H ₂ S) and methyl mercaptan and organic acid compounds are oxidized by the action of aerobic microorganisms such as sulfur-oxidizing bacteria and other aerobic bacteria. It is decomposed to form oxides such as SO ₂ and sulfuric acid and is deodorized.

In particular, the biological deodorizing apparatus 10 of the present embodiment configured as described above has the following features.
First, in the biological deodorizing apparatus 10 of the present embodiment, the pressure loss is 30 to 120 Pa at the beginning of operation when the introduction of odor gas G and the watering are started, and the pressure increases over time, but after 3 years Even in this case, the pressure drop was suppressed to 200 Pa or less.
As a precaution, FIG. 5 shows the results of measuring the pressure loss over time. The pressure loss is obtained by measuring the differential pressure between the feed pressure (total pressure) of the blower 5 and the total pressure of the outlet from which air is discharged on the biofilter 21.

As shown in FIG. 5, the pressure loss is within the range of 0 to 200 mm H ₂ O even though there is a change in pressure loss due to changes in season, concentration of odor source, etc. It has been maintained with little pressure loss. In addition, the measurement of a pressure loss is a measurement regardless of the time of the water sprinkling of the water sprinkling means 30 operated intermittently, or the time of a water spout stop.

The increase in pressure loss due to use is small because the ventilation resistance is suppressed low by configuring the biofilter 21 with wood chips 21a with a predetermined bulk density, and clogging (constriction, blockage) does not easily occur even after use, and Excess water W ₁ that has passed through the biofilter 21 by the circulation means 40 is recycled to watering that maintains the moisture content of the wood chips at 150% or more and 300% or less, resulting from the distribution of microorganisms and decomposition of microorganisms This is because the accumulation of decomposition products is less likely to be biased, and the entire biofilter 21 is efficiently used. In particular, in the case of the biofilter 21 formed by filling the wood chips 21a with a predetermined bulk density, the air flow resistance is low and the pressure loss is small, so that the water content of the wood chips 21a is 150% to 300%. Even if it is increased, the influence on the pressure loss is also small, and the uneven flow of the odor gas G hardly occurs even by use.

Moreover, in the biological deodorizing apparatus 10 of a present Example, pH of the biofilter 21 was maintained in the range of 6.5-7.5. In particular, the water of the water receiving portion 41 which collects and circulates the surplus water W ₁ from the biofilter 21 of the circulating water is also maintained in the neutral region, and pH adjustment is performed on the water used for the sprinkling 31. The pH was maintained within the range of 6.5 to 7.5 in the biofilter 21 even if the odorant or the decomposition product was adsorbed by the odorant reducing member such as, or denitrification was performed.

Here, when the odor gas G contains ammonia, the ammonium is dissolved in water to become ammonium ion (NH ₄ ⁺ ) in the wet state of the biofill 21, and this ammonium ion (NH ₄ ⁺ ) is In the water film covering the wood chip 21A, it is oxidized and decomposed to nitrite ion (NO ₂ ⁻ ) or nitrate ion (NO ₃ ⁻ ) by nitrification by ammonia oxidizing bacteria and nitrite oxidizing bacteria which inhabit the wood chip 21A. At this time, the pH rises due to the presence of ammonium ions (NH ₄ ⁺ ) before nitrification, but if decomposition products of these nitrite ions (NO ₂ ⁻ ) and nitrate ions (NO ₃ ⁻ ) are formed, the inside of the water film The pH drops when the pH drops, and generally as their concentration increases. In particular, when the water is circulated, the pH tends to be acidic in a short time, and when the environment around the microorganism in the biofilter 21 becomes acidic, the activity of only a specific microorganism and only a specific odor component are removed. It is easy to occur.

However, the biological deodorization apparatus 10 of the present embodiment, even if to recover surplus water W ₁ is circulated watering from biofilter 21, a water content of 150% or more, the wood chips 21A to maintain 300% or less the high water retention, high buffering action in pH, addition, ammonium ion by circulation of water spray (NH ₄ ⁺⁾ decomposition proceeds without accumulating further nitrite ion (NO ₂ ^-) and nitrate ions (NO ₃ ^-) decomposition product is distributed load evenly in the biofilter 21 is not be locally concentrated in such. Also it is diluted with replenishing water W ₂ as necessary. For this reason, the pH is maintained in a neutral environment.

In particular, in the case of the biofilter 21 formed by filling the wood chips 21a with a predetermined bulk density, the air flow resistance is low and the pressure loss is small, so that the water content of the wood chips 21A is 150% or more and 300% or less. Even if it is increased, the influence on the pressure loss is also small, and the high water retention of the wood chip 21A and the thick water film around the wood chip 21 can be secured. Furthermore, the moisture content of wood chips 21A 0.99% or more, depending on the configuration of excess water W ₁ is collected in a space S of a predetermined volume of high wet and the housing H bottom of biofilter 21 maintained at 300% or less, the housing H The moisture at the bottom is high, and the odor gas G introduced to the bottom of the housing H can be humidified. Thereby, the fluctuation of pH can be mitigated, and the concentration can be mitigated even for high concentration odor. In particular, in the deodorizing apparatus 10 of the present embodiment, it is considered that the nitrification and the introduction of ammonia are balanced.

  And according to the deodorizing apparatus 10 of a present Example, since pH can be maintained in a neutral area in this way, the activity of the microbial species which can respond to decomposition | disassembly of various odor components can be maintained. That is, the environment in which the pH is in the neutral range is suitable for a microorganism growth environment that is advantageous for dealing with various odorous compounds. Therefore, it is possible to exhibit long-term stable deodorizing performance even for odor gas G in which the odor concentration and odor quality change. In particular, according to the deodorizing apparatus 10 of the present embodiment, a drop in pH is suppressed even when water is circulated, and a microorganism group growing in a neutral environment can remove a large number of odorous compounds, and therefore odor concentration and odor It is possible to maintain a stable deodorizing performance for a long time without a decrease in the processing capacity even for the odor gas G whose quality varies.

According to the biological deodorizing apparatus 10 of this embodiment, the biofilter efficiency (%) calculated by the following formula (B) showing the deodorizing effect is 90 to 95%, and even after 3 years or more Deodorization efficiency of 90 to 95% is obtained.
Biofilter efficiency (BFE) (%)
= 100 x (IOC-EOC) / IOC · · · (B)
IOC: Odor concentration of introducing air (ODER unit; OU _E )
EOC: Odor concentration of exhaust air (ODER unit; OU _E )

For example, with the air on the discharge side after passing through the biofilter 21 of the biological deodorizing apparatus 10 of the present embodiment when the introduction side air has an odor concentration of 2500 to 6000 order units, an odor concentration of 200 to 450 order units on average. Has been confirmed.
However, even when odorless air is introduced, the air on the discharge side never falls below the odor concentration of the 150-order unit due to the smell of the wood chip 21A of the biofilter 21 itself. Moreover, in the air on the discharge side, even if the odor concentration is an average of 200 to 450 order units, the odor is greatly improved compared to the source odor of the odor gas G on the introduction side by the action of the biofilter 21 .

The odor concentration here is the dilution factor (unit; order) up to the odor threshold when the odor is diluted with odorless air using a human olfactometer by the dynamic olfactometer method. Indicates a unit (OU _E ). That is, according to the biological deodorizing apparatus 10 of the said Example, the removal rate of 90 to 95% was shown by the odor concentration which shows the parameter | index of the odor measured by the sensory test.
Incidentally, the odor concentration (unit; order unit (OU _E )) by the dynamic olfactometer method and the odor index employed in Japan can be expressed by the relationship of the following formula (C). The three-point comparison type odor bag method adopted in Japan and the measurement result by the dynamic olfactometer method are generally agreed.
Odor index = 10 × log (odor concentration) · · (C)
For example, the odor concentration of the 2500 to 6000 order units described above is 34 to 38 when converted to an odor index, and 23 to 27 when the odor concentration of 200 to 450 order units is converted to an odor index. The 150-order unit odor concentration is 22 when converted to an odor index.

In addition, according to the biological deodorizing apparatus 10 of the present embodiment, when the ammonia concentration is measured on the output side where the odor gas G is emitted by passing through the biofilter 21, 1 day in several days after the introduction of the odor is started. It was suppressed to an ammonia concentration of ~ 2 mg / Nm ³ , and was suppressed below that figure even after 3 years. In aerobic fermentation treatment in composting facilities (fermentation treatment facilities) such as municipal waste, aldehydes, terpenes, VAF, etc. have become problems as offensive odor causing substances, but high deodorization is also possible for such odors. The effect has been confirmed, and its deodorizing effect lasted for more than 3 years.
In particular, in the biological deodorizing apparatus 10 configured with the specifications of Table 5, a high deodorizing effect lasting for three years or more without the treatment of the chemical deodorizing apparatus 3 or the acid scrubber treatment by the scrubber apparatus 4 in the previous stage. Is obtained.

Furthermore, according to the biological deodorizing apparatus 10 of this embodiment, the deodorizing function does not deteriorate due to the temperature change of the surrounding (environmental atmosphere) due to the seasonal change, and the high deodorizing function is maintained throughout the year regardless of the surrounding temperature change. It was
Here, focusing on the temperature of the biofilter 21, as shown in FIG. 6, the temperature of the intermediate layer of the biofilter 21 is measured with time (measurement by a thermocouple), the temperature of the biofilter 21 is around Even in winter when the environmental temperature is 0 ° C, the odor gas G is introduced at 12 ° C or higher during the operation, and even in the summer when the ambient temperature is 40 ° C, it can be suppressed to 45 ° C or less by watering. Met.

  In particular, when the surface (upper layer) temperature of the biofilter 21 is measured by infrared thermography in midsummer, there is a place where the temperature of the odor gas G partially exceeds 50 ° C., but at about 20 ° C. at a low temperature. It was maintained. In summer, the temperature rise of the biofilter 21 can be suppressed by the heat of vaporization due to the high humidity of the wood chip 21A in which the water sprinkling and the moisture content are maintained at 150% or more and 300% or less.

On the other hand, in winter, it is introduced into the space S of a predetermined volume by the high humidity of the biofilter 21 maintaining the moisture content of the wood chips 21A at 150% or more and 300% or less and the collection of excess water W ₁ at the bottom of the biofilter 21 Since the odorous gas G can be humidified, the latent heat of the biofilter 21 is hardly deprived even when the odorous gas G passes through the biofilter 21, and the temperature drop of the biofilter 21 can be suppressed. That is, in winter, relatively dry odor gas G is fed from the composting device 2, and such odor gas G tends to deprive the biofilter 21 of latent heat when passing through the biofilter 21, and the temperature of the biofilter 21 It will cause a decline. However, if the moisture of the odor gas G input to the biofilter 21 can be increased, it is possible to prevent the latent heat from being taken away from the biofilter 21 and to suppress the temperature drop of the biofilter 21.
And since biofilter 21 consists of wood chip 21A, there is also a possibility that the humidity change in housing H is controlled by the humidity control characteristic of wood. In winter, due to the influence of the low temperature of the ambient temperature, the odor concentration generated from the composting device 2 is also relatively small and the load on the biofilter 21 is also relatively small. , Deodorizing effect can be maintained.

  Thus, according to the biological deodorizing apparatus 10 of the present embodiment, the temperature of the biofilter 21 does not drop significantly compared to the ambient temperature, and the high deodorizing performance is stable even when the ambient temperature fluctuates. It was maintained. That is, even if the heating or cooling means is not provided, the fluctuation of the processing capacity due to the ambient temperature is small, and the stable deodorizing performance is maintained, so that the cost can be reduced.

However, in the case of practicing the present invention, the drainage provided at the lower part of the housing H, the water sprinkling means 30, and the housing H in order to ensure an extremely stable processing capacity which is not influenced by the influence of the ambient temperature. From the configuration of the supply path from the output of the water receiving portion 41 and the water receiving portion 41 to the input of the water sprinkling means 30 via the water sprinkling supply path 43 from the water receiving portion 41 and the water receiving portion 41 A heating or cooling means may be disposed in the circulation path to control and adjust the temperature of the biofilter 21 and the water temperature of the water sprinkling.
When the temperature of the biofilter 21 exceeds 45 ° C. depending on the installation place or the like, the temperature can be suppressed to 45 ° C. or less by maintaining the amount of water sprinkling, and the deodorizing performance can be maintained.
And in order to maintain the activity of microorganisms and to exhibit the stable deodorizing performance, preferably, the temperature of the biofilter 21 and the temperature of the odor gas G are maintained in 10-55 degreeC range.

  In addition, according to the biological deodorizing device 10 of the present embodiment, the composting device 2 is in a resting state, for example, for 1 to 2 weeks, and the air from the composting device 2 is continuously supplied to the biological deodorizing device 10 by the blower 5. Even if the interior of the housing H is continuously ventilated but the odor gas G is not present, microorganisms can grow with the wood chip 21A as a nutrient source. Then, even when the composting device 2 resumes the fermentation and decomposition treatment, the microorganisms of the wood chip 21A immediately start decomposition of the odorous components in the odor gas G, forming an environment where the microorganisms are not killed, and bio The deodorizing ability of the filter 21 is maintained. Therefore, the deodorizing effect can be sustained over a long period with low maintenance costs and running costs.

In the experimental research of the present inventors, after 3-4 years have passed since the operation of the biological deodorizing apparatus 10, wood chips 21A shredded and reduced due to consumption, metabolism and deterioration of the wood chips 21 by microorganisms. If the pressure drop exceeds 200 Pa, sieving of the wood chips 21A forming the biofilter 21 removes, for example, the subdivided wood chips 21A that pass through a sieve with an opening of 10 mm. Until the filling height h reaches 2 m, for example, the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, The wood chips 21a having a radial thickness in the range of 4 mm to 10 mm are replenished. The coarse wood chips 21b between the wood chips 21a and the floor material 22 are replenished as needed. This confirms that the high deodorizing effect lasts for a longer period of time. Thus, by removing the wood chips 21A and repeatedly replenishing the wood chips 21A, it is possible to maintain the deodorizing effect semipermanently at low cost without addition of predetermined bacteria or addition of a microbial active substance.
In addition, if the pH becomes less than 4.5 due to the quality of the source odor, temporarily increase the proportion of replenishment water W ₂ and increase the amount of watering to restore the pH to 6.5 or more. It is possible to maintain deodorizing performance.

  And, in the biological deodorizing apparatus 10 of this embodiment, the pressure loss does not rise too much by the water sprinkling from the water sprinkling means 30, so even if the blower 5 is not temporarily interrupted at the time of water sprinkling, I can not get up. That is, by configuring the biofilter 21 with the wood chips 21A formed by deposition at a predetermined bulk density, the water of the sprinkled water easily passes below the biofilter 21, and the water content is maintained at 150% or more and 300% or less Even when the amount of watering is reduced, the water which has been watered will not hold up and cause a sharp increase in pressure loss. Therefore, maintenance and management are easy, low in cost, and the processing efficiency is good due to the continuous operation of the blower 5. Also, as described above, even if the direction of introduction of the odor gas G and the direction of water sprinkling are made to flow (countercurrently flow), the water does not wipe up, so high cost and high treatment capacity are obtained.

As described above, the biological deodorizing apparatus 10 according to the present embodiment is made by filling the wood chips 21A in a bulk density range of 150 to 500 kg / m ³ , and the water content of the wood chips 21A in the upper layer is increased by watering. Is a deodorization process in which the odorous gas G introduced from below the biofilter 21 is digested by biological treatment with the biofilter 21 and released above the biofilter 21 with the biofilter 21 maintained at 150% or more and 300% or less It comprises a processing means 20, a water sprinkling means 30 for sprinkling the biofilter 21 from above, and a circulating means 40 for collecting surplus water that has passed through the biofilter 21 and circulating it to sprinkling.
The circulation means 40 of the present embodiment includes the drainage path and the drainage portion 41 and the drainage portion 41 which are input to the drainage portion 41 through the drainage path 42 from the drainage port 42 a provided in the lower part of the housing H. The configuration of the supply path from the output to the input of the water sprinkling means 30 via the water sprinkling supply path 43 is shown.

Thus, in the biological deodorizing method according to the present embodiment, the biofilter 21 formed by filling the wood chips 21A at a bulk density of 150 to 500 kg / m ³ is sprayed with water from above, and the biofilter 21 is also provided. The excess water that has passed through is circulated as water sprinkling, and the odorous gas G is digested by biological treatment with the biofilter 21 by supplying the odorous gas G from below the biofilter 21.

In the biological deodorizing method according to the present embodiment, a biofilter 21 filled with wood chips 21A, and a floor material 22 having a large number of vent holes 22a and disposed under the biofilter 21, and a floor Material H and a biofilter 21 disposed thereon, housing H having an inlet 24a to which odor gas G is introduced below, water sprinkling means 30 for sprinkling biofilter 21 from above, bio The system comprises a circulation means 40 for collecting excess water having passed through the filter 21 and circulating it to water sprinkling, measuring the weight (weight before drying) of the wood chip 21 containing water by water sprinkling, and further drying it to obtain water Moisture content (%) = (weight before drying-total dry weight) / total dry weight x 10 when the weight (total dry weight) of the wood chips 21 in the free state is measured
The odor gas G introduced from the introduction port 24a below the housing H in the state that the moisture content of the wood chip 21 containing water is maintained at 150% or more and 300% or less by watering calculated as It is circulated from the vents 22 a to the biofilter 21, digested by biological treatment with the biofilter 21, and released above the biofilter 2.

According to the biological deodorizing apparatus 10 according to the present embodiment configured as described above, the biofilter with the wood chip 21A deposited at a predetermined bulk density by selecting the size of the wood chip A and setting the predetermined deposition height The air flow resistance can be suppressed to a low level by forming 21 and the excess water that has passed through the biofilter 21 by the circulation means is reused for watering that maintains the moisture content of the wood chip 21A at 150% or more and 300% or less. As a result, the distribution of microorganisms and the accumulation of decomposition products generated by the decomposition of microorganisms are less likely to be biased.
That is, since the water spray is circulated, the microorganisms and the decomposition products are moved from the top to the bottom, and the microorganisms and the decomposition products are displaced in the biofilter 21, so that the load does not concentrate locally. It can be processed efficiently overall.

Therefore, clogging of the air passage is unlikely to occur even if the use is continued, and an increase in pressure loss is also suppressed. There is a possibility that crystalline substances such as salts produced by the decomposition of the odor component may not easily adhere to the wood chips 21A whose water content is maintained at 150% or more and 300% or less by circulation of watering.
That is, even if the amount of microorganisms is large, and even if decomposition products of the odor component increase, it is difficult for those microorganisms and decomposition products to stay in a certain place by the circulation of watering It is hard to cause clogging (stenosis, occlusion).

As a result, it becomes less likely to produce a diversion in which the path of the odor gas G is limited in the biofilter 21 and a short pass that slips through a specific path, and the entire biofilter 21 is used uniformly for effective digestion of the odor gas G. High deodorizing performance can be maintained for a long time.
And since pressure loss is small, it is suitable for odor gas G of a large air volume, and it can digest odor gas G at low cost and high processing efficiency.

  In particular, the high water retentivity of the wood chips 21A maintaining the moisture content at 150% or more and 300% or less prevents the pH from decreasing with continued use, and the pH can be maintained in a neutral environment. For this reason, a variety of odors and microbial species that can cope with the decomposition even at high concentrations of odor are likely to be activated.

