JP3410505B2 - Biological deodorizing method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for deodorizing malodorous gas containing odorous components such as sulfur and amines discharged from a sewage treatment plant, a human waste treatment plant, a rayon plant, a paper and pulp processing plant, and the like. More specifically, the present invention relates to a method for deodorizing a biologically malodorous gas by decomposing an odor component mainly by using microbial cells (hereinafter simply referred to as cells) in activated sludge and to the deodorizing apparatus. . The deodorization includes decomposition and removal of odor components and other components of organic substances and harmful substances discharged from a process using an organic solvent and other chemical substances.

[0002]

2. Description of the Related Art Conventionally, as a method for deodorizing the above-mentioned types of malodorous gas, a method in which activated carbon adsorption is combined with a cleaning treatment using a chemical such as an acid or an alkali solution is generally used. In the case of this type of deodorizing method, the amine-based odor components such as ammonia and trimethylamine are washed and neutralized with an aqueous acid solution such as hydrochloric acid and sulfuric acid, and the sulfur-based odor components such as hydrogen sulfide and methyl mercaptan are converted to alkaline. After being washed and oxidatively decomposed with an aqueous solution of sodium hypochlorite, the residual odor is removed by adsorbing it on activated carbon.

As shown in FIG. 14, the apparatus used in the above-mentioned conventional deodorizing method is provided with two towers, an acid washing tower 51 and an alkaline sodium hypochlorite washing tower 61, in that order. An activated carbon adsorption tower 71 is provided on the downstream side. As ancillary equipment, an acid storage tank 52 and a circulation tank 54 equipped with a pH meter 53 are connected to the acid washing tower 51, and an alkaline sodium hypochlorite washing tank 61 is connected to the alkaline sodium hypochlorite washing tank 61. 62, in addition to the alkaline solution storage tank 63, a circulation tank 6 for maintaining alkalinity
4. A pH meter 65 and a sodium hypochlorite concentration meter 66 are connected.

[0004]

However, the above-mentioned conventional deodorizing method or deodorizing apparatus has the following problems.

[0005] The use of powerful chemicals such as sulfuric acid and hydrochloric acid as an aqueous acid solution poses a high risk. In addition to the need for ancillary equipment for PH (pH) management and periodic maintenance, alkaline sodium hypochlorite is required. The running cost of the aqueous solution increases as the concentration of the sulfur-based substance increases, and if it exceeds 20 ppm, the cost is considerably increased. In addition, when sodium hypochlorite becomes acidic, it is decomposed into toxic chlorine gas, so that PH management and concentration management are required, and additional facilities and regular maintenance and management thereof are required.

[0006] Sodium hypochlorite reacts and is consumed by amine-based odor substances, and sodium hypochlorite decomposes spontaneously during washing and decomposes during reaction with amine-based odor substances and sulfur-based organic substances. The life of the activated carbon is very short because the chlorine or hypochlorous acid that is stripped off significantly reduces the life of the activated carbon.

When the acid comes in contact with sodium hypochlorite,
Since chlorine gas is generated, the storage tank must be individually managed by providing a dike, etc., and requires enormous maintenance including daily equipment management.

[0008] The present invention has been made in view of the above-mentioned point, and utilizes a microorganism that decomposes an odorous component inhabiting in activated sludge such as an aeration tank to decompose odorous components in an odorous gas. It is an object of the present invention to provide a biological deodorizing method and a deodorizing apparatus which can deodorize biologically, reduce running costs and greatly extend the life of activated carbon.

[0009]

In order to achieve the above-mentioned object, a biological deodorizing method of the present invention uses a large number of porous ceramic carriers of a predetermined shape containing calcium oxide and alumina in the middle of a path through which malodorous gas passes. After the microbial cells that decompose odor components (have a deodorizing effect) are implanted on the ceramic carrier, water is intermittently sprayed on the ceramic carrier, and the malodorous gas is introduced into the ceramic carrier. A biological deodorization method that deodorizes by passing through
Naturally, woven or non-woven fabric made of cellulose or synthetic fiber
Represents a large number of sponge-like carriers,
In the middle of the odor gas passage on the upstream side, and into the carrier,
After implantation of microbial cells that decompose odor components,
While spraying water intermittently or continuously on the carrier,
By passing the system's highly concentrated malodorous gas through the carrier.
Two routes for preliminary deodorization and gas introduction to both systems
The input volume is divided into a high ratio and a low ratio, and the high ratio side has a static pressure loss limit.
When the gas flow reaches the low
Switching the rate side to a high rate of gas introduction
Things .

[0010] As in the method of claim 2, the content of calcium oxide in the ceramic carrier is 2 to 50%, the content of alumina is 30% or less, and the water absorption is 30% or more.
The firing temperature of the ceramic carrier is preferably set to 800 to 1200 ° C. In addition, calcium oxide content is 2.5 to
42%, alumina content 7-25%, firing temperature 90
It is more preferable that the temperature is 0 to 1150 ° C. and the water absorption is 32% or more. When the ceramic carrier is specified by apparent porosity, it becomes 20 to 85%.

According to a third aspect of the present invention, at least one through hole is provided in the ceramic carrier, and the filling porosity of the ceramic carrier is 0.8 or less, more preferably 0.65 or less.
It is better to do the following. The shape of the ceramic carrier may be arbitrary as long as the filling porosity is satisfied.

According to a fourth aspect of the present invention, it is more preferable that the ceramic carrier is a gear-shaped column.

According to a fifth aspect of the present invention, the ceramic support is provided with a pore size of 0.4 to 100 μm and an occupancy of 50%.
It is desirable to set the occupation ratio of the pore diameter 4 to 20 μm to 2% or more.

