JP6445665B1 - Biological deodorization method - Google Patents

Abstract

An object of the present invention is to provide a stable deodorizing performance for a long period of time at a low cost even for a odor gas of a complex odor accompanied by fluctuations in odor concentration and odor quality.
A biofilter 21 that digests odorous gas G by biological treatment is configured by filling wood chips 21A in a bulk density range of 150 to 500 kg / m ³ , and a sprinkling means 30 is disposed above the biofilter 21. The water content of the wood chip 21A is maintained at 150% or more and 300% or less by watering. Moreover, the water sprinkled by the water sprinkling means 30 is circulated by collecting surplus water that has passed through the biofilter 21 by the circulation means 40 and supplying it to the water sprinkling means 30.
[Selection] Figure 2

Description

  The present invention is a biological deodorization treatment that deodorizes organic waste such as garbage, food processing residues, and odor gas generated when fermenting and decomposing organic matter such as livestock dung, sludge from sewage and sewage treatment by a biological deodorization method. In particular, the present invention relates to a biological deodorization method capable of exhibiting stable deodorization performance at a low cost for a long period of time even with respect to odor gas having a complex odor accompanied by variations in odor concentration and odor quality.

  Organic waste, for example, waste disposal facilities that compost (compost) raw food such as raw vegetables, fruits, and meat, and food processing residues, and poultry farms that raise livestock and treat livestock excreta・ As a countermeasure against odors and odors in livestock facilities and sewage and sewage wastewater treatment facilities that produce organic sludge, etc., odorous substances are adsorbed by adsorbents such as combustion deodorization method that deoxidizes and decomposes odorous substances by combustion and activated carbon. Adsorption and deodorization methods to deodorize, cleaning deodorization method (chemical treatment method) to deodorize chemical solution by contacting chemical solution with chemical solution, biological deodorization method to deodorize by decomposing odorous substance by microorganism Yes.

In particular, the biological deodorization method that decomposes odorous substances into microorganisms requires post-treatment of adsorbents (waste activated carbon, etc.), chemical sludge, waste liquid, etc., as in the combustion deodorization method, adsorption deodorization method, and cleaning deodorization method. The odor component can be decomposed into harmless substances such as carbon dioxide (CO ₂ ) and water (H ₂ O) and inorganic ions such as SO ₄ ⁻ and NO ₃ ⁻ without generating a large residue. Further, unlike the combustion method, it is an environmentally friendly deodorization method because it does not emit soot, dioxin, and a large amount of CO ₂ and NO _x . In addition, expensive materials such as chemicals are not used, and since the adsorbent does not require frequent replacement or fuel, operation costs can be reduced.

In particular, in recent years, there has been a great interest in environmental issues in Japan. Regarding 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 fertilizing and composting garbage etc. and composting it is used as an organic fertilizer. For this reason, the necessity of the odor countermeasure of the gas containing the odor discharged | emitted from such composting facilities is increasing.
As for the livestock industry, about 90% of livestock excreta are composted, but the actual situation is that it is difficult to cost odor countermeasures that do not lead to productivity. Therefore, deodorization technology with low equipment costs and operation costs is desired as a countermeasure for the odor.

  And, in the composting treatment of organic waste such as garbage and livestock excrement, since it is mainly aerobic fermentation treatment (decomposition of organic matter by aerobic microorganisms), odor generated in the decomposition process of the organic matter (fermentation process) Is a complex odor that contains a variety of odor components and has a relatively low concentration and a large air volume compared to odors generated in chemical factories, etc., and odors in livestock excreta treatment facilities and anaerobic fermentation treatment facilities. Components and concentrations can also vary. For this reason, a deodorization technique that reliably and continuously performs deodorization performance even with a low-concentration and high-volume odor that is a complex odor containing various odor components and whose odor components and concentrations can also vary is desired.

Here, as a conventional biological deodorization method, a soil deodorization method, a rock wool deodorization method, and the like are mainly known.
In the soil deodorization method, the odor component of the odor gas sent from under the soil layer is dissolved in the moisture on the surface of the soil particle while passing through the soil layer, adsorbed on the surface of the soil particle, and further by soil microorganisms. Although it is a mechanism that deodorizes by being decomposed, a large site area is required because the ventilation resistance of the soil layer is high. Therefore, the rock wool deodorization method has been developed to compensate for the drawback, and the ventilation resistance can be improved by using rock wool. And the rock wool deodorization method enables the installation area to be reduced as compared with the soil deodorization method. However, since rock wool is an inorganic substance, it lacks the ability to adsorb odor components and the activity of microorganisms. For this reason, the device which mixes with organic substance and raises the activity of the microorganisms which contribute to deodorizing is required.

  For example, Patent Document 1 mainly includes a mixture of granular cotton made of inorganic fibers such as rock wool granular cotton in which particles having a particle diameter of 1 mm to 40 mm are mixed, and wood chips, and further includes livestock manure / A deodorizing material in which a microbially active substance composed of a manure or surplus sludge alone or a mixture of two or more is mixed is disclosed. In this patent document 1, a wood 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 that exerts an initial adsorption effect.

WO2011 / 024507 JP-A-2004-024353 JP-A-2005-246106 JP 2006-035028 A

However, in the biological deodorization apparatus using conventional rock wool such as Patent Document 1 as a microorganism carrier, although the initial ventilation resistance is improved as compared with the soil deodorization method, moisture management and microorganism management are difficult, and pressure is increased depending on use. Loss was likely to increase. For this reason, it is necessary to apply a high pressure or increase the volume of the deodorizing material in order to increase and maintain the processing capacity and processing efficiency, and it is difficult to reduce the cost. Rock wool material is also expensive.
In addition, biological deodorization equipment using conventional rock wool as a microbial carrier is effective for fixed odor gas, but it is poor in dealing with fluctuations in odor concentration and odor quality, and maintains a stable deodorization effect. The sex was low. In particular, conventionally, from the emphasis on deodorization efficiency for fixed odor gas, there are cases where effective microorganisms are inoculated and planted for specific odor components, or microbial active substances are added, It is costly to develop technology to select microorganisms suitable for odor sources. In addition, when a specific microorganism is inoculated, planted, or added with a microbial active substance, it is vulnerable to changes in odor concentration and odor quality. A load exceeding the activity was sometimes applied. In such a case, measures to control the odor to be introduced can be considered, but the operation management cost becomes high.

  Moreover, in the technique of Patent Document 1, the filling property is high due to the combination of the inorganic fiber granular cotton and the wood chip, and the size of the air passage is also non-uniform, so that the malodor can be distributed evenly. In addition, a large amount of bad odor is likely to pass through a specific air passage, and the air passage is easily blocked there. For this reason, pressure loss tends to increase with the introduction of odor, and it is difficult to maintain high deodorization efficiency. Naturally, the equipment operating cost (power cost) increases as the pressure loss increases. Furthermore, since it is difficult to obtain a biological deodorizing action unless microbial active substances such as livestock manure, manure and surplus sludge are mixed, the management of microorganisms is complicated and the price of materials becomes expensive.

By the way, in this type of biological deodorization apparatus, water is sprayed to prevent the microbial carrier from being dried and to maintain the microbial activity. In order to reduce costs, for example, Patent Documents 2 to 4 disclose a technique that employs a circulating watering system that circulates watering water.
In Patent Document 2, a countercurrent packed bed filled with a carrier carrying microorganisms is allowed to pass treated water and an odor gas introduced from an odor gas inlet in a countercurrent direction, and the countercurrent packed bed is passed through the countercurrent packed bed. The treated gas that has passed through and deodorized is discharged from the treated gas discharge port, while the treated water that 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 microorganisms. In the deodorization method for treating the odor gas by passing through the single flow packed bed, the treated water that has passed through the counter flow packed bed passes through the single flow packed bed, and subsequently the downstream direction of the treated water flow. And after passing through the countercurrent packed bed and the single-flow packed bed to the water-stored section again through the single-flow packed bed. Between after 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.

  Patent Document 3 discloses a container into which malodorous gas is introduced, a filling carrier that is filled in the container and carries a deodorizing microorganism or an enzyme derived therefrom, and water in the container is sprinkled on the filling carrier. In the circulating watering operation type biological deodorizing apparatus, comprising a watering device and a watering pipe that collects the water in the container as watering water and circulates and supplies the watering water to the watering device, and biologically deodorizes the malodorous gas. The technique which arrange | positioned the odorous substance reduction member which can reduce the at least 1 or more types of odorous substance contained in the said water for watering in the middle of the watering piping is disclosed.

  Furthermore, Patent Document 4 discloses that a biological deodorizing apparatus of a circulating sprinkling operation type in which ammonia is converted to nitric acid and / or nitrous acid by a microorganism having a nitrifying action and deodorizing is provided separately from the biological deodorizing apparatus. A biological deodorization device comprising: a denitrification device that converts nitric acid and / or nitrous acid to nitrogen by a microorganism having an action; and an organic substance supply device that supplies the organic matter as nutrients for the microorganism having the denitrification action to the denitrification device. In a biological deodorization method using a biological deodorization device configured to circulate circulating water between a device and the denitrification device, nitric acid and / or nitrous acid is removed by a microorganism having a denitrification action in the denitrification device. It discloses a technique for performing 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 such a circulating sprinkling system that circulates water used for sprinkling, degradation products generated by decomposition of odorous substances and odorous substances by microorganisms gradually accumulate in the circulating water and become a high concentration. Such odorous substances and decomposed products It is difficult to maintain the deodorizing effect because the activity of microorganisms is hindered by the sprinkling of circulating water enriched with water.
Therefore, in Patent Documents 2 to 4, the pH of the circulating water is adjusted, the odorous substance and decomposition products are adsorbed by an odorous substance reducing member such as an ion adsorbent, or a denitrification process is provided in the circulating waterway. Technology is used.
However, on the other hand, there is a problem that the apparatus and control are complicated, and new costs such as material cost, equipment cost, and running cost are required.

Therefore, an object of the present invention is to provide a biological deodorization method that can exhibit stable deodorization performance at low cost for a long period of time even with respect to odor gas of complex odor accompanied by fluctuations in odor concentration and odor quality.

The biological deodorization method of the invention of claim 1 is directed to a biofilter formed by filling wood chips within a bulk density of 150 to 500 kg / m ³ , and water is sprinkled from above and surplus that has passed through the biofilter. Water is circulated as the water spray, the moisture content of the wood chips is maintained at 150% or more and 300% or less, and the odor gas introduced from below that digests the odor gas by biological treatment by the biofilter is biologically It is digested by processing.

The biofilter is formed by filling wood chips within a bulk density of 150 to 500 kg / m ³ , and digests odorous gas introduced from below by biological treatment.
Here, digestion by the above biological treatment means that the odor component in the odor gas is decomposed and deodorized by the enzymatic action of microorganisms.
In addition, the above wood chips are made of raw wood (trunks, whole trees, shrubs, endwoods, branches, pruned branches, root stocks, etc.), lumber (backboards, end materials, stripped cores, etc.), building demolition materials, building materials, packing materials, Plywood, laminated timber, particle board, waste pallet, etc. are cut or crushed with a chipper, shredder, mill, crusher, hammer, punching, etc. to obtain a piece of wood, which is sieved to select a predetermined size.

The present inventors have conducted extensive experimental research on biofilters that can stably exhibit long-term deodorization performance against odor gas of complex odors accompanied by changes in odor concentration and odor quality, and can be configured at low cost. As a result, it has been found that by configuring a biofilter with wood chips, the ability to follow complex odors with odor concentration and odor quality is high, and the deodorizing effect can be stably maintained over a long period of time. It was.
In particular, the biofilter formed by depositing wood chips has a predetermined bulk density and is less likely to be clogged and has little increase in pressure loss due to use. According to the experiments by the present inventors, the bulk density for depositing the wood chips is specified to be within the range of 150 kg / m ³ or more and 500 kg / m ³ or less.
The bulk density (Kg / m ³ ) is an initial value, and the volume of the wood chip of the predetermined size is obtained from the filling height of the wood chip filled and the cross-sectional area of the biofilter and filled. It is calculated by dividing by the volume value obtained for the total weight of the wood chips of the predetermined size.

Moreover, the said watering sprinkles with respect to the said bio filter from the upper side on the opposite side to the introduction side of odor gas. This watering makes the biofilter wet and maintains the wood chip at a predetermined moisture content. Watering may be intermittent or may be performed continuously.
And the said watering is circulated. That is, water that has been sprinkled from above the biofilter and passed through the biofilter from above, that is, excess water that has flowed downward without being retained in the biofilter is recovered and reused as water spray. The water for watering may be configured to be supplemented with water from the outside in addition to the surplus water that has passed through the biofilter.

In the biological deodorization method of the invention of claim 2 , the water sprayed to the biofilter is such that the water that has passed through the biofilter is 36 vol% or more when the amount of water sprayed per unit time is 100 vol%. Water to be replenished is 64% by volume or less.
Here, the water that has passed through the biofilter is 36% by volume or more, and the water that is replenished from the outside is 64% by volume or less means that water for sprinkling from the watering means to the biofilter is newly introduced from the outside. The surplus water collected by the circulation means without any water, that is, it may be covered only with the circulating water, or even when newly replenishing water from the outside, with respect to 100% of the total water for sprinkling, It means that the ratio of the water to be replenished is 64% or less by volume, and the surplus water recovered by the circulation means, that is, the circulating water is contained by 36% by volume or more.

According to the biological deodorization method of the first aspect of the present invention, it is configured by filling wood chips within a bulk density of 150 to 500 kg / m ³ , and the water sprayed on the biofilter is circulated by a circulation means. I am letting. As a result, low-cost and long-term stable deodorization performance is exhibited even for odor gas of complex odor accompanied by fluctuations in odor concentration and odor quality.

  As a result of accumulating earnest experimental research, the present inventors have constructed a biofilter as a microbial carrier with a wood chip as a result of accumulating earnest experimental research, and circulating water sprayed on the biofilter by a circulation means. By functioning as a biofilter that digests odorous components by biological treatment with microorganisms at an early start-up, without the need to sow and plant microorganisms or add microbial active substances to impart microbial activity. It was found that the deodorizing effect can be sustained over a long period of time with little increase in pressure loss over time and high odor concentration and odor quality. Based on this, the present invention has been completed.