In addition, depending on the characteristics of the wood to maintain the moisture content at 150% or more and 300% or less, inoculating a specific fungus, planting, without the addition of a microbial active substance, the function of natural and natural microorganisms, Microorganism species that can cope with odor decomposition immediately propagate.
In particular, it is an environment in which microbial species that can cope with the decomposition of various odors are easily proliferated and active depending on the characteristics of wood, and a working environment of microbial species that can cope with the decomposition of various odors can be created. It is possible to construct a microbial environment that follows the changes in odor quality and odor concentration.
Furthermore, by circulating the water spray, it is easy to maintain effective microbial groups and microbial activity.

In addition, since the biofilter 21 is made of wood chips 21A, it is possible that the humidity control characteristics of the wood prevent the humidity fluctuation of the biofilter 21 and contribute to the maintenance of the optimum humidity environment of microorganisms and the alleviation of the pH fluctuation. There is also. In other words, the characteristics of wood make it a suitable moisture condition for microbial activity.
In addition, since the wood chip 21A is an organic substance, even if the odor gas G is not continuously fed, and even if the odor with a very low concentration is continuous, the microbial activity is well maintained without killing the microorganisms. Ru.

  In other words, by making the biofilter 21 composed of wood chips 21A that maintain a predetermined moisture content, and by circulating the watering, an environment that is optimal for the growth of microbes that can cope with various odors. Can be maintained, not specialized to a specific odor component, and can cope with odor variations.

  And, in the biofilter 21 in which the moisture content is thus maintained at 150% or more and 300% or less and the wood chip 21a is filled with a predetermined bulk density, the odor is high due to the high water retention and high surface area of the wood chip 21A. Since the gas G is easily dissolved in the liquid phase, and the amount of contact with the odor gas G is also large, it has high processing capacity.

  In particular, since wood chips 21A capable of maintaining the water content to 150% or more and 300% or less are filled with a predetermined bulk density, and water spray is circulated, clogging does not easily occur, and biofilter 21 is always made by water spray. It is easy to distribute the water evenly throughout the whole, and there is little bias of the microorganisms. That is, since the biofilter 21 is configured by the wood chips 21 a filled with a predetermined bulk density, water of the watering can easily pass below the biofilter 21. Therefore, the entire biofilter 21 is effectively used, the odor component is easily dissolved and captured in the water film around the wood chip 21A, and is effectively degraded by microorganisms. Therefore, it has high deodorizing efficiency.

Furthermore, the moisture characteristic (high water retention, thick water film around the wood chip 21A) of maintaining the moisture content of the wood chip 21A at 150% or more and 300% or less, and the wood chip 21A around by circulation of watering. Since the change in water buffers the pH fluctuation and the concentration of decomposition products, even if the excess water W ₁ that has passed through the biofilter 21 by circulation means is reused for watering, the microbial activity is reduced and the microbial activity is reduced. It is hard to produce a drop.

In other words, the high wetness of the biofilter 21 makes it highly adaptable to fluctuations in odor concentration, and it is also highly relaxing of pH fluctuations, maintaining the working environment of the microbial species that can cope with the decomposition of various odors, and the activity of microorganisms Be done.
Therefore, even if the odor concentration or odor quality to be introduced fluctuates, stable deodorizing performance can be maintained for a long time.

In addition, in this embodiment, the moisture content of wood chips 21A 0.99% or more, excessive water W ₁ reaches the space S of a predetermined volume of high wet and the housing H bottom of biofilter 21 maintained at 300% or less Depending on the configuration, the moisture in the bottom of the housing H is high, and the odor gas G introduced to the bottom of the housing H can be humidified. Thus, the effect of alleviating the concentration fluctuation of the odor can be enhanced. Also, the thick water film around the wood chip 21 can reduce the fluctuation of the odor concentration. Furthermore, when the moisture of the odor gas G is high, it also contributes to the uniform distribution of the moisture content of the biofilter 21. Therefore, it is possible to cope with the fluctuation of the odor concentration without taking measures to dilute the odor with air or to extremely reduce the apparent wind speed.

  And, if the odor gas G introduced to the bottom of the housing H can be humidified, the odor gas G is difficult to take away the latent heat of the biofilter 21 even when the ambient temperature in winter is low, and the temperature drop of the biofilter 21 is prevented it can. Also, when the ambient temperature in summer is high, due to the high heat of the biofilter 21 maintaining the high moisture content of the odor gas G and the moisture content of the wood chip 21A at 150% or more and 300% or less, the biofilter 21 Temperature rise can be suppressed. Therefore, it is possible to follow the temperature change of the surroundings, the fluctuation of the deodorizing performance is small, and the stable high deodorizing performance can be exhibited.

  Furthermore, by selecting the size of the wood chip 21A, the wood chip 21A is filled with a predetermined bulk density to constitute the biofilter 21 with the wood chip 21a, and the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less As a result, the air flow resistance can be suppressed to a low level, and the increase in pressure loss is small, so that the running cost for blowing the odor gas G can be suppressed.

In addition, the wood chips 21A can be obtained at low cost, and the biofilter 21 composed of the wood chips 21A filled with a predetermined bulk density has a small pressure loss, and a high processing capacity can ensure a high throughput even with a small size. Also, the volume can be small.
And the high water retentivity of biofilter 21 which maintains the moisture content of wood chip 21A to 150% or more and 300% or less, that is, the thick water film around wood chip 21 and the water around wood chip 21A by the circulation of watering. Because the pH and decomposition products are buffered by the transition, there is no need to provide a means to control the pH or decomposition products of circulating water or to control the amount of odor gas introduced, and a simple device design is required, maintenance and management Is also easy.
By circulating the water, the cost of water for watering can be reduced. In addition, maintenance frequency such as switching of the biofilter 21 and replacement of the wood chip 21A can be reduced.
Accordingly, the material cost, the equipment cost, and the running cost can be reduced, so the cost can be reduced.

  Thus, the low-cost and long-term stable deodorizing performance becomes the sustainable biological deodorizing apparatus 10 also with respect to the odor gas having the complex odor accompanied by the fluctuation of the odor concentration and the odor quality.

And according to the biological deodorizing apparatus 10 which concerns on this Embodiment, since the biofilter 21 is comprised by the wood chip 21A of the specific size which maintains a moisture content at 150% or more and 300% or less, it is from the characteristic of the wood Because of the function of natural and natural microorganisms, it is possible to propagate microbial species that can cope with odor decomposition immediately, and to cope with deodorization of various odors. Therefore, it is not limited to the odor generated from composting facilities such as household waste and urban waste, and poultry and livestock facilities for raising livestock and treating excrement of livestock, and sewage and sewage generated by organic sludge etc. The deodorizing effect can be highly sustained even for odors generated from wastewater treatment facilities, agricultural settlement wastewater treatment facilities, food factory wastewater treatment facilities, etc. That is, it is a deodorizing technology that is not specialized for a specific odor component, and it can cope with the fluctuation of the odor, so the application range is wide.

  Moreover, according to the biological deodorizing apparatus 10 according to the present embodiment, the odor gas is generated by the floor material 22 having the vent holes 22A whose opening is in the range of 20 mm to 100 mm in the range of 5 to 95% of the opening ratio. Since G can be rectified, the processing efficiency of the odorous gas G can be enhanced. Further, the pressure loss of the odorous gas G can be reduced, and the load due to the fluctuation of the amount of odor can be reduced.

  Furthermore, according to the biological deodorizing apparatus 10 according to the above embodiment, the length in the fiber direction of wood is, for example, in the range of 350 mm to 700 mm, and the width in the tangential direction of wood is 10 mm to After laying the wood chip 21b which is in the range of 80 mm and the radial thickness of the wood is in the range of 5 mm to 50 mm, the length in the fiber direction of the wood is, for example, in the range of 10 mm to 300 mm Length of wood in the fiber direction, since the wood chip 21a is filled in such a manner that the tangential width of the wood is in the range of 5 mm to 30 mm and the radial thickness of the wood is in the range of 4 mm to 10 mm 10 mm to 300 mm, the tangential width of the wood is 5 mm to 30 mm, and the radial thickness of the wood is 4 mm to 10 mm. Then, the biofilter 21 is configured with a predetermined bulk density, and does not close the ventilation holes 22A of the predetermined diameter of the floor material 22, and is introduced from the lower side of the housing H through the inlet 24a to the floor material 22. The rectification effect is exerted to make the flow of the odorous gas G which passes through the vent holes 22A of the above and input to the biofilter H smoother. And the ventilation resistance of odor gas G can be eased and pressure loss can be eased. Thus, processing efficiency can be enhanced.

  In addition, in the biological deodorizing apparatus 10 according to the present embodiment, the projecting wall 28 is provided along the side wall of the housing H above or below the position of the floor material 22, and the side wall on the housing H side has a predetermined projecting length By projecting inward, it is possible to block off the odor along the side wall of the housing H and to suppress the odor leak along the side wall of the housing H. In addition, since the odor gas G can be rectified and the odor gas can be uniformly fed to the entire area of the biofilter, the processing efficiency can be enhanced. For example, as shown in FIG. 4 and FIG. 7A, the inner side wall of the housing H itself is formed to protrude toward the side surface of the biofilter 21 or a plate between the housing H and the biofilter 21 The side wall on the housing H side is made to project toward the side surface of the biofilter 21 from the position of the floor material 22 by installing another member (protruding wall 28) such as a shape. Further, as shown in FIG. 7 (b), from the position of the floor material 22 to the projection of the inner side wall of the housing H itself or the installation of another member (projection wall 28) such as a plate, etc. Are protruded toward the inside of the housing H. As a result, it is possible to block off the odor along the side wall of the housing H and to suppress the odor leak along the side wall of the housing H.

Further, according to the biological deodorization apparatus 10 according to the embodiment, the water sprinkling to biofilters 21, excessive water W ₁ which has passed through the biofilter 21 and 36 volume% or more, the water to be replenished from the outside 64 volume% By setting it as the following, it is low cost and can maintain higher deodorizing ability.

  Furthermore, according to the biological deodorizing apparatus 10 according to the above embodiment, since the thickness h of the biofilter 21 in the direction in which the odor gas G passes upward from below is within the range of 1.5 m to 3 m, A high deodorizing effect can be obtained at low cost, and the high deodorizing effect can be further sustained.

In the case of carrying out the present invention, the design and specifications of the biological deodorizing apparatus 10 are not limited to the above embodiment. The volume of the biofilter 21 is determined using the apparent velocity, the load characteristics of the biofilter 21, the linear velocity, etc., obtained in the present embodiment according to the requirements of the type, concentration, removal rate of treated odor gas G, etc. , Cross-sectional area, filling height h can be determined. In particular, the pressure loss is proportional to the filling height h and the linear velocity, and if the pressure loss rises too much, the cost increases and the processing efficiency decreases due to the uneven flow of the odor gas G. It is desirable to design the pressure drop to be maintained in the range of 0 to ₂₀₀ mm H ₂ O.

  In the case of practicing the present invention, the configuration of the floor material 22 is not limited to the above, and for example, a conduit provided with a vent 22A of a predetermined diameter is embedded in the bottom of the housing H or formed at predetermined intervals. It is also possible to form the floor material 22 by disposing a sleeve in the hole and burying a conduit provided with a vent 22A made of a sleeve.

  Moreover, when implementing this invention, the inlet 24 of the odor gas G sent as compressed air from the blower 5 is not limited to one, You may provide multiple. It is good also as composition connected to a plurality of fermenters of a composting facility, and using a specific inlet 24 among a plurality of inlets 24 by a fermenter made into a target of deodorization. That is, the plurality of inlets 24 may be selectively used selectively by control. Alternatively, the water receiver 41 may be provided at the bottom of the housing H.

DESCRIPTION OF SYMBOLS 10 Biological deodorizing apparatus 20 Deodorization processing part 21 Biofilter 21A Wood chip 24 introduction port 30 Watering means 40 Circulating means H Housing

WO2011 / 024507 Japanese Patent Laid-Open No. 2000-342928 Patent document 1: JP-A-2005-246106 Japanese Patent Application Publication No. 2006-035028

  The present invention is a biological deodorizing process that deodorizes odorous gases generated when fermenting and decomposing organic wastes such as food waste and food processing residues, and organic matter such as livestock manure and sludge of sewage and sewage treatment using a biological deodorizing system. In particular, the present invention relates to a biological deodorizing method which can exhibit stable deodorizing performance at low cost for a long period of time, even for an odor gas having a complex odor accompanied by fluctuations in odor concentration and odor quality.

  Waste disposal facilities for composting organic wastes such as raw vegetables, fruits, meats, food processing residues, etc. and poultry farming for raising livestock and treating livestock excrement · As a measure against odors and odors in livestock facilities and wastewater and sewage treatment facilities where organic sludge etc. are generated, combustion deodorization method in which odorous substances are oxidatively decomposed and deodorized by combustion, odorous substances are adsorbed by adsorbents such as activated carbon There are known adsorption deodorization methods to deodorize, cleaning deodorization methods (chemical treatment methods) to deodorize chemical substances by contacting chemical substances with chemical substances and biological deodorization methods to decompose odorous substances by microorganisms and deodorize, etc. There is.

Above all, according to the biological deodorization method that causes microorganisms to decompose odorous substances, it is necessary to post-process adsorbents (waste activated carbon etc.), chemical sludge, waste liquid, etc. like combustion deodorization method, adsorption deodorization method, cleaning deodorization method without also generate a residue, odor components are carbon dioxide (CO _2), and water (H ₂ O) harmless substances or SO _4, such as ^- and NO ₃ ^- can be decomposed into inorganic ions such. Also, as the combustion process, dust, dioxins and, since there is no possible to discharge a large amount of CO ₂ and NO _x, a gentle deodorization method environment. Furthermore, since expensive materials such as chemicals are not used, and frequent replacement is required as in the case of adsorbents, no fuel is required, and operating costs can be reduced.

In particular, in recent years there has been a high level of interest in Japan's environmental problems, and with regard to waste disposal, efforts have been made to reduce the amount of incineration by reusing organic waste as a resource from the viewpoint of environmental impact. The method of fermenting and aging waste, composting it, and using it as an organic fertilizer is actively carried out. For this reason, the need for odor control of gas containing odor emitted from such composting facilities is increasing.
In addition, in the livestock industry, about 90% of livestock excrement is composted, but it is difficult to add cost to odor control that does not lead to productivity. Therefore, the deodorization technology whose installation cost and operating cost are cheap is desired for the odor control.

  And, in the composting treatment of organic wastes and livestock manure such as garbage, since it is mainly aerobic fermentation treatment (organic matter decomposition by aerobic microorganisms), the odor generated in the decomposition process (fermentation process) of the organic matter Is a complex odor that has a relatively low concentration and a large air volume, and also contains various odor components, compared to odors generated in chemical factories etc. and odors in livestock night processing facilities and anaerobic fermentation processing facilities Ingredients, concentrations may also vary. For this reason, there is a demand for a deodorizing technique that achieves a deodorizing performance reliably and continuously even with a low concentration and multi-volume odor which is a combined odor containing various odorous components and in which the odorous components and the concentration can also vary.

Here, the soil deodorization method, the rock wool deodorization method, etc. are mainly known as conventional biological deodorization methods.
In the soil deodorization method, the odorous components of the odorous gas sent from under the soil layer dissolve in the water on the surface of the soil particles or adsorb on the surface of the soil particles while passing through the soil layer, and further by soil microorganisms Although it is a deodorizing system by being decomposed, it requires a large site area because the ventilation resistance of the soil layer is high. Therefore, rock wool deodorization has been developed to compensate for the defects, and the use of rock wool can improve the air flow resistance. And, in the rock wool deodorization method, the installation area can be reduced as compared with the soil deodorization method. However, since rock wool is an inorganic substance, it lacks the ability to adsorb odorous components and the activity of microorganisms. For this reason, the device which raises the activity of the microorganism which mixes with organic matter and contributes to deodorization is required.

  For example, Patent Document 1 mainly uses a mixture of inorganic fiber-made granular cotton such as rock wool granular cotton in which particles having a particle size of 1 mm or more and 40 mm or less are mixed, and woody chip; There is disclosed a deodorizing material in which a microbial activity substance consisting of compost manure and excess sludge alone or a mixture of two or more is mixed. In this patent document 1, a wood-based chip is introduced as an organic substance that serves as a carbon source for maintaining the activity of microorganisms that inhabit the rock wool layer, and exhibits an initial adsorption effect.

WO2011 / 024507 Japanese Patent Application Publication No. 2004-024353 Patent document 1: JP-A-2005-246106 Japanese Patent Application Publication No. 2006-035028

However, in the conventional biological deodorizing apparatus using rock wool as a microorganism carrier including the patent document 1, although the initial aeration resistance is improved by the soil deodorizing method, the water management and the microorganism management are difficult, and the pressure by the use The loss was likely to be large. For this reason, it is necessary to apply a high pressure or to increase the volume of the deodorizing material in order to increase and maintain the treatment capacity and treatment efficiency, and it is difficult to reduce the cost. Rock wool materials are also expensive.
In addition, the biological deodorizing device using conventional rock wool as a microorganism carrier is effective for fixed odor gas, but is poor in response to fluctuation of odor concentration and fluctuation of odor quality, and maintains stable deodorizing effect The sex was low. In particular, due to the prior art emphasis on deodorizing efficiency with respect to fixed odorous gases, microorganisms effective for specific odorous components may be infested or seeded, or microbial active substances may be added. In addition to the cost of technological development for adopting microorganisms suitable for odor sources, when a specific microorganism is inoculated, inoculated or inoculated with a microorganism active substance, it is vulnerable to fluctuations in odor concentration and odor quality, and There was a case that a load exceeding the activity was applied. In such a case, although measures to control the odor to be introduced may be considered, the operation management cost becomes expensive.

  Further, in the technology of Patent Document 1, the packing property is also high due to the combination of the inorganic fiber-made granular cotton and the woody chip, and furthermore, the size of the air passage becomes nonuniform. Instead, a large amount of offensive odor is likely to pass through a specific air passage, and the air passage may be easily closed there. For this reason, pressure loss is likely to increase with the introduction of odor, and it is also difficult to maintain high deodorizing efficiency. Naturally, the facility operating cost (power cost) also increases as the pressure loss increases. Furthermore, since the action of biological deodorization is difficult to be obtained unless microbial active substances such as livestock manure, compost manure and surplus sludge are mixed, the management of the microbes is complicated and the price of the material is also expensive.

By the way, in this kind of biological deodorizing apparatus, watering is performed to prevent the drying of the microorganism carrier and maintain the microbial activity. Therefore, in order to reduce the cost, for example, Patent Literatures 2 to 4 disclose a technique that adopts a circulating water sprinkling method in which water of sprinkled water is circulated.
In Patent Document 2, a treated water and an odorous gas introduced from an odorous gas inlet are mutually passed in a countercurrent direction to a countercurrent packed bed filled with a carrier carrying a microorganism, and the countercurrent packed bed is The treated water having passed through and deodorized treated gas is discharged from the treated gas outlet, while the treated water which has passed through the countercurrent packed bed is provided in the downstream direction of the treated water flow, and is filled with a carrier carrying a microorganism. In the deodorizing method for treating the odorous gas by passing the single flow packed bed, the treated water having passed the countercurrent packed bed is allowed to pass through the single flow packed bed, and subsequently, the downstream direction of the treated water flow After being stored in the water storage section provided in the water storage section, circularly passing from the water storage section to the water storage section via the countercurrent packed bed and the single flow packed bed, and passing the single flow packed bed Between before and before reaching the countercurrent packed bed By adding an alkali to serial processing water, discloses a technique for maintaining the pH value of the treated water immediately after passing through the single-flow packed bed 6.5.