[0014]

[0015]

[0016] In order to carry out the above deodorizing method, the deodorizing apparatus of the present invention (claim 6) is provided with a fixed bed in the middle of a malodorous gas passage in a deodorizing tower having an inlet and an outlet for malodorous gas,
The fixed bed is filled with a large number of porous ceramic carriers having a predetermined shape on which a microorganism cell containing calcium oxide and alumina and decomposing odor components is implanted, and above the ceramic carrier in the deodorization tower, Biological deodorizer with a sprinkler nozzle and a drain at the bottom of the deodorization tower
Having an inlet and an outlet for the odorous gas, and the odorous gas in the tower.
Decompose odorous components on a fixed bed
Natural cellulose or synthetic fiber for implantation of microbial cells
Of woven, non-woven or sponge-like carriers consisting of
Can be filled and static pressure loss can be measured across the fixed bed
Equipped with a pressure gauge, a watering nozzle above the carrier in the preliminary tower
And two spares, each with a drain at the bottom of the tower
Deodorization towers are installed on the upstream side of the deodorization tower, respectively,
The gas outlet of the preliminary deodorization tower and the gas inlet of the deodorization tower
High concentration malodorous gas mainly composed of sulfur, connected by piping
From the common source through the introduction pipe branched into two systems
Introducing malodorous gas into the gas inlet of each of the preliminary deodorization towers,
Each inlet pipe has a gas introduction ratio to each of the preliminary deodorization towers.
Electric damper that switches between control units
And a large amount in one of the two spare towers
Odorous gas is introduced, while a small amount of odorous gas is introduced.
Adjust the opening of each damper so that
One of the preliminary deodorization towers based on the static pressure loss
When the static pressure loss of
Switch the damper opening in the opposite direction
Is controlled.

As in the apparatus according to claim 7 , the content of calcium oxide in the ceramic carrier is set to 2 to 50% and the content of alumina to 30% or less, and at least one through hole is provided in the ceramic carrier. The filling porosity of the ceramic carrier is preferably 0.8 or less. It is more preferable that the filling porosity be 0.65 or less.

[0018]

[0019]

[0020]

[0021]

According to the biological deodorizing method of the present invention having the above-mentioned structure, the odorous component in the malodorous gas is decomposed by the microbial cells when the malodorous gas comes into contact with the cells immobilized on the porous ceramic carrier. It is deodorized. The cells adhered to the ceramic carrier maintain their activity by intermittent watering buffering action, and also decompose sulfur-based and amine-based odorous components to sulfuric acid,
An acid such as nitric acid is generated and retained on the ceramic carrier. When the amount of such acid increases, watering reduces the acidity and maintains the activity of the cells. In addition, there is a method of constantly spraying water. However, if water is constantly sprayed, the bacteria adhered to the ceramic carrier are peeled off and washed away, and the number of bacteria is significantly reduced (see FIG. 10). The calcium oxide contained in the ceramic carrier neutralizes the acid at the same time that the cells produce the acid, so that the activity of the cells is not affected, and the odor component is maintained at a high resolution. Alumina contained in the ceramic carrier also contributes to the adhesion of bacterial cells. Furthermore, since the ceramic carrier is porous and water-absorbing, intermittently sprayed water is retained on the ceramic carrier, and the activity of the cells is maintained. Furthermore, since the ceramic carrier is easy to process, it can be formed in any shape such as a gear shape. According to the biological deodorizing method of the present invention,
When the element concentration exceeds the limit load, the surface of the carrier such as sponge
Sulfur precipitates on the surface, increasing airflow resistance and causing odorous bacterial cells
Diffusion into the layer is inhibited, and high static pressure is at the high ratio side of the gas introduction volume
The deodorization efficiency decreases as the loss occurs (Tables 10 and 1).
At this time, the gas on the low ratio side and the gas on the high ratio side
By switching the introduction volume in the opposite direction, the carrier
Sulfur deposited on the surface reduces the amount of gas introduced and reduces load
As a result, the reaction of oxidizing sulfur to sulfuric acid progresses,
As a result, sulfur disappears completely within two or three days and returns to its original state.
Therefore, a high deodorization rate is maintained. In addition, natural cellulo
The sponge-like carrier made of base or synthetic fiber
Resistant to acid generated by cell decomposition
Excellent in stability and stable for a long time.
Dissolution is performed and preliminary deodorization is performed.

The biological deodorizing method according to claim 2, wherein the calcium oxide content of the ceramic carrier is 2 to 50%.
The reason is that if the amount is less than 2%, the adherence of the cells is poor, and conversely, 5%
When it is 0% or more, the alkaline strength becomes too large,
This is because it inhibits the attachment of bacterial cells (see FIG. 5). The reason for setting the alumina content to 30% or less is that adhesion of bacteria cannot be expected at 30% or more (see FIG. 6). The firing temperature of the ceramic carrier was set to 800 to 1200 ° C.
If the temperature is 800 ° C. or less, the ceramic carrier is too fragile to maintain the shape of the ceramic carrier. If the temperature is 1200 ° C. or more, the strength is increased, but the pore diameter becomes extremely small, and the adhesive ability is lost (see FIG. 7). The reason why the water absorption is set to 30% or more is that almost no adhesion occurs when the water absorption is 30% or less (see FIG. 8).

In the biological deodorizing method according to the third aspect, the through holes are provided in the ceramic carrier because the static pressure loss of the packed bed is lower than that without the through holes.
(See Table 2). In addition, the provision of the through-holes increases the microbial attachment area, thereby increasing the contact area with the odor component, and effectively decomposing the odor. Further, the filling porosity of the ceramic carrier is set to 0.8 or less because the filling porosity directly affects gas-solid contact efficiency, and the deodorizing efficiency starts to rapidly decrease at 0.65 or more, and becomes 0.8 or more. This makes it impossible to perform the deodorizing function (see FIG. 11).

In the biological deodorizing method according to the fourth aspect, the shape of the ceramic carrier is formed into a gear-shaped column. The comparison is made between a gear-shaped column, a cylinder, a triangular column, a quadrangular column, and a saddle. This is because the gear-type columnar shape had the best adhesion amount (see Table 1).

According to the biological deodorizing method of the fifth aspect, the deodorizing action is improved from the relationship between the pore size distribution (occupancy) and the amount of adhered cells.

[0026]

[0027]

According to the biological deodorizing apparatus of the present invention, the above-described biological deodorizing method of the present invention can be reliably performed. In particular, according to the biological deodorizing device of the present invention ,
Also certainly deodorizing when malodorous gas is highly concentrated, also a high concentration of malodorous gases of sulfur-based generated in sewage treatment plants, can be stably deodorized long time.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The biological deodorizing method of the present invention will be described below with reference to the drawings, together with an embodiment of a biological deodorizing apparatus for carrying out the method.