That is, by filling the wood chip with a bulk density in the range of 150-500 kg / m ³ and configuring the biofilter, the ventilation resistance can be kept low, and the water filter is sprayed on the wood chip by the circulation means. By reusing the water that has passed, microorganisms and degradation products (metabolites) generated by the decomposition of odorous components by microorganisms are distributed in the biofilter without bias.
Therefore, narrowing, blockage, and clogging of the ventilation path of the biofilter are unlikely to occur, and 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 easy to breed. And in the biofilter formed by filling wood chips within a bulk density 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 the wood chips In addition, the effect of mitigating concentration fluctuations and pH fluctuations is high. For this reason, it is hard to produce the fall of pH with time, and can maintain pH of neutral range.
Therefore, microbial species capable of coping with the degradation of various odors are easily activated and the activity can be maintained. In particular, even if the water that has passed through the biofilter by the circulation means is reused as water spray, the activity of microorganisms and the activity of microorganisms are hardly reduced. In addition, in the biofilter comprising such wood chips, due to the water retention characteristics and high surface area of the wood chips, the gas of odor gas is easily dissolved in the liquid phase around the wood chips, and the amount of contact between the wood chips and the odor gas Is large, so the processing capacity is high.
Therefore, stable deodorization performance can be maintained for a long time even if the odor concentration or odor quality to be introduced varies.

Furthermore, by filling the wood chips with a bulk density in the range of 150-500 kg / m ³ and configuring the biofilter, the ventilation resistance can be suppressed and clogging is less likely to occur. Therefore, the running cost for blowing odor gas can be reduced.
Wood chips are also available at a low price. In addition, the biofilter configured in this way has a high processing capacity and can further suppress pressure loss. Therefore, a predetermined high processing amount can be secured even with a small volume. And even if the water that has passed through the biofilter by the circulation means is reused as sprinkling, the high water retention capacity of the biofilter has a high buffering effect on pH fluctuations, so the degradation products generated by the decomposition of the pH and odor of the circulating water There is no need to provide means for controlling the amount of odor gas or the amount of odor gas introduced.
Therefore, material costs, equipment costs, and running costs can be suppressed, and costs can be reduced.

According to the biological deodorization method according to the invention of claim 2 , the water sprayed onto the biofilter is such that the water that has passed through the biofilter is equal to or greater than 36 vol% when the amount of water sprayed per unit time is 100 vol%. By making the water replenished from the outside 64% by volume or less, the cost is low and high deodorizing ability can be maintained.

  As a result of accumulating earnest experiment research, the present inventors have collected a surplus water that has passed through the biofilter by a circulation means and used for watering in a biological deodorization apparatus that uses wood chips of a predetermined size as a microorganism carrier of a biofilter. When circulating in water, water may be replenished from the outside. However, the present invention has been completed by finding that the deodorizing ability decreases as the proportion of the replenishing water increases in the water for sprinkling.

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, the cost is low and high deodorizing ability can be sustained.

FIG. 1 is a conceptual diagram illustrating a flow until odor gas is introduced into the biological deodorization apparatus according to the embodiment of the present invention. FIG. 2 is an explanatory diagram showing the overall configuration of the biological deodorization apparatus according to the embodiment of the present invention. FIG. 3 (a) is an explanatory view showing the flooring of the biological deodorization apparatus according to the embodiment of the present invention and the surrounding structure, and FIG. 3 (b) is the biological deodorization apparatus according to the embodiment of the present invention. It is a perspective view which shows the structure of the flooring of FIG. 3, FIG.3 (c) is XX sectional drawing of FIG.3 (b). FIG. 4 is an enlarged view of a main part for explaining the configuration inside the housing of the biological deodorization apparatus according to the embodiment of the present invention. FIG. 5 is a graph showing changes in pressure loss over time in the biological deodorization apparatus according to the embodiment of the present invention. FIG. 6 is a graph showing a temperature change with time 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 protrusion wall provided in the housing of the biological deodorizing apparatus which concerns on embodiment of this invention, FIG.7 (b) is the biological organism which concerns on embodiment of this invention. It is the elements on larger scale explaining another example of the protruding wall provided in a deodorizing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that, in the embodiments, the same reference numerals and the same reference numerals are the same or corresponding functional parts, and therefore, redundant description thereof is omitted here.

First, the flow until the odor gas G is introduced into the biological deodorization 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 deodorization apparatus 10 according to the present embodiment is, for example, a waste treatment facility that composts raw food such as raw vegetables, fruits, meat, and food processing residues (composting), or livestock. Odor generated from poultry farming and animal husbandry facilities that produce livestock and compost livestock excreta, sewage and sewage treatment facilities that produce organic sludge, agricultural settlement wastewater treatment facilities, food factory wastewater treatment facilities, etc. It assumes the odor generated during the aerobic fermentation / decomposition treatment of organic matter. The odor gas G generated during the aerobic fermentation / decomposition treatment of organic substances is, for example, ammonia, trimethylamine, dimethyl sulfide (DMS), hydrogen sulfide, methyl sulfide, methyl disulfide, methyl mercaptan, volatile fatty acid ( VFA), aldehydes such as acetaldehyde, and terpenes and other odor components, and a composite odor containing a plurality of odor components and various odor qualities. The odors from facilities that aerobically ferment and decompose organic matter are low in concentration and large air volume compared to odors from livestock excreta treatment facilities and anaerobic treatment fermentation facilities. Odor quality, odor concentration, air volume, etc. Fluctuates greatly.

That is, in FIG. 1, in the composting apparatus 2, an aerobic fermentation / decomposition process such as organic waste or livestock dung is performed, and an odor gas G is generated. In this composting apparatus 2, for example, collected food residue, organic waste such as pruned branches, or composting materials such as animal manure or sewage sludge are placed with bacteria holding chips attached with aerobic bacteria, and temperature, oxygen, humidity The aerobic fermentation / decomposition process is performed by controlling the surrounding annular conditions such as the predetermined conditions. A variety of devices have been proposed for composting by aerobic fermentation, such as a device for composting in a closed concrete housing called a biocell system. In particular, in recent years, composting methods in sealed containers or buildings have become mainstream due to the influence on the surrounding environment and the problem of bad odor.
Then, the odor gas G generated in the aerobic fermentation / decomposition process in the composting apparatus 2 is appropriately collected using a blower, a fan, or the like, and is supplied as pressure air to the biological deodorization apparatus 10 according to the present embodiment. Will be sent.

The odor gas G discharged from the composting apparatus 2 is reduced in odor concentration by the chemical deodorization apparatus 3 as necessary before being sent to the biological deodorization apparatus 10.
Furthermore, if necessary, the scrubber device 4 removes harmful substances and dust contained in the odor gas G discharged from the composting device 2. The scrubber device 4 uses, for example, a cleaning dust collecting device (dust removing device, gas cleaning device), and collects and separates particles in the odor gas G with a cleaning liquid or a liquid film.

In particular, when an acid scrubber treatment is performed by the scrubber device 4 in the previous stage of the biological deodorization device 10 for odors containing sulfur compounds and ammonia generated from sludge in a sewage treatment plant, the biological deodorization device 10 is clogged ( (Stenosis, occlusion) can be prevented and the load can be reduced.
In addition, if there is a wet scrubber device 4 that captures and removes dust by spraying water at the stage before introducing the odor gas G into the biological deodorization device 10, the odor gas G is humidified. Gas G can be introduced into the biofilter 21. If the moisture of the odor gas G introduced into the biofilter 21 can be increased, it is effective for suppressing temperature fluctuations of the biofilter 21 as described later.

  The odor gas G discharged from the composting apparatus 2 and appropriately passing through the chemical deodorization apparatus 3 and the scrubber apparatus 4 is sucked and pressurized by the blower 5 and blown to the biological deodorization apparatus 10. The blower 5 that guides the odor gas G to the biological deodorization apparatus 10 is inverter-controlled so that the number of revolutions can be controlled as necessary. Therefore, for example, when the processing amount of the odor gas G discharged from the composting apparatus 2 and the odor concentration are extremely small, the energy saving operation can be performed by reducing the rotation speed. However, the blower 5 is always operated to send an air flow to the biological deodorizing apparatus 10, thereby preventing clogging (stenosis or blockage) of the biofilter 21 of the biological deodorizing apparatus 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, but according to the biological deodorization apparatus 10 of the present embodiment, there is little pressure loss as will be described later. In addition, since the increase in pressure loss with time is also suppressed, a high throughput can be secured even without using an expensive fan with high blowing capacity, that is, with a small fan with low 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 deodorization apparatus 10 according to the present embodiment includes a biofilter 21 that digests odorous gas G by biological treatment, and a deodorizing treatment unit 20 in which a flooring 22 provided at the bottom of the biofilter 21 is housed in a housing H, Sprinkling means 30 for sprinkling water from the upper part of the biofilter 21 constituting the deodorization processing section 20, collecting and storing the water receiving section 41 for collecting and storing water sprinkled from the sprinkling means 30, and supplying water from the water receiving section 41 to the sprinkling means 30. Then, a supply path 42 to be circulated is configured, and a surplus water that has passed through the biofilter 21 and the flooring 22 is collected and circulated means 40 that circulates to the sprinkler means 30.

  The deodorization processing unit 20 of the present embodiment is configured such that the floor material 22 is disposed via the support legs 23 in a box-shaped housing H in which the upper side is opened and the lower surface and the left and right side surfaces are made of, for example, reinforced concrete. The biofilter 21 is formed by arranging and filling the wood chip 21A thereon.

  The size of the housing H is designed according to the processing amount of the odor gas G, the target deodorization rate, and the like. For example, the volume h is set to about 1.5 to 4 times the tunnel volume of the composting facility. From the viewpoint 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 any material that does not easily corrode, and a heat insulating material may be used on the outside. It is also possible to maintain a good microbial growth environment and to stabilize the deodorization efficiency by the heat insulating material. However, in the present embodiment, as will be described later, the deodorization efficiency can be stably maintained regardless of seasonal fluctuations, and therefore there is no problem even if a heat insulating material is not used.

  An inlet 24 for introducing the odor gas G pumped by the blower 5 is provided at the bottom of the housing H. The inlet 24 is formed of a duct or the like that connects the output of the blower 5 to the inlet 24 at the bottom of the housing H. The odor gas G pumped from the blower 5 is introduced from the introduction port 24 through the path 24a. The introduction port 24 and the introduction part 24a are sized so that no pressure loss occurs there. For example, the introduction port 24 is provided below any one of the four side surfaces of the housing H.

  And in the housing H of the space partitioned with concrete, as shown in FIG. 3, the several support leg 23 for maintaining the flooring 22 to predetermined | prescribed height is installed in the bottom face of the housing H, and these A flooring 22 is placed on the support legs 23. The support leg 23 is made of, for example, concrete formed in a columnar shape or a cylindrical shape, and has a structure and layout design that can withstand the weight of the flooring 22 and the heavy pressure of the biofilter 21 that is wetted by water spraying. Thus, after the support leg 23 is erected on the floor surface of the housing H, the floor material 22 is disposed on the support leg 23 and the floor material 22 is held at a predetermined height. A predetermined space S communicating with the inlet 24 a of the housing H is defined between the materials 22. That is, the bottom of the housing H and the floor material 22 are separated from each other by the support legs 23, and a predetermined space S is formed between the bottom of the housing H and the floor material 22. By providing such a predetermined space S that communicates with the introduction port 24a of the housing H, the odor gas G introduced from the introduction port 24a of the housing H can be circulated through the entire bottom portion of the housing H.

The floor material 22 is placed on the support leg 23 erected on the bottom of the housing H in this way, spread over the entire cross section in the housing H, and the wood chip 21A is loaded thereon.
For example, as shown in FIG. 3, the flooring 22 has a predetermined thickness in which a plurality of through holes 22 a having a predetermined shape that penetrates the wall thickness are provided, and a plurality of grooves 22 b that pass through the wall thickness are provided on the side surface. A plurality of concrete parts are combined and laid in the concrete H.

  Thus, the floor material 22 is provided with, for example, a ventilation hole 22A formed by a combination of a ventilation hole 22A that is a cylindrical (circular cross section) through hole 22a and a groove 22b provided around the part. Then, the odor gas G introduced from the introduction port 24a of the housing H and distributed through the entire bottom of the housing H is introduced into the wood chip 21A laid on the floor material 22 through the vent hole 22A of the floor material 22. Will be. The vent holes 22A are distributed over the entire flooring 22 so that the odor gas G can be uniformly supplied to the entire area of the biofilter 21.

Here, according to the experiments by the present inventors, the floor material 22 disposed below the biofilter 21 filled with the wood chip 21A having 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 a minimum, and even if the amount of odor gas introduced varies or varies, it can be prevented from being loaded by a predetermined fluid resistance. About the opening, it specified by opening ratio.
That is, if the opening area and opening ratio of the air holes 22A provided in the flooring 22 are too large, the mechanical strength is weak and a tough material is required, resulting in high costs. On the other hand, even if the opening area and the opening ratio are too low, the pressure loss is high, and powerful air blowing is required, so the running cost becomes high.
Therefore, it is preferable that the floor material 22 has an opening of the vent hole 22A in a range of 20 mm to 100 mm and an opening ratio in a range of 5% to 95%.

In addition, the said opening and an opening rate represent the magnitude | size and density of 22 A of ventilation holes of the flooring 22. The mesh opening also indicates, for example, the vertical width or the lateral width of an opening (space) per mesh formed by intersecting vertical and horizontal lines such as a mesh shape. If it is a square, it corresponds to one side of the square. The shape of the vent hole is not specified to be circular or square, but it is a shape with low air resistance and a large surface area. A hole is preferred.
In addition, the opening and the opening ratio of the flooring 22 are measured in accordance with the sieve wire mesh standard, the floor area of the flooring is S, the number of flooring meshes is M, and the diameters of the vertical and horizontal lines are d. The aperture is calculated by the following formula (B), and the aperture ratio is calculated by the following formula (C).
Aperture A (mm) = S / M−d (B)
Opening ratio ε (%) = (A / A + d) ² × 100 (C)

  Thus, in the flooring material 22 on which the wood chip 21A having a predetermined diameter is laid, if the opening is in the range of 20 mm to 100 mm and the opening ratio is in the range of 5% or more and 95% or less, the pressure loss Therefore, even if there are fluctuations and variations in the amount of odor gas introduced, the load can be reduced by a predetermined fluid resistance. More preferably, the aperture is in the range of 30 mm to 90 mm, and the aperture ratio is 10% or more and 90% or less.