  Further, in Patent Document 3, a container into which an offensive odor gas is introduced, a filling carrier which is filled in the container and carries a deodorizing microorganism or an enzyme derived therefrom, and water in the container is sprayed to the filling carrier. A biological water treatment dewatering device of the circulation watering operation type, comprising: a water sprinkler; and a water sprinkler pipe for recovering water in the container as water for water irrigation and circulatingly supplying the water to the water sprinkler, wherein the odorous gas is biologically deodorized. The technique which arrange | positioned the odor substance reduction member which can reduce the at least 1 type or more of odor substance contained in the said water for irrigation in the middle of a water spray piping is disclosed.

  Furthermore, Patent Document 4 is provided separately from a biological deodorizing apparatus of a circulating watering operation type that converts ammonia into nitric acid and / or nitrous acid to deodorize ammonia by microorganisms having a nitrifying action, and the biological deodorizing apparatus, A denitrifying apparatus for converting nitric acid and / or nitrous acid into nitrogen by a microorganism having an action, and an organic matter supplying apparatus for supplying an organic matter serving as a nutrient of the microorganism having the denitrifying action to the denitrifying apparatus In a biological deodorizing method using a biological deodorizing apparatus configured to circulate circulating water between an apparatus and the denitrifying apparatus, nitric acid and / or nitrous acid is reduced by a microorganism having a denitrifying action in the denitrifying apparatus. A technology is disclosed that performs control to maintain the concentration of nitrate nitrogen and nitrite nitrogen contained in the circulating water at a value of 2500 ppm or less by changing to nitrogen.

In the case of a circulating watering system in which water used for watering is circulated, decomposition products produced by decomposition of odorous substances by odorous substances or microorganisms are gradually accumulated in circulating water and become high in concentration, and such odorous substances or decomposition products It is difficult to maintain the deodorizing effect because the activity of the microorganisms is inhibited by the sprinkling of the circulating water concentrated.
Therefore, in Patent Documents 2 to 4, the pH of circulating water is adjusted, odor substances and decomposition products are adsorbed by an odor substance reducing member such as an ion adsorbent, and a denitrification step is provided in a circulating water channel. Technology is used.
However, on the other hand, there is a problem that equipment and control become complicated, and new costs such as material cost, equipment cost, and running cost are required.

Then, this invention makes it a subject to provide the biological deodorizing method which can exhibit the deodorizing performance stable for a long time at low cost also with respect to odor gas of the complex odor accompanied by the fluctuation | variation of odor concentration or odor quality.

According to the biological deodorizing method of the first aspect of the present invention, a biofilter formed by packing wood chips in a bulk density range of 150 to 500 kg / m ³ is sprayed with water from above, and the surplus passed through the biofilter Water is circulated as the water spray, the moisture content of the wood chip is maintained at 150% or more and 300% or less, and the odor gas introduced from below is digested by the biological treatment with the biofilter. It is digested by treatment.

The biofilter is made by packing wood chips at a bulk density of 150 to 500 kg / m ³ , and digests odor gas introduced from the bottom by biological treatment.
Here, the term "digestion by biological treatment" means that the odorous components in the odorous gas are decomposed and deodorized by the enzyme action or the like of the microorganism.
In addition, the wood chips are raw wood (stems, whole trees, shrubs, end trees, branches, pruning branches, rootstocks, etc.), lumbers (backboards, scraps, peeled cores, etc.), building demolition materials, building materials, packaging materials Plywood, laminated wood, particle board, waste pallets and the like are cut or crushed by a chipper, shredder, mill, crusher, hammer, punching or the like to obtain a wood piece, which is sieved and a predetermined size is selected.

The present inventors have repeatedly conducted intensive research on biofilters that can stably exhibit long-term deodorizing performance and can be configured at low cost stably even for odorous gases with a complex odor accompanied by fluctuations in odor concentration and odor quality. As a result, it has been found that, by constructing the biofilter with wood chips, the ability to follow odor gas of complex odor accompanied by fluctuation of odor concentration and odor quality is high, and high deodorizing effect can be stably maintained for a long time The
In particular, it has been found that biofilters formed by depositing wood chips are less likely to clog and have less increase in pressure loss due to use if they have a predetermined bulk density, and that high deodorizing effect over a long period of time is maintained. According to the experiments of the present inventors, the bulk density for depositing wood chips is specified to be in the range of 150 kg / m ³ or more and 500 kg / m ³ or less.
In addition, this bulk density (Kg / m ³ ) is a value of the initial setting, and the volume of the wood chip of the predetermined size is determined from the integration of the packing height filled with wood chips and the cross sectional area of the biofilter. It is calculated by dividing the total weight of the wood chips of the predetermined size by the calculated volume value.

Further, the watering is performed on the biofilter from above on the side opposite to the side on which the odor gas is introduced. The water spray wets the biofilter to maintain the wood chips at a predetermined moisture content. Watering may be intermittent or continuous.
And the said watering is circulated. That is, water sprayed from above the biofilter to pass through the biofilter from below, that is, excess water flowing down without being retained in the biofilter is recovered and used again as water spray. The water for sprinkling may be configured to be supplemented with water from the outside in addition to the excess water that has passed through the biofilter.

According to the biological deodorizing method of the second aspect of the present invention, the water sprayed to the biofilter has a volume of water passing through the biofilter of 36% by volume or more when the amount of water sprayed per unit time is 100 vol. The amount of water to be replenished is 64% by volume or less.
Here, 36% by volume or more of water passed through the biofilter and 64% by volume or less of externally replenished water means that the water for sprinkling water sprayed from the sprinkling means to the biofilter is newly taken from the outside The excess water of the watering collected by the circulation means may be used, that is, only the circulation water may be used, or even when the water is newly replenished from the outside, 100% of the total volume of water for watering, The proportion of water to be replenished is 64% or less, meaning that the excess water recovered by the circulating means, that is, 36% by volume or more of the circulating water, is included.

According to the biological deodorizing method of the first aspect of the present invention, it is constituted by filling wood chips within a bulk density of 150 to 500 kg / m ³ , and the water sprinkled on the biofilter is circulated by the circulating means. I am doing it. As a result, low-cost and long-term stable deodorizing performance is exhibited even for an odor gas having a complex odor accompanied by a change in odor concentration or odor quality.

  As a result of intensive research and research, the present inventors constructed a biofilter with wood chips as a microorganism carrier and circulated water sprinkling water to the biofilter by circulation means. Function as a biofilter that digests odorous components by biological treatment with microorganisms at an early start-up, even if the microorganisms do not feed or breed microorganisms, or do not add microbial active substances for imparting microbial activity, etc. In addition, it has been found that the deodorizing effect can be sustained over a long period of time, and there is little increase in pressure loss with time, and the ability to follow fluctuations in odor concentration and odor quality is high. The present invention has been completed on the basis of this.

That is, the air flow resistance is suppressed to a low level by filling the wood chips in a volume density of 150 to 500 kg / m ^{3 to form} the biofilter, and the water is sprayed to the wood chips by the circulation means. By recycling the water which has passed through, the decomposition products (metabolites) produced by the decomposition of the odorous components by the microorganisms or the microorganisms are distributed evenly in the biofilter.
Therefore, the narrowing, clogging, and clogging of the air passage of the biofilter are unlikely to occur, and an increase in pressure loss over time can be suppressed.

In particular, due to the water retention characteristics of wood chips by watering, microbial species that can cope with the decomposition of various odors are also easily propagated. And, in the biofilter in which wood chips are packed in a bulk density range of 150 to 500 kg / m ³ , the flow path is wide, water is uniformly distributed throughout the biofilter, and the high water retention of wood chips , The effect of alleviating concentration fluctuation and pH fluctuation is high. For this reason, it is hard to produce the fall of pH one by one, and can maintain pH of a neutral region.
Therefore, even for various odors, a microorganism species that can cope with its decomposition is likely to be active, and its activity can be sustained. In particular, even if the water that has passed through the biofilter by recycling means is reused as water sprinkling, the activity of the microorganism and the decrease in the activity of the microorganism hardly occur. In addition, in biofilters composed of such wood chips, the odorous gas is easily dissolved in the liquid phase around the wood chips due to the water retention characteristics and high surface area of the wood chips, and the amount of contact between the wood chips and the odor gas Processing capacity is high.
Therefore, even if the odor concentration or odor quality to be introduced fluctuates, stable deodorizing performance can be maintained for a long time.

Furthermore, air resistance can be suppressed by filling wood chips within a bulk density of 150 to 500 kg / m ^{3 to form} a biofilter, and clogging is less likely to occur, and pressure loss increases with time. Also, the running cost for blowing off the odorous gas can be reduced.
Also, wood chips can be obtained inexpensively. Moreover, since the biofilter configured as described above has high processing capacity and can suppress pressure loss, a predetermined high throughput can be ensured even with a small volume. And, even if the water that has passed through the biofilter by recycling means is reused as water sprinkling, the buffer effect of pH fluctuation is high due to the high water retentivity of the biofilter. It is not necessary to provide means to control the amount of odor gas introduced or to control the amount of odor gas introduced.
Therefore, the material cost, the equipment cost, and the running cost can be suppressed and the cost can be reduced.

According to the biological deodorizing method according to the second aspect of the present invention, the water sprinkled to the biofilter is 36 vol% or more of the water passing through the biofilter when the amount of water sprinkled per unit time is 100 vol%. By making the externally replenished water 64% by volume or less, the cost can be low and the high deodorizing ability can be maintained.

  The inventors of the present invention accumulated the earnest experimental research, and as a result, in a biological deodorizing apparatus using wood chips of a predetermined size as a microbe carrier of a biofilter, surplus water having passed through the biofilter is recovered by circulation means for watering The water may be externally replenished when it is circulated in water, but it has been found that the deodorizing ability decreases when the ratio of the replenishment water in the water for sprinkling increases, and the present invention is completed.

That is, the ratio of the replenishing water out of the water for watering is not more than 64 volume%, the excess water that has passed through the biofilter, i.e., if the proportion of circulating water circulating 36% volume or more, in claim 1 In addition to the described effects, it is low in cost and can sustain high deodorizing ability.

FIG. 1 is a conceptual diagram for explaining the flow until the odor gas is introduced into the biological deodorizing apparatus according to the embodiment of the present invention. FIG. 2 is an explanatory view showing the entire configuration of the biological deodorizing apparatus according to the embodiment of the present invention. FIG. 3 (a) is an explanatory view showing a floor material of the biological deodorizing apparatus according to the embodiment of the present invention and the configuration around it, and FIG. 3 (b) is a biological deodorizing apparatus according to the embodiment of the present invention 3 (c) is a cross-sectional view taken along line X-X of FIG. 3 (b). FIG. 4: is a principal part enlarged view explaining the structure in the housing of the biological deodorizing apparatus based on embodiment of this invention. FIG. 5 is a graph showing changes in pressure loss over time in the biological deodorizing apparatus of the example according to the embodiment of the present invention. FIG. 6 is a graph showing the time-dependent temperature change of the biofilter in the biological deodorizing apparatus of the example according to the embodiment of the present invention. Fig.7 (a) is the elements on larger scale explaining an example of the protruding wall provided in the housing of the biological deodorizing apparatus based on embodiment of this invention, FIG.7 (b) is biological organisms based on embodiment of this invention It is the elements on larger scale explaining another example of the protruding wall provided in the deodorizing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that, in the embodiment, the same symbols and symbols in the drawings are the same or corresponding functional parts, and thus the description thereof will not be repeated.

First, the flow until the odor gas G is introduced into the biological deodorizing apparatus 10 according to the embodiment of the present invention will be described with reference to FIG.
The odor gas G targeted by the biological deodorizing apparatus 10 according to the present embodiment is, for example, a waste processing facility that composts (composts) food waste such as raw vegetables, fruits, meats and food processing residues, and livestock. Are odors that arise from poultry and livestock facilities that produce livestock and composting livestock excrement, sewage and sewage treatment facilities where agricultural sludge etc. occur, agricultural settlement drainage treatment facilities, food factory drainage treatment facilities, etc. And the odor generated during aerobic fermentation and decomposition of organic matter. The odor gas G produced during the aerobic fermentation and decomposition of such organic substances is, for example, ammonia, trimethylamine, dimethyl sulfide (DMS), hydrogen sulfide, methyl sulfide, methyl disulfide, methyl mercaptan, volatile fatty acid ( VFA), an aldehyde component such as acetaldehyde and the like, and an odor component such as terpenes, and it is a combined odor containing a plurality of odor components and various odors. In addition, the odor from the facility that aerobically ferments and decomposes organic matter is lower than the odor of the livestock's human waste treatment facility and anaerobic treatment and fermentation facility, and has a large air volume, and the odor quality, odor concentration, air volume, etc. Greatly fluctuate.

That is, in FIG. 1, in the composting device 2, aerobic fermentation / decomposition treatment of organic waste or livestock manure is performed, and an odor gas G is generated. In this composting apparatus 2, for example, the bacteria-retaining chip having aerobic bacteria attached to organic waste such as collected food residue, pruned branches or composting material such as livestock manure or sewage sludge is put, temperature, oxygen, humidity Aerobic fermentation and decomposition treatment is carried out by controlling the surrounding annular conditions such as in a predetermined manner. A wide variety of devices have been proposed for composting by aerobic fermentation. For example, there is a device for composting in a closed concrete housing called a biocell system. In particular, in recent years, the composting method in a closed container or in a building has become mainstream due to the influence on the surrounding environment, the problem of odor and the like.
And odor gas G which arose in the aerobic fermentation and decomposition process process in this composting device 2 is collected suitably using a blower, a fan, etc., and it is made as pressure wind to biological deodorizing device 10 concerning this embodiment. It will be sent.

In addition, before the odor gas G discharged | emitted from the composting apparatus 2 is sent to the biological deodorizing apparatus 10, the odor concentration is reduced by the chemical deodorizing apparatus 3 as needed.
Furthermore, the scrubber device 4 removes harmful substances and dust contained in the odor gas G discharged from the composting device 2 as necessary. The scrubber device 4 uses, for example, a washing and collecting device (dust removing device, gas washing device) to collect and separate particles in the odor gas G with a washing solution or a liquid film.

In particular, when the acid scrubber treatment is performed by the scrubber device 4 at the stage before the biological deodorizing device 10, the biological deodorizing device 10 is clogged with an odor containing sulfur compounds and ammonia generated from sludge of a sewage treatment plant ( Constriction, obstruction) can be prevented and the load can be reduced.
It should be noted that if there is a wet scrubber 4 that captures and removes dust by spraying water, the odor gas G is humidified before introducing the odor gas G to the biological deodorizing device 10, so that the odor is high in humidity. Gas G can be introduced into the biofilter 21. If the humidity of the odorous gas G introduced into the biofilter 21 can be increased, it is also effective in suppressing the temperature fluctuation of the biofilter 21 as described later.

  The odor gas G discharged from the composting device 2 and appropriately through the chemical deodorizing device 3 and the scrubber device 4 is sucked and pressurized by the blower 5 and blown to the biological deodorizing device 10. In addition, the blower 5 which guides odor gas G to the biological deodorizing apparatus 10 is inverter-controlled so that rotation speed control can be performed as needed. Therefore, for example, when the treated amount of the odorous gas G discharged from the composting device 2 and the odor concentration are extremely small, the energy saving operation can be performed by reducing the rotational speed. However, the blower 5 is operated at all times to send an air flow to the biological deodorizing device 10, thereby preventing clogging (constriction, blockage) of the biofilter 21 of the biological deodorizing device 10. The capacity of the blower 5 is determined by the processing amount of the odor gas G, the volume, size, etc. of the biofilter 21. According to the biological deodorizing apparatus 10 of the present embodiment, the pressure loss is small as described later. In addition, since an increase in pressure loss over time is also suppressed, a high throughput can be ensured even with a low-performance, small-sized fan, without using an expensive one with high blowing capacity.

  Next, the whole structure which implements the biological deodorizing apparatus 10 which concerns on embodiment of this invention is demonstrated with reference to FIG.

  The biological deodorizing apparatus 10 of the present embodiment includes a deodorizing unit 20 in which a biofilter 21 for digesting odor gas G by biological treatment and a floor material 22 provided under the biofilter 21 are accommodated in a housing H, The water sprinkling means 30 sprinkling water from the upper part of the biofilter 21 constituting the deodorizing processing portion 20, the water receiving portion 41 collecting and storing the water sprinkling water from the water sprinkling means 30, and the water receiving portion 41 are supplied to the water sprinkling means 30 The supply path 42 to be circulated is configured, and the surplus water that has passed through the biofilter 21 and the floor material 22 is recovered and circulated to the water sprinkling means 30.

  In the deodorization processing unit 20 of the present embodiment, the floor material 22 is opened via the support legs 23 in a box-like housing H formed of reinforced concrete, and the lower surface and the left and right side surfaces are opened upward. It arrange | positions and the wood chip | tip 21A is filled on it, and the biofilter 21 is formed.

  The size of the housing H is designed in accordance with the amount of odor gas G to be treated, the desired rate of deodorization, and the like. For example, the volume is set to about 1.5 to 4 times the tunnel volume of the composting facility, and in terms of pressure loss, the height h of the biofilter 21 is 1.5 m or more and 3.5 m or less as described later preferable. The housing H is not limited to reinforced concrete, and may be made of a material that is resistant to corrosion, and a heat insulator may be used on the outside. It is also possible to maintain the growth environment of microorganisms favorably by the heat insulating material and to stabilize the deodorizing efficiency. However, in the present embodiment, as described later, since the deodorizing efficiency can be stably maintained regardless of the seasonal variation, there is no problem even if the heat insulating material is not used.

  At the bottom of the housing H, an introduction port 24 for introducing the odorous gas G pressure-fed by the blower 5 is provided, and an introduction consisting of a duct or the like connecting the output of the blower 5 to the introduction port 24 at the bottom of the housing H The odor gas G pressure-fed from the blower 5 is introduced from the inlet 24 through the passage 24 a. The inlet 24 and the inlet 24a have such a size that pressure loss does not occur therein. For example, the inlet 24 is provided below any one of the four side surfaces of the housing H.

  Then, in the housing H of the space partitioned by concrete, as shown in FIG. 3, a plurality of support legs 23 for maintaining the floor material 22 at a predetermined height are erected on the bottom surface of the housing H, The floor material 22 is placed on the support legs 23. The support leg 23 is made of, for example, concrete formed in a columnar or cylindrical shape, and is designed and arranged to withstand the pressure of the floor material 22 and the pressure of the biofilter 21 which is made wet by watering. In this manner, after the support legs 23 are erected on the floor surface of the housing H, the floor material 22 is disposed thereon, and the floor material 22 is held at a predetermined height, so that the bottom and the floor of the housing H A predetermined space S communicating with the inlet 24 a of the housing H is defined between the members 22. That is, the bottom of the housing H and the floor material 22 are spaced apart by the support leg 23, and a predetermined space S is formed between the bottom of the housing H and the floor material 22. By providing the predetermined space S communicating with the inlet 24 a of the housing H, the odor gas G introduced from the inlet 24 a of the housing H can be distributed to the entire bottom of the housing H.

The floor material 22 is thus placed on the support legs 23 erected at the bottom of the housing H, and is spread over the entire cross section in the housing H, and the wood chips 21A are loaded thereon.
For example, as shown in FIG. 3, the floor material 22 is provided with a plurality of through holes 22a of a predetermined shape which penetrates the wall thickness, and a predetermined thickness which is provided with a plurality of grooves 22b which penetrate the wall thickness on the side surface A plurality of concrete parts are combined and laid in concrete H.