FIG. 1 is a drawing of a processing flow showing an outline of an apparatus for biologically removing odorous gas in a sewage treatment plant, and FIG. 2 is a perspective view of a ceramic carrier. As shown in FIG.
Has a fixed bed 2 provided with a malodorous gas inlet 1a at a lower portion and filled with a large number of ceramic carriers 3 (FIG. 2) for adhering cells in activated sludge at an intermediate portion in the deodorization tower 1. ing. The fixed floor 2 is usually a mesh floor, and may have a plurality of stages. However, the gas inlet 1a may be provided in the upper part and the gas outlet 1b may be provided in the lower part. In this embodiment, the ceramic carrier 3 is a gear-shaped columnar body as shown in FIG. 2A, and a through hole 3a is formed in the center in the axial direction. The ceramic carrier 3 has an outer diameter of about 10 mm and a length of about 10 mm. In addition, as shown in FIG.
The shape of is not limited to a gear-type columnar body, and may be, for example, a spherical body 3-1 as shown in FIG. 2 (b) or a rectangular columnar body 3-2 as shown in FIG. 2 (c).

The composition of the ceramic carrier 3 is composed of silicon dioxide, calcium oxide, alumina, iron, magnesium, etc., and is fired to form a porous carrier having countless small holes. It is preferable that the ceramic carrier 3 has a calcium oxide content of 2.5 to 42%, an alumina content of 7 to 25%, a firing temperature of 900 to 1150 ° C., and a water absorption of 32% or more. This is as described above. At this time, the apparent porosity of the ceramic carrier 3 is 20 to 85%.

When a large number of ceramic carriers 3 are filled on the fixed bed 2, the filling porosity is set to 0.65 or less.

The upper end of the deodorization tower 1 is formed in a conical shape, and an outlet 1b for the deodorizing gas is provided at the center thereof.
Is connected to a gas exhaust pipe 4. In the middle of the exhaust pipe 4,
The fan 5 is interposed and branches off downstream of the fan 5. Further, in the middle of each of the branch pipes 5a and 5b, a damper 6a
6b are respectively provided, and an activated carbon adsorption tower 7 is provided in the middle of one branch pipe 5a to open one end to the outside air, and one end of the other branch pipe 5b is directly opened to the outside air.

In the deodorization tower 1, a watering nozzle 8 is disposed downward above the ceramic carrier 3 on the fixed bed 2, and the bottom of the regulating tank 9 and the watering nozzle 8 are connected by a water supply pipe 10.
A watering pump 11 is interposed in the water supply pipe 10. This watering pump 11 is connected to a timer (not shown),
Watering is performed at predetermined time intervals (for example, 90 minute intervals) for a predetermined time (for example, 10 minutes). Deodorization tower 1
A drain port 12 is opened at the bottom of the container, and a drain pipe 13 is led from the drain port 12 to a sand basin 19. An on-off valve 14 is provided in the middle of the drain pipe 13, and the drain pipe 13 is branched upstream of the on-off valve 14, and the branch pipe 15 is guided to the upper end of the adjusting tank 9. An on-off valve 16 is also provided in the middle of the branch pipe 15. Further, the treated water supply pipe 17 is guided to the upper end of the regulating tank 9, and treated water is supplied from the treated water flow path 20 and the like to the regulating tank 9 by a supply pump 18 provided in the middle of the supplying pipe 17.
To be able to inject. The supply of the treated water to the adjusting tank 9 is performed by, for example, a supply pump 18 by a level switch.
It is good to operate automatically.

Next, a biological deodorizing method of the present invention using the biological deodorizing apparatus having the above configuration will be described. In addition,
In the case of malodorous gas generated in a sewage treatment plant, there are almost no amine-based odor components and mainly sulfur-based odor components.

First, the activated sludge water in the sewage treatment plant or a liquid obtained by culturing the cells in the activated sludge is poured into the adjusting tank 9. Then, the on-off valve 14 is closed, and the on-off valve 1 is closed.
In a state where 6 is opened, the sprinkling pump 11 is operated to sprinkle the activated sludge water in the adjusting tank 9 or the cell culture solution in the activated sludge onto the ceramic carrier 3 in the deodorization tower 1 and circulate it. This watering is performed continuously for 2 to 3 days, and when the sludge water or the cell culture medium in the adjusting tank 9 is no longer turbid (the MLSS becomes almost 0), the odorous gas is introduced from the inlet 1a to the deodorization tower. Introduce into 1. This is because if the sludge water or the cell culture liquid circulating in the adjusting tank 9 is no longer turbid, it means that the cells contained therein have adhered to the ceramic carrier 3.

When introducing odorous gas, the on-off valve 1
After the valve 4 is opened, the on-off valve 16 is closed, and the treated water sprinkled on the ceramic carrier 3 in the deodorization tower 1 is caused to flow to the sand basin 19 by a so-called one-pass flow without being circulated. The wastewater that has passed through the ceramic carrier 3 and stored in the sand basin in this way is filtered and eventually becomes treated water. Therefore,
This treated water is supplied to the adjusting tank 9 by the supply pump 18, and the treated water in the adjusting tank 9 is intermittently sprinkled on the ceramic carrier 3 by the sprinkling pump 11. If necessary, a buffer or a trace amount of a nutrient may be added to the treated water in the adjusting tank 9. The buffer may be, for example, according to the description in the Chemical Handbook.
^{_{3 2 ~, HCO 3 ~,}} HPO 4 2 ~, alkali metal salts and alkaline earth metal salts containing ions H ₂ PO ₄ ~ and the like are preferable. Nutrient sources include nitrogen, phosphoric acid, potassium and the like.

The period from the start of the introduction of the offensive odor gas to the time when the cells adhered to the ceramic carrier 3 sufficiently correspond to the sulfur-based odor component in the offensive odor gas, that is, the adaptation period, depends on the cells. Since the ability to decompose odor components is low and the number of cells suitable for decomposing the odor components is small, the deodorization rate of malodorous gas is slightly low. Therefore, since the gas passing through the ceramic carrier 3 has a slightly low deodorization rate, the dampers 6a and 6b are switched so that the gas flows toward the activated carbon adsorption tower 7, and the gas is discharged after activated carbon treatment. Then, after the acclimatization in which the deodorization rate of the cells has improved after about 2 to 7 days, the dampers 6a and 6b are switched so that the gas from the deodorization tower 1 is directly discharged to the outside through the branch pipe 5b. .

In order to shorten the adaptation period, before introducing the malodorous gas into the deodorization tower 1, the substrate of the odor component (in the case of the sulfur odor, the sulfur-based main component) is added to the water in the adjusting tank 9. Into the deodorization tower 1, water is circulated and circulated in the deodorization tower 1, and after confirming that the substrate has been decomposed to 100%, if the malodorous gas is introduced into the deodorization tower 1, it can be efficiently deodorized immediately after the introduction is started. .