  In FIG. 3, in order to increase the rectification effect and to reduce the influence of pressure fluctuation due to the flow rate of the odor gas G, the diameters of the plurality of vent holes 22 </ b> A are directed upward, that is, the biofilter 21. The diameter gradually decreases toward the side. Further, according to Bernoulli's theorem, the odor gas G from the blower 5 may be adjusted so that the change in the flow rate is reduced by adjusting the size, shape, and opening ratio of the vent hole 22a so that the flow rate is not affected by the flow rate.

In FIG. 3, the plurality of vent holes 22A of the flooring 22 are circular in cross section, that is, formed in a circle when viewed from the front. It may be an oval, a cross-sectional triangle, a cross-sectional square, a cross-sectional hexagon, or the like. A shape having a small fluid resistance is preferable, for example, a cross section is circular, elliptical, oval, square or the like. Also, the configuration of the housing H, the support legs 23, and the flooring 22 is made of concrete. In carrying out the present invention, other materials may be used as long as a predetermined strength is ensured with a material that does not easily corrode.

Thus, in the present embodiment, the floor material 22 is installed on the support leg 23 erected on the bottom of the housing H, and the wood chip 21 </ b> A that forms 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 the side wall of the housing H, and wood is placed in a 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 protrusion of the protruding wall 28 with respect to the laying area of the flooring 22. That is, the bottom area of the biofilter 21 disposed on the floor material 22 is narrower than the area of the floor material 22 on which the biofilter 21 is placed. That is, the floor area (planar area) on the input side at the lower end of the biofilter 21 is smaller than the planar area on the output side of the flooring 22 without the side surface of the biofilter 21 and the side surface of the flooring 22 being coincident. .

  Thus, the plate-like protruding wall 28 is provided on the flooring 22 so as to surround the side wall of the housing H, and the area ratio of the input side region where the odor gas G is input to the biofilter 21 is determined. By making it smaller than the area of the upper surface of the flooring 22, the rectifying effect can be enhanced, 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. By supplying G, the processing efficiency with respect to the volume of the biofilter 21 can be increased. Furthermore, the pressure change at the boundary between the floor material 22 and the biofilter 21 is increased, so that the clogging on the input side where the odor gas G is introduced into the biofilter 21 can be easily eliminated. However, if the installation area of the biofilter 21 is too small with respect to the laying area of the flooring 22 having the vent hole 22A having a predetermined cross-sectional area at a predetermined opening ratio, that is, the plate-shaped protruding wall 28 causes the biofilter 21 to When the flow velocity of the odor gas G that has passed through the flooring 22 at the entrance is greatly limited, the pressure loss increases to secure a predetermined processing amount, resulting in an increase in cost due to an increase in the sending pressure of the blower 5. Become. For this reason, considering the 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.

In this example, the protruding wall 28 is provided between the biofilter 21 and the housing H on the floor material 22. However, the inner wall of the biofilter 21 itself is located on the inner side from the position of the floor material 22 (biofilter). 21 side) may be formed so as to protrude.
Further, as shown in FIG. 4A, the protruding wall 28 does not need to be provided up to the position of the filling height h of the biofilter 21, and as shown in FIG. For example, it is good also as a height position of 10 cm-20 cm. In any case, it is only necessary to prevent leakage of the odor gas G that rises along the wall surface of the housing H.

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

Furthermore, in the present embodiment, as shown in FIG. 2, water that has sprinkled from the sprinkling means 30 above the biofilter 21 and passed (flowed down) through the biofilter 21 and the flooring 22 at the bottom of the housing H. Is provided with a drain outlet 42 through which water flows out to the water receiving portion 41. Here, water that has passed through the biofilter 21 and the flooring 22 and has reached the bottom of the housing H (hereinafter also referred to as surplus water W ₁ ) does not accumulate in the bottom of the housing H more than a predetermined amount from the drain port 42. The drain port 42 is designed to have a predetermined position so as to flow out to the water receiving part 41. This is because if the amount of water stored at the bottom of the housing H is large, the deodorization performance is reduced due to the propagation of organisms such as insects.
However, in the space S below the flooring 22, the water that has passed through the biofilter 21 and the flooring 22 is collected at the bottom of the housing H, so that 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 moisture of the odor gas G introduced into the biofilter 21 can be increased, it is effective for suppressing temperature fluctuations of the biofilter 21 as described later.
When the present invention is carried out, the outflow of water that has reached the bottom of the housing H gives an inclination to the bottom surface of the lower portion of the housing Hn and collects the water receiving portion 41 and the water receiving portion 41 without stopping the water. You may be made to do. A plurality of drain ports 42 may be provided.

The surplus water W ₁ flowing out from the drain port 42 of the housing H is collected and collected by the water receiving unit 41 via a drain channel 42 a composed of a pipe connecting the drain port 42 to the water receiving unit 41.
From this water receiving part 41, a watering supply path 43 comprising a pipe line or the like is disposed up to above the housing H, and above the housing H, a watering pipe constituting the watering means 30 connected to the watering supply path 43. 31 is disposed. A pump and a valve are provided in the middle of the sprinkling supply path 43.
The sprinkling pipe 31 has a necessary number of sprinkling nozzles 32 for sprinkling water, and has a structure capable of spraying water substantially uniformly on the upper surface of the biofilter 21 in the housing H. Usually, the water spray is sprayed as water droplets. 1 and 2, the direction of the watering nozzle 32 is directed downward on the biofilter 21 side, but the direction of the watering nozzle 32 is not limited thereto, and the watering nozzle 31 is spouted upward. You may do it. In any case, by sprinkling water toward the biofilter 21 from above the housing H, the sprinkled water falls onto the biofilter 21 by gravity, and moisture is supplied to the wood chip 21A constituting the biofilter 21. To do.

Thus, the surplus water W ₁ collected in the water receiving section 41 is supplied to the water sprinkling pipe 31 as the water sprinkling means 30 for sprinkling water from the upper side of the housing H to the bio filter 21 through the water sprinkling supply path 43. Used for watering to humidify. That is, in this embodiment, the water sprinkling to biofilters 21, which uses the surplus water W ₁ which has passed through the biofilter 21, by circulating water spray.

Further, in the water receiving part 41 of the present embodiment, a water guide part 44 for introducing industrial water (industrial water or the like) as a replenishing means for replenishing the circulation means 40 from the outside and supplying it to the water is also connected. In addition to the drainage water W ₁ (surplus water W ₁ ), supplementary water W ₂ can be newly taken in from the water guide section 44 through a valve as necessary. 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 watering in the water receiving part 41 and the supplementary water ₂ supplied from the outside as needed are collected together and pumped up and supplied to the watering pipe 31 via the watering supply path 43. Is done. Then, the water supplied to the water spray pipe 31 is supplied to the biofilter 21 by watering from the water spray nozzle 31 directed to the upper surface of the biofilter 21. At this time, watering may be intermittent or may be performed continuously.
In addition, a filter or a scrubber device 4 for filtering dust, sand, and fine particles is installed in the water guide section 44 for introducing water such as industrial water as necessary. Thereby, the clogging of the biofilter 21 can be prevented without containing dust, sand and fine particles in the water spray.

Thus, in the biological deodorization apparatus 10 according to the present embodiment, the surplus water W _{1 that} has been sprayed from the sprinkling means 30 and passed through the biofilter 21 is mainly used for moisture adjustment and humidification of the biofilter 21 and, if necessary, further. Since the supplementary water W ₂ is supplemented from external industrial water or the like, waste water is completely discharged. 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 of the present embodiment includes, for example, raw wood (trunks, whole trees, shrubs, end trees, branches, pruned branches, root stocks, etc.), lumber (backboards, end materials, peeled cores, etc.), building demolition materials, construction Wood chips 21A are deposited by cutting or crushing materials, packing materials, plywood, laminated wood, particle boards, waste pallets, etc. with chippers, shredders, mills, crushers, hammers, punching, etc. to form wood chips. It is not limited to raw wood chips obtained by cutting and crushing raw wood (including felled wood, thinned wood, and small-diameter wood), but factory residual wood chips, forest land residual wood chips, demolition / waste wood chips, and the like may be used. That is, the wood chip 21A is not limited to the solid material chip, and may include a laminated material chip, an MDF chip, and a particle board chip. However, since the laminated wood chips, MDF chips, particle board chips, etc. adhere 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 weight% or less, More preferably, it is 20 weight% or less. The wood chip 21 is mainly composed only of a wood part and a pith of wood, but a bark chip and a chip with bark are mixed (preferably 20% by weight or less of the whole, more preferably 5% by weight of the whole). The following).
The wood chip 21A may be a cutting chip obtained by cutting a raw wood, lumber, waste, or the like with a blade using a wood chipper (a disk chipper or the like), or a shredder, a mill, a hammer, a crusher, or the like. It may be a crushing chip (pin chip, crusher chip, etc.) obtained by crushing raw wood, lumber, waste material and the like.

  The wood used for the wood chip 21A is cedar, cypress, red pine, pine, pine, yew, rat, fir, fir, sawara, asunaro, hiba, inugaya, spruce, spruce, eastern white pine, western larch, western fur , Western hemlock, Tamarac, conifers, birch, linden, quail, beech, sina, poplar, eucalyptus, acacia, oak, itaya maple, senoki, elm, kiri, honoki, willow, sen, ubamegashi, konara It may be a broad-leaved tree such as cucumber, cypress, zelkova, earthworm, dogwood, aodamo, aokokutan.

  Incidentally, the present inventors are performing various evaluation tests of the deodorizing effect by the biological deodorizing apparatus 10 by changing the material type of the wood chip 21A that is a microorganism carrier of the biofilter 21 to be used. The results are shown in Table 1.

  As shown in Table 1, as wood chip 21A, crushed products of thinned timber and sawn timber of mixed conifers (cedar and cypress), thinned timber and sawn timber of broadleaf trees (mixed birch and linden) The biological deodorizing apparatus 10 shown in Table 1 was used by using five types: crushed products, hardwood ring-hole materials (Mizunara) thinned timber and sawn timber shredded products, building waste crushed products, and pruned branch crushed products. The deodorizing effect of the odor gas G was tested under 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.
To evaluate the deodorizing effect, 12 persons (hereinafter referred to as monitors) recruited from ordinary people sniff the odor gas G of the source odor and the treated air after passing through the biofilter 21 at 5 hour intervals. 6 levels (0: odorless, 1: I don't know what smell is, 2: unpleasant smell, 3: unpleasant smell, 4: strong smell, 5: Very smelly, intense smell) and sensory evaluation. The 12 monitors were divided into 2 groups of 6 people, one group smelled in the order of source odor gas G and treated air, and the other group smelled in order of treated air and odor gas G. The sensory evaluation is performed by smelling The numerical values shown in Table 1 above are average values of odor evaluation 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 into the biological deodorization apparatus 10 is started.

  As shown in Table 1, no matter what kind of wood chip 21A is used, no matter how much it smells even after one year from the start of the introduction of the odor gas G (1) or It was an evaluation of a smell (2) that does not become a high smell, and a high deodorizing effect was maintained. In other words, the wood chip 21 may continue to have a high deodorizing effect for a long time regardless of whether it is a crushed product from thinned wood or sawn timber, a crushed product of building waste, or a crushed product of pruned branches. I understand.

  In particular, according to the experimental study by the present inventors, the wood chip 21A made of conifers such as pine, cedar and cypress contains a large amount of resin, so that the deodorizing effect for a longer period of time is maintained, and the biofilter 21 is used. It has been confirmed that the service life will be higher. On the other hand, in the hardwood wood chip 21A, compared to the softwood wood chip 21A, the acclimation of microorganisms effective for the decomposition of the odorous gas G and the formation of the microflora (biofilm) are quick, and the initial rise is shown. It has been confirmed that the biofilter 21 has a high deodorizing ability.

In addition, when reusing waste materials such as factory residual materials and dismantling residual materials as the wood chips 21A, the foreign matter removal processing is usually performed before and after the cutting or crushing processing.
In the wood chip 21A of the present embodiment, after cutting or crushing wood, for example, wood chips classified (sorted) into a predetermined size (granularity) using a vibrating sieve, a roll classifier, or the like are used. .
Such wood chip 21A is resistant to acidity and alkalinity, hardly deteriorates or loses its shape, and has high shape retention. For this reason, the increase in the pressure loss with time and the decrease in the deodorizing efficiency due to use can be suppressed.

  The size of the wood chip 21 is, for example, the length of the wood in the fiber 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 radial thickness of the wood is It is in the range of 4 mm to 10 mm.

Here, the length of the wood chip in the fiber direction of the wood is within the range of 10 mm to 300 mm. When the length direction of the wood grain is the length of the wood chip, the length of the wood chip is 10 mm or more and 300 mm or less. It is within the range of.
The width of the wood chip tangent direction within the range of 5 mm to 30 mm means that the width of the wood chip is 5 mm or more and 30 mm or less when the tangential direction in contact with the wood annual ring circle is the width of the wood chip. Indicates that it is within.
Further, the radial thickness of the wood chip in the range of 4 mm to 10 mm means that 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 rings is the thickness of the wood chip. It shows that.
However, for example, when it is difficult to determine the direction of the wood, such as an MDF chip or a PB chip, 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. And the direction perpendicular to the length and width is the thickness of the wood chip.

  For cutting chips and crushing chips, the longest width in the fiber direction of the wood is the length of the wood chip 21A, the longest width in the tangential direction of the wood is the width of the wood chip 21A, and the longest width in the radial direction of the wood is the thickness of the wood chip 21A. To do. For MDF chips, PB chips, etc., in which the fiber direction, tangential direction, and radial direction of wood cannot be distinguished, the longest side of the wood chip 21A is the longest length, the longest width in the direction perpendicular to the long side is the wide, long side The longest width in the direction perpendicular to the width is the thickness of the wood chip 21.

Depending on the size of the wood chip 21 as described above, filling with a bulk density in the range of 150 to 500 kg / m ³ is possible. However, due to differences in wood raw materials, tree species, crushing or cutting processing means / mechanisms, the shape of the wood chips is not constant, but varies and has a complicated shape. This is an approximate value including an error due to, and does not deny an error of several percent.