  Thus, the floor material 22 is provided with, for example, a vent hole 22A formed by a combination of a vent hole 22A which is a through hole 22a having a cylindrical shape (circular cross section) and a groove 22b provided around the part. The odor gas G introduced from the inlet 24a of the housing H and circulated through the entire bottom of the housing H is introduced into the wood chip 21A laid on the floor 22 through the vents 22A of the floor 22. It will be done. Note that the vent holes 22A are distributed over the entire floor material 22, thereby enabling uniform supply of the odorous gas G to the entire area of the biofilter 21.

Here, according to experiments of the present inventors, the floor material 22 disposed under the biofilter 21 filled with the wood chips 21A of the predetermined size is controlled by controlling the size and density of the air holes 22A. Since the fluid loss generated there can be set to the minimum, and even if the introduced amount of odorous gas fluctuates, the load can not be applied by a predetermined fluid resistance. About the open and specified by the aperture ratio.
That is, if the opening area and the opening ratio of the vents 22A provided in the floor material 22 are too large, the mechanical strength is weak, and a tough material is required, resulting in a cost increase. On the other hand, even if the opening area and the opening ratio are too low, the pressure loss is high, and a strong air flow is required, resulting in an increase in running cost.
Therefore, the floor material 22 preferably has an opening of the vent holes 22A in the range of 20 mm to 100 mm, and an opening ratio in the range of 5% to 95%.

In addition, the said opening and the aperture ratio represent the magnitude | size and air density of ventilation hole 22A of the flooring 22. As shown in FIG. The above-mentioned openings also indicate, for example, the top-bottom width or the left-right width at the opening (space) per eye formed by crossing a vertical line and a horizontal line such as mesh, etc. If it is a square, it corresponds to one side of a square. The air holes do not specify the shape of the circular eye or square, but the air resistance is small and the surface area is large. Therefore, a circular hole with a circular cross section or a square with a square cross section Holes are preferred.
In addition, the opening of the floor material 22 and the open area ratio are measured according to the standard of sieve wire mesh, the plane area of the floor material is S, the number of floor material floors is M, and the wire diameter of vertical and horizontal lines is d. When this is done, the opening is calculated by the following equation (B), and the aperture ratio is calculated by the following equation (C).
Opening A (mm) = S / M-d (B)
Opening ratio ε (%) = (A / A + d) ² × 100 (C)

  As described above, in the floor material 22 on which the wood chips 21A having a predetermined diameter are laid, the pressure drop is within the range of 20 mm to 100 mm, and the opening ratio is within the range of 5% to 95%. The load is reduced by a predetermined fluid resistance even if there are fluctuations or variations in the amount of introduced odor gas. More preferably, the opening is in the range of 30 mm to 90 mm, and the aperture ratio is 10% to 90%.

  Further, in FIG. 3, in order to enhance the rectification effect and to reduce the influence of pressure fluctuation due to the flow velocity of the odor gas G, the diameters of the plurality of vents 22A are directed upward, ie, the biofilter 21. The diameter is gradually reduced toward the side. Furthermore, according to Bernoulli's theorem, the odor gas G from the blower 5 may be adjusted to reduce the change in flow rate by adjusting the size, shape and aperture ratio of the vents 22a.

In addition, in FIG. 3, the plurality of air holes 22A of the floor material 22 are formed in a circular cross-sectional shape, that is, a circle when viewed from the front, but in the case of practicing the present invention, the cross-sectional oval It may be oval, triangular in cross section, rectangular in cross section, hexagonal in cross section or the like. A shape with small fluid resistance is preferable, for example, a cross section having a circular shape, an oval shape, an oval shape, a square shape, etc. is preferable. Further, the configuration of the housing H, the support leg 23 and the floor material 22 is made of concrete. In the case of practicing the present invention, another material may be used as long as the material is resistant to corrosion and the predetermined strength can be ensured.

Thus, in the present embodiment, the floor material 22 is installed on the support legs 23 erected at the bottom of the housing H, and the wood chip 21A forming the biofilter 21 is filled on the floor material 22.
At this time, as shown in FIG. 4, a plate-like projecting wall 28 is installed on the floor material 22 so as to surround along the side wall of the housing H, and wood is provided in the space surrounded by the plate-like projecting wall 28. The chip 21A may be filled. Thus, the installation area (bottom area) of the biofilter 21 filled with the wood chips 21A is reduced by the amount of protrusion of the projecting wall 28 with respect to the laying area of the floor material 22. That is, the bottom area of the biofilter 21 disposed on the floor material 22 is smaller than the top area of the floor material 22 on which the biofilter 21 is placed. That is, the floor area (plane area) on the input side of the lower end portion of the biofilter 21 is smaller than the plane area on the output side of the floor material 22 without the side surface of the biofilter 21 and the side surface of the floor material 22 coinciding .

  Thus, the plate-like projecting wall 28 is provided on the floor material 22 so as to surround along the side wall of the housing H, and the area ratio of the input side area where the odor gas G is input to the biofilter 21 is By making the area smaller than the area of the upper surface of the floor material 22, the rectification effect can be enhanced, the odor leakage along the side wall of the housing H can be suppressed, and the odor gas more uniformly over the entire area of the biofilter 21 G can be supplied to increase the processing efficiency with respect to the volume of the biofilter 21. Furthermore, the increase in pressure change at the boundary between the floor material 22 and the biofilter 21 makes it easy to eliminate the clogging on the input side where the odor gas G is introduced into the biofilter 21. However, if the installation area of the biofilter 21 is too small relative to the installation area of the floor material 22 having the vent holes 22A of a predetermined cross-sectional area at a predetermined aperture ratio, the plate-like protruding wall 28 When the flow velocity of the odorous gas G passing through the floor material 22 at the entrance is greatly restricted, the pressure loss becomes large to secure a predetermined throughput, and the cost increase due to the increase of the sending pressure of the blower 5 Become. Therefore, in consideration of pressure loss, for example, the protruding length of the protruding wall 28 is set in the range of 150 mm to 1000 mm, more preferably in the range of 250 mm to 600 mm.

Here, although it has been described that the projecting wall 28 is provided between the biofilter 21 and the housing H on the floor material 22, the inner side wall of the biofilter 21 itself is located inside from above the position of the floor material 22 (biofilter 21) may be formed so as to protrude toward the side 21).
Further, the projecting wall 28 does not have to be provided up to the position of the filling height h of the biofilter 21 as shown in FIG. 4A, and as shown in FIG. For example, the height position may be 10 cm to 20 cm. In any case, the leakage of the odor gas G rising along the wall surface of the housing H may be prevented.

  Furthermore, when implementing this invention, as shown in FIG.7 (b), the range of 150 mm-1000 mm below from the surface opposite to the mounting surface of the flooring 22 in which wood chip 21A is loaded, for example There may be provided a plate-like projecting wall 28 projecting inward from the side wall of the housing H with an inner projecting length, more preferably within a range of 250 mm to 600 mm. Also by this, it is possible to rectify the odor gas G input to the biofilter 21 and to suppress the odor leakage along the side wall of the housing H. In the case of practicing the present invention, as shown in FIG. 7B, the projecting wall 28 may be provided with a thickness (length in the vertical direction) of 10 cm to 20 cm from below the floor material 22, Alternatively, the volume of the space S may be reduced by providing a plate-like protruding wall 28 or a plurality of support legs 23 along the side wall of the housing H in the lower space S of the floor material 22 or the inner side wall of the biofilter 21 itself. May be formed to project toward the inside of the housing H. Even in this case, it is possible to prevent the leakage of the odorous gas G rising along the wall surface of the housing H.

Furthermore, in the present embodiment, as shown in FIG. 2, the bottom of the housing H is water that has been sprinkled from the water sprinkling means 30 above the biofilter 21 and has passed through (flowing down) the biofilter 21 and the floor material 22. A drainage port 42 is provided to allow the water to flow out to the water receiving portion 41. Here, reaches the water in the bottom of the housing H through the biofilter 21 and flooring 22 (hereinafter sometimes referred to excess water W ₁₎ from the drain port 42 without accumulating a predetermined amount or more to the bottom of the housing H The drainage port 42 is designed to be in a predetermined position so as to flow out to the water receiving portion 41. When the amount of water stored in the bottom of the housing H is large, there is also reproduction of an organism such as an insect and the deodorizing performance is lowered.
However, in the space S below the floor material 22, the water passing through the biofilter 21 and the floor material 22 is collected at the bottom of the housing H, so the humidity is high, and the odor introduced from the inlet 24 below the housing H It is also possible to increase the humidity of the gas G. If the humidity of the odorous gas G introduced into the biofilter 21 can be increased, it is also effective in suppressing the temperature fluctuation of the biofilter 21 as described later.
In the case of carrying out the present invention, the outflow of water reaching the bottom of the housing H is sloped on the bottom surface of the lower part of the housing Hn to collect water from the water receiving portion 41 and the drainage port 42 without stopping water retention. It may be done. A plurality of drains 42 may be provided

Excess water W ₁ flowing out of the drain outlet 42 of the housing H through the drain passage 42a consisting of conduits or the like that connects the drain outlet 42 to the water receiving portion 41, is recovered is collected in the water receiving portion 41.
From the water receiving portion 41, a water sprinkling supply path 43 formed of a pipe or the like is disposed up to the upper side of the housing H, and above the housing H, a water sprinkling pipe constituting the water sprinkling means 30 connected to the water sprinkling supply path 43 31 are arranged. In the middle of the water sprinkling supply path 43, a pump and a valve are provided.
The water sprinkling pipe 31 has a required number of water sprinkling nozzles 32 for sprinkling water, and has a structure capable of sprinkling water substantially uniformly on the upper surface of the biofilter 21 in the housing H. Water spray is usually sprayed as water droplets. 1 and 2, the direction of the water spray nozzle 32 is directed downward on the biofilter 21 side, but the direction of the water spray nozzle 32 is not limited thereto, and the water spray nozzle 31 is directed upward. You may do so. In any case, by sprinkling water from above the housing H toward the biofilter 21, the sprayed water falls to the biofilter 21 by gravity, and the water is supplied to the wood chip 21A constituting the biofilter 21. Do.

Thus, the surplus water W ₁ collected in the water receiving portion 41 is supplied to the water sprinkling pipe 31 as the water sprinkling means 30 for sprinkling water from above the housing H to the biofilter 21 by the water sprinkling supply path 43. Used for humidifying water spray. That is, in the present embodiment, the surplus water W ₁ which has passed through the biofilter 21 is used as water to be sprayed to the biofilter 21, and the water is circulated.

Furthermore, in the water receiving unit 41 of the present embodiment, the water conveyance unit 44 for introducing industrial water (industrial water etc.) as a replenishment means for replenishing water from the outside to the circulation means 40 and supplying water to the circulation means 40 is also connected. In addition to the waste water W ₁ (surplus water W ₁ ), new water W ₂ can be newly taken in from the water conveyance unit 44 through a valve as needed. That can be summarized in the water receiving unit 41, a replenishing water W ₂ from the drainage W ₁ (excess water W ₁₎ water conduit 44 as required from the housing H.
Therefore, the surplus water W ₁ used for sprinkling in the water receiving section 41 and the supplementary water ₂ supplied from the outside as needed are put together and pumped up, and supplied to the sprinkling pipe 31 through the sprinkling supply passage 43. Be done. Then, the water supplied to the water sprinkling pipe 31 is supplied to the biofilter 21 by the water sprinkling from the water sprinkling nozzle 31 directed to the upper surface of the biofilter 21. At this time, water sprinkling may be intermittent or may be performed continuously.
In addition, in the water conveyance part 44 which introduce water, such as industrial water, the filter for filtering refuse, sand, and microparticles | fine-particles and the scrubber apparatus 4 are installed as needed. As a result, clogging of the biofilter 21 can be prevented without the inclusion of dust, sand and fine particles in the watering.

Thus, in the biological deodorizing apparatus 10 of the present embodiment, surplus water W ₁ sprinkled from the water sprinkling means 30 and passed through the biofilter 21 is used mainly for moisture adjustment and humidification of the biofilter 21, and further, if necessary Since the replenishing water W ₂ is supplemented from the external industrial water etc., the waste water is completely eliminated. That is, the water spray is circulated without draining to the outside.

Here, the configuration of the biofilter 21 of the present embodiment will be described in detail.
The biofilter 21 according to the present embodiment is, for example, raw wood (trunk, whole wood, shrubs, end trees, branches, pruning branches, rootstocks, etc.), lumber (backboard, end material, peeled core, etc.), building demolition material, construction The material, packing material, plywood, laminated wood, particle board, waste pallet and the like are cut or crushed by a chipper, shredder, mill, crusher, hammer, punching or the like to deposit wood chips 21A in the form of wood chips. Not limited to raw wood chips obtained by cutting and crushing raw wood (including harvested wood, thinned wood, and small diameter wood), factory residual wood chips, forest residual wood chips, dismantling wood chips, etc. may be used. That is, the wood chips 21A are not limited to solid wood chips, and may include laminated wood chips, MDF chips, and particle board chips. However, since wood fiber chips, MDF chips, particle board chips, etc. are attached with impurities such as adhesives and paints, their content is preferably 40% by weight or less in consideration of the influence on the microbial environment. More preferably, it is 30 wt% or less, more preferably 20 wt% or less. Wood chips 21 mainly consist of wood xylem and pulp only, but bark chips and bark chips are mixed (preferably 20% by weight or less of the whole, more preferably 5% by weight of the whole) Or less).
The wood chip 21A may be a cutting chip obtained by cutting a raw wood, a lumber, a waste material or the like with a cutter using a wood chipper (a disc-type chipper or the like), a shredder, a mill, a hammer, a crusher or the like. It may be a crushed chip (pin chip, crusher chip or the like) obtained by crushing raw wood, lumber, waste material or the like by using it.

  In addition, wood used for wood chip 21A is cedar, cypress, red pine, tsuga, pine, yew, nezuko, fir, fir, sawara, asunaro, hiba, inuigaya, spruce, spruce, eastern white pine, western larch, western fur Or coniferous trees such as Western Hemlock or Tamarac, or birch, birch, linden, birch, beech, china, poplar, eucalyptus, acacia, narcissus, maple, birch, elm, persimmon, persimmon, willow, sen, persimmon, oak It may also be a broadleaf tree such as kunugi, horsetail, zelkova, mizume, mizuki, aodamo, or blueberry.

  In addition, the present inventors are changing the material type of wood chip 21A used as the microbial carrier of the biofilter 21 to be used, and are carrying out the evaluation test of the deodorizing effect by the biological deodorizing apparatus 10. The results at that time are shown in Table 1.

  As shown in Table 1, as lumber chips 21A, shredded lumber and lumber scraps of softwood (mixture of cedar and cypress), lumber of lumber lumber (blend of birch and leek) lumber and lumber of lumber Using five types of crushed products, crushed materials of lumber and lumber scraps of crushed wood, perforated hardwood with porous wood (Mizunara), crushed products of construction waste, and crushed products of pruned branches, the biological deodorizing apparatus 10 shown in Table 1 The deodorizing effect of the odor gas G was tested under the specifications and test conditions.

Here, the numerical values shown in Table 1 are the results of sensory evaluation of odor by a monitor for evaluating the deodorizing effect.
For evaluation of the deodorizing effect, 12 people (hereinafter referred to as monitors) collected from the general public smell the odor gas G of the source odor and the processing air after passing through the biofilter 21 five times each at 1 hour intervals. Received, the smell intensity is shown in the lower table 1 Table 6 (0: no odor, 1: I do not know what smell is in the haze, 2: I do not mind, 3: I do not care, 4: strong odor, 5: Very smelly, intense smell) received sensory evaluation. The 12 monitors were divided into two groups of six each, and in one group they smelled in the order of odor gas G of source odor and treated air, and in the other group smell in the order of treated air and odor gas G Have a sense of smell and perform a sensory evaluation. The numerical values shown in Table 1 above are average values of odor evaluations by 12 monitors. However, when calculating the average value, it is an integer of the average value of 10 people excluding the highest value and the lowest value. Further, the odor evaluation here is performed three times, one month, three months, and one year after the introduction of the odor gas G to the biological deodorizing apparatus 10.

  As shown in Table 1, even if wood chips 21A are of any material type, no odor is known even one year after the start of the introduction of the odor gas G (1) or It is an evaluation that the odor does not become (2), and a high deodorizing effect was maintained. That is, it is possible that the high deodorizing effect continues for a long time regardless of whether the wood chips 21 are crushed products from thinnings and lumber scraps, crushed products from construction wastes or broken products from pruned branches. I understand.

  In particular, according to the experimental research of the present inventors, the wood chip 21A made of conifers such as pine, cedar and cypress etc. contains a large amount of resin, so the deodorizing effect for a longer period is sustained and It has been confirmed that the life is increased. On the other hand, in the hardwood wood chip 21A, compared with the softwood wood chip 21A, the acclimatization of microorganisms effective for the decomposition of the odor gas G and the formation of the microflora (biofilm) are quickened, showing a quick start-up. It has been confirmed that the deodorizing ability of the biofilter 21 is high.

In addition, when recycling waste materials, such as a factory residual material and a demolition residual material, as wood chip 21A, processing of foreign substance removal is usually performed before and after cutting or crushing processing.
Then, in the wood chip 21A of the present embodiment, after cutting or crushing of wood, for example, wood chips classified (sorted) to a predetermined size (grain size) with a vibrating screen, a roll classifier or the like are used. .
Such wood chips 21A have resistance to acidity and alkalinity, are less likely to deteriorate or lose their shape, and have high shape retention. Therefore, it is possible to suppress an increase in pressure loss over time and a decrease in deodorizing efficiency due to use.

  The size of the wood chip 21 is, for example, that the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of wood is It is in the range of 4 mm to 10 mm.

Here, when the length of the wood chip in the fiber direction of the wood chip is in the range of 10 mm to 300 mm, the length of the wood chip is 10 mm or more and 300 mm or less when the length direction of wood grain is the wood chip length. Indicates that it is within the range of
In addition, when the width of the wood chip in the tangential direction is 5 mm to 30 mm, the width of the wood chip is in the range of 5 mm to 30 mm when the tangential direction in contact with the annual ring circle of wood is the width of the wood chip. Indicates that it is within.
Furthermore, when the radial thickness of the wood chip is in the range of 4 mm to 10 mm, the thickness of the wood chip is in the range of 4 mm or more and 10 mm or less when the radial direction of the wood annual ring is the thickness of the wood chip. Indicates that.
However, for example, when it is difficult to determine the direction of the wood, such as MDF chip, PB chip, etc., the long side direction of the wood chip is the length of the wood chip, and the direction perpendicular to the long side direction is the width of the wood chip Let the direction perpendicular to the length and width be the thickness of the wood chip.

  For cutting chips and crushing chips, the longest width in the fiber direction of wood is the length of wood chip 21A, the longest width in the tangential direction of wood is the width of wood chip 21A, the longest width in the radial direction of wood is the thickness of wood chip 21A and Do. In addition, for MDF chips, PB chips, etc., in which the fiber direction, tangential direction, and radial direction can not be determined, the longest side of the wood chip 21A is the length, the longest width in the direction perpendicular to the long side is the width, and the long side And let the longest width in the direction perpendicular to the width be the thickness of the wood chip 21.

Depending on the size of the wood chips 21 as described above, filling can be performed in the range of bulk density 150 to 500 kg / m ³ . However, due to differences in the wood raw materials, wood species, processing means or mechanism of crushing or cutting, the shape of the wood chip is not a fixed shape, but has variations and a complicated shape. It is a rough value including an error due to the above, and it does not deny several errors.