By the way, the following experiment was conducted to find the optimum conditions for the following items with respect to the biological deodorizing apparatus (including the biological deodorizing method) of the present invention according to the above embodiment, and the results will be described. . Aerobic cells of the genus Thiobacillus are effective in decomposing and removing sulfur-based odor components.However, the ability of these cells to adhere to the carrier is comparable, but that of the genus Brevibacterium is easy to culture. The following experiment was performed using the cells.

Relationship between CaO Content in Ceramic Carrier and Bacterial Cell Attachment (See FIG. 5 ) Several types of alumina content of 7 to 45%, water absorption of 34 to 108%, and firing temperature of carrier of 900 to 1050 ° C. The relationship between the CaO content and the amount of bacterial cells was examined using the ceramic carrier of Example 1. As shown in FIG. 5, when the calcium oxide content in the ceramic carrier 3 exceeded 1.8%, The amount of bacterial cells attached to the bacterium gradually increased to about 4.8 mg-cells / cm ³ at 2.5%, and the content was 6.6 to 30.
%, The average amount of adhered cells is 13 mg-cells / cm ³ . However, the calcium oxide content decreases when the content is 30% or more, and is about 4.5 mg-cells / cm ^{3 at} 42%. However, when the calcium oxide content is still 50% or more, the content is still sufficient. Since the alkaline strength became too large, the amount of attached bacterial cells became zero. In addition, the same content is 0.16-1.
At 8%, the average amount of attached cells was 2.5 mg-cells / cm ³ .

Relationship between the content of Al ₂ O ₃ in the ceramic carrier and the amount of adhered cells (see FIG. 6) Calcium oxide content 0.85 to 40%, water absorption 14 to
The relationship between the content of Al ₂ O _{3 and} the amount of attached bacterial cells was examined using several types of ceramic carriers in the range of 108% and a carrier sintering temperature of 900 to 1050 ° C. As shown in FIG. In the case where the alumina content in the sample No. 3 is about 7 to 15%, the average amount of the adhered cells becomes 13 mg-cells / cm ³ , and when the content exceeds 18%, it rapidly decreases. Approximately 5 mg-cells / cm ³ , still having a sufficient amount of adhesion.
Further, when the content is around 30%, the amount of adhered cells is 1.
It was 5 mg-cells / cm ³ , and when the content was 45% or more, the amount of attached bacterial cells became zero.

Relationship between the sintering temperature of the ceramic carrier and the amount of bacterial cells attached (see FIG. 7) In the range of 0.16 to 40% of calcium oxide, 7 to 22% of alumina, and 23 to 88% of water absorption, The occupancy in the range of pore diameter 0.4 to 100 μm is 50% or more and the occupancy in the pore diameter range of 4 to 20 μm is 2% or more (see FIG. 9).
The relationship between the sintering temperature and the amount of bacterial cell adhesion was examined using several types of ceramic carriers. As shown in FIG. 7, when the sintering temperature of the ceramic carrier 3 was about 850 to 1200 ° C., The average amount was 13 mg-cells / cm ³ and the temperature was 1
When the temperature exceeds 050 ° C, the temperature starts to decrease sharply.
Even at 150 ° C., the amount of adhered cells was 5.8 mg-cells / cm ³ , indicating a sufficient amount of adhered cells.
Significantly decreased with 5mg-cells / cm ^3, the temperature hardly adhere and 0.68mg-cells / cm ³ at 1300 ° C.. This is because the strength increases when the temperature is 1200 ° C or higher,
It is considered that the amount of adhered cells was reduced due to the extremely small pore diameter. On the other hand, when the firing temperature is 800 ° C. or lower, the shape of the ceramic carrier cannot be maintained because it is too brittle.

Relationship between Water Absorption of Ceramic Carrier and Bacterial Cell Amount (See FIG. 8) Calcium oxide content 0.16 to 40%, alumina content 7 to 22%, water absorption 23 to 88%, carrier firing temperature 90
Using several types of ceramic carriers in the range of 0 to 1050 ° C., the relationship between the water absorption and the amount of bacterial cells was examined. As shown in FIG. Hardly adhered, and when the water absorption exceeded 30%, the amount of adhered cells rapidly increased. At 32%, the amount of adhered cells was about 5 mg-cells / cm ³ , and the water absorption was about 46%. %
When the ratio exceeded, the average amount of the adhered cells was about 17 mg-cells / cm ³ .

Pore size distribution (occupancy) of ceramic carrier
(See FIG. 9) Calcium oxide content 0.16-40%, alumina content 7-22%, water absorption 23-88%, carrier firing temperature 90
Using several types of ceramic carriers in the range of 0 to 1300 ° C., the occupancy of the pores in the range of 0.4 to 100 μm is 50%
In the above case, the relationship between the water absorption rate and the amount of adhered cells was examined. As shown in FIG. 9, adherence of the cells was observed when the occupation ratio in the pore diameter range of 4 to 20 μm was 2% or more. %, The attached amount of 5.2 mg-cells / cm ³ , especially when the amount is 5% or more, the attached amount of the cells increases greatly, and the attached amount of the cells tends to be the most excellent in the range of 5 to 30%. However, when the occupancy was 2.5% or more, the cells had a sufficient amount of adhered cells. The occupancy of each range of the pore diameter is determined by the mercury intrusion method.

Relationship between Permanent Watering and Intermittent Watering in the Method of Watering Ceramic Carrier (See FIG. 10) As shown in FIG. 10, in the case of constant watering, for example, after 29 days, the number of cells in the circulating recovered water after watering reaches 65. × 10 ⁴ mg-ce
It became lls / cm ^3. On the other hand, for intermittent watering, 30 to 50 days
Even after a lapse of days, the number of cells in the circulated recovered water after watering is 4.
5 × 10 ⁴ mg-cells / cm ³ , ceramic carrier 3
Very little detachment of the bacterial cells from the cells. The thickness of the packed bed of the ceramic carrier 3 on the fixed bed 2 is 600
mm.

Relationship between Porosity of Ceramic Carrier and Removal Rate of Hydrogen Sulfide (See FIG. 11) As shown in FIG. 9, when the porosity of the ceramic carrier 3 is 0.65% or less, hydrogen sulfide (H ₂ S) is used. Although the gas removal rate was 98% or more, when the filling porosity exceeded 0.65%, the gas removal rate gradually decreased. The volume of the packed bed of the ceramic carrier 3 is 150 × 150 × 1000 mm, the intermittent water spray amount is 20 (l / Hr), the concentration of H ₂ S gas is 12 ppm, and the suction amount by the fan 5 (FIG. 1) at this time. Was 9.6 Nm ³ / h.