  Here, the present inventors have performed an evaluation test of the deodorizing effect by changing the size of the wood chip 21A group constituting the biofilter 21 in various ways. The results are shown in Table 2. The wood chip 21A shown in Table 2 is expressed by the length dimension of the wood chip 21a (the fiber direction of the wood).

  Here, the deodorizing effect of the odor gas G is tested in the same manner as described above under the specifications and test conditions of the biological deodorizing apparatus 10 shown in Table 2, and the numerical values shown in Table 2 are based on the above-mentioned 12 monitors. It is a result of sensory evaluation (average value) of odor. 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 deodorization apparatus 10 was started.

  As shown in Table 2, in the wood chip group having a wood length of 10 mm or more and 100 mm or less, the evaluation one month after the start of the introduction of the odor gas G does not matter (2) After three months The evaluation of No. 1 does not know what smell (1), and the evaluation after one year does not know what smell (1), the high deodorizing effect lasted for a long time. In addition, in wood chip groups having a length of wood of 150 mm or more and 300 mm or less, the evaluation after one month from the start of the introduction of the odor gas G does not matter (2), three months later, one year later and The evaluation after 3 years did not show any smell (1), and a higher deodorizing effect lasted for a long time. Here, about the wood chip | tip whose length of such a timber is 10 mm or more and 300 mm or less, the width | variety was 5 mm-30 mm, and the thickness was 4 mm-10 mm, for example.

  On the other hand, in the wood chip group having a wood length of less than 10 mm, the evaluation after 1 month and 3 months after the start of the introduction of the odor gas G is an unpleasant smell (2). The evaluation after and after 3 years was an odor of interest (3) or a strong odor (4), and the deodorizing effect was clearly reduced one year after the introduction of the odor gas G was started. Such wood chips having a wood length of less than 10 mm have, 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 a wood chip. It was included.

  This is because the flow path of the odor gas G is small because the size (particle diameter) of the wood chip 21A is small, so that the deposition of decomposition products (metabolites) caused by decomposition of odor components by microbial films (biofilms) and microorganisms. This is considered to be because clogging (stenosis, occlusion) is likely to occur due to the like. When the wood chip 21A is partially clogged, a drift that restricts the passage of the odor gas G occurs, the amount of contact with the wood chip 21A necessary for decomposition of the odor components of the odor gas G decreases, and the entire biofilter 21 It seems that it will not be used evenly and effectively.

  On the other hand, in the wood chip group having a wood length of 400 mm or more and 700 mm or less, the smell is anxious (3) one year after the introduction of the odor gas G, and the deodorization effect of the odor gas G is low. It was a thing. Such wood chips having a length of 400 mm or more have, for example, a width of about 20 mm to 50 mm and a thickness of about 5 mm to 20 mm.

  This is because the size of the wood chip group increases the flow path of the odor gas G, and the contact rate between the odor component in the odor gas G and the wood chip 21A decreases, or the whole wood filter 21A has the wood filter 21A. This is probably because the amount of water retained and the amount of microorganisms effective for decomposing odorous components are small due to the small surface area.

  Although wood chips with a wood length of 150 mm or more and 300 mm or less are used, the volume is 80% of the entire biofilter 21, and wood chips with a wood length of less than 10 mm are mixed into the remaining 20% volume. The evaluation after 1 month and 3 months after the start of the introduction of the odor gas G is an unpleasant odor (2), but the evaluation after 1 year is an irritating odor (3) Yes, the deodorizing effect was low.

  This is because the packing density increases due to the combination of small-diameter wood chips (wood length is less than 10 mm) and large-diameter wood chips (wood length is 150 mm or more and 300 mm or less), and the flow of odor gas G Since the path is small, clogging and drift of the odor gas G are likely to occur, the amount of contact with the wood chip 21A necessary for the decomposition of the odor components of the odor gas G is reduced, and the entire biofilter 21 is uniformly and effectively obtained. This is thought to be because it is no longer used.

As described above, the wood chip 21 is less likely to be clogged in a crowd whose size is too small, such as chip dust, particles, etc. On the other hand, even in a crowd whose size is too large, the biofilter 21 has a predetermined size. It does not have a bulk density and cannot exhibit an effective deodorizing effect.
Therefore, for example, the length in the fiber direction of the wood is in the range of 10 mm to 300 mm, the width in the tangential direction of the wood 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. If it is a community of a certain wood chip 21A, clogging is unlikely to occur, the odor gas G can be passed through the entire biofilter 21, and the water retention and microbial retention are good due to the high surface area. Sustainability is improved. That is, regardless of the difference in the raw material of wood, it is possible to form an optimum flow path size that hardly causes narrowing, blockage, and clogging, and has little increase in pressure loss, thereby ensuring a high deodorizing effect.

  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 When the thickness of the wood chip is in the range of 4 mm to 10 mm and the wood chip of this size is 80% by mass or more, it is easy to obtain optimum conditions for forming a path that is difficult to clog. That is, when looking at the size distribution of the wood chip group, the length of the wood in the fiber direction is 150 mm to 300 mm, although the difference in the raw material, tree species, processing means / mechanism of crushing or cutting is reflected in the size distribution. The wood chip size of wood chips having a wood tangential width of 5 mm to 25 mm and a wood radial thickness of 4 mm to 10 mm is 80% by mass or more of the whole. If it exists, it is possible to obtain stable characteristics as a wood chip constituting a biofilter having a high deodorizing effect.

Such a group of wood chips 21A having a predetermined size can be obtained, for example, by sieving a piece of wood after cutting or crushing. Usually, the sieving of the wood chips is classified by using a sieve and shaking the sieve.
The wood chip group 21A having the predetermined size can be obtained, for example, as a size of the wood chip group that passes (passes) a sieve having an opening of 60 mm and does not pass (pass) a sieve having an opening of 10 mm. For example, an undersized wood chip having a sieve opening of 60 mm is obtained, and then the undersized wood chip having a sieve opening of 60 mm is further passed through a sieve having a mesh opening of 10 mm. An oversized wood chip that does not pass through 10 mm is obtained. In this way, it is possible to obtain an oversized wood chip that has an undersize that passes through a sieve with a mesh opening of 60 mm and does not pass through a sieve with a mesh opening of 5 mm, thereby obtaining a wood chip 21 with a predetermined size. The sieving may be classified by a sieve shaker in which the sieves are designed in a stacked structure. In addition, the term “mesh” refers to the vertical width or the horizontal width of an opening (space) per eye formed by crossing vertical and horizontal lines. Here, circular eyes (circular holes) or square eyes ( A square-hole sieve was used. In the case of a sieve having a mesh opening of 60 mm, the diameter of the circular hole is 60 mm in the case of a circular shape, and one side of the square is 60 mm in the case of a square shape. In the case of a sieve having an opening of 10 mm, the diameter of the circular hole is 10 mm in the case of a circular shape, and one side of the square is 10 mm in the case of a square shape. However, due to differences in wood raw materials, tree species, crushing or cutting processing means / mechanisms, the shape of the wood chips is not constant, but also has a complicated shape and has a complicated shape. It is not always possible to obtain a group of wood chips 21A having a size and shape. More preferably, it is a wood chip that passes (passes) through a sieve having an opening of 40 mm by sieving and does not pass (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. Depending on the selection of the size of the vent hole 22a of the floor material 22, the wood chip 21A May fill the ventilation holes 22a of the flooring 22.

Therefore, when the present invention is carried out, as shown in FIG. 4 (b), a timber chip 21b having a coarse size is laid on the floor surface of the flooring 22, and then, for example, the above-described wood fibers are used. A fine wood chip 21a having a length in the direction within a range of 10 mm to 300 mm, a tangential width of the wood within a range of 5 mm to 30 mm, and a radial thickness of the wood within a range of 4 mm to 10 mm. It is also possible to fill.
For example, as the coarse-sized wood chip 21b, the length of the wood in the fiber direction is in the range of 350 mm to 700 mm, the width in the tangential direction of the wood is in the range of 10 mm to 40 mm, and the radial thickness of the wood Is in the range of 5 mm to 20 mm, more preferably, the length in the fiber direction of the wood is in the range of 400 mm to 500 mm, the tangential width of the wood is in the range of 10 mm to 80 mm, and the radial thickness of the wood Wood chips 21b having a thickness of 5 mm to 50 mm can be used.

Thus, by laying the coarse timber chip 21b in the vent hole 22A of the floor material 22 so that the fine timber chip 21a does not fall, the fine timber chip 21a is filled. In addition, relief of pressure loss and narrowing of the air passage due to consolidation of the lower part of the biofilter 21 can be alleviated, and deodorization efficiency can be improved. In addition, since the powerful ventilation is not required for the odor gas G due to the effect of reducing the pressure loss, the running cost of the blower 5 can be reduced.
Such coarse wood chips 21b are filled with 5% or less of the volume of the fine wood chips 21a.

  Thus, for the biofilter 21 configured by the wood chip 21A (hereinafter, the wood chip 21a and the wood chip 21b may be collectively referred to as the wood chip 21A when not particularly distinguished), the wood chip 21A is dried. In order to prevent and maintain the biological treatment activity by the biofilter 21, the biofilter 21 is moistened by humidification by watering from the watering means 30. That is, if the moisture of the wood chip 21A is small, the growth of microorganisms is suppressed, and the deodorizing action is reduced because the odor components in the odor gas G cannot be captured in the wood chip 21A. In the biofilter 21, the wet state is maintained by watering from the watering means 30.

  Here, the present inventors have further investigated the conditions for optimizing the dissolution, adsorption and microbial environment of odorous components in the biofilter 21 composed of the wood chip 21A serving as the microorganism carrier. It has been found that when the moisture content of the wood chip 21a is controlled by adjustment, a high deodorizing effect is obtained and the effect is maintained. Table 3 shows the results when an evaluation test was performed on the relationship between the moisture content of the wood chip 21a and the deodorizing effect.

Here, the moisture content of the wood chip 21a is adjusted to 20% to 220% by adjusting the amount of water sprayed and maintained, and the deodorization of the odor gas G is performed under the specifications and test conditions of the biological deodorization 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 odor by the above-mentioned 12 monitors. 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 deodorization apparatus 10 was started.

About the moisture content of the wood chip | tip 21a, the moisture content was regularly measured whether the wood chip | tip 21a was maintained at each moisture content, and the water spray was adjusted and managed so that it might be maintained at each moisture content.
At the time of measurement, a predetermined amount of wood chips 21a are collected from the biofilter 21, and the moisture content is obtained by measuring the weight before and after drying.
The moisture content of the wood chip 21a at this time represents the ratio of the moisture weight to the weight (total dry weight, dry base) of the wood chip 21A in a state not containing moisture, and the moisture content is expressed by the following formula (A). Seeking rate.
Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100 (A)
The total dry weight was a value obtained by drying at 105 ° C. 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 anxious (3) or not concerned. Although it was an odor (2), the evaluation after 3 months was (1). In addition, in the evaluation after one year, the smell is unclear (1), and even after three years, it is an unpleasant odor (2), and a high deodorizing effect is maintained for a long time. It was.

On the other hand, if the moisture content of the wood chip 21a was less than 150%, the deodorizing effect was poor. That is, when the moisture content of the wood chip 21 is 120%, the evaluation is a strong smell (4) even after one month from the start of the introduction of the odor gas G, and even the evaluation after three months is worrisome. The smell was (3), and the evaluation after one year was a strong smell (4).
Further, when the moisture content of the wood chip 21a is 80% or less, the evaluation has a strong smell (4) even after one month from the start of the introduction of the odor gas G, or a very odor and a strong smell. (5), and the odor (3), strong odor (4), or very strong odor, intense odor (5) Deodorizing effect was not obtained.

Therefore, by maintaining the moisture content of the wood chip 21a at 150% or more, a high deodorizing effect can be maintained for 3 years or more. According to the experiments by the present inventors, it is more preferably 160% or more, and still more preferably 180% or more.
In the experimental research conducted by the present inventors, there is an upper limit on the moisture content of the wood chip 21a from the characteristics of the wood, and the upper limit is determined by the characteristics of the wood chip tree species and the like, but is about 300% at the maximum. is there.

  In addition, by maintaining the moisture content of the wood chip 21a at 150% or more and 300% or less by watering from the watering means 30, the high deodorizing effect is maintained due to the water retention of the wood chip 21a to the moisture of the odor component. It is presumed that the dissolution, adsorption and microbial environment are optimized. In particular, in the wood chip 21a having a moisture content in the range of 150% or more and 300% or less, a thick water film is formed in the periphery, the microbial activity can be increased, and the gas is easily dissolved in the liquid phase and easily adsorbed. It may have become. Furthermore, it is assumed that such a thick water film has a high pH buffering effect against fluctuations in the concentration of odor components and also in the production of degradation products generated by the decomposition of odor components, thereby suppressing fluctuations in pH. Is done. And since the fluctuation | variation of pH is suppressed in this way and pH is maintained in a neutral range, it is hard to deactivate microbial activity, the activity of multiple types of microorganism group is maintained, and it can respond also to various odors. It seems to be possible. That is, it is thought that it can be maintained in an optimum environment for the growth of a microorganism group capable of dealing with various odors.

Thus, in the present embodiment, the water content of the wood chip 21a is maintained at 150% or more and 300% or less by watering from the watering means 30.
In addition, about the amount of watering, it is set as the amount of watering which maintains the moisture content of the wood chip 21a at 150% or more and 300% or less, but the wood chip 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 present inventors further investigated the conditions for maintaining a high deodorizing effect. In the present embodiment, the surplus water W ₁ used for watering in the water receiving unit 41 and externally as necessary. The replenishing water W ₂ supplied from the water is collected and pumped up by a pump, supplied to the watering pipe 31 through the watering supply path 43 and watered, but depending on the conditions of the water used for watering at this time, the deodorizing performance Was found to fluctuate.
That is, as shown in Table 4, the water to be sprinkled by the sprinkling means 30 is drained from the housing H as surplus water W ₁ , collected by the water receiving portion 41, and reused as sprinkled water as circulating water W _1. , 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 Was seen. Table 4 shows the results when an evaluation test was conducted on the relationship between the water conditions used for watering and the deodorizing effect.