  Here, the present inventors are changing the size of the wood chip 21A group which comprises the biofilter 21 variously, and are carrying out the evaluation test of the deodorizing effect. The results at that time are shown in Table 2. Wood chips 21A shown in Table 2 are expressed by the length dimension (the fiber direction of wood) of the wood chips 21a.

  Here too, the deodorizing effect of the odor gas G is tested in the same manner as described above under the specifications of the biological deodorizing apparatus 10 shown in Table 2 and the test conditions, and the numerical values shown in Table 2 are obtained by the above-mentioned 12 monitors It is a result of sensory evaluation (average value) of odor. The odor evaluation was performed four times, one month, three months, one year, and three years after the introduction of the odor gas G to the biological deodorizing apparatus 10.

  As shown in Table 2, in the wood chip group where the length of the wood is 10 mm or more and 100 mm or less, the odor one month after the start of the introduction of the odor gas G does not matter (2), 3 months after The evaluation of (1) does not know what kind of smell, Furthermore, the evaluation after one year also does not understand what kind of smell (1), and the high deodorizing effect continued for a long time. In addition, in the wood chip group where the length of wood is 150 mm or more and 300 mm or less, the odor one month after the start of the introduction of the odor gas G does not mind the smell (2), three months, one year later and The evaluation three years later also shows no smell (1) and a higher deodorizing effect has been sustained for a long time. Here, for such wood chips having a length of 10 mm or more and 300 mm or less, for example, the width is 5 mm to 30 mm, and the thickness is 4 mm to 10 mm.

  On the other hand, in the wood chip group where the length of wood is less than 10 mm, the evaluation one month and three months after the introduction of the odor gas G starts is the unnoticeable odor (2), but one year The evaluation after 3 years was anxious odor (3) or strong odor (4), and the deodorizing effect clearly decreased one year after the introduction of the odor gas G was started. Such a wood chip having a length of less than 10 mm has, for example, a width of about 1 to 10 mm, a thickness of about 1 mm to 5 mm, and a so-called chip dust called wood chip It was included.

  This is because the flow path of the odor gas G is small due to the small size (particle diameter) of the wood chip 21A, and therefore the deposition of decomposition products (metabolites) produced by the decomposition of the odor component by the microorganism film (biofilm) or microorganisms It is considered that clogging (constriction, obstruction) is likely to occur due to the like. When the wood chip 21A is partially clogged, a partial flow which the passage of the odor gas G is limited occurs, the contact amount with the wood chip 21A necessary for the decomposition of the odor component of the odor gas G decreases, and the entire biofilter 21 It seems that it will not be used uniformly and uniformly.

  On the other hand, wood chips with a length of 400 mm or more and 700 mm or less have an odor (3) that is anxious one year after the start of the introduction of odor gas G, and the deodorizing effect of odor gas G is low It was a thing. In addition, the width | variety was about 20 mm-50 mm, for example, and the thickness of the wood chip whose length of such a wood is 400 mm or more was about 5 mm-20 mm.

  This is because the size of the wood chip group is large, the flow path of the odor gas G becomes large, the contact ratio between the odor component in the odor gas G and the wood chip 21A decreases, or the wood chip 21A in the entire biofilter 21 This is considered to be because the water holding amount and the amount of microorganisms effective for the decomposition of the odor component are small due to the small surface area of

  In addition, even if wood chips with a length of 150 mm or more and 300 mm or less are used, the volume is 80% of the entire biofilter 21 and the remaining 20% volume is mixed with wood chips less than 10 mm in length. If you do, the evaluation one month and three months after the start of the introduction of the odor gas G is a smell that you do not mind (2), but the evaluation after one year is a scent that you care about (3) Yes, the sustainability of the deodorizing effect was low.

  This is due to the combination of small-diameter wood chips (wood length less than 10 mm) and large-diameter wood chips (wood length 150 mm or more, 300 mm or less), the packing density is increased, and odor gas G flows Smaller channels tend to cause clogging and uneven flow of odor gas G, and the amount of contact with wood chips 21A necessary for decomposition of odor components of odor gas G decreases, and the entire biofilter 21 is effectively uniform. It is considered to be because it is not used.

Thus, with regard to wood chips 21, clumps are less likely to occur in a community where the size is too small, such as chip dust, particles, etc., while biofilters 21 are predetermined even in communities where the size is too large. It does not become bulk density and can not exhibit an effective deodorizing effect.
Therefore, for example, the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of wood is in the range of 4 mm to 10 mm If there is a certain group of wood chips 21A, clogging is unlikely to occur, and odor gas G can pass through the entire biofilter 21 evenly, and the high surface area ensures good water retention and retention of microorganisms, and deodorizing effect Sustainability is improved. That is, regardless of the difference in the raw material of wood, it is difficult to cause narrowing, clogging, clogging, increase in pressure loss and formation of an optimal flow path size, and the sustainability of high deodorizing effect can be ensured.

  More preferably, the size of the wood chip 21 is such that the length in the fiber direction of the wood is in the range of 150 mm to 300 mm, the width in the tangential direction of the wood is in the range of 5 mm to 25 mm, and the radial direction of the wood The thickness of 4 mm to 10 mm in the range of 80% by mass or more of wood chips of this size makes it easy to obtain the optimum conditions for forming a passage that is hard to clog. That is, when the size distribution of the wood chip group is seen, the length of the fiber direction of the wood is 150 mm to 300 mm even though the difference between the wood raw material and tree species and the processing means or mechanism of crushing or cutting is reflected in the size distribution. 80% by weight or more of wood chips of wood chip size in which the tangential width of the wood is in the range of 5 mm to 25 mm and the radial thickness of the wood is in the range of 4 mm to 10 mm If it is, it is possible to obtain stable characteristics as a wood chip which constitutes a biofilter having a high durability of deodorizing effect.

The wood chips 21A group of such a predetermined size can be obtained, for example, by sieving wood chips after cutting or crushing. Usually, sieving of wood chips is classified using a screen, shaking the sieve.
And about wood chip 21A group of the above-mentioned predetermined size, for example, a sieve of 60 mm of openings passes (pass), and it is available as a size of a wood chip group which does not pass of a sieve of 10 mm of openings. For example, an undersized wood chip having a sieve opening of 60 mm is obtained, and then the undersize wood chip having a mesh opening of 60 mm is further passed through a sieve having a mesh size of 10 mm. Obtain an oversized wood chip that does not pass the opening 10 mm. In this way, it is possible to obtain an oversized wood chip which is an undersize having a mesh size of 60 mm and which does not pass through a mesh size of 5 mm to obtain a wood chip 21 having a predetermined size. In addition, sieving may be classified with a sieve shaker in which sieves are designed in a stacked structure. In addition, the opening indicates the width or the width in the opening (space) of one eye formed by crossing the vertical line and the horizontal line, but here, circular eyes (round holes) or square eyes ( A square hole) sieve was used. In the case of a sieve having an opening of 60 mm, in the case of a circular eye, the diameter of the circular hole is 60 mm, and in the case of a square, one side of the square is 60 mm. In the case of a sieve having a mesh size of 10 mm, in the case of a circular mesh, the diameter of the circular hole is 10 mm, and in the case of a square grid, one side of the square is 10 mm. However, the shape of wood chips is not a fixed shape but has a dispersion and a complicated shape due to the difference between the raw materials of wood, the species of wood, and the processing means / mechanism of crushing or cutting. It is not always possible to obtain a wood chip 21A group having a size and a size. More preferably, it is a wood chip which passes through a sieve having an opening of 40 mm by sieving and does not pass through a sieve having an opening of 20 mm.

  By the way, such a wood chip 21A is filled on the floor material 22 to constitute the biofilter 21 with a predetermined bulk density, but depending on the size of the vents 22a of the floor material 22, the wood chip 21A may be used. May fill the vents 22a of the floor material 22.

Therefore, in the case of carrying out the present invention, as shown in FIG. 4 (b), after laying the wood chips 21b of coarse size on the floor surface of the floor material 22, for example, the fibers of wood as described above The length of the direction is in the range of 10 mm to 300 mm, the width of the tangential direction of the wood is in the range of 5 mm to 30 mm, and the thickness of the wood in the radial direction is in the range of 4 mm to 10 mm It is also possible to fill.
For example, as coarse size wood chips 21b, the length in the fiber direction of wood is in the range of 350 mm to 700 mm, the width in the tangential direction of wood is in the range of 10 mm to 40 mm, and the thickness in the radial direction of wood Is in the range of 5 mm to 20 mm, more preferably, the length in the fiber direction of wood is in the range of 400 mm to 500 mm, the width in the tangential direction of wood is in the range of 10 mm to 80 mm, the radial thickness of wood Can be used in the range of 5 mm to 50 mm.

In this manner, by laying coarse-sized wood chips 21b so that fine-sized wood chips 21a do not fall into the vents 22A of the floor material 22 and then filling the fine-sized wood chips 21a. Also, the pressure loss can be alleviated, and the narrowing of the air passage due to the consolidation under the biofilter 21 can be alleviated, and the deodorizing efficiency can also be improved. In addition, since the strong ventilation is not required for ventilation of odor gas G by the reduction effect of pressure loss, it is also possible to reduce the running cost of the blower 5.
Such coarse wood chips 21b are filled with 5% or less of the volume of the fine wood chips 21a.

  Thus, the drying of the wood chips 21A is performed on the biofilter 21 configured of the wood chips 21A (hereinafter, the wood chips 21a and the wood chips 21b may be collectively referred to as the wood chips 21A unless otherwise distinguished). In order to prevent it and maintain the activity of the biological treatment by the biofilter 21, the water is sprayed from the water spray means 30 to humidify the biofilter 21. That is, when the moisture of the wood chip 21A is small, the growth of microorganisms is suppressed, and the deodorizing action is reduced because the wood chip 21A can not catch the odor component in the odor gas G. The biofilter 21 maintains the wet state by water sprinkling from the water sprinkling means 30.

  Here, the inventors further investigated the conditions for optimizing the dissolution, adsorption, and microbial environment of the odor component in water, and the amount of water sprinkling of the biofilter 21 composed of the wood chip 21A serving as a microorganism carrier. It has been found that when the moisture content of the wood chips 21a is controlled by adjustment, a high deodorizing effect is obtained and the effect is sustained. Table 3 shows the results when an evaluation test was conducted on the relationship between the moisture content of the wood chip 21 a and the deodorizing effect.

Here, the wood chip 21a is adjusted to each moisture content to 20% to 220% by adjusting the amount of watering and maintained, and the deodorization of odor gas G in the test conditions and the specifications of the biological deodorizing apparatus 10 shown in Table 3 The effect was tested.
The numerical values shown in Table 3 are also the results of sensory evaluation (average value) of the odor by the above-mentioned 12 monitors. The odor evaluation was performed four times, one month, three months, one year, and three years after the introduction of the odor gas G into the biological deodorizing apparatus 10.

With regard to the moisture content of the wood chips 21a, the moisture content was measured periodically whether or not the wood chips 21a were maintained at each moisture content, and the amount of water spray was adjusted and managed so as to be maintained at each moisture content.
At the time of measurement, a predetermined amount of wood chips 21a is collected from the biofilter 21, and the weight is measured before and after drying to determine the moisture content.
The moisture content of the wood chips 21a at this time represents the ratio of the water weight to the weight (total dry weight, dry basis) of the wood chips 21A in a state not containing water, and the water content is obtained by the following formula (A) The rate is being sought.
Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100 (A)
The total dry weight was 105 ° C., and the value in the dried state was used until there was no change in weight.

  As shown in Table 3, when the moisture content of the wood chip 21a is 150% or more, the evaluation one month after the start of the introduction of the odorous gas G is annoyed odor (3) or does not care Smell (2), but the evaluation after 3 months was (1) which I do not know what smell of garnet. In addition, even in the evaluation one year later, it does not know what smell is present (1), and even after three years, it does not mind (2), and a high deodorizing effect is maintained for a long time. The

On the other hand, it was inferior to the deodorizing effect as the moisture content of the wood chip 21a is less than 150%. That is, when the moisture content of the wood chip 21 is 120%, the evaluation has a strong smell (4) even one month after the start of the introduction of the odor gas G, and it is anxious even in the evaluation after three months It was odor (3), and the evaluation one year later was a strong odor (4).
In addition, when the moisture content of the wood chips 21a is 80% or less, the evaluation has a strong odor (4) or a very strong odor, even one month after the start of the introduction of the odor gas G (5), 3 months after, 1 year later, 1 year later, 3 years after evaluation also annoyed in the evaluation (3), strong smell (4) or very strong smell, intense smell (5) Deodorizing effect was not obtained.

Therefore, the high deodorizing effect can be maintained for 3 years or more by maintaining the moisture content of the wood chips 21a at 150% or more. According to the experiments of the present inventors, it is more preferably 160% or more, still more preferably 180% or more.
And in the experimental research of the present inventors, there is an upper limit to the moisture content of the wood chip 21a from the characteristic of the wood, and the upper limit is determined by the characteristics of the wood species of the wood chip etc. is there.

  The water content of the wood chips 21a is maintained at 150% or more and 300% or less by water sprinkling from the water spray means 30, and the high deodorizing effect is sustained by the water retention of the wood chips 21a to the moisture of the odor component. It is speculated that the dissolution, adsorption, and microbial environment are optimized. In particular, in the case of wood chips 21a having a moisture content of 150% or more and 300% or less, a thick water film is formed around them, which can increase the microbial activity and gas is easily dissolved in the liquid phase and easily adsorbed. It may have become. Furthermore, it is speculated that such a thick water film has high pH buffering action against the concentration fluctuation of the odor component and also against the production of decomposition products generated by the decomposition of the odor component, and the fluctuation of pH is suppressed. Be done. And, by thus suppressing the fluctuation of pH and maintaining the pH in the neutral range, it is difficult for the microbial activity to be inactivated, and the activities of a plurality of types of microbial groups are maintained to cope with various odors. It seems to be possible. That is, it is thought that it can maintain in the optimal environment for the growth of the microbe group which can respond to various odors.

Thus, in the present embodiment, the water content of the wood chips 21 a is maintained at 150% or more and 300% or less by watering from the watering means 30.
The amount of water spray is such that the water content of the wood chips 21a is maintained at 150% or more and 300% or less. However, regardless of the upper and lower layers of the biofilter 21, the wood chips 21a, It is assumed that the moisture content of the wood chip 21b is maintained at 150% or more and 300% or less.

Here, the inventors further investigated the conditions for maintaining a high deodorizing effect, and in the present embodiment, the excess water W ₁ used for watering in the water receiving portion 41 and the outside as needed The replenishment water W ₂ supplied from the pump is put together, pumped up, and supplied to the water pipe 31 via the water supply path 43 and watered. Depending on the conditions of the water used for watering at this time, the deodorizing performance Was found to fluctuate.
That is, for the water to be sprinkled with water spray means 30, as shown in Table 4, is recovered is drained as excess water W ₁ from the housing H by in the water receiving portion 41, the water to be used as a water spray the circulating water W ₁ again , difference in deodorizing performance when water is replenished from the water conduit 44 and the replenishing water W _2, the ratio of the circulating water W ₁ and replenishing water W ₂ of water used as a watering for certain watering amount per unit time It was seen. Table 4 shows the results of an evaluation test on the relationship between the condition of water used for watering and the deodorizing effect.

Here, the water to be sprinkled with water spray means 30, the specification of biological deodorization apparatus 10 shown by adjusting the ratio of the circulating water W ₁ and replenishing water W ₂ in Table 4, the test of deodorizing effects of odorous gas G test conditions Did.
The numerical values shown in Table 4 are also the results of the sensory evaluation (average value) of the odor by the 12 monitors described above. The odor evaluation is performed four times, one month, three months, one year, and three years after the introduction of the odor gas G into the deodorizing apparatus 10.

As shown in Table 4, the water for sprinkling consists of 100% by volume of circulating water W ₁ when a fixed amount of water discharge per unit time is 100% by volume, or it is assumed that replenishment water W ₂ is taken from the outside Even if the water for sprinkling is circulating water W ₁ / supplemented water W ₂ 7 7/12 by volume ratio, the odor after one month after the start of the introduction of the odorous gas G is annoyed (3) Or, I do not mind (2), and the evaluation after 3 months was (1) which I do not know what smell of garnet. In addition, in the evaluation one year later, it does not know what smell is present (1) or odor (2), and even after three years, it does not know what odor does occur. (1) or odor that does not bother (2), and high deodorizing effect was maintained for a long time.

On the other hand, water for sprinkling is not circulated (circulating water W ₁ : replenishing water W ₂ = 0: 10), water for sprinkling in volume ratio is circulating water W ₁ / replenishing water W ₂ <7 / When it was 12, it was inferior to the deodorizing effect. That is, at 0/10 ≦ circulating water W ₁ / replenished water W ₂ <7/12, the evaluation has a strong smell (4) even one month after the start of the introduction of the odor gas G, and 3 months The later evaluation also showed a strong odor (4).

Therefore, when the constant water discharge amount per unit time is 100% by volume, the water W sprinkled by the water spray means 30 has the circulating water W ₁ of about 36% by volume or more and the replenishment water W ₂ of 64% by volume or less. High deodorizing effect can be sustained for over 3 years.
The reason is that the water that has passed through the biofilter 21 contains microorganisms effective for odor decomposition, and the circulating water W ₁ containing such microorganisms is reused as watering without being discharged to the outside (waste water) Therefore, the amount of microbes in the biofilter 21 is maintained by the fact that the water sprayed to the biofilter 21 contains effective microorganisms, and the bias of the microbiota is prevented, and the microflora in the entire biofilter 21 is It is considered that they are uniformly distributed, and the entire biofilter 21 is effectively used. In addition, it is considered that the followability and responsiveness to the odor gas G of the complex odor accompanied by the fluctuation of the odor concentration and the odor quality are also enhanced. In particular, by reducing the dilution with replenishment water W _{2 with} respect to circulating water W ₁ , that is, when the ratio of circulating water W ₁ to water used for sprinkling is high, microorganisms having high concentration are effective biofilter 21 Since the water is sprayed, the high microbial load of the biofilter 21 and the microbial activity are maintained, and it is possible to continuously maintain a high deodorizing effect even on the odor gas G having a complex odor accompanied with the fluctuation of odor concentration and odor quality. . In addition, odor components (such as ammonia ions) that cause a rise in pH and decomposition products (such as nitrate ions) of an odor component that cause a decrease in pH are balanced by the circulation of such water spray, and the neutral range of pH is It is assumed that it has been maintained and has maintained a high deodorizing effect.

Thus, in the present embodiment, assuming that the fixed water discharge amount per unit time is 100% by volume, the volume ratio of water sprayed by the water spray means 30: 0/10 ≦ replenished water W ₂ / circulating water W ₁ It is assumed that ≦ 12/7. That is, the water receiving portion in 41 using the watering surplus water W ₁ was passed through the biofilter 21 (circulating water W _1), the replenishing water from the outside not exceed 64% by volume of water used for watering as needed W ₂ Is supplied from the water spray means 30 to the biofilter 21 as water spray.