Relationship between the shape of the ceramic carrier and the amount of bacterial cells attached (Table 1)

[Table 1] Carrier shape Gear type columnar cylinder Triangular columnar quadratic columnar saddle type cell adhesion 12.3 6.2 4.9 5.5 8.7 mg-cells / cm ³ Composition of each carrier; SiO ₂ : 60% Al ₂ O ₃ : 22% CaO : 6.6% Other (F
e, Ti, Mg, Na, K, etc.): 11.4% Water absorption of each carrier: 36% Firing temperature of each carrier: 900 ° C As is clear from the above table, cells of any shape have a deodorizing effect. Although it can be used because the amount of adhesion can be obtained, a gear-shaped column is the most excellent.

Relationship between static pressure loss depending on the presence or absence of through holes in gear type columnar carrier (Table 2)

[Table 2] The thickness of the packed bed of the ceramic carrier 3 on the fixed bed 2 is 500
mm, the superficial velocity in the deodorization tower 1 is 0.12 m / s,
60 (l / min ・ m^Two)Met.

As is clear from the above table, the carrier having the through-hole at the center of the carrier had a lower static pressure loss than the carrier having no through-hole.

Further, in order to confirm the effects of the biological deodorizing apparatus (including the biological deodorizing method) of the present invention according to the above-described embodiment, the following experiments were conducted with respect to the following items, and the results will be described.

(1) Influence of the presence or absence of through holes in the ceramic carrier on the deodorizing ability (Table 3)

[Table 3] (Through hole: None) Inlet concentration (ppm) 12 15 32 46 Removal rate (%) 92.3 93.3 89.2 80.6 (Through hole: Yes) Inlet concentration (ppm) 10 22 41 51 Removal rate (%) 99.3 99.3 98.9 97.5 Space velocity of deodorization tower 1: 400 (l / h), intermittent watering rate: 60 (l / min)
・ M ² ), shape of carrier 3: gear type columnar Filled porosity of carrier 3: 0.46 Odor component: composition of hydrogen sulfide carrier; SiO ₂ : 60% Al ₂ O ₃ : 22% CaO: 6.6% Other (Fe,
From the above table, the carrier 3 is provided with the through-holes, thereby increasing the microbial adhesion area, increasing the contact area with the odor component, and effectively decomposing. Is recognized.

(2) Ca contained in the ceramic carrier
O and buffer effect of treated water (Tables 4 and 5)

[Table 4] (High-concentration malodorous gas) Measurement position / odor component Hydrogen sulfide Methyl mercaptan Methyl sulfide Dimethyl sulfide Odor concentration inlet (ppm) 90 0.2 − − − Outlet (ppm) 0.0078 0.0090 0.020 0.0030 − Removal rate (%) 99.99 95.5 − − (Low-concentration odorous gas) Measurement position / odor component Hydrogen sulfide Methyl mercaptan Methyl sulfide Sulfuric acid methyl sulfide Inlet concentration (ppm) 8.0 0.10 0.024 0.012 3100 Outlet (ppm) 0.0028 0.0012 0.0034 0.0017 23 Removal rate (%) 99.99 95.5 85.8 85.8 Space velocity of deodorization tower 1: 200 (l / h), intermittent watering rate: 60 (l / min)
・ M ² ) One-pass washing of secondary treatment water Filled porosity of carrier 3: 0.61 Composition of carrier; SiO ₂ : 60% Al ₂ O ₃ : 22% CaO: 6.6% Other (Fe,
Ti, Mg, Na, K, etc .: 11.4% Calcium oxide (Ca
O) and the buffer effect of the treated water work effectively, and it is recognized that the removal rate of each odor component is high. The cells adhering to the carrier 3 decompose sulfur-based and amine-based odor components to generate acids such as sulfuric acid and nitric acid, and are retained on the carrier. The activity of the body is reduced, and the efficiency of decomposing odor components is poor. Hydrogen sulfide maintains the activity of the cells up to pH 2 and is decomposable, but methyl mercaptan, methyl sulfide, dimethyl sulfide and the like have a lower activity at pH 5 and lower the decomposition efficiency. However, by containing calcium oxide, the acid is neutralized at the same time as the production, and the high decomposition rate is maintained without affecting the activity of the cells.

For comparison, the following Table 5 shows the removal rates when tap water was used in place of the secondary treated water.

[0055]

[Table 5] (High concentration malodorous gas) Measurement position / odor component Hydrogen sulfide Methyl mercaptan Methyl sulfide Dimethyl sulfide Odor concentration inlet (ppm) 20 0.16 0.11 <0.01- Outlet (ppm) 0.068 0.076 0.046 <0.01- Removal rate (%) 99.7 52.5 58.2 − (Low-concentration malodorous gas) Measurement position / odor component Hydrogen sulfide Methyl mercaptan Methyl sulfide Dimethyl sulfide Odor concentration inlet (ppm) 5.8 0.09 <1.6 0.005 − Outlet (ppm) 0.0028 0.041 0.018 <0.01 − Removal rate (%) 99.5 54.4-- Space velocity of deodorization tower 1: 200 (l / h), intermittent watering rate: 60 (l / min)
・ M ² ), One-pass washing of tap water Filling porosity of carrier: 0.1
7 Carrier composition: SiO ₂ : 60% Al ₂ O ₃ : 22% CaO: 6.6% Other (Fe,
Ti, Mg, Na, K, etc.): 11.4% tap water has a poor buffering effect on the acid generated by the decomposition of sulfur-based odor components, which affected the decomposition ability of methyl mercaptan, methyl sulfide and dimethyl sulfide. However, hydrogen sulfide had little effect.