Here, for the water to be sprinkled by the sprinkling means 30, the ratio of the circulating water W ₁ and the supplementary water W ₂ is adjusted to test the deodorizing effect of the odor gas G under the specifications and test conditions of the biological deodorizing apparatus 10 shown in Table 4. Went.
The numerical values shown in Table 4 are also the results of sensory evaluation (average value) of odor by the above-mentioned 12 monitors. 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 is started.

As shown in Table 4, assuming that the constant watering amount per unit time is 100% by volume, the water for watering consists of 100% by volume of the circulating water W ₁ or the supplementary water W ₂ is taken in from the outside. However, if the water for sprinkling is circulating water W ₁ / replenishment water W ₂ ≧ 7/12 in volume ratio, the evaluation one month after the introduction of odor gas G starts to be worrisome (3) Or, it was an unpleasant odor (2), and the evaluation after 3 months was an unclear smell (1). Also, in the evaluation after one year, the smell does not know what smell (1) or it does not care (2), and even after three years, the smell does not know what smell (1) Or smell (2) which does not matter, and a high deodorizing effect was maintained for a long time.

On the other hand, water for sprinkling is not circulated (circulating water W ₁ : supplement water W ₂ = 0: 10), or the water for water spray is circulating water W ₁ / supplement water W ₂ <7 / When it was 12, it was inferior to the deodorizing effect. That is, in the case of 0/10 ≦ circulated water W ₁ / replenished water W ₂ <7/12, the evaluation is a strong smell (4) even after one month from the start of the introduction of the odor gas G, and three months. In the later evaluation, it was a strong odor (4).

Therefore, the water W sprayed by the water spray means 30 when the constant water spray amount per unit time is 100% by volume is that the circulating water W ₁ is about 36% by volume or more and the supplementary water W ₂ is 64% by volume or less. High deodorizing effect can be maintained for 3 years or more.
This is because microorganisms effective for odor decomposition are present in the water that has passed through the biofilter 21 and the circulating water W ₁ containing such microorganisms is reused as water spray without being discharged (waste water) to the outside. In the water sprayed to the biofilter 21, since effective microorganisms are contained, the amount of microorganisms in the biofilter 21 is maintained, and the bias of the microflora is prevented, so that the microbiota is formed in the entire biofilter 21. It is considered that the entire biofilter 21 is effectively used because it is uniformly distributed. In addition, it is considered that the followability and responsiveness to the odor gas G of the complex odor accompanied by the change in odor concentration and odor quality are also improved. In particular, by reducing the dilution with the replenishing water W _{2 with} respect to the circulating water W ₁ , that is, when the ratio of the circulating water W ₁ to the water used for sprinkling is high, effective microorganisms with a high concentration can be obtained. Since the water is sprayed, the high microbial amount and microbial activity of the biofilter 21 are maintained, and a high deodorizing effect can be continuously maintained even for the odor gas G having a complex odor accompanied by fluctuations in odor concentration and odor quality. . In addition, the circulation of watering balances the odorous components (ammonia ions, etc.) that cause the pH increase and the degradation products (nitrate ions, etc.) of the odorous components that cause the pH drop, thereby neutralizing the pH. It is presumed that the high deodorizing effect was maintained.

Thus, in this embodiment, when the constant watering amount per unit time is 100% by volume, the water to be sprinkled by the watering means 30 is 0/10 ≦: supplementary water W ₂ / circulated water W _1. ≦ 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 to the biofilter 21 from the watering means 30 as watering.

In addition, in such a biological deodorizing apparatus 10, the bottom of the housing H includes the introduction path 24 a through which the odor gas G from the blower 5 is introduced, the drainage path 42 a through which the excess water W ₁ is discharged, and the water receiving section 41. While the odor gas G is a closed system that does not leak to the outside, the upper portion of the housing H through which the deodorized air passing through the biofilter 21 is discharged is generally opened. In the housing H provided with a ceiling, an opening is provided so that deodorized air can be released into the atmosphere. In this case, the watering pipe 31 or the like may be embedded in the ceiling, and the watering nozzle 31 may be disposed on the ceiling.
Such biological deodorization apparatus 10 may be installed indoors or outdoors, and when installed outdoors, the biofilter 21 in the housing H is prevented from entering the rain and being exposed to direct sunlight as necessary. Therefore, a roof such as a tent place for covering the housing H may be provided above the water spray pipe 31. The housing H may be a buried type in the ground.

In addition, the biological deodorization apparatus 10 of this Embodiment has desirable computer control.
If only main information management is taken up, for example, information on the amount of sending and the sending pressure of the blower 5 is detected and input to the computer COMP. In addition, information on the pressure on the air discharge side on the biofilter 21 and the internal temperature of the biofilter 21 is detected by the sensor and input to the computer COMP. Furthermore, the computer COMP receives and manages information on the moisture content of the wood chip 21 measured artificially, and the amount of water sprayed by the watering means 30 is determined based on the information. Further, the amount of water in the water receiving unit 41 is also detected, and the amount of water from the water guiding unit 44 is determined based on the amount of water sprayed by the sprinkling means 30 and used as an input to the computer COMP. The drive of the pump, valve, flow meter for pumping the water stored in the water receiving part 41 to the sprinkling means 30, and the valve disposed in the water guiding part 44 for taking in water from the outside are controlled by the computer COMP. Thus, the amount of water sprayed from the water spraying means 30 can be adjusted. Usually, the watering pump is controlled by a timer. Further, the odor concentration is detected by the sensor above the biofilter 21 and input to the computer COMP. The pressure, temperature, odor concentration, etc. of the odor gas G may be detected at the entrance where the odor gas G is introduced into the biological deodorization apparatus 10 and input to the computer COMP.

Thus, the information on the moisture content of the wood chip 21A is mainly used for the watering amount of the watering means 30, that is, the drive control of the pump and the valve. In addition, the pressure on the air discharge side on the biofilter 21 and the information on the sending amount and sending pressure of the blower 5 are mainly used for controlling the blower 5. These information, including odor concentration information, can be controlled and managed as schedule management information by the monitor, and can be used for proof of conformity to local government regulations, leaving a processing record. In addition, the chemical deodorizing apparatus 3 and the scrubber apparatus 4 in FIG. 1 are also monitored and operated independently.
Moreover, when the filling height h of the wood chip 21A falls below a predetermined amount by visual monitoring, a new predetermined wood chip 21A is replenished.
Furthermore, the pressure loss calculated from the sending pressure of the blower 5 and the jet pressure on the biofilter 21 is managed, and when the pressure loss exceeds a predetermined amount, the sending amount and sending pressure of the blower 5 are controlled. Further, when the size of the wood chip 21A is visually monitored, if fine particles increase and the pressure loss increases, sieving is performed to eliminate the fine particles, and a new wood chip 21A is replenished. To do.

Hereinafter, the example which actualized biological deodorizing device 10 of this embodiment is described.
In this embodiment, as shown in FIG. 3, a support leg 23 is erected on the bottom of a concrete housing H for odor gas G generated in composting facilities such as household waste and municipal waste. Further, a flooring 22 having an opening in the range of 20 mm to 100 mm and an opening ratio in the range of 5 to 95% is installed on the flooring 22. A wood chip 21b having a length in the direction of 350 mm to 700 mm, a tangential width of the wood in the range of 10 mm to 80 mm, and a radial thickness of the wood in the range of 5 mm to 50 mm is laid. Then, for example, the length in the fiber direction of the wood is in the range of 10 mm to 300 mm, the width in the tangential direction of the wood is in the range of 5 mm to 30 mm, and the thickness in the radial direction of the wood is 4 mm to 10 mm. Is in 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 portion of the housing H and the bottom surface of the flooring 22 is set to, for example, 10 cm to 50 cm, preferably 20 cm to 40 cm, and the coarse wood chip 21b is filled with 10% or less of the volume of the fine wood chip 21a. Is done.
In composting facilities such as household waste, municipal waste, etc., the waste treated there is not always a constant property, and various miscellaneous raw materials are fermented and decomposed every time. It is an odor, and its odor concentration and odor quality fluctuate. In addition, in a composting facility where compost is turned over, concentration fluctuations due to compost turnover also increase.

  At this time, in this embodiment, as shown in FIG. 7A, a plate-like shape having a protruding length within the range of 150 mm to 1000 mm, preferably within the range of 250 mm to 600 mm, on the flooring 22. The protruding wall 28 is installed at a predetermined height from the upper surface of the flooring 28 along the four side walls of the housing H, and a wood chip 21A of a predetermined size is placed in the space in the housing H provided with the protruding wall 28. Filled. That is, on the flooring 22, the side wall on the housing H side protrudes toward the biofilter 21 by the protruding wall 28.

As shown in FIG. 2, the bottom of the housing H is provided with an introduction port 24 for the odor gas G connected to the blower 5 through the introduction path 24a, and a water receiving section through the drainage path 42a. A discharge port 42 through which the excess water W ₁ connected to 41 and passing through the biofilter 21 and the flooring 22 is drained is provided.
The water receiving section 41 is connected to a water supply supply path 43 including a pipe connected to a water spray pipe 31 having a water spray nozzle 32 disposed above the housing H, and industrial water (industrial water, etc.) as necessary. ) For introducing water is connected. The sprinkling supply path 43 is provided with a valve and a pump, and the water guide 44 is also provided with a valve.
Table 5 shows the specifications and design of the biological deodorization apparatus 10 according to this example. In the present embodiment, the watering means 30 is intermittently operated, and watering was intermittently performed by a timer-controlled watering pump.

When designing the biological deodorization apparatus 10, the desired processing air volume (m ³ / min) and processing speed (mm / sec) are determined from the amount of odor gas G (source odor) generated in composting facilities such as municipal waste. The installation area (cross-sectional area) of the biofilter 21 that secures a predetermined processing capacity that does not exceed the load was determined based on the processing air volume (m ³ / min) and the processing speed (mm / sec). For example, the cross-sectional area, volume, and the like of the biofilter 21 are determined so that the odor gas G is 15 to 30 mm / second, more preferably 20 to 25 mm / second, in terms of apparent wind speed. The apparent speed is obtained by dividing the flow rate (mm ³ / sec) of the odor gas G to be processed by the cross-sectional area (mm ² ) of the biofilter 21.
Here, in order to ensure stable deodorization performance at a low cost for a long period of time, the present inventors further have a thickness of a layer of the biofilter 21 that is filled with wood chips 21A (wood chips 21a, wood chips 21b). That is, the filling height (stacking height) h of the wood chip 21A was investigated. About the filling height h of the biofilter 21, an experiment was performed with an initial setting of 1.0 to 3.5 m, and an evaluation test of the deodorizing effect was performed. The results at that time are shown in Table 6.

  The numerical values shown in Table 6 are also the results of sensory evaluation (average value) of odor by the above-mentioned 12 monitors. 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 deodorization apparatus 10 was started.

As shown in Table 6, when the filling height h of the wood chip 21A is 1.5 m or more and 3.0 m or less, the evaluation one month after the start of the introduction of the odor gas G is not concerned. It was (2), and the high deodorizing effect was maintained for a long period of time when it was not noticeable in the evaluation after 3 months, 1 year, 3 years later, or (1).
In particular, the sustainability of the high deodorizing effect was high when the filling height of the wood chip 21A was 2.0 m or more and 2.5 m or less.

On the other hand, if the filling height of the wood chip 21A is 1.4 m or less, it is an evaluation of an odor (3) or a strong odor (4) after 1 year, especially at 1.0 m or less. The deodorizing effect could not be obtained with the evaluation of always a strong smell (4) or a very smelly and strong smell (5).
This is because a sufficient amount of contact between the odor component of the odor gas G and the wood chip 21A was not obtained.

Moreover, even if the filling height h of the wood chip 21A was 3.5 m or more, it was an evaluation of the smell (3) to be worried after 3 months, and the sustainability of the deodorizing effect was lowered.
This is because the filling height h of the wood chip 21A is too high, the compaction is high in the lower part of the biofilter 21, and the odor gas G is liable to drift. This is thought to be because the amount of contact with the chip 21A is reduced, and the entire biofilter 21 is not uniformly and effectively used.

  Therefore, if the filling height h of the wood chip 21A constituting the biofilter 21 is a height in 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 chip 21A is in the range of 2.0 m to 2.5 m.

In the present embodiment, the bulk density when the wood chips 21A are filled is preferably in the range of 150 to 500 kg / m ³ . Thereby, clogging of the flow path (ventilation path) is difficult to occur, and the increase in pressure loss with time is small.

That is, if the bulk density is too high, the cost of blowing the odor gas G increases because the pressure loss is large. Moreover, since clogging is likely to occur and the odor gas G is drifted, sustainability of the deodorizing effect is lowered. 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 is reduced, so that the deodorizing effect is reduced. If the bulk density by the wood chip 21A is in the range of 150 to 500 Kg / m ³ , the pressure loss can be suppressed and the cost can be suppressed, and a high deodorizing effect can be maintained. A more preferable bulk density is in the range of 200 to 400 Kg / m ³ .

Therefore, in this embodiment, the initial filling height h of the wood chips 21A (wood chips 21a, 21b) constituting the biofilter 21 is set to 2.0 m.
In the experimental study by the present inventors, the wood chip 21A is shredded and reduced due to the consumption and metabolism of the wood chip 21A by microorganisms and the deterioration of the wood chip 21A, and the volume of the biofilter 21 is reduced over time. . When the initial filling height h is less than 1.7 m by use, the length in the fiber direction of the wood is newly within a range of 10 mm to 300 mm, for example, and the tangential direction of the wood The deodorizing effect is obtained by replenishing the wood chip 21a having a width of 5 to 30 mm and a thickness of 4 to 10 mm in the radial direction of the wood and recovering the filling height h to 2 m. It has been confirmed that a high deodorizing effect for a long period of 3 years or more can be maintained without reduction.

In this embodiment, the water content of the wood chip 21a is maintained at 150% or more and 300% or less by watering from the watering means 30.
In addition, about the moisture content of the wood chip | tip 21a, since the water retention amount also changes with the change of the humidity conditions of the circumference (atmosphere environment), and the fragmentation | decrease and reduction | decrease of the wood chip | tip 21a, the wood chip | tip 21a regularly The moisture content is measured, and the amount of water spray is adjusted so that the moisture content of the wood chip 21a is maintained at 150% or more and 300% or less.