In such organisms deodorizing device 10, including the drainage 42a and the water receiving unit 41 introduction path 24a and the surplus water W ₁ is discharged odor gas G is introduced from the blower 5, at the bottom of the housing H is While the odor gas G is a closed system that does not leak to the outside, the upper part of the housing H from which the deodorized air is discharged through the biofilter 21 is generally opened. In the housing H provided with a ceiling, an opening is provided so that deodorized air can be released to the atmosphere. In this case, the water spray pipe 31 and the like may be embedded in the ceiling, and the water spray nozzle 31 may be disposed in the ceiling.
Installation of such a biological deodorizing apparatus 10 may be indoors or outdoors, and when installed outdoors, it prevents the penetration of rain or the irradiation of direct sunlight to the biofilter 21 in the housing H as necessary. In order to cover the housing H, a roof such as a tent for covering the housing H may be provided above the water spray pipe 31. Also, the housing H may be of the underground type.

In addition, as for the biological deodorizing apparatus 10 of this Embodiment, computer control is desirable.
Taking up only the main information management, for example, the information of the sending amount and sending pressure of the blower 5 is detected and input to the computer COMP. Further, in the computer COMP, information on the pressure on the air discharge side above the biofilter 21 and the internal temperature of the biofilter 21 is detected by a sensor and is input. Further, information on the moisture content of the wood chip 21 artificially measured is input to the computer COMP and managed, and based on that, the amount of water sprayed by the water spray means 30 is determined. Further, the amount of water in the water receiving portion 41 is also detected, and the amount of water from the water guiding portion 44 is determined based on the amount of water sprayed by the water sprinkling means 30, and is used as the input of the computer COMP. The computer COMP controls the drive of the pump, valve, flow meter, and valve disposed in the water conveyance unit 44 for taking in water from the outside, for pumping the water stored in the water receiving unit 41 to the sprinkling means 30. Control of the amount of water spouted from the water sprinkling means 30. Usually, the pump for watering is timer-controlled. Further, the odor concentration is detected by the sensor above the biofilter 21 and is input to the computer COMP. The pressure, temperature, odor concentration and the like of the odor gas G may be detected at the inlet where the odor gas G is introduced into the biological deodorizing apparatus 10 and may be input to the computer COMP.

Thus, the information on the moisture content of the wood chip 21A is mainly used for the amount of water sprinkling of the water sprinkling means 30, that is, the drive control of the pump and the valve. Further, the information on the pressure on the air discharge side on the biofilter 21 and the sending amount of the blower 5 and the sending pressure are mainly used for control of the blower 5. These information, including the odor concentration information, can be controlled and managed as schedule management information by the monitor, and can be used for proof of compliance with local government regulations by keeping a processing record. The chemical deodorizing device 3 and the scrubber device 4 in FIG. 1 are also monitored and operated independently.
Further, by visual monitoring with respect to the filling height h of the wood chips 21A, when it falls below a predetermined amount, new predetermined wood chips 21A are replenished.
Furthermore, the pressure loss calculated from the sending pressure of the blower 5 and the ejection pressure on the biofilter 21 is managed, and when the pressure loss exceeds a predetermined amount, the sending amount of the blower 5 and the sending pressure are controlled. Further, when the size of the wood chips 21A is visually monitored, fine grains are increased and the pressure loss is large, screening is performed to eliminate the fine grains and replenish the new wood chips 21A. Do.

Hereinafter, the Example which materialized the biological deodorizing apparatus 10 of this Embodiment is described.
In the present embodiment, odor gas G generated at a composting facility such as household waste and urban waste is targeted, and supporting legs 23 are erected as shown in FIG. 3 at the bottom of a concrete housing H. The floor material 22 with an opening in the range of 20 mm to 100 mm and an opening ratio in the range of 5 to 95% is placed thereon, and, for example, a fiber of wood is placed on the floor material 22. The length of the direction is in the range of 350 mm to 700 mm, the width of the tangential direction of the wood is in the range of 10 mm to 80 mm, and the thickness in the radial direction of the wood is in the range of 5 mm to 50 mm Then, for example, the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of wood is 4 mm to 10 mm Within range The biofilter 21 is formed by filling the timber chip 21a, to constitute a deodorization treatment unit 20.
At this time, the separation distance between the bottom of the housing H and the bottom of the floor material 22 is set to, for example, 10 cm to 50 cm, preferably 20 cm to 40 cm, and the coarse wood chips 21b are filled with 10% or less of the volume of the fine wood chips 21a. Be done.
In addition, in composting facilities such as household waste and urban waste, the wastes processed there are not always a fixed property, and various miscellaneous raw materials that are different each time are fermented and decomposed, so the odor gas G generated there is a complex It is an odor, and furthermore, its odor concentration and odor quality fluctuate. In addition, in composting facilities that perform compost turning, concentration fluctuations due to compost turning also increase.

  At this time, in the present embodiment, as shown in FIG. 7A, a plate-like member having a projection length in the range of 150 mm to 1000 mm, preferably in the range of 250 mm to 600 mm is provided on the floor material 22. Protruding wall 28 is installed along the four side walls of housing H at a predetermined height from the upper surface of floor material 28, and in a space in housing H provided with such a projecting wall 28, a wood chip 21A of a predetermined size is provided. It was filled. That is, on the floor material 22, a side wall on the housing H side protrudes toward the biofilter 21 by the protruding wall 28.

As shown in FIG. 2, at the bottom of the housing H, an inlet 24 for the odor gas G connected to the blower 5 via the introduction passage 24 a is provided, and a water receiving portion via the drainage passage 42 a outlet 42 which excess water W ₁ which has passed through the biofilter 21 and flooring 22 connected is drained is provided 41.
The water receiving portion 41 is connected with a water sprinkling supply path 43 formed of a pipe line connected to a water sprinkling pipe 31 having a water sprinkling nozzle 32 disposed above the housing H, and industrial water (industrial water etc. as necessary). The water conveyance part 44 for introduce | transducing water of 2.) is connected. The water sprinkling supply passage 43 is provided with a valve and a pump, and the water conduit 44 is also provided with a valve.
The specifications and design of the biological deodorizing apparatus 10 according to the present embodiment are as shown in Table 5. In the present embodiment, the water sprinkling means 30 is operated intermittently, and water sprinkling is intermittently performed by a timer-controlled water distribution pump.

At the time of design of the biological deodorization device 10, the processing air volume (m ³ / min) and the processing speed (mm / sec) desired from the amount of odor gas G (source odor) generated in composting facilities such as urban waste The installation area (cross-sectional area) of the biofilter 21 that secures a predetermined processing capacity that does not exceed the load is set based on the processing air volume (m ³ / min) and the processing speed (mm / sec). For example, the cross-sectional area, volume, etc. of the biofilter 21 are determined such that the odor gas G has an apparent wind speed of 15 to 30 mm / sec, more preferably 20 to 25 mm / sec. The apparent velocity is obtained by dividing the flow rate (mm ³ / sec) of the odorous gas G to be processed by the cross-sectional area (mm ² ) of the biofilter 21.
Here, in order to ensure low cost and long-term stable deodorizing performance, the present inventors further thickness of the layer of the biofilter 21 formed by filling the wood chip 21A (wood chip 21a, wood chip 21b) That is, the filling height (loading height) h of the wood chips 21A was investigated. About the filling height h of the biofilter 21, it experimented by setting an initial setting to 1.0 m-3.5 m, and the evaluation test of the deodorizing effect was done. The results at that time are shown in Table 6.

  The numerical values shown in Table 6 are also the results of the sensory evaluation (average value) of the odor by the 12 monitors described above. The odor evaluation was performed four times, one month, three months, one year, and three years after the introduction of the odor gas G into the biological deodorizing apparatus 10.

As shown in Table 6, when the filling height h of the wood chips 21A is 1.5 m or more and 3.0 m or less, the odor after one month after the start of introducing the odor gas G does not mind It is (2), and a high deodorizing effect has been maintained for a long time, such as an odor (2) which does not matter in an evaluation after three months, one year, and three years, or (2) which smell does not know.
In particular, when the filling height of the wood chips 21A was 2.0 m or more and 2.5 m or less, the sustainability of the high deodorizing effect was high.

On the other hand, when the filling height of the wood chips 21A is 1.4 m or less, after one year, it is an evaluation of offending odor (3) or strong odor (4), particularly in 1.0 m or less Evaluation of a strong odor (4) or a very strong odor (5) always resulted in no deodorizing effect.
This is because the contact amount between the odor component of the odor gas G and the wood chip 21A can not be obtained sufficiently.

In addition, even if the filling height h of the wood chips 21A is 3.5 m or more, it is an evaluation of offensive odor (3) after 3 months, and the sustainability of the deodorizing effect is reduced.
This is because the packing height h of the wood chip 21A is too high, and the consolidation is high at the lower part of the biofilter 21, and the drift of the odor gas G is easily generated. It is considered that the amount of contact with the chip 21A is reduced, and the entire biofilter 21 can not be effectively used uniformly.

  Therefore, if the filling height h of the wood chips 21A constituting the biofilter 21 is a height within the range of 1.5 m to 3.0 m, a high deodorizing effect is maintained for a long time. More preferably, the filling height h of the wood chips 21A is in the range of 2.0 m to 2.5 m.

And, in the present embodiment, the bulk density when filled with the wood chips 21A is preferably in the range of 150 to 500 kg / m ³ . As a result, clogging of the flow path (air passage) is unlikely to occur, and the increase in pressure loss over time is also small.

That is, if the bulk density is too high, the pressure loss is large, and the cost of blowing the odor gas G also becomes high. In addition, clogging easily occurs, and uneven flow of the odor gas G is caused, so that the durability of the deodorizing effect is reduced. On the other hand, even if the bulk density is too low, the amount of contact between the odor component and the wood chip 21A decreases, so the deodorizing effect decreases. If the bulk density of the wood chips 21A is in the range of 150 to 500 kg / m ³ , the pressure loss can be suppressed to suppress the cost, and high durability of the deodorizing effect can be obtained. A more preferred bulk density is in the range of 200 to 400 kg / m ³ .

Therefore, in the present embodiment, the initial filling height h of the wood chips 21A (the wood chips 21a and the wood chips 21b) constituting the biofilter 21 is set to 2.0 m.
In the experimental research of the present inventors, the wood chip 21A is shredded and shrunk due to the consumption, metabolism, and deterioration of the wood chip 21A by microorganisms over time, and the volume of the biofilter 21 decreases. . For example, when the filling height h of the initial setting falls below 1.7 m due to use, the length in the fiber direction of the wood is, for example, 10 mm to 300 mm, and the wood tangential direction The deodorizing effect is achieved by replenishing the wood chips 21a whose width is in the range of 5 mm to 30 mm and the thickness in the radial direction of the wood is in the range of 4 mm to 10 mm and recovering the filling height h to 2 m. It has been confirmed that a long-term high deodorizing effect can be maintained for three years or more without reduction.

Then, in the present embodiment, the water content of the wood chips 21 a is maintained at 150% or more and 300% or less by watering from the water sprinkling means 30.
The moisture content of the wood chips 21a is changed periodically due to changes in the humidity conditions of the surrounding (ambient environment), and also because the water holding amount changes due to the fragmentation and shrinkage of the wood chips 21a. The water content is measured, and the amount of watering is adjusted so that the water content of the wood chips 21a is maintained at 150% or more and 300% or less.

  In the biological deodorizing apparatus 10 configured as described above, the odor gas G from the composting apparatus 2 is diffused from the introduction port 42 to the space S of a predetermined volume at the bottom of the housing through the introduction path 42a by driving the blower 5; As it flows, it rises up into the biofilter 21 through the vents 22A of the floor material 22. Since the air passes through the ventilation holes 22A of a predetermined diameter of the floor material 22 before being input to the biofilter 21, the odor gas G introduced from the inlet 42 is rectified and is input to the biofilter 21, and the odor The air flow resistance of the gas G can be relaxed to suppress the pressure loss.

At this time, the water content of the wood chips 21a of the biofilter 21 is maintained at 150% or more and 300% or less by water sprinkling from the water sprinkling means 30, and the inside of the biofilter 21 is maintained in a wet state. In the initial stage of startup of the apparatus, fresh water is taken from the water conveyance unit 44 to the water reception unit 41, and the water in the water reception unit 41 is pumped up to the water injection pipe 31 through the water supply passage 43 by the pump. Water to the biofilter 21. Then, the excess water W _{1 which} has passed through the air holes 22 a of the biofilter 21 and the floor material 22 and reached the bottom portion of the housing H does not accumulate in the space S of a predetermined volume or more. Are collected by the water receiving unit 41 through the drainage channel 42a. The water collected and stored by the water receiving portion 41 is pumped up from the water sprinkling supply path 43 to the water sprinkling pipe 31 by a pump at the timing of water sprinkling without being discharged to the outside, and used again as water sprinkling. The moisture content of the wood chips 21a 0.99% or more, at the timing of the watering to maintain 300% or less, but surplus water W ₁ recovered in the water receiving portion 41 is sprinkled pumped up sprinkler pipe 31, the water receiving portion When the amount of recovery at 41 is small, water is replenished from the water conveyance unit 44 as necessary. In particular, in the present embodiment, the water used for water sprinkling is adjusted to 0/10 ≦: replenishment water W2 / circulation water W1 ≦ 12/7.

In the biofilter 21 maintained in a wet state by water sprinkling from the water sprinkling means 30, appropriate moisture is held in the wood chip 21A, whereby the microorganisms propagate and the activity is maintained.
In particular, wood chip 21A, which is a natural resource, is an organic substance and is excellent in water retention function, so that it can inoculate and plant a specific fungus by leaving it under appropriate moisture and temperature environment, or a microbial active substance When the odor gas G is allowed to pass through, the microorganisms involved in the decomposition of the odor component propagate immediately, and the deodorizing function can be exhibited as the biofilter 21 even if the odor gas G is not added. And in such a wood chip 21A, it is in the environment where many kinds of microbes are possessed from the beginning, or various kinds of microbes which are directly or indirectly involved in the decomposition of a plurality of odor components are easily inhabited In the biofilter 21 composed of wood chips 21A, both an aerobic environment and an anaerobic environment are present, and microorganisms directly or indirectly involved in deodorization are not limited to aerobic microorganisms, either. It is presumed that sexual microorganisms also contribute. In such a biofilter 21, the microorganism uses the component of the wood chip 21A (polysaccharide etc.) and the odor component as nutrient source and energy source (utilization), and the microorganism propagates to form a biofilm. There is. For example, nitrite bacteria, nitrifying bacteria, denitrifying bacteria, sulfur oxidizing bacteria, other aerobic microorganisms, anaerobic microorganisms, etc. live on the wood chip 21A.

  Therefore, when the odor gas G is introduced from below to the biofilter 21 in which the wet state is maintained, the odor gas G flows through the biofilter 21 in upward flow. At this time, the water-soluble compound or the like of the odor component contained in the odor gas G dissolves in the water held by the wood chip 21A constituting the biofilter 21 or the water around the wood chip 21A. The odor components are decomposed by the microorganisms which are adsorbed, collected and held on the wood chips 21A and which inhabit and adhere to the wood chips 21A and the surrounding water. Thus, the odorous gas G is deodorized (cleansed) by digestion by biological treatment while rising the biofilter 21 and emitted from above the biofilter 21.

Odor components contained in the case odorous gas G, for example carbon dioxide (CO _2), water (H ₂ O) such harmless materials and SO ₄ ^- or NO ₃ ^- inorganic ions, sulfuric acid or nitric acid, such as Etc. are decomposed into inorganic substances.
For example, focusing on ammonia, which is a typical odor component in the odor gas G, ammonia (NH ₃ ) is NO ₂ (nitrite form), NO due to the nitrification of aerobic microorganisms such as nitrite bacteria and nitrifying bacteria. ₃ Decomposed to nitrogen oxides (NOx) such as (nitrate) and deodorized. Furthermore, it may be degraded to N ₂ (nitrogen) or the like by denitrifying bacteria or an anmox reaction.
Also, the odor component of sulfur compounds (sulfides) such as hydrogen sulfide (H ₂ S) and methyl mercaptan and organic acid compounds are oxidized by the action of aerobic microorganisms such as sulfur-oxidizing bacteria and other aerobic bacteria. It is decomposed to form oxides such as SO ₂ and sulfuric acid and is deodorized.

In particular, the biological deodorizing apparatus 10 of the present embodiment configured as described above has the following features.
First, in the biological deodorizing apparatus 10 of the present embodiment, the pressure loss is 30 to 120 Pa at the beginning of operation when the introduction of odor gas G and the watering are started, and the pressure increases over time, but after 3 years Even in this case, the pressure drop was suppressed to 200 Pa or less.
As a precaution, FIG. 5 shows the results of measuring the pressure loss over time. The pressure loss is obtained by measuring the differential pressure between the feed pressure (total pressure) of the blower 5 and the total pressure of the outlet from which air is discharged on the biofilter 21.

As shown in FIG. 5, the pressure loss is within the range of 0 to 200 mm H ₂ O even though there is a change in pressure loss due to changes in season, concentration of odor source, etc. It has been maintained with little pressure loss. In addition, the measurement of a pressure loss is a measurement regardless of the time of the water sprinkling of the water sprinkling means 30 operated intermittently, or the time of a water spout stop.

The increase in pressure loss due to use is small because the ventilation resistance is suppressed low by configuring the biofilter 21 with wood chips 21a with a predetermined bulk density, and clogging (constriction, blockage) does not easily occur even after use, and Excess water W ₁ that has passed through the biofilter 21 by the circulation means 40 is recycled to watering that maintains the moisture content of the wood chips at 150% or more and 300% or less, resulting from the distribution of microorganisms and decomposition of microorganisms This is because the accumulation of decomposition products is less likely to be biased, and the entire biofilter 21 is efficiently used. In particular, in the case of the biofilter 21 formed by filling the wood chips 21a with a predetermined bulk density, the air flow resistance is low and the pressure loss is small, so that the water content of the wood chips 21a is 150% to 300%. Even if it is increased, the influence on the pressure loss is also small, and the uneven flow of the odor gas G hardly occurs even by use.

Moreover, in the biological deodorizing apparatus 10 of a present Example, pH of the biofilter 21 was maintained in the range of 6.5-7.5. In particular, the water of the water receiving portion 41 which collects and circulates the surplus water W ₁ from the biofilter 21 of the circulating water is also maintained in the neutral region, and pH adjustment is performed on the water used for the sprinkling 31. The pH was maintained within the range of 6.5 to 7.5 in the biofilter 21 even if the odorant or the decomposition product was adsorbed by the odorant reducing member such as, or denitrification was performed.

Here, when the odor gas G contains ammonia, the ammonium is dissolved in water to become ammonium ion (NH ₄ ⁺ ) in the wet state of the biofill 21, and this ammonium ion (NH ₄ ⁺ ) is In the water film covering the wood chip 21A, it is oxidized and decomposed to nitrite ion (NO ₂ ⁻ ) or nitrate ion (NO ₃ ⁻ ) by nitrification by ammonia oxidizing bacteria and nitrite oxidizing bacteria which inhabit the wood chip 21A. At this time, the pH rises due to the presence of ammonium ions (NH ₄ ⁺ ) before nitrification, but if decomposition products of these nitrite ions (NO ₂ ⁻ ) and nitrate ions (NO ₃ ⁻ ) are formed, the inside of the water film The pH drops when the pH drops, and generally as their concentration increases. In particular, when the water is circulated, the pH tends to be acidic in a short time, and when the environment around the microorganism in the biofilter 21 becomes acidic, the activity of only a specific microorganism and only a specific odor component are removed. It is easy to occur.

However, the biological deodorization apparatus 10 of the present embodiment, even if to recover surplus water W ₁ is circulated watering from biofilter 21, a water content of 150% or more, the wood chips 21A to maintain 300% or less the high water retention, high buffering action in pH, addition, ammonium ion by circulation of water spray (NH ₄ ⁺⁾ decomposition proceeds without accumulating further nitrite ion (NO ₂ ^-) and nitrate ions (NO ₃ ^-) decomposition product is distributed load evenly in the biofilter 21 is not be locally concentrated in such. Also it is diluted with replenishing water W ₂ as necessary. For this reason, the pH is maintained in a neutral environment.