(3) Buffering effect by buffer (Table 6)

[Table 6] Measurement position / odor components Hydrogen sulfide Methyl mercaptan Methyl sulfide Dimethyl sulfide Odor concentration inlet (ppm) 16 0.10 0.083 0.010- Outlet (ppm) 0.03 0.0059 0.0057 0.0025- Removal rate (%) 99.8 94.1 93.1 75.1 Deodorization tower 1 Space velocity: 200 (l / h), intermittent watering rate: 60 (l / min)
・ M ² ), one-pass washing of tap water with buffer added Filling porosity of carrier 3: 0.17 Composition of carrier; SiO ₂ : 60% Al ₂ O ₃ : 22% CaO: 6.6% Other (Fe,
Ti, Mg, Na, K, etc.): The addition of a buffer to 11.4% tap water greatly improved the removal rate, indicating that the buffer was effective. That is, water such as secondary treatment water, sand filtration water, well water, tap water, etc. has a more or less aggressive action, and the activity of the bacterial cells is maintained by the buffering effect. In such a case, it is found to be effective to add a buffer to the water, since the effect will not work.

(4) Effect of extending the life of activated carbon (Table 7)

[Table 7] Biological deodorization method (Figure 1) Chemical deodorization method (Figure 11) Activated carbon annual consumption (kg) 1789 6497 Sulfur-based gas; Hydrogen sulfide: 18ppm Methyl mercaptan:
0.28 ppm methyl sulfide: 0.15 ppm dimethyl sulfide: 0.0073 pp
m Gas amount: 100 m ³ / min According to the biological deodorizing method of the present invention, the life of activated carbon is extended about 3.6 times as compared with the conventional chemical deodorizing method.

(5) Economic Effect (Relationship Between Depreciation Cost of Ceramic Carrier and Hydrogen Sulfide Concentration) As shown in FIG. 13, the biological deodorization method of the present invention is more effective than the conventional chemical deodorization method in depreciation cost of ceramic carrier. Even when only the consumption cost of sodium hypochlorite was considered, it was recognized that when the concentration of hydrogen sulfide was 10 ppm or more, it was economical in proportion to the increase in the concentration. The amount of gas suction by the fan 5 was 100 m ³ / min, the cost of sodium hypochlorite was 25 yen / kg, the cost of the ceramic carrier was 600 yen / kg, and the amortization period of the carrier was 3 years.

If the concentration of hydrogen sulfide is less than 10 ppm, the cost will increase if only the amortization cost of the ceramic carrier is taken. However, the biological deodorizing method of the present invention reduces the cost of the auxiliary equipment, and controls the pH and concentration. Considering that the maintenance work is labor-saving because of no need for maintenance, and the life of the activated carbon is extended, it is judged that it is more advantageous than the conventional deodorization method and equipment even when the hydrogen sulfide concentration is less than 10 ppm. Is done.

Next, an embodiment of the biological deodorizing apparatus of the present invention, which is suitable when the concentration of the malodorous gas (sulfur-based) is high, will be described with reference to the drawings.

FIG. 3 is a view showing only a part corresponding to the deodorization tower 1 of the biological deodorization apparatus of FIG. 1. The deodorization towers according to the three embodiments shown in FIG. 3 are different from the above-described embodiment (FIG. 1). Layer 23 (FIGS. 3 (a) and 3 (b)) or tower 21 for preliminarily deodorizing (pre-deodorizing treatment) the odor components of the high concentration malodorous gas.
(FIG. 3C) is provided on the upstream side. The other configuration is common to the configuration other than the deodorization tower 1 of FIG.

In the deodorization tower 1-1 of FIG. 3A, a fixed bed 22 is provided below (upstream) the fixed bed 2 filled with the ceramic carrier 3 in the deodorization tower 1 of FIG. The carrier 23 is filled with a woven fabric, a nonwoven fabric, or a sponge of polypropylene fiber, polyethylene fiber, or the like. When the synthetic fiber woven or non-woven fabric carrier 23 is used, if the carrier 23 is directly filled, the carrier 23 may be closed by filling and consolidation, and contact between the attached microorganisms and the odorous gas may be inhibited. It is desirable to use a filling method such as filling in a punched porous hollow body or a porous capsule-shaped cap, or filling an interdigitated body with the upper and lower parts fixed, or with the upper part only partially fixed. The hollow body or the cap can be packed with one synthetic fiber body having a size corresponding to the shape or a plurality of rod-shaped or chip-shaped synthetic fiber bodies. When the reaction product is acidic such as a sulfur compound or a nitride, the synthetic fiber, the hollow body, and the cap need to have acid resistance.

The deodorization tower 1-1 has a remarkable fluctuation in the gas concentration of the object to be treated. Even if sulfur is precipitated when a high concentration is generated, the sulfur is oxidized and disappears at a low concentration. is there.

In the deodorization tower 1-2 shown in FIG. 3B, a watering nozzle 28 is disposed below the fixed bed 2 of the deodorization tower 1-1 shown in FIG. The branch 10 is connected to a watering nozzle 28 to spray water through a watering pump 11.

According to the deodorization tower 1-2, even when the high concentration of gas continues for a long time and sulfur does not disappear, the amount of water sprayed on the synthetic fiber carrier 23 can be increased as compared with the ceramic carrier 3, By shortening the intermittent time of watering,
Since the acidity of the carrier 23 can be reduced, sulfur can be oxidized and eliminated.

The deodorization tower 1-3 shown in FIG. 3 (c) is completely independent of the deodorization tower 1 filled with the ceramic carrier 3 with the preliminary deodorization layer filled with the synthetic fiber carrier 23 as the preliminary deodorization tower 21. Things.

According to the deodorization tower 1-3, the filling amount of the synthetic fiber carrier 23 can be greatly increased.

(A) Table 8 below shows the deodorizing treatment performance of the deodorizing tower 1-3.

[0069]

[Table 8] Measurement position Inlet Preparatory tower outlet Final outlet concentration (ppm) 210 23 0.01 Removal rate (%)--99.995 Space velocity of preliminary deodorizing tower 21: 400 (l / h), intermittent watering amount: 60
(l / min · m ² ), average temperature in the preliminary deodorization tower 21: 26 ° C. Space velocity of the deodorization tower 1: 200 (l / h), intermittent water spray: 60 (l / min ·
m ² ), average temperature in the preliminary deodorization tower 21: 26 ° C. Odor component: hydrogen sulfide As described above, each of the deodorization towers (FIG. 3) is suitable for deodorizing sulfur-based gas. If an acid is generated without performing the treatment, it may be used depending on the gas concentration.

(B) Relationship between Water Retention and Cell Adhesion of Synthetic Fiber Carrier (See FIG. 12) The relationship between the water retention and cell adhesion of the synthetic fiber carrier 23 was examined. As shown in
When the water retention of the carrier 23 is 10% or less, the cells hardly adhere, and when the water retention exceeds 30%, the cells adhere sufficiently,
As the water retention rate increased, the amount of cells attached also increased. In addition,
Water retention (%) is (water retention) / (unit volume of synthetic fiber) x 1
The water density was 1 g / cm ^{3 at} this time.