  In the biological deodorization 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 having a predetermined volume at the bottom of the housing through the introduction path 42a by driving the blower 5. As it circulates, it rises into the biofilter 21 through the vent holes 22A of the flooring 22. Since it passes through the vent 22A of a predetermined diameter of the flooring 22 before being input to the biofilter 21, the odor gas G introduced from the introduction port 42 is rectified and input to the biofilter 21, and the odor The gas resistance of the gas G can be relaxed and the pressure loss can be suppressed.

At this time, the water content of the wood chip 21a of the biofilter 21 is maintained at 150% or more and 300% or less by watering from the watering means 30, and the inside of the biofilter 21 is maintained in a wet state. At the initial stage of startup of the apparatus, fresh water is taken into the water receiving section 41 from the water guiding section 44, and the water in the water receiving section 41 is pumped up to the sprinkling pipe 31 through the sprinkling supply passage 43 by the pump. The water is sprinkled on the biofilter 21. The surplus water W ₁ that has passed through the ventilation holes 22a of the biofilter 21 and the flooring 22 and reached the bottom of the housing H does not accumulate in a predetermined volume or more in the space S of a predetermined volume, and does not accumulate in a predetermined amount. Is collected by the water receiving part 41 through the drainage channel 42a. The water collected and stored in the water receiving unit 41 is pumped up from the water spray supply path 43 to the water spray pipe 31 by the pump at the timing of water spraying without being discharged to the outside, and is used again as water spray. At the timing of watering to maintain the moisture content of the wood chip 21a at 150% or more and 300% or less, the excess water W ₁ collected in the water receiving part 41 is pumped up to the watering pipe 31 and sprinkled. When the amount collected at 41 is small, water is replenished from the water guide section 44 as necessary. In particular, in this embodiment, the water used for watering is adjusted to 0/10 ≦: supplementary water W2 / circulating water W1 ≦ 12/7.

In the biofilter 21 maintained in a wet state by watering from the watering means 30, microorganisms are propagated and its activity is maintained by maintaining appropriate moisture in the wood chip 21 </ b> A.
In particular, the wood chip 21A, which is a natural resource, is an organic substance and has an excellent moisture retention function, so that it can be inoculated and planted with specific fungi by leaving it in an appropriate moisture and temperature environment, or a microbial active substance. Even if odor gas G is allowed to pass through without being added, microorganisms involved in the decomposition of the odor component immediately propagate and the biofilter 21 can exert its deodorizing function. And in such a wood chip 21A, there are many kinds of microorganisms from the beginning, or an environment in which various kinds of effective microorganisms that are directly or indirectly involved in decomposition of a plurality of kinds of odor components are liable to live. It is assumed that the biofilter 21 composed of the wood chip 21A has both an aerobic environment and an anaerobic environment. Microorganisms directly or indirectly involved in deodorization are not limited to aerobic microorganisms. It is speculated that sex microorganisms also contribute. In such a biofilter 21, microorganisms use (utilize) the components (polysaccharides, etc.) and odor components of the wood chip 21A as nutrients and energy sources, and the microorganisms propagate to form a biofilm. Yes. For example, nitrite bacteria, nitrifying bacteria, denitrifying bacteria, sulfur-oxidizing bacteria, other aerobic microorganisms, anaerobic microorganisms, etc. inhabit the wood chip 21A.

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

At this time, the odor components contained in the odor gas G include, for example, harmless substances such as carbon dioxide (CO ₂ ) and water (H ₂ O), inorganic ions such as SO ₄ ⁻ and NO ₃ ⁻ , sulfuric acid and nitric acid. It is decomposed into inorganic substances such as
For example, when attention is focused on typical ammonia as an odor component in the odor gas G, ammonia (NH ₃ ) is converted into NO ₂ (nitrite), NO by the nitrification action of aerobic microorganisms such as nitrite bacteria and nitrifying bacteria. ₃ Decomposed into nitrogen oxides (NOx) such as (nitrate form) and deodorized. Furthermore, it may be decomposed to N ₂ (nitrogen) or the like by denitrifying bacteria or anammox reaction.
Also, sulfur compounds (sulfides) such as hydrogen sulfide (H ₂ S) and methyl mercaptan, and odor components of organic acid compounds are oxidized by the action of aerobic microorganisms such as sulfur-oxidizing bacteria and other aerobic bacteria. It is decomposed to become oxides such as SO ₂ and sulfuric acid and deodorized.

In particular, the biological deodorization apparatus 10 of the present embodiment configured as described above has the following characteristics.
First, in the biological deodorization apparatus 10 of the present example, the pressure loss is 30 to 120 Pa at the initial stage of operation where the introduction of the odor gas G and the sprinkling are started, and the pressure rises over time, but after 3 years have passed. Even so, the pressure loss was suppressed to 200 Pa or less.
As a precaution, FIG. 5 shows the results of measuring the pressure loss over time. This pressure loss is obtained by measuring a differential pressure between the pressure (total pressure) of the blower 5 and the total pressure at the outlet from which air is discharged on the biofilter 21.

As shown in FIG. 5, the pressure loss is in the range of 0 to 200 mmH ₂ O even though the pressure loss varies depending on the season, the concentration of the odor source, etc., and the pressure loss increases remarkably with time. It is maintained with little pressure loss. The pressure loss is measured regardless of whether the watering means 30 that is intermittently operated is watered or stopped.

The increase in pressure loss due to use is small because the ventilation resistance is kept low by configuring the biofilter 21 with the wood chip 21a at a predetermined bulk density, and clogging (stenosis, blockage) is less likely to occur due to use. The excess water W ₁ that has passed through the biofilter 21 by the circulation means 40 is reused in the water spray that maintains the moisture content of the wood chips at 150% or more and 300% or less. This is because the accumulated biodegradation product 21 can be used efficiently because the accumulation of the decomposed products is not easily biased. In particular, in the biofilter 21 in which the wood chip 21a is filled with a predetermined bulk density, the ventilation resistance is low and the pressure loss is small, so that the water content of the wood chip 21a is set to 150% or more and 300% or less. Even if it increases, there is little influence on pressure loss, and the drift of the odor gas G does not easily occur even if it is used.

Moreover, in the biological deodorization apparatus 10 of a present Example, pH of the bio filter 21 was maintained in the range of 6.5-7.5. In particular, the water of the water receiving part 41 that collects and circulates the surplus water W ₁ from the biofilter 21 of the circulating water is also maintained in the neutral region, and the pH of the water used for the sprinkling 31 is adjusted, or the ion adsorbent Even if the odorous substance or decomposition product is adsorbed by the odorous substance reducing member such as the above, or the denitrification is performed, the biofilter 21 maintains the pH within the range of 6.5 to 7.5.

Here, when ammonia is contained in the odor gas G, in the biofill 21 in a wet state, ammonium is dissolved in water to become ammonium ions (NH ₄ ⁺ ), and these ammonium ions (NH ₄ ⁺ ) The water film covering the wood chip 21A is oxidatively decomposed into nitrite ions (NO ₂ ⁻ ) and nitrate ions (NO ₃ ⁻ ) by nitrification by ammonia-oxidizing bacteria and nitrite-oxidizing bacteria living in the wood chips 21A. At this time, the pH rises due to the presence of ammonium ions (NH ₄ ⁺ ) before nitrification, but when decomposition products of these nitrite ions (NO ₂ ⁻ ) and nitrate ions (NO ₃ ⁻ ) are generated, In general, the pH tends to become acidic as the concentration thereof increases. In particular, when watering is circulated, the pH tends to become acidic in a short period of time, and when the environment around the microorganisms in the biofilter 21 becomes acidic, only the activities of specific microorganisms and only specific odor components are removed. Prone to occur.

However, in the biological deodorization apparatus 10 of the present embodiment, even when the excess water W ₁ from the biofilter 21 is recovered and sprinkling is circulated, the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less. Due to the high water retention, the pH buffering action is high, and the decomposition proceeds without the accumulation of ammonium ions (NH ₄ ⁺ ) due to the circulation of watering. Furthermore, nitrite ions (NO ₂ ⁻ ) and nitrate ions (NO ₃ ^-) decomposition product is distributed load evenly in the biofilter 21 is not be locally concentrated in such. Further, it is diluted with supplementary water W _{2 as} necessary. For this reason, the pH is maintained in a neutral environment.

In particular, in the biofilter 21 filled with the wood chip 21a with a predetermined bulk density, the ventilation resistance is low and the pressure loss is small, so that the water content of the wood chip 21A is 150% or more and 300% or less. Even if it increases, there is little influence on pressure loss, and high water retention of the wood chip 21A and a thick water film around the wood chip 21 can be secured. Further, the housing H is constructed by collecting the surplus water W _{1 in} the high wet state of the biofilter 21 in which the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less and the space S having a predetermined volume at the bottom of the housing H. The moisture at the bottom is high, and the odor gas G introduced into the bottom of the housing H can be humidified. As a result, pH fluctuations can be reduced, and the concentration can be reduced even for high-concentration odors. In particular, in the deodorizing apparatus 10 of this example, it seems that nitrification and ammonia introduction are balanced.

  And according to the deodorizing apparatus 10 of a present Example, the activity of the microorganism species which can respond to decomposition | disassembly of various odor components can be maintained by maintaining pH in a neutral range in this way. That is, the environment in which the pH is neutral is suitable for the growth environment of microorganisms that are advantageous for dealing with various odorous compounds. Therefore, stable deodorization performance can be exhibited for a long period of time against the odor gas G in which the odor concentration and odor quality fluctuate. In particular, according to the deodorizing apparatus 10 of the present embodiment, even when circulating water is circulated, the decrease in pH is suppressed, and the microorganism group that grows in a neutral environment can remove a large number of odorous compounds. Stable deodorization performance can be maintained for a long period of time without deteriorating the treatment capacity even for the odor gas G whose quality varies.

According to the biological deodorizing apparatus 10 of this example, the biofilter efficiency (%) calculated by the following formula (B) indicating the deodorizing effect is 90 to 95%, and after 3 years or more have passed. A deodorization efficiency of 90 to 95% is obtained.
Biofilter efficiency (BFE) (%)
= 100 x (IOC-EOC) / IOC (B)
IOC: Odor concentration in the introduction side air (odder unit; OU _E )
EOC: Odor concentration of exhaust air (odder unit; OU _E )

For example, when the introduction-side air has an odor concentration of 2500 to 6000 order units, the discharge-side air after passing through the biofilter 21 of the biological deodorization apparatus 10 of this embodiment has an average odor concentration of 200 to 450 order units. It has been confirmed that
However, even when odorless air is introduced, due to the smell of the wood chip 21A itself of the biofilter 21, the air on the discharge side does not become lower than the odor concentration of 150 order units. Further, in the air on the discharge side, even if the odor concentration is on the order of 200 to 450 order units, the odor quality is greatly improved by the action of the biofilter 21 compared with the source odor of the odor gas G on the introduction side. .

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

Moreover, according to the biological deodorization apparatus 10 of the present embodiment, when the ammonia concentration is measured on the output side where the odor gas G passes through the biofilter 21, the odor gas G is measured within a few days after the introduction of the odor. It was suppressed to an ammonia concentration of ˜2 mg / Nm ³ and was kept below that value even after 3 years. In aerobic fermentation treatment in composting facilities (fermentation treatment facilities) such as municipal waste, aldehydes, terpenes, VAF, etc. are problematic as odor-causing substances, but they are also highly deodorized against such odors. The effect has been confirmed, and the deodorizing effect lasted for more than 3 years.
In particular, the biological deodorization apparatus 10 configured according to the specifications shown in Table 5 has a high deodorization effect that lasts for 3 years or more without the treatment of the chemical deodorization apparatus 3 or the acid scrubber treatment by the scrubber apparatus 4 in the previous stage. Is obtained.

Furthermore, according to the biological deodorization apparatus 10 of the present embodiment, the deodorization function is not deteriorated due to the temperature change of the surrounding (environmental atmosphere) due to the seasonal change, and the high deodorization function is maintained throughout the year regardless of the ambient temperature change. It was.
Here, paying attention to the temperature of the biofilter 21, as shown in FIG. 6, the temperature of the intermediate layer of the biofilter 21 is measured over time (measured by a thermocouple). Even in the winter when the ambient temperature is 0 ° C, the odor gas G is introduced at 12 ° C or higher, and even in the summer when the ambient temperature is 40 ° C, it can be kept below 45 ° C by watering. Met.

  In particular, in midsummer, when the surface (upper layer) temperature of the biofilter 21 is measured by infrared thermography, there are some places where the odor gas G exhausts partially exceeds 50 ° C., but the temperature is low at about 20 ° C. It was maintained. In the 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 spray and water content are maintained at 150% or more and 300% or less.

On the other hand, in winter, the moisture content of the wood chip 21A is introduced into the space S of a predetermined volume by collecting the excess water W ₁ at the bottom of the biofilter 21 and the high humidity of the biofilter 21 maintained at 150% or more and 300% or less. Since the odor gas G can be humidified, even when the odor gas G passes through the biofilter 21, the latent heat of the biofilter 21 is difficult to be removed, and the temperature drop of the biofilter 21 can be suppressed. That is, in winter, relatively dry odor gas G is sent from the composting apparatus 2, and such odor gas G tends to take latent heat from the biofilter 21 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 the biofilter 21 consists of the wood chip | tip 21A, the humidity fluctuation | variation in the housing H may be suppressed by the humidity control characteristic of wood. In winter, due to the low temperature of the ambient temperature, the concentration of odor generated from the composting apparatus 2 is relatively small and the load applied to the biofilter 21 is relatively small. Therefore, even if the temperature of the biofilter 21 is somewhat decreased. The deodorizing effect can be maintained.

  Thus, according to the biological deodorization apparatus 10 of the present embodiment, the temperature of the biofilter 21 does not significantly decrease compared to the ambient temperature, and high deodorization performance is stable even if the ambient temperature varies. It was maintained. That is, even if no heating or cooling means is provided, there is little variation in processing capacity due to the ambient temperature, and stable deodorization performance is maintained, so that the cost can be reduced.