In particular, in the case of the biofilter 21 formed by filling the wood chips 21a with a predetermined bulk density, the air flow resistance is low and the pressure loss is small, so that the water content of the wood chips 21A is 150% or more and 300% or less. Even if it is increased, the influence on the pressure loss is also small, and the high water retention of the wood chip 21A and the thick water film around the wood chip 21 can be secured. Furthermore, the moisture content of wood chips 21A 0.99% or more, depending on the configuration of excess water W ₁ is collected in a space S of a predetermined volume of high wet and the housing H bottom of biofilter 21 maintained at 300% or less, the housing H The moisture at the bottom is high, and the odor gas G introduced to the bottom of the housing H can be humidified. Thereby, the fluctuation of pH can be mitigated, and the concentration can be mitigated even for high concentration odor. In particular, in the deodorizing apparatus 10 of the present embodiment, it is considered that the nitrification and the introduction of ammonia are balanced.

  And according to the deodorizing apparatus 10 of a present Example, since pH can be maintained in a neutral area in this way, the activity of the microbial species which can respond to decomposition | disassembly of various odor components can be maintained. That is, the environment in which the pH is in the neutral range is suitable for a microorganism growth environment that is advantageous for dealing with various odorous compounds. Therefore, it is possible to exhibit long-term stable deodorizing performance even for odor gas G in which the odor concentration and odor quality change. In particular, according to the deodorizing apparatus 10 of the present embodiment, a drop in pH is suppressed even when water is circulated, and a microorganism group growing in a neutral environment can remove a large number of odorous compounds, and therefore odor concentration and odor It is possible to maintain a stable deodorizing performance for a long time without a decrease in the processing capacity even for the odor gas G whose quality varies.

According to the biological deodorizing apparatus 10 of this embodiment, the biofilter efficiency (%) calculated by the following formula (B) showing the deodorizing effect is 90 to 95%, and even after 3 years or more Deodorization efficiency of 90 to 95% is obtained.
Biofilter efficiency (BFE) (%)
= 100 x (IOC-EOC) / IOC · · · (B)
IOC: Odor concentration of introducing air (ODER unit; OU _E )
EOC: Odor concentration of exhaust air (ODER unit; OU _E )

For example, with the air on the discharge side after passing through the biofilter 21 of the biological deodorizing apparatus 10 of the present embodiment when the introduction side air has an odor concentration of 2500 to 6000 order units, an odor concentration of 200 to 450 order units on average. Has been confirmed.
However, even when odorless air is introduced, the air on the discharge side never falls below the odor concentration of the 150-order unit due to the smell of the wood chip 21A of the biofilter 21 itself. Moreover, in the air on the discharge side, even if the odor concentration is an average of 200 to 450 order units, the odor is greatly improved compared to the source odor of the odor gas G on the introduction side by the action of the biofilter 21 .

The odor concentration here is the dilution factor (unit; order) up to the odor threshold when the odor is diluted with odorless air using a human olfactometer by the dynamic olfactometer method. Indicates a unit (OU _E ). That is, according to the biological deodorizing apparatus 10 of the said Example, the removal rate of 90 to 95% was shown by the odor concentration which shows the parameter | index of the odor measured by the sensory test.
Incidentally, the odor concentration (unit; order unit (OU _E )) by the dynamic olfactometer method and the odor index employed in Japan can be expressed by the relationship of the following formula (C). The three-point comparison type odor bag method adopted in Japan and the measurement result by the dynamic olfactometer method are generally agreed.
Odor index = 10 × log (odor concentration) · · (C)
For example, the odor concentration of the 2500 to 6000 order units described above is 34 to 38 when converted to an odor index, and 23 to 27 when the odor concentration of 200 to 450 order units is converted to an odor index. The 150-order unit odor concentration is 22 when converted to an odor index.

In addition, according to the biological deodorizing apparatus 10 of the present embodiment, when the ammonia concentration is measured on the output side where the odor gas G is emitted by passing through the biofilter 21, 1 day in several days after the introduction of the odor is started. It was suppressed to an ammonia concentration of ~ 2 mg / Nm ³ , and was suppressed below that figure even after 3 years. In aerobic fermentation treatment in composting facilities (fermentation treatment facilities) such as municipal waste, aldehydes, terpenes, VAF, etc. have become problems as offensive odor causing substances, but high deodorization is also possible for such odors. The effect has been confirmed, and its deodorizing effect lasted for more than 3 years.
In particular, in the biological deodorizing apparatus 10 configured with the specifications of Table 5, a high deodorizing effect lasting for three years or more without the treatment of the chemical deodorizing apparatus 3 or the acid scrubber treatment by the scrubber apparatus 4 in the previous stage. Is obtained.

Furthermore, according to the biological deodorizing apparatus 10 of this embodiment, the deodorizing function does not deteriorate due to the temperature change of the surrounding (environmental atmosphere) due to the seasonal change, and the high deodorizing function is maintained throughout the year regardless of the surrounding temperature change. It was
Here, focusing on the temperature of the biofilter 21, as shown in FIG. 6, the temperature of the intermediate layer of the biofilter 21 is measured with time (measurement by a thermocouple), the temperature of the biofilter 21 is around Even in winter when the environmental temperature is 0 ° C, the odor gas G is introduced at 12 ° C or higher during the operation, and even in the summer when the ambient temperature is 40 ° C, it can be suppressed to 45 ° C or less by watering. Met.

  In particular, when the surface (upper layer) temperature of the biofilter 21 is measured by infrared thermography in midsummer, there is a place where the temperature of the odor gas G partially exceeds 50 ° C., but at about 20 ° C. at a low temperature. It was maintained. In summer, the temperature rise of the biofilter 21 can be suppressed by the heat of vaporization due to the high humidity of the wood chip 21A in which the water sprinkling and the moisture content are maintained at 150% or more and 300% or less.

On the other hand, in winter, it is introduced into the space S of a predetermined volume by the high humidity of the biofilter 21 maintaining the moisture content of the wood chips 21A at 150% or more and 300% or less and the collection of excess water W ₁ at the bottom of the biofilter 21 Since the odorous gas G can be humidified, the latent heat of the biofilter 21 is hardly deprived even when the odorous gas G passes through the biofilter 21, and the temperature drop of the biofilter 21 can be suppressed. That is, in winter, relatively dry odor gas G is fed from the composting device 2, and such odor gas G tends to deprive the biofilter 21 of latent heat when passing through the biofilter 21, and the temperature of the biofilter 21 It will cause a decline. However, if the moisture of the odor gas G input to the biofilter 21 can be increased, it is possible to prevent the latent heat from being taken away from the biofilter 21 and to suppress the temperature drop of the biofilter 21.
And since biofilter 21 consists of wood chip 21A, there is also a possibility that the humidity change in housing H is controlled by the humidity control characteristic of wood. In winter, due to the influence of the low temperature of the ambient temperature, the odor concentration generated from the composting device 2 is also relatively small and the load on the biofilter 21 is also relatively small. , Deodorizing effect can be maintained.

  Thus, according to the biological deodorizing apparatus 10 of the present embodiment, the temperature of the biofilter 21 does not drop significantly compared to the ambient temperature, and the high deodorizing performance is stable even when the ambient temperature fluctuates. It was maintained. That is, even if the heating or cooling means is not provided, the fluctuation of the processing capacity due to the ambient temperature is small, and the stable deodorizing performance is maintained, so that the cost can be reduced.

However, in the case of practicing the present invention, the drainage provided at the lower part of the housing H, the water sprinkling means 30, and the housing H in order to ensure an extremely stable processing capacity which is not influenced by the influence of the ambient temperature. From the configuration of the supply path from the output of the water receiving portion 41 and the water receiving portion 41 to the input of the water sprinkling means 30 via the water sprinkling supply path 43 from the water receiving portion 41 and the water receiving portion 41 A heating or cooling means may be disposed in the circulation path to control and adjust the temperature of the biofilter 21 and the water temperature of the water sprinkling.
When the temperature of the biofilter 21 exceeds 45 ° C. depending on the installation place or the like, the temperature can be suppressed to 45 ° C. or less by maintaining the amount of water sprinkling, and the deodorizing performance can be maintained.
And in order to maintain the activity of microorganisms and to exhibit the stable deodorizing performance, preferably, the temperature of the biofilter 21 and the temperature of the odor gas G are maintained in 10-55 degreeC range.

  In addition, according to the biological deodorizing device 10 of the present embodiment, the composting device 2 is in a resting state, for example, for 1 to 2 weeks, and the air from the composting device 2 is continuously supplied to the biological deodorizing device 10 by the blower 5. Even if the interior of the housing H is continuously ventilated but the odor gas G is not present, microorganisms can grow with the wood chip 21A as a nutrient source. Then, even when the composting device 2 resumes the fermentation and decomposition treatment, the microorganisms of the wood chip 21A immediately start decomposition of the odorous components in the odor gas G, forming an environment where the microorganisms are not killed, and bio The deodorizing ability of the filter 21 is maintained. Therefore, the deodorizing effect can be sustained over a long period with low maintenance costs and running costs.

In the experimental research of the present inventors, after 3-4 years have passed since the operation of the biological deodorizing apparatus 10, wood chips 21A shredded and reduced due to consumption, metabolism and deterioration of the wood chips 21 by microorganisms. If the pressure drop exceeds 200 Pa, sieving of the wood chips 21A forming the biofilter 21 removes, for example, the subdivided wood chips 21A that pass through a sieve with an opening of 10 mm. Until the filling height h reaches 2 m, for example, the length in the fiber direction of wood is in the range of 10 mm to 300 mm, the width in the tangential direction of wood is in the range of 5 mm to 30 mm, The wood chips 21a having a radial thickness in the range of 4 mm to 10 mm are replenished. The coarse wood chips 21b between the wood chips 21a and the floor material 22 are replenished as needed. This confirms that the high deodorizing effect lasts for a longer period of time. Thus, by removing the wood chips 21A and repeatedly replenishing the wood chips 21A, it is possible to maintain the deodorizing effect semipermanently at low cost without addition of predetermined bacteria or addition of a microbial active substance.
In addition, if the pH becomes less than 4.5 due to the quality of the source odor, temporarily increase the proportion of replenishment water W ₂ and increase the amount of watering to restore the pH to 6.5 or more. It is possible to maintain deodorizing performance.

  And, in the biological deodorizing apparatus 10 of this embodiment, the pressure loss does not rise too much by the water sprinkling from the water sprinkling means 30, so even if the blower 5 is not temporarily interrupted at the time of water sprinkling, I can not get up. That is, by configuring the biofilter 21 with the wood chips 21A formed by deposition at a predetermined bulk density, the water of the sprinkled water easily passes below the biofilter 21, and the water content is maintained at 150% or more and 300% or less Even when the amount of watering is reduced, the water which has been watered will not hold up and cause a sharp increase in pressure loss. Therefore, maintenance and management are easy, low in cost, and the processing efficiency is good due to the continuous operation of the blower 5. Also, as described above, even if the direction of introduction of the odor gas G and the direction of water sprinkling are made to flow (countercurrently flow), the water does not wipe up, so high cost and high treatment capacity are obtained.

As described above, the biological deodorizing apparatus 10 according to the present embodiment is made by filling the wood chips 21A in a bulk density range of 150 to 500 kg / m ³ , and the water content of the wood chips 21A in the upper layer is increased by watering. Is a deodorization process in which the odorous gas G introduced from below the biofilter 21 is digested by biological treatment with the biofilter 21 and released above the biofilter 21 with the biofilter 21 maintained at 150% or more and 300% or less It comprises a processing means 20, a water sprinkling means 30 for sprinkling the biofilter 21 from above, and a circulating means 40 for collecting surplus water that has passed through the biofilter 21 and circulating it to sprinkling.
The circulation means 40 of the present embodiment includes the drainage path and the drainage portion 41 and the drainage portion 41 which are input to the drainage portion 41 through the drainage path 42 from the drainage port 42 a provided in the lower part of the housing H. The configuration of the supply path from the output to the input of the water sprinkling means 30 via the water sprinkling supply path 43 is shown.

Thus, in the biological deodorizing method according to the present embodiment, the biofilter 21 formed by filling the wood chips 21A at a bulk density of 150 to 500 kg / m ³ is sprayed with water from above, and the biofilter 21 is also provided. The excess water that has passed through is circulated as water sprinkling, and the odorous gas G is digested by biological treatment with the biofilter 21 by supplying the odorous gas G from below the biofilter 21.

In the biological deodorizing method according to the present embodiment, a biofilter 21 filled with wood chips 21A, and a floor material 22 having a large number of vent holes 22a and disposed under the biofilter 21, and a floor Material H and a biofilter 21 disposed thereon, housing H having an inlet 24a to which odor gas G is introduced below, water sprinkling means 30 for sprinkling biofilter 21 from above, bio The system comprises a circulation means 40 for collecting excess water having passed through the filter 21 and circulating it to water sprinkling, measuring the weight (weight before drying) of the wood chip 21 containing water by water sprinkling, and further drying it to obtain water Moisture content (%) = (weight before drying-total dry weight) / total dry weight x 10 when the weight (total dry weight) of the wood chips 21 in the free state is measured
The odor gas G introduced from the introduction port 24a below the housing H in the state that the moisture content of the wood chip 21 containing water is maintained at 150% or more and 300% or less by watering calculated as It is circulated from the vents 22 a to the biofilter 21, digested by biological treatment with the biofilter 21, and released above the biofilter 2.

According to the biological deodorizing apparatus 10 according to the present embodiment configured as described above, the biofilter with the wood chip 21A deposited at a predetermined bulk density by selecting the size of the wood chip A and setting the predetermined deposition height The air flow resistance can be suppressed to a low level by forming 21 and the excess water that has passed through the biofilter 21 by the circulation means is reused for watering that maintains the moisture content of the wood chip 21A at 150% or more and 300% or less. As a result, the distribution of microorganisms and the accumulation of decomposition products generated by the decomposition of microorganisms are less likely to be biased.
That is, since the water spray is circulated, the microorganisms and the decomposition products are moved from the top to the bottom, and the microorganisms and the decomposition products are displaced in the biofilter 21, so that the load does not concentrate locally. It can be processed efficiently overall.

Therefore, clogging of the air passage is unlikely to occur even if the use is continued, and an increase in pressure loss is also suppressed. There is a possibility that crystalline substances such as salts produced by the decomposition of the odor component may not easily adhere to the wood chips 21A whose water content is maintained at 150% or more and 300% or less by circulation of watering.
That is, even if the amount of microorganisms is large, and even if decomposition products of the odor component increase, it is difficult for those microorganisms and decomposition products to stay in a certain place by the circulation of watering It is hard to cause clogging (stenosis, occlusion).

As a result, it becomes less likely to produce a diversion in which the path of the odor gas G is limited in the biofilter 21 and a short pass that slips through a specific path, and the entire biofilter 21 is used uniformly for effective digestion of the odor gas G. High deodorizing performance can be maintained for a long time.
And since pressure loss is small, it is suitable for odor gas G of a large air volume, and it can digest odor gas G at low cost and high processing efficiency.

  In particular, the high water retentivity of the wood chips 21A maintaining the moisture content at 150% or more and 300% or less prevents the pH from decreasing with continued use, and the pH can be maintained in a neutral environment. For this reason, a variety of odors and microbial species that can cope with the decomposition even at high concentrations of odor are likely to be activated.

In addition, depending on the characteristics of the wood to maintain the moisture content at 150% or more and 300% or less, inoculating a specific fungus, planting, without the addition of a microbial active substance, the function of natural and natural microorganisms, Microorganism species that can cope with odor decomposition immediately propagate.
In particular, it is an environment in which microbial species that can cope with the decomposition of various odors are easily proliferated and active depending on the characteristics of wood, and a working environment of microbial species that can cope with the decomposition of various odors can be created. It is possible to construct a microbial environment that follows the changes in odor quality and odor concentration.
Furthermore, by circulating the water spray, it is easy to maintain effective microbial groups and microbial activity.

In addition, since the biofilter 21 is made of wood chips 21A, it is possible that the humidity control characteristics of the wood prevent the humidity fluctuation of the biofilter 21 and contribute to the maintenance of the optimum humidity environment of microorganisms and the alleviation of the pH fluctuation. There is also. In other words, the characteristics of wood make it a suitable moisture condition for microbial activity.
In addition, since the wood chip 21A is an organic substance, even if the odor gas G is not continuously fed, and even if the odor with a very low concentration is continuous, the microbial activity is well maintained without killing the microorganisms. Ru.

  In other words, by making the biofilter 21 composed of wood chips 21A that maintain a predetermined moisture content, and by circulating the watering, an environment that is optimal for the growth of microbes that can cope with various odors. Can be maintained, not specialized to a specific odor component, and can cope with odor variations.

  And, in the biofilter 21 in which the moisture content is thus maintained at 150% or more and 300% or less and the wood chip 21a is filled with a predetermined bulk density, the odor is high due to the high water retention and high surface area of the wood chip 21A. Since the gas G is easily dissolved in the liquid phase, and the amount of contact with the odor gas G is also large, it has high processing capacity.

  In particular, since wood chips 21A capable of maintaining the water content to 150% or more and 300% or less are filled with a predetermined bulk density, and water spray is circulated, clogging does not easily occur, and biofilter 21 is always made by water spray. It is easy to distribute the water evenly throughout the whole, and there is little bias of the microorganisms. That is, since the biofilter 21 is configured by the wood chips 21 a filled with a predetermined bulk density, water of the watering can easily pass below the biofilter 21. Therefore, the entire biofilter 21 is effectively used, the odor component is easily dissolved and captured in the water film around the wood chip 21A, and is effectively degraded by microorganisms. Therefore, it has high deodorizing efficiency.

Furthermore, the moisture characteristic (high water retention, thick water film around the wood chip 21A) of maintaining the moisture content of the wood chip 21A at 150% or more and 300% or less, and the wood chip 21A around by circulation of watering. Since the change in water buffers the pH fluctuation and the concentration of decomposition products, even if the excess water W ₁ that has passed through the biofilter 21 by circulation means is reused for watering, the microbial activity is reduced and the microbial activity is reduced. It is hard to produce a drop.

In other words, the high wetness of the biofilter 21 makes it highly adaptable to fluctuations in odor concentration, and it is also highly relaxing of pH fluctuations, maintaining the working environment of the microbial species that can cope with the decomposition of various odors, and the activity of microorganisms Be done.
Therefore, even if the odor concentration or odor quality to be introduced fluctuates, stable deodorizing performance can be maintained for a long time.

In addition, in this embodiment, the moisture content of wood chips 21A 0.99% or more, excessive water W ₁ reaches the space S of a predetermined volume of high wet and the housing H bottom of biofilter 21 maintained at 300% or less Depending on the configuration, the moisture in the bottom of the housing H is high, and the odor gas G introduced to the bottom of the housing H can be humidified. Thus, the effect of alleviating the concentration fluctuation of the odor can be enhanced. Also, the thick water film around the wood chip 21 can reduce the fluctuation of the odor concentration. Furthermore, when the moisture of the odor gas G is high, it also contributes to the uniform distribution of the moisture content of the biofilter 21. Therefore, it is possible to cope with the fluctuation of the odor concentration without taking measures to dilute the odor with air or to extremely reduce the apparent wind speed.