[0071]

[Table 9] Water retention (%) 4.5 37 59 64 95 120 190 Cell adhesion 0.47 3.6 6.0 6.5 9.4 11 27 mg-cells / cm ³

Subsequently, the odorous gas is constantly kept at a high concentration for a long period of time, so that sulfur cannot be eliminated in each of the above deodorizing apparatuses shown in FIG. 3, the sulfur deposition increases, and sulfur crystals are deposited on the surface of the carrier 23. An embodiment of the biological deodorizing apparatus of the present invention, which is particularly effective in such a case, will be described with reference to the drawings, and the deodorizing method will also be described. FIG. 4 is a drawing of a processing flow showing an outline of a biological deodorizing device for high-concentration malodorous gas in a sewage treatment plant. The deodorizing apparatus according to the present embodiment is different from the above-described embodiment (FIG. 1) in that the odor component of the high-concentration malodorous gas is preliminarily deodorized (pre-deodorization treatment) to a low-concentration gas. On the side, two deodorization towers 21 and 31
It is to have. The structure of each of the deodorization towers 21 and 31 is common to the deodorization tower 1, but the fixed beds 22 and 32 have
In place of the ceramic carrier 3, woven, non-woven or sponge-like carriers (hereinafter referred to as sponge-like carriers) 23 and 33 made of natural cellulose or synthetic fiber are filled. Of course, each sponge-like carrier 23
-At 33, cells that decompose odor components are implanted.

The reason why the sponge-like carriers 23 and 33 are used is that when high-concentration malodorous gas is introduced into the deodorization towers 21 and 31, a component that is decomposed by cells to produce an acid is produced. Long-term influx of high concentrations will far exceed the buffering capacity of watering. For this reason, in the ceramic carrier 3, the constituent components such as alumina, iron, and magnesium react with the acid to be dissolved, and the ceramic carrier 3 is disintegrated. On the other hand, natural cellulose, synthetic fibers, and the like are resistant to generated acids and excellent in adhesion of bacterial cells. However, in the case of natural cellulose, when there is a risk of being decomposed by aquatic protozoa and molds, synthetic fibers are used.

The two deodorization towers 21 and 31 have introduction pipes 41 and 42 branched from a common gas generation source into two systems.
Through each of the introduction pipes 41 and 42 and each deodorization tower 21
The control unit 45 controls the gas introduction ratio to 31
The electric dampers 43 and 44 which are switched according to are provided. The gas exhausted from the deodorizing towers 21 and 31 through the exhaust pipes 24 and 34 is introduced into the deodorizing tower 1 from the common exhaust pipe 25.

Further, the treated water is supplied from the adjusting tank 9 to the watering nozzles 28 and 38 in the respective deodorization towers 21 and 31 via the water supply pipe 29 branched from the water supply pipe 10 and intermittently watered. Then, the wastewater discharged from the bottom of each of the deodorization towers 21 and 31 flows into the sand basin 19. The fixed floor 22 of each deodorization tower 21/31
・ Provide pressure gauges 26 and 36 across 32 to reduce static pressure loss
(△ p) can be measured.

Now, the biological deodorizing method of the present invention using the biological deodorizing apparatus of the embodiment configured as described above will be described.

First, a high-concentration malodorous gas was introduced into each of the introduction pipes 41.4.
Introduce into each deodorization tower 21 and 31 from 2. At this time, a large amount of gas (for example, 80 to 90% of the total gas amount) flows into one (for example, 21) of the deodorization towers 21 and 31, and a small amount of gas (for example, 10 to 10% of the total gas amount) flows into the other (for example, 31). 20%)
Of the electric dampers 43 and 44 is adjusted so that the fluid flows in. As a result, the high-concentration malodorous gas is removed from the deodorization tower 21.
-The odor component is decomposed by the bacterial cells attached to the sponge-like carriers 23 and 33 in 31 to become low-concentration odorous gas. The low-concentration malodorous gas from which the odor components have been almost removed is deodorized by the deodorizer of the above-described embodiment in the same manner as described above, and is discharged to the atmosphere.

When the hydrogen sulfide concentration exceeds the critical load, sulfur is precipitated and the static pressure loss (△ p) of the fixed bed is increased.
And the deodorizing efficiency also decreases. This is because the sulfur covers the carrier surface, so that the ventilation resistance increases and the diffusion of the odor component into the bacterial cell layer is inhibited. Tables 10 and 11 show that after introducing a high-concentration malodorous gas having a hydrogen sulfide concentration of 16 to 720 (average 150) ppm for one month into the deodorization tower 1 (FIG. 1) of the above embodiment, It shows a decrease in deodorizing performance when sulfur is deposited on the carrier 3 and an increase in static pressure loss of the fixed bed.

[0079]

[Table 10]Measurement position / odor component Hydrogen sulfide Methyl mercaptan Methyl sulfide Dimethyl sulfide Odor concentration   Inlet (ppm) 16 0.17 0.058 0.016 −   Outlet (ppm) 0.82 0.08 0.031 0.015 −   Removal rate (%) 94.9 52.9 46.6 6.3   Measurement position / odor component Hydrogen sulfide Methyl mercaptan   Inlet (ppm) 720 2.5   Outlet (ppm) 400 2.0   Removal rate (%) 44.4 20.0   Measurement position / odor component Hydrogen sulfide Methyl mercaptan   Inlet (ppm) 140 0.25   Outlet (ppm) 27 0.1   Removal rate (%) 80.7 60.0

Table 11 below shows the difference in static pressure loss (Δp) depending on the presence or absence of sulfur deposition.

[Table 11] Space velocity of deodorization tower 1: 200 (l / h), intermittent watering rate: 60 (l / min)
・ M2) One-pass washing of secondary treatment water Filling porosity of carrier: 0.61 Composition of carrier: SiO2: 60% Al2O3: 22% CaO: 6.6% Other (Fe,
Ti, Mg, Na, K, etc.): 11.4% In the deodorizer of the present embodiment described above, the static pressure loss (△ p) in the deodorizer towers 21 and 31 is controlled by the control unit based on the numerical values of the pressure gauges 26 and 36. 45
In by controlling, when the static pressure loss in one of the deodorization tower 21 is increased, it switches the opening of the electric damper 43, 44 at all conversely, to introduce a large amount of gas into the de-Nioito 31 side. As a result, the sulfur adhering to the fixed bed 22 (sponge-like carrier 23) of the deodorization tower 21 gradually changes to sulfuric acid and
It disappears in about three days and returns to its original state. In this way, by switching the introduction ratio of the high-concentration malodorous gas to the deodorization towers 21 and 31 by the electric dampers 43 and 44, the high-concentration malodorous gas can be stably deodorized for a long time.