However, when practicing the present invention, the housing H, the water spraying means 30, and the drainage provided in the lower part of the housing H in order to ensure a very stable treatment capacity that is not affected by the influence of the ambient temperature. From the structure of the supply path from the outlet 42a to the water receiving part 41 via the drainage path 42 and the output of the water receiving part 41 and the water receiving part 41 to the input of the watering means 30 via the watering supply path 43 A heating or cooling means may be provided in the circulation path to control and adjust the temperature of the biofilter 21 and the water temperature of the water spray.
When the temperature of the biofilter 21 exceeds 45 ° C. depending on the installation location or the like, the temperature can be suppressed to 45 ° C. or less by increasing the amount of water sprayed, 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 within the range of 10-55 degreeC.

  In addition, according to the biological deodorization apparatus 10 of the present embodiment, the composting apparatus 2 is in a dormant state of, for example, 1 to 2 weeks, and air from the composting apparatus 2 is continuously supplied to the biological deodorization apparatus 10 by the blower 5. Even when the housing H is continuously ventilated and the odor gas G is not present, microorganisms can grow using the wood chip 21A as a nutrient source. After that, even when the fermentation / decomposition process is resumed by the composting apparatus 2, the microorganisms of the wood chip 21A immediately start to decompose the odor components in the odor gas G, and an environment is formed in which the microorganisms are not killed. The deodorizing ability of the filter 21 is maintained. Therefore, the deodorizing effect can be sustained for a long time with low maintenance costs and running costs.

In the experimental research conducted by the present inventors, after 3 to 4 years from the operation of the biological deodorizing apparatus 10, the wood chip 21 </ b> A shredded and reduced due to consumption, metabolism, and deterioration of the wood chip 21 by microorganisms. When the pressure loss exceeds 200 Pa due to the accumulation of the slag, the timber chips 21A passing through the sieve having a mesh size of 10 mm, for example, are removed by sieving the wood chips 21A forming the biofilter 21, and the biofilter 21 Until the filling height h becomes 2 m, for example, the length of the wood in the fiber direction is within the range of 10 mm to 300 mm, the width of the tangential direction of the wood is within the range of 5 mm to 30 mm, The wood chip 21a having a radial thickness in the range of 4 mm to 10 mm is replenished. If necessary, coarse wood chips 21b between the wood chips 21a and the flooring 22 are replenished. This confirms that a high deodorizing effect lasts for a longer period of time. Thus, by removing the wood chip 21A and replenishing the wood chip 21A, it is possible to maintain the deodorizing effect semi-permanently at a low cost without adding a predetermined fungus or a microbial active substance.
In addition, when the pH becomes less than 4.5 due to the quality of the source odor, the pH is recovered to 6.5 or more by temporarily increasing the ratio of the replenishing water W ₂ and increasing the amount of water spray. It is possible to maintain the deodorizing performance.

  In the biological deodorization apparatus 10 of the present embodiment, the pressure loss does not increase excessively even by watering from the watering means 30, so that the water can be removed by the biofilter 21 during watering without temporarily interrupting the blower 5 during watering. Will not be lifted. That is, by configuring the biofilter 21 with the wood chips 21A deposited with a predetermined bulk density, the water spray easily passes below the biofilter 21, and the water content is maintained at 150% or more and 300% or less. Even if the amount of water sprayed is, the sprinkled water will not hold up and cause a sudden increase in pressure loss. Therefore, maintenance is easy, the cost is low, and the processing efficiency is good due to the continuous operation of the blower 5. In addition, even when the direction of introducing the odor gas G and the direction of water spraying are faced (counterflowed) in this way, the water does not blow up, and thus high processing capacity is obtained at low cost.

As described above, the biological deodorization apparatus 10 according to the present embodiment is filled with the wood chips 21A within the range of the bulk density of 150 to 500 kg / m ³ , and the water content of the upper layer wood chips 21A by watering. Has a biofilter 21 that is maintained at 150% or more and 300% or less, and the odor gas G introduced from below the biofilter 21 is digested by biological treatment by the biofilter 21 and released above the biofilter 21. The treatment means 20, the sprinkling means 30 that sprinkles water from above the biofilter 21, and the circulation means 40 that collects surplus water that has passed through the biofilter 21 and circulates it to the sprinkling water are provided.
In addition, the circulation means 40 of this Embodiment is the discharge path which inputs into the water receiving part 41 from the drain port 42a provided in the lower part of the housing H via the drainage path 42, the water receiving part 41, and the water receiving part 41 This is a configuration of the supply path from the output to the input of the watering means 30 through the watering supply path 43.

Thus, in the biological deodorization method according to the present embodiment, water is sprayed from above on the biofilter 21 that is filled with the wood chip 21A within the range of the bulk density of 150 to 500 kg / m ^3. The surplus water that has passed through is circulated as water spray, and the odor gas G is digested by biological treatment by the biofilter 21 by supplying the odor gas G from below the biofilter 21.

In addition, the biological deodorization method according to the present embodiment includes a biofilter 21 that is filled with wood chips 21A, a flooring 22 that has a large number of ventilation holes 22a and is disposed below the biofilter 21, and a floor. A housing H having a material 22 and a biofilter 21 disposed thereon and having an introduction port 24a into which an odor gas G is introduced below; a watering means 30 for sprinkling the biofilter 21 from above; Circulating means 40 for collecting and circulating the surplus water that has passed through the filter 21 is measured, and the weight (pre-drying weight) of the wood chip 21 containing moisture is measured by the watering, and the moisture is removed by drying it. When the weight (total dry weight) of the wood chip 21 in the state of not containing was measured, the moisture content (%) = (weight before drying−total dry weight) / total dry weight × 10
The odor gas G introduced from the inlet 24a below the housing H in the state where the moisture content of the wood chip 21 containing water by the watering calculated as follows is maintained at 150% or more and 300% or less is used as the floor material 22. It is made to distribute | circulate to the biofilter 21 from the ventilation hole 22a, is digested by the biological process by the biofilter 21, and discharge | releases above the biofilter 2. FIG.

According to the biological deodorizing apparatus 10 according to the present embodiment configured as described above, the biofilter is formed by the wood chip 21A that is deposited with a predetermined bulk density by selecting the size of the wood chip A and setting the predetermined deposition height. By configuring 21, the ventilation resistance is kept low, and the surplus water that has passed through the biofilter 21 by the circulation means is reused to sprinkle the water content of the wood chip 21 </ b> A at 150% or more and 300% or less. This makes it difficult for the distribution of microorganisms and the accumulation of degradation products caused by the decomposition of microorganisms to be biased.
That is, since the sprinkling is circulated, the microorganisms and degradation products are moved from the top to the bottom, and the microorganisms and degradation products are displaced in the biofilter 21, so that the load is not concentrated locally and the biofilter 21 is not concentrated. Can be processed efficiently as a whole.

Therefore, clogging (stenosis, blockage) 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 crystals such as salts generated by decomposition of odor components are difficult to adhere to the wood chip 21A whose water content is maintained at 150% or more and 300% or less by circulation of water spray.
In other words, even if the amount of microorganisms is large or the decomposition products of odor components increase, the microorganisms and decomposition products do not stay in a certain place due to the circulation of watering. Clogging (stenosis, occlusion) is unlikely to occur.

As a result, a drift in which the path of the odor gas G is limited in the biofilter 21 and a short path through a specific path are less likely to occur, and the entire biofilter 21 is uniformly and effectively used for digestion of the odor gas G. High deodorization performance can be maintained for a long time.
And since the pressure loss is small, it is suitable for the odor gas G with a large air volume, and the odor gas G can be digested with low cost and high processing efficiency.

  In particular, due to the high water retention of the wood chip 21A that maintains the water content at 150% or more and 300% or less, it is difficult for the pH to decrease due to continued use, and the pH can be maintained in a neutral environment. For this reason, microbial species capable of coping with the degradation of various odors and even high-concentration odors are easily activated.

In addition, due to the characteristics of the wood that maintains the water content at 150% or more and 300% or less, it is possible to inoculate and inoculate specific fungi, without the addition of microbial active substances, by the action of natural and natural microorganisms, Immediately microbial species that can cope with odor decomposition will propagate.
In particular, it is an environment in which microbial species capable of coping with the decomposition of various odors are easy to grow and act depending on the characteristics of wood, and an environment in which the microbial species capable of coping with the decomposition of various odors can be created. It is possible to construct a microbial environment that can follow changes in odor quality and odor concentration.
Furthermore, the effective microbial group and microbial activity are easily maintained by circulating the water spray.

In addition, since the biofilter 21 is made of the wood chip 21A, the humidity control characteristics of the wood may prevent the humidity fluctuation of the biofilter 21 and contribute to the maintenance of the optimal humidity environment of microorganisms and the mitigation of pH fluctuation. There is also. In other words, the moisture conditions are suitable for the activity of microorganisms due to the characteristics of the wood.
In addition, since the wood chip 21A is organic, even if the odor gas G is not sent continuously, or even if the odor at a very low concentration is continuous, the microorganism activity is maintained well without the microorganisms being killed. The

  In other words, because the biofilter 21 is composed of the wood chip 21A that maintains a predetermined moisture content, and the water spray is circulated, it is an optimum environment for the growth of microorganism groups that can cope with various odors. Therefore, it is not specialized for a specific odor component and can cope with odor fluctuation.

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

  In particular, wood chips 21A that can be maintained at a moisture content of 150% or more and 300% or less are filled with a predetermined bulk density, and since water spray is circulated, clogging is unlikely to occur. Water is easily distributed evenly throughout, and there is little bias to microorganisms. That is, since the biofilter 21 is configured by the wood chips 21 a that are filled with a predetermined bulk density, water sprayed easily passes below the biofilter 21. Therefore, the entire biofilter 21 is effectively used, and the odor component is easily dissolved and trapped in the water film around the wood chip 21A and is effectively decomposed by microorganisms. Therefore, it has high deodorizing efficiency.

Furthermore, the moisture characteristics (high water retention, thick water film around the wood chip 21A) of the biofilter 21 in which the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less, and the surroundings of the wood chip 21A by circulation of water spray Due to the change of water, the fluctuation of pH and the concentration of decomposed products are buffered. Therefore, even if the surplus water W ₁ that has passed through the biofilter 21 by the circulation means is reused for sprinkling, the activity of microorganisms is reduced and the activity of microorganisms is reduced. Decline is unlikely to occur.

In other words, the highly humid state of the biofilter 21 is highly adaptable to fluctuations in odor concentration, and also has high ease of pH fluctuation, maintaining the environment in which microbial species that can cope with the decomposition of various odors and the activity of microorganisms are maintained. Is done.
Therefore, stable deodorization performance can be maintained for a long time even if the odor concentration or odor quality to be introduced varies.

In addition, in the present embodiment, the surplus water W ₁ reaches the high wet state of the biofilter 21 in which the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less and the space S having a predetermined volume at the bottom of the housing H. According to the configuration, the humidity at the bottom of the housing H is high, and the odor gas G introduced into the bottom of the housing H can be humidified. Therefore, the mitigation effect with respect to the odor concentration fluctuation can be enhanced. Also, the thick water film around the wood chip 21 can alleviate fluctuations in odor concentration. Furthermore, when the moisture of the odor gas G is high, it contributes to the uniform distribution of the moisture content of the biofilter 21. Therefore, it is possible to cope with fluctuations in odor concentration without taking measures to dilute the odor with air or extremely reduce the apparent wind speed.

  If the odor gas G introduced to the bottom of the housing H can be humidified, even when the ambient temperature in winter is low, the odor gas G hardly captures the latent heat of the biofilter 21 and thus prevents the temperature of the biofilter 21 from decreasing. it can. In addition, when the ambient temperature in summer is high, the biofilter 21 is heated by the heat of vaporization due to the high humidity of the odor gas G and the high moisture state of the biofilter 21 in which the moisture content of the wood chip 21A is maintained at 150% or more and 300% or less. It is possible to suppress the temperature rise. Therefore, it is possible to follow changes in ambient temperature, there is little variation in deodorization performance, and high deodorization performance can be exhibited stably.

  Furthermore, the wood chip 21A is filled with a predetermined bulk density by selecting the size of the wood chip 21A to form 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. Thus, the ventilation resistance is kept low 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 chip 21A can be obtained at a low cost, and the biofilter 21 composed of the wood chip 21A filled with a predetermined bulk density has a small pressure loss and can secure a high throughput even though it is small due to its high processing capacity. The volume is small.
And the high water retention of the biofilter 21 that maintains the moisture content of the wood chip 21A at 150% or more and 300% or less, that is, the thick water film around the wood chip 21 and the moisture around the wood chip 21A by circulation of water spray Since the pH and decomposed products are buffered by the transition, there is no need to provide means for controlling the pH and decomposed products of the circulating water or the amount of odorous gas introduced. Is also easy.
By circulating the watering, the cost for watering can be reduced. Further, the maintenance frequency such as switching of the biofilter 21 and replacement of the wood chip 21A can be reduced.
Therefore, the material cost, equipment cost, and running cost can be suppressed, and the cost can be reduced.

  In this way, the biodeodorization apparatus 10 can maintain a stable deodorization performance at a low cost for a long period of time even with respect to a odor gas having a complex odor accompanied by fluctuations in odor concentration and odor quality.

And according to the biological deodorization apparatus 10 which concerns on this Embodiment, by comprising the biofilter 21 with the wood chip 21A of the specific size which maintains a moisture content to 150% or more and 300% or less, from the characteristic of the wood By the action of natural and natural microorganisms, microbial species that can immediately cope with odor decomposition can be propagated and can cope with deodorization of various odors. Therefore, it is not limited to odors generated from composting facilities such as household waste, municipal waste, etc., but sewage and sewage that produce livestock and treat livestock excrement, poultry farming and livestock facilities, organic sludge, etc. Sustainability of high deodorizing effect can be exerted against odors generated from wastewater treatment facilities, agricultural settlement wastewater treatment facilities, food factory wastewater treatment facilities, and the like. In other words, it is a deodorization technique that is not specialized for a specific odor component, and can be applied to fluctuations in odor.

  Moreover, according to the biological deodorizing apparatus 10 according to the present embodiment, the odor gas is generated by the flooring 22 having the vent hole 22A having an opening within a range of 20 mm to 100 mm within an opening ratio of 5 to 95%. Since G can be rectified, the processing efficiency of the odor gas G can be increased. Further, the pressure loss of the odor gas G can be reduced, and the load due to the fluctuation of the odor amount can be reduced.