  And, if the odor gas G introduced to the bottom of the housing H can be humidified, the odor gas G is difficult to take away the latent heat of the biofilter 21 even when the ambient temperature in winter is low, and the temperature drop of the biofilter 21 is prevented it can. Also, when the ambient temperature in summer is high, due to the high heat of the biofilter 21 maintaining the high moisture content of the odor gas G and the moisture content of the wood chip 21A at 150% or more and 300% or less, the biofilter 21 Temperature rise can be suppressed. Therefore, it is possible to follow the temperature change of the surroundings, the fluctuation of the deodorizing performance is small, and the stable high deodorizing performance can be exhibited.

  Furthermore, by selecting the size of the wood chip 21A, the wood chip 21A is filled with a predetermined bulk density to constitute the biofilter 21 with the wood chip 21a, and the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less As a result, the air flow resistance can be suppressed to a low level, and the increase in pressure loss is small, so that the running cost for blowing the odor gas G can be suppressed.

In addition, the wood chips 21A can be obtained at low cost, and the biofilter 21 composed of the wood chips 21A filled with a predetermined bulk density has a small pressure loss, and a high processing capacity can ensure a high throughput even with a small size. Also, the volume can be small.
And the high water retentivity of biofilter 21 which maintains the moisture content of wood chip 21A to 150% or more and 300% or less, that is, the thick water film around wood chip 21 and the water around wood chip 21A by the circulation of watering. Because the pH and decomposition products are buffered by the transition, there is no need to provide a means to control the pH or decomposition products of circulating water or to control the amount of odor gas introduced, and a simple device design is required, maintenance and management Is also easy.
By circulating the water, the cost of water for watering can be reduced. In addition, maintenance frequency such as switching of the biofilter 21 and replacement of the wood chip 21A can be reduced.
Accordingly, the material cost, the equipment cost, and the running cost can be reduced, so the cost can be reduced.

  Thus, the low-cost and long-term stable deodorizing performance becomes the sustainable biological deodorizing apparatus 10 also with respect to the odor gas having the complex odor accompanied by the fluctuation of the odor concentration and the odor quality.

And according to the biological deodorizing apparatus 10 which concerns on this Embodiment, since the biofilter 21 is comprised by the wood chip 21A of the specific size which maintains a moisture content at 150% or more and 300% or less, it is from the characteristic of the wood Because of the function of natural and natural microorganisms, it is possible to propagate microbial species that can cope with odor decomposition immediately, and to cope with deodorization of various odors. Therefore, it is not limited to the odor generated from composting facilities such as household waste and urban waste, and poultry and livestock facilities for raising livestock and treating excrement of livestock, and sewage and sewage generated by organic sludge etc. The deodorizing effect can be highly sustained even for odors generated from wastewater treatment facilities, agricultural settlement wastewater treatment facilities, food factory wastewater treatment facilities, etc. That is, it is a deodorizing technology that is not specialized for a specific odor component, and it can cope with the fluctuation of the odor, so the application range is wide.

  Moreover, according to the biological deodorizing apparatus 10 according to the present embodiment, the odor gas is generated by the floor material 22 having the vent holes 22A whose opening is in the range of 20 mm to 100 mm in the range of 5 to 95% of the opening ratio. Since G can be rectified, the processing efficiency of the odorous gas G can be enhanced. Further, the pressure loss of the odorous gas G can be reduced, and the load due to the fluctuation of the amount of odor can be reduced.

  Furthermore, according to the biological deodorizing apparatus 10 according to the above embodiment, the length in the fiber direction of wood is, for example, in the range of 350 mm to 700 mm, and the width in the tangential direction of wood is 10 mm to After laying the wood chip 21b which is in the range of 80 mm and the radial thickness of the wood is in the range of 5 mm to 50 mm, the length in the fiber direction of the wood is, for example, in the range of 10 mm to 300 mm Length of wood in the fiber direction, since the wood chip 21a is filled in such a manner that the tangential width of the wood is in the range of 5 mm to 30 mm and the radial thickness of the wood is in the range of 4 mm to 10 mm 10 mm to 300 mm, the tangential width of the wood is 5 mm to 30 mm, and the radial thickness of the wood is 4 mm to 10 mm. Then, the biofilter 21 is configured with a predetermined bulk density, and does not close the ventilation holes 22A of the predetermined diameter of the floor material 22, and is introduced from the lower side of the housing H through the inlet 24a to the floor material 22. The rectification effect is exerted to make the flow of the odorous gas G which passes through the vent holes 22A of the above and input to the biofilter H smoother. And the ventilation resistance of odor gas G can be eased and pressure loss can be eased. Thus, processing efficiency can be enhanced.

  In addition, in the biological deodorizing apparatus 10 according to the present embodiment, the projecting wall 28 is provided along the side wall of the housing H above or below the position of the floor material 22, and the side wall on the housing H side has a predetermined projecting length By projecting inward, it is possible to block off the odor along the side wall of the housing H and to suppress the odor leak along the side wall of the housing H. In addition, since the odor gas G can be rectified and the odor gas can be uniformly fed to the entire area of the biofilter, the processing efficiency can be enhanced. For example, as shown in FIG. 4 and FIG. 7A, the inner side wall of the housing H itself is formed to protrude toward the side surface of the biofilter 21 or a plate between the housing H and the biofilter 21 The side wall on the housing H side is made to project toward the side surface of the biofilter 21 from the position of the floor material 22 by installing another member (protruding wall 28) such as a shape. Further, as shown in FIG. 7 (b), from the position of the floor material 22 to the projection of the inner side wall of the housing H itself or the installation of another member (projection wall 28) such as a plate, etc. Are protruded toward the inside of the housing H. As a result, it is possible to block off the odor along the side wall of the housing H and to suppress the odor leak along the side wall of the housing H.

Further, according to the biological deodorization apparatus 10 according to the embodiment, the water sprinkling to biofilters 21, excessive water W ₁ which has passed through the biofilter 21 and 36 volume% or more, the water to be replenished from the outside 64 volume% By setting it as the following, it is low cost and can maintain higher deodorizing ability.

  Furthermore, according to the biological deodorizing apparatus 10 according to the above embodiment, since the thickness h of the biofilter 21 in the direction in which the odor gas G passes upward from below is within the range of 1.5 m to 3 m, A high deodorizing effect can be obtained at low cost, and the high deodorizing effect can be further sustained.

In the case of carrying out the present invention, the design and specifications of the biological deodorizing apparatus 10 are not limited to the above embodiment. The volume of the biofilter 21 is determined using the apparent velocity, the load characteristics of the biofilter 21, the linear velocity, etc., obtained in the present embodiment according to the requirements of the type, concentration, removal rate of treated odor gas G, etc. , Cross-sectional area, filling height h can be determined. In particular, the pressure loss is proportional to the filling height h and the linear velocity, and if the pressure loss rises too much, the cost increases and the processing efficiency decreases due to the uneven flow of the odor gas G. It is desirable to design the pressure drop to be maintained in the range of 0 to ₂₀₀ mm H ₂ O.

  In the case of practicing the present invention, the configuration of the floor material 22 is not limited to the above, and for example, a conduit provided with a vent 22A of a predetermined diameter is embedded in the bottom of the housing H or formed at predetermined intervals. It is also possible to form the floor material 22 by disposing a sleeve in the hole and burying a conduit provided with a vent 22A made of a sleeve.

  Moreover, when implementing this invention, the inlet 24 of the odor gas G sent as compressed air from the blower 5 is not limited to one, You may provide multiple. It is good also as composition connected to a plurality of fermenters of a composting facility, and using a specific inlet 24 among a plurality of inlets 24 by a fermenter made into a target of deodorization. That is, the plurality of inlets 24 may be selectively used selectively by control. Alternatively, the water receiver 41 may be provided at the bottom of the housing H.

The biological deodorizing method according to the above embodiment comprises a biofilter for digesting odorous gas by biological treatment composed of wood chips, and a large number of pipes are inserted in a housing below the inlet through which the odorous gas is introduced. A floor material having pores is accommodated, and the wood chips are filled thereon, and the water content of the wood chips is maintained at 150% or more and 300% or less by watering performed from above the biofilter by a watering means. It is a thing. Further, the surplus water having passed through the biofilter is recovered by a circulating means and supplied to the water sprinkling means, whereby the water sprinkled by the water sprinkling means is circulated.

The above-mentioned biofilter is made by filling wood chips and digests odorous gas by biological treatment.
Here, the term "digestion by biological treatment" means deodorizing by decomposing the odor component in the odor gas by the enzyme action or the like of the microorganism.
In addition, the above wood chips are raw wood (stems, whole trees, shrubs, end trees, branches, pruning branches, rootstocks, etc.), lumbers (backboards, scraps, peeled cores, etc.), building demolition materials, building materials, packaging materials, Plywood, laminated wood, particle board, waste pallets and the like are cut or crushed by a chipper, shredder, mill, crusher, hammer, punching or the like to obtain a wood piece, which is sieved and a predetermined size is selected.

The present inventors have repeatedly conducted intensive research on biofilters that can stably exhibit long-term deodorizing performance and can be configured at low cost stably even for odorous gases with a complex odor accompanied by fluctuations in odor concentration and odor quality. As a result, it has been found that, by constructing the biofilter with wood chips, the ability to follow odor gas of complex odor accompanied by fluctuation of odor concentration and odor quality is high, and high deodorizing effect can be stably maintained for a long time The
In particular, the biofilter formed by depositing wood chips has high ability to follow odor gas of complex odor accompanied with fluctuation of odor concentration and odor quality by control of predetermined moisture content, and it is stable and high for a long time It was determined that the deodorizing effect was maintained, and it was specified by the experiments of the present inventors that the water content was maintained at 150% or more and 300% or less by watering. That is, by maintaining the water content of the wood chips at 150% or more and 300% or less by watering, high treatment capacity can be obtained due to the high water retention property of the wood chips, and the odor of the complex odor accompanied by the fluctuation of odor concentration and odor quality Even for gas, the high water retention property of wood chips can stably exhibit a long-term high deodorizing effect.
The moisture content of the wood chip represents the ratio of the water weight to the weight (total dry weight, dry basis) of the wood chip not containing water, and is calculated by the following equation (A).
  Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100 (A)
The total dry weight is 105.degree. C., which is a value in a dry state until the change in weight disappears.

The housing is formed of at least three surfaces of a lower surface and left and right side surfaces, and accommodates a floor material and a biofilter thereon. There is provided an inlet below which the odorous gas is introduced, so that the odorous gas introduced does not leak to the outside. On the other hand, the odorous gas introduced from the lower inlet rises, passes through the floor material and the biofilter disposed thereon, and is released from the upper surface of the biofilter, so the upper side of the biofilter Is released. The air released from the biofilter may be released to the atmosphere without forming the upper surface of the housing, or the air opening may be provided even if the upper surface is formed, and the air is discharged from the biofilter from the air opening. Air may be released to the atmosphere.
In addition, since the water of the sprinkling water is circulated, the surplus water of the sprinkling water is usually below the housing in order to recover the water that has passed through the biofilter and the floor material and reached the bottom of the housing and circulates it to the sprinkling means. A drainage outlet is also provided.

Further, the floor material is accommodated in the housing together with the biofilter, and defines a space of a predetermined volume between the bottom of the biofilter and the bottom of the housing, ie, It is disposed in the housing at a predetermined distance from the bottom of the housing. Therefore, the wood chips are loaded on the floor in the housing. The floor material is a space defining a space of a predetermined volume communicating with the introduction port of the housing into which the odor gas is introduced, and the floor material is provided with a large number of vent holes penetrating vertically. Therefore, the odorous gas introduced from the inlet below the housing is circulated in the entire bottom surface direction of the biofilter by a space of a predetermined volume, and is input to the biofilter through the air vents of the floor material. It will be.

And as for the said flooring, it is preferable that the opening of the said ventilating hole is in the range of 20 mm-100 mm, and an opening ratio is in the range of 5% or more and 95% or less.
According to the experiments of the present inventors, according to the floor material disposed in the lower part of the biofilter filled with wood chips of the above-mentioned predetermined size, the fluid loss generated there by the control of the size and density of the vents. The structure of such floor material is specified by the opening ratio and the opening ratio, since it is possible to set the minimum of the floor material and to prevent the load from being applied by the predetermined fluid resistance even if the introduced amount of odorous gas fluctuates. It is
Here, the openings and the opening ratio represent the size and density of the vents of the floor material. The above-mentioned openings also indicate, for example, the top-bottom width or the left-right width at the opening (space) per eye formed by crossing a vertical line and a horizontal line such as mesh, etc. If it is a square, it corresponds to one side of a square. The air holes do not specify the shape of the circular eye or square, but the air resistance is small and the surface area is large. Therefore, a circular hole with a circular cross section or a square with a square cross section Holes are preferred.
The opening of the floor material and the opening ratio are measured in accordance with the standard of sieve wire mesh, and the plane area of the floor material is S, the number of floor materials is M, and the diameter of the vertical and horizontal lines is d. When it is assumed, the opening is calculated by the following equation (B), and the aperture ratio is calculated by the following equation (C).
Opening A (mm) = S / M-d (B)
Aperture ratio ε (%) = (A / A + d) ² × 100 (C)

The water sprinkling means supplies water to the biofilter contained in the housing by water sprinkling from the upper side opposite to the odor gas introduction side. The water spray makes the biofilter wet and maintains the moisture content of the wood chips at 150% or more and 300% or less. Watering may be intermittent or continuous.

The circulating means is water that has been sprayed from above the biofilter and passed from above to below the biofilter, ie, flows down through the vents of the floor material down the housing without being retained in the biofilter. Surplus water is collected and supplied to the water sprinkling means to circulate the water of the water sprinkling. The excess water that has passed through the biofilter may be collected at the lower portion in the housing and stored there, or a separate water receiving portion may be provided outside the housing and stored there.
Further, the water for sprinkling may be configured to be replenished with water from the outside in addition to the surplus water that has passed through the biofilter.

According to the biological deodorizing method according to the above embodiment, the biofilter comprising wood chips is provided, the water content of the wood chips is maintained at 150% or more and 300% or less by watering, and the water is sprayed to the biofilters. Water is circulated by circulation means. As a result, low-cost and long-term stable deodorizing performance is exhibited even for an odor gas having a complex odor accompanied by a change in odor concentration or odor quality.

As a result of the intensive research conducted by the present inventors, the present inventors constructed the biofilter with wood chips as a microorganism carrier, and circulated the water sprinkling water to the biofilter by the circulating means, and the water content of the wood chips was By maintaining the microorganism at 150% or more and 300% or less, it is possible to quickly start up the odorous component of the microorganism by using the microorganism, even if it does not feed or breed microorganisms or add a microorganism active substance or the like for imparting microbial activity. It can function as a biofilter that digests by chemical treatment, and the increase in pressure loss over time is also small, and the odor concentration fluctuation and odor quality fluctuation are highly responsive, and the deodorizing effect can be long over a long period of time It has been found that it can be sustained, and the present invention has been completed based on this finding.

That is, by configuring the biofilter with wood chips, the air flow resistance can be suppressed to a low level by selecting the size of the wood chips, the air flow resistance can be suppressed to a low level, and watering for maintaining the water content of the wood chips at a predetermined level. In addition, by recycling the water that has passed through the biofilter by the circulation means, decomposition products (metabolites) generated by the decomposition of the odor by the microorganism and the microorganism are distributed without bias in the biofilter.
Therefore, the narrowing, clogging, and clogging of the air passage of the biofilter are unlikely to occur, and an increase in pressure loss over time can be suppressed.

In particular, due to the characteristics of wood maintained at a moisture content of 150% or more and 300% or less, microbial species that can cope with the decomposition of various odors are also easily propagated. And, in the biofilter composed of wood chips, the flow path can be broadened by selecting the size thereof, and water is uniformly distributed throughout the biofilter, and the wood chip maintaining the moisture content at 150% or more and 300% or less Has a high effect of alleviating pH fluctuations. For this reason, it is hard to produce the fall of pH one by one, and can maintain pH of a neutral region.
Therefore, even if it is many odors, the microbial species which can respond to the decomposition are easy to be active, and the activity can be sustained. In particular, even if the water that has passed through the biofilter by the circulation means is reused as water sprinkling, it is difficult to cause a reduction in the activity of microorganisms and a decrease in the activity of microorganisms. Also, in a biofilter consisting of wood chips whose water content is maintained at 150% or more and 300% or less, the odorous gas is easily dissolved in the liquid phase around the wood chips due to the water retention characteristics and high surface area of the wood chips. In addition, since the amount of contact between the wood chips and the odorous gas is large, the processing capacity is high. Furthermore, pressure loss can be mitigated also by the rectification effect by the many vents of the floor material disposed under the biofilter, and processing efficiency can be enhanced.
Therefore, even if the odor concentration or odor quality to be introduced fluctuates, stable deodorizing performance can be maintained for a long time.

Furthermore, by configuring the biofilter with wood chips, the air flow resistance can be suppressed by selecting the size of the wood chips, and clogging is less likely to occur, so there is little increase in pressure loss with time, so odor gas blowing Running costs can be reduced.
Also, wood chips can be obtained inexpensively. Moreover, a biofilter consisting of wood chips maintained at a water content of 150% or more and 300% or less has high processing capacity and can suppress pressure loss, so the biofilter has a predetermined high throughput even with a small volume. Can be secured. And, even if water that has passed through the biofilter by cyclic means is reused as water spray, the buffer effect of pH fluctuation is high due to the high water retentivity of the biofilter, so the decomposition products generated by the decomposition of pH and odor of circulating water It is not necessary to provide means to control the amount of odor gas introduced or to control the amount of odor gas introduced.
Therefore, the material cost, the equipment cost, and the running cost can be suppressed and the cost can be reduced.

DESCRIPTION OF SYMBOLS 10 Biological deodorizing apparatus 20 Deodorization processing part 21 Biofilter 21A Wood chip 24 introduction port 30 Watering means 40 Circulating means H Housing

Claims (3)

Water is sprinkled from above to a biofilter in which wood chips are packed in a bulk density range of 150 to 500 kg / m ³ , and water passing through the biofilter is circulated as the sprinkle, and A biological deodorizing method comprising digesting the odor gas by biological treatment with the biofilter by supplying an odor gas from below the biofilter. A biofilter that is filled with wood chips and digests odorous gases by biological treatment,
A housing that houses the biofilter and has an inlet below which an odor gas is introduced;
The biofilter is disposed in the housing with a vent and defining a space of a predetermined volume communicating with the inlet of the housing between the bottom of the housing and the biofilter disposed on the upper floor surface. Flooring to be set up,
Water sprinkling means for sprinkling water from above the biofilter disposed on the floor material in the housing;
It comprises: a circulation means for collecting the water of the watering that has passed through the biofilter and circulating it to the watering means;
When the weight (weight before drying) of the wood chip containing water is measured by the watering, and it is further dried to measure the weight (total dry weight) of the wood chip in the state containing no water. Moisture content (%) = (weight before drying-total dry weight) / total dry weight × 10
The odor gas introduced from the inlet below the housing is passed through the floor material in a state where the moisture content of the wood chip containing water is maintained by 150% to 300% by the watering calculated as A biological deodorizing method comprising: circulating it from the pores to the biofilter, digesting it by biological treatment with the biofilter, and releasing it above the biofilter. The water sprinkling water to the biofilter by the water sprinkling means, when the amount of water sprinkling per unit time is 100% by volume, the water passing through the biofilter is 36% by volume or more, and the water replenished from the outside is 64 The biological deodorization method according to claim 1 or 2, characterized in that the volume percentage or less.

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