  Furthermore, according to the biological deodorization apparatus 10 according to the above embodiment, on the flooring 22, for example, the length in the fiber direction of the wood is in the range of 350 mm to 700 mm, and the width in the tangential direction of the wood is 10 mm to After laying the wood chip 21b within the range of 80 mm and the radial thickness of the wood within the range of 5 mm to 50 mm, the length of the wood in the fiber direction is, for example, within the range of 10 mm to 300 mm. And the wood chip 21a in which 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 is filled, the length of the wood in the fiber direction The wood chip 21a having a thickness in the range of 10 mm to 300 mm, a tangential width of the wood in the range of 5 mm to 30 mm, and a radial thickness of the wood in the range of 4 mm to 10 mm is filled. Then, the biofilter 21 is configured with a predetermined bulk density, and does not block the vent hole 22A having a predetermined diameter of the flooring 22 and is introduced from the lower side of the housing H through the introduction port 24a to the flooring 22 The rectifying effect that makes the flow of the odorous gas G that passes through the vent hole 22A and is input to the biofilter H more smooth is exhibited. And the ventilation resistance of the odor gas G can be eased and the pressure loss can be eased. Therefore, processing efficiency can be increased.

  In addition, in the biological deodorization apparatus 10 according to the present embodiment, the protruding wall 28 is provided along the side wall of the housing H above or below the position of the flooring 22, and the side wall on the housing H side has a predetermined protruding length. By projecting inwardly, it is possible to block the odor transmitted along the side wall of the housing H and suppress the odor leakage along the side wall of the housing H. Moreover, 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 increased. For example, as shown in FIGS. 4 and 7A, the inner wall of the housing H itself is formed in a protruding shape toward the side surface of the biofilter 21, or a plate is formed between the housing H and the biofilter 21. By installing another member (projecting wall 28) such as a shape, the side wall on the housing H side protrudes from the position of the floor material 22 toward the side surface of the biofilter 21. Further, as shown in FIG. 7 (b), the inner wall on the housing H side is provided by installing a protruding structure of the inner wall of the housing H itself or a separate member (projecting wall 28) such as a plate shape below the position of the floor material 22. Projecting inward of the housing H. As a result, it is possible to block the odor transmitted along the side wall of the housing H and suppress the odor leakage along the side wall of the housing H.

Moreover, according to the biological deodorizing apparatus 10 according to the above embodiment, the water sprayed on the biofilter 21 is 36% by volume or more of the surplus water W ₁ that has passed through the biofilter 21 and 64% by volume of water replenished from the outside. By setting it as the following, it is low-cost and can maintain a higher deodorizing capability.

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

In addition, when implementing this invention, the design and specification of the biological deodorizing apparatus 10 are not limited to the said Example. The volume of the biofilter 21 is determined by using the apparent speed, the load characteristics of the biofilter 21, the linear velocity, etc., as parameters in accordance with the requirements for the type, concentration, removal rate, processing air volume, etc. of the target odor gas G. , 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. If the pressure loss increases too much, the cost increases and the processing efficiency decreases due to the drift of the odor gas G. In addition, it is desirable that the pressure loss be maintained within a range of 0 to ₂₀₀ mmH ₂ O.

  In the case of carrying out the present invention, the configuration of the flooring 22 is not limited to the above. For example, a pipe line provided with a vent hole 22A having a predetermined diameter is embedded in the bottom of the housing H or formed at a predetermined interval. It is also possible to form the flooring 22 by placing a sleeve in the hole and burying a pipe line provided with a vent hole 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 a structure which connects to the several fermenter of composting facilities, and uses the specific inlet 24 among several inlets 24 with the fermenter made into the object of deodorizing. That is, it is good also as a structure which selectively uses the some inlet 24 selectively by control. Further, the water receiving portion 41 may be provided at the bottom of the housing H.

In the biological deodorization method of the above embodiment, a biofilter for digesting odor gas by biological treatment is constituted by a wood chip, and a large number of passages are provided in a housing having an inlet to which odor gas is introduced below. A floor material having pores is accommodated, and the wood chip is filled thereon, and the water content of the wood chip is maintained at 150% or more and 300% or less by watering from above the biofilter by watering means. Is. Moreover, the water sprinkled by the water sprinkling means is circulated by collecting surplus water that has passed through the biofilter by the circulation means and supplying it to the water sprinkling means.

The biofilter is formed by filling wood chips, and digests odorous gas by biological treatment.
Here, digestion by the above biological treatment means that the odor component in the odor gas is decomposed and deodorized by the enzymatic action of microorganisms.
In addition, the above wood chips are made of raw wood (trunks, whole trees, shrubs, end trees, branches, pruned branches, root stocks, etc.), lumber (backboards, end materials, peeled cores, etc.), building demolition materials, building materials, packaging materials, Plywood, laminated timber, particle board, waste pallet, etc. are cut or crushed by chipper, shredder, mill, crusher, hammer, punching, etc. to obtain a piece of wood, which is sieved to select a predetermined size.

The present inventors have conducted extensive experimental research on biofilters that can stably exhibit long-term deodorization performance against odor gas of complex odors accompanied by changes in odor concentration and odor quality, and can be configured at low cost. As a result, it has been found that by configuring a biofilter with wood chips, the ability to follow complex odors with odor concentration and odor quality is high, and the deodorizing effect can be stably maintained over a long period of time. It was.
In particular, biofilters made of wood chips are highly followable to odor gas of complex odors with fluctuations in odor concentration and odor quality by controlling a predetermined moisture content, and stable and high for a long period of time. It has been found that the deodorizing effect is maintained, and the inventors' experiments have specified that the water content is maintained at 150% or more and 300% or less by watering. In other words, by maintaining the moisture content of wood chips at 150% or more and 300% or less by watering, a high treatment capacity is obtained due to the high water retention characteristics of the wood chips, and the odor of a complex odor accompanied by fluctuations in odor concentration and odor quality The high deodorizing effect for a long period of time can be stably exhibited by the high water retention property of the wood chip against gas.
The moisture content of the wood chip represents the ratio of the moisture weight to the weight of the wood chip not containing moisture (total dry weight, dry base), and is calculated by the following formula (A).
  Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100 (A)
The total dry weight is a value obtained by drying at 105 ° C. until there is no change in weight.

The housing is formed of at least three surfaces including a lower surface and left and right side surfaces, and accommodates a flooring and a biofilter thereon. Below that, there is provided an inlet for introducing odor gas, so that the odor gas introduced does not leak outside. On the other hand, the odor gas introduced from the lower introduction port rises, passes through the flooring and the biofilter disposed thereon, and is discharged from the upper surface 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 even if the upper surface is formed, a vent opening is provided, and the vent is released from the biofilter. The air may be released into the atmosphere.
In addition, since the water spray is circulated, surplus water for the water spray is usually located below the housing in order to collect the water that has passed through the biofilter and the flooring and has reached the bottom of the housing and circulate it to the water spray means. A drain outlet is also provided.

Further, the floor material is housed 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, that is, It is arrange | positioned in the said housing at predetermined intervals between the bottom parts of the said housing. Accordingly, the wood chips are loaded on the floor material in the housing. The flooring is an arrangement that defines a space of a predetermined volume that communicates with the introduction port of the housing through which odorous gas is introduced, and the flooring is provided with a number of ventilation holes penetrating vertically. Therefore, the odor gas introduced from the introduction port below the housing is circulated through the entire area of the bottom surface of the biofilter through a predetermined volume of space, and then is input to the biofilter through the vent hole of the flooring material. It will be.

And it is preferable that the said flooring material has the opening of the said ventilation hole in the range of 20 mm-100 mm, and the opening rate is in the range of 5% or more and 95% or less.
According to the experiments by the present inventors, the floor loss placed in the lower part of the biofilter formed by filling the above-mentioned predetermined size wood chips is controlled by controlling the size and density of the air holes, and the fluid loss generated there Is set to the minimum, and even if there are fluctuations and variations in the amount of odorous gas introduced, it is possible to prevent the load from being applied by the prescribed fluid resistance. It is a thing.
Here, the opening and the aperture ratio represent the size and density of the vent holes of the flooring. The mesh opening also indicates, for example, the vertical width or the lateral width of an opening (space) per mesh formed by intersecting vertical and horizontal lines such as a mesh shape. If it is a square, it corresponds to one side of the square. The shape of the vent hole is not specified to be circular or square, but it is a shape with low air resistance and a large surface area. A hole is preferred.
The opening and opening ratio of the flooring material are measured in accordance with the sieve wire mesh standard. The floor area of the flooring material is S, the number of flooring meshes is M, and the diameters of vertical and horizontal lines are d. The aperture is calculated by the following formula (B), and the aperture ratio is calculated by the following formula (C).
Aperture A (mm) = S / M−d (B)
Opening ratio ε (%) = (A / A + d) ² × 100 ... (C)

The watering means supplies water to the biofilter accommodated in the housing by watering from above the opposite side of the odor gas introduction side. The water filter is moistened by this watering, and the moisture content of the wood chip is maintained at 150% or more and 300% or less. Watering may be intermittent or may be performed continuously.

The circulating means is water sprayed from above the biofilter and passed through the biofilter from the top to the bottom, that is, the water is not retained in the biofilter and flows down the housing through the floor vent. The surplus water is collected and supplied to the watering means to circulate the water. The surplus water that has passed through the biofilter may be collected at the lower part in the housing and stored there, or a separate water receiving part may be provided outside the housing and stored there.
In addition to the surplus water that has passed through the biofilter, the water for watering may be replenished with water from the outside.

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

As a result of accumulating earnest experimental research, the present inventors constituted a wood filter as a microbial carrier with a wood chip, and circulated water sprayed on the bio filter by a circulation means, thereby reducing the moisture content of the wood chip. By maintaining it at 150% or more and 300% or less, it is possible to quickly produce odorous components from microorganisms without seeding or planting microorganisms or adding microbial active substances for imparting microbial activity. It is possible to function as a biofilter that digests by a chemical process, and there is little increase in pressure loss over time, and it is highly followable to fluctuations in odor concentration and odor quality, and has a deodorizing effect over a long period of time. Based on this finding, the present invention has been completed.

That is, by configuring the biofilter with wood chips, the ventilation resistance can be kept low by selecting the size of the wood chips, the ventilation resistance can be kept low, and the water spray for maintaining the moisture content of the wood chips at a predetermined level. In addition, by reusing the water that has passed through the biofilter by the circulation means, microorganisms and degradation products (metabolites) generated by the decomposition of odors by the microorganisms are distributed in the biofilter without being biased.
Therefore, narrowing, blockage, and clogging of the ventilation path of the biofilter are unlikely to occur, and increase in pressure loss over time can be suppressed.

In particular, due to the characteristics of wood whose moisture content is maintained at 150% or more and 300% or less, microbial species that can cope with the decomposition of various odors are also easily propagated. In the biofilter composed of wood chips, the flow path can be widened by selecting the size thereof, and the water chips are uniformly distributed throughout the biofilter and the water content is maintained at 150% or more and 300% or less. Due to its high water retention, the effect of alleviating pH fluctuation is high. For this reason, it is hard to produce the fall of pH with time, and can maintain pH of neutral range.
Therefore, microbial species capable of coping with the degradation of various odors are easily activated and the activity can be maintained. In particular, even if the water that has passed through the biofilter by the circulation means is reused as water spray, the activity of microorganisms and the activity of microorganisms are hardly reduced. In addition, in the biofilter composed of wood chips whose moisture content is maintained at 150% or more and 300% or less, due to the water retention characteristics and high surface area of the wood chips, the gas of odor gas is easily dissolved in the liquid phase around the wood chips, Moreover, since the contact amount of a wood chip and odor gas is large, processing capacity is high. Furthermore, the pressure loss can be alleviated by the rectifying effect of a large number of ventilation holes in the floor material arranged below the biofilter, and the processing efficiency can be increased.
Therefore, stable deodorization performance can be maintained for a long time even if the odor concentration or odor quality to be introduced varies.

Furthermore, by configuring the biofilter with wood chips, the ventilation 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 over time. Running costs can be reduced.
Wood chips are also available at a low price. In addition, the biofilter made of wood chips whose moisture content is maintained at 150% or more and 300% or less has a high processing capacity and can suppress pressure loss. Therefore, the biofilter has a predetermined high throughput even with a small volume. Can be secured. And even if the water that has passed through the biofilter by the ring means is reused as sprinkling, the high water retention of the biofilter has a high buffering effect on pH fluctuations, so the degradation products generated by the decomposition of the pH and odor of the circulating water There is no need to provide means for controlling the amount of odor gas or the amount of odor gas introduced.
Therefore, material cost, equipment cost, and running cost can be suppressed, and the cost can be reduced.

DESCRIPTION OF SYMBOLS 10 Biological deodorizing apparatus 20 Deodorizing process part 21 Bio filter 21A Wood chip 24 Inlet 30 Watering means 40 Circulating means H Housing

Claims (2)

To biofilter made by Hama wood chips charged, watering from above, also the and the water passed through the biofilter was circulated as the sprinkler, and supplies the odorous gas from below the biofilter A biological deodorization method for digesting the odorous gas by biological treatment with the biofilter ,
The biofilter measures the weight (weight before drying) of the wood chips containing water by the watering, and further drys the wood chips and does not contain the water (total dry weight). When measuring
Moisture content (%) = (weight before drying−total dry weight) / total dry weight × 100
The water content of the wood chips containing water by the watering calculated as follows is maintained at 150% or more and 300% or less,
The thickness accumulation of the biofilter in the direction in which the odor gas passes from below to above is within a range of 1.5 m or more and 3 m or less,
The biofilter has a wood fiber length in the range of 10 mm to 300 mm, a tangential width of the wood in the range of 5 mm to 30 mm, and a radial thickness of the wood of 4 mm to 10 mm. The biological deodorization method characterized by depositing the said wood chip | tip which exists in the range, and having a bulk density in the range of 150-500 kg / m < ³ > . The water sprayed onto the biofilter is such that when the constant water spray amount per unit time is 100% by volume, the water that has passed through the biofilter is 36% by volume or more, and the water replenished from the outside is 64% by volume or less. The biological deodorization method according to claim 1 , wherein:

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