In each of the above embodiments, the deodorization of the odorous gas of the sulfur component in the sewage treatment plant has been described. However, it can be said that the same can be applied to the deodorization of the odorous gas of the amine component and the decomposition and removal of the organic solvent vapor. Not even. However,
Amine-based odorous gas has a high solubility in water, contrary to sulfur-based components, so it can be dealt with by one-pass washing with water that has a buffering action, and the wastewater is fed back to the raw water inlet such as a sand basin. Can also be taken. The cells attached to a ceramic carrier or the like and used to decompose odor components are not particularly limited. For example, various cells living in activated sludge can be used.
Aerobic cells such as cillus, Nitrosomonas and Nitrobacter are effective.

[0082]

As is apparent from the above description,
The biological deodorizing method and apparatus of the present invention have the following effects.

(A) In the deodorizing method according to the first aspect, since the odor components in the offensive odor gas are decomposed and deodorized by the cells adhered to the ceramics carrier, the deodorizing method is maintained compared to the conventional deodorizing method by chemical cleaning. The management work is easy and the cost is low. In addition, since no chemical is used, the operation is safe, and even when activated carbon is used, its life is greatly extended. further,
The deodorizing method of the present invention is suitable for deodorizing high-concentration odorous gas.
Yes, especially suitable for sulfur-based odorous gases.

(B) According to the deodorizing method of the second to fourth aspects, the deodorizing efficiency is improved. In particular, in the deodorizing method according to claim 3 or 4, since the ceramic carrier has a through-hole, even if the sprinkled water contains flocs or slurries of sludge, algae, etc., it is necessary to land on those carriers. A sudden increase in static pressure loss can be prevented.

(C) The carrier according to the method for deodorizing according to claim 5
Can be used not only for preliminary deodorization but also
This is especially effective.

(D) The deodorizing device according to the eighth aspect can reliably execute the above-described deodorizing method of the present invention.

(E) The deodorizing device of the present invention stably improves the deodorizing efficiency over a long period of time. In addition, since the ceramic carrier is provided with the through-holes, the through-holes are hardly closed even when flocks or slurries are deposited on the floor , and the danger such as blockage of the tower is prevented. Also suitable for deodorizing high-concentration odorous gas,
Most suitable for sulfur-based odorous gas.

[0088]

[Brief description of the drawings]

FIG. 1 is a drawing of a processing flow showing an outline of an apparatus for biologically removing odorous gas in a sewage treatment plant according to an embodiment of the present invention.

FIGS. 2A to 2C are perspective views each showing an embodiment of a ceramic carrier.

FIG. 3 is a process flow chart showing an outline of a high-concentration malodorous gas biological deodorizing apparatus in a sewage treatment plant according to another embodiment of the present invention.

FIG. 4 is a drawing of a processing flow showing an outline of a biological deodorizing apparatus for high-concentration malodorous gas in a sewage treatment plant according to another embodiment of the present invention.

FIG. 5 is a diagram showing the relationship between the content of CaO in a ceramic carrier and the amount of adhered cells.

FIG. 6 is a graph showing the relationship between the content of Al ₂ O ₃ in a ceramic carrier and the amount of adhered cells.

FIG. 7 is a diagram showing the relationship between the firing temperature of a ceramic carrier and the amount of adhered cells.

FIG. 8 is a diagram showing the relationship between the water absorption of the ceramic carrier and the amount of adhered cells.

FIG. 9 is a diagram showing the relationship between the occupation ratio of the pore diameter of the ceramic carrier of 4 to 20 μm and the amount of adhered cells.

FIG. 10 is a diagram showing the relationship between continuous watering and intermittent watering in a method of watering a ceramic carrier.

FIG. 11 is a diagram showing a relationship between a filling porosity of a ceramic carrier and a removal rate of hydrogen sulfide.

FIG. 12 is a graph showing the relationship between the water retention rate of a synthetic fiber carrier and the amount of adhered cells.

FIG. 13 is a graph showing the relationship between the depreciation cost of a ceramic carrier and the consumption cost of sodium hypochlorite based on the concentration of hydrogen sulfide.

FIG. 14 is a process flow diagram showing an outline of a conventional general chemical cleaning type deodorizing apparatus.

[Explanation of symbols]

1,21,31 Deodorization tower 2.22 / 32 fixed floor 3 ceramic carrier 23 ・ 33 Sponge carrier 4 Exhaust pipe 5 fans 6a ・ 6b ・ 43 ・ 44 Damper 7 activated carbon deodorization tower 8 Watering nozzle 9 Adjusting tank

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Yasushi 4-1-1, Mizu-cho, Amagasaki-shi, Hyogo Seiko Kakoki Co., Ltd. (56) References JP-A-1-107830 (JP, A) JP-A-4-281817 (JP, A) JP-A-3-275194 (JP, A) JP-A-3-65295 (JP, A) JP-A-2-4496 (JP, A) (JP, U) JP-A 3-123597 (JP, U) JP-B 2-6589 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B01D 53/34-53 / 85

Claims (7)

(57) [Claims] 1. A large number of porous ceramic carriers having a predetermined shape containing calcium oxide and alumina are filled in the middle of a path of a malodorous gas, and microbial cells that decompose odor components are implanted on the ceramic carriers. after while intermittently spraying water onto the ceramic support, a biological deodorization method of deodorizing by passing the malodor gas into the ceramic support, fabric made of natural cellulose or synthetic fibers, non-woven fabric if
A large number of sponge-like carriers,
Filled in the middle of the odor gas passage on the more upstream side, the carrier
After implanting microbial cells that decompose odor components,
While spraying water intermittently or continuously on the carrier,
Passing high-concentration odorous odorous gas through the carrier
In this way, two routes for preliminary deodorization are provided, and the amount of gas introduced into both systems is divided into a high ratio and a low ratio.
When the rate side reaches the static pressure loss limit, the gas introduction rate is low.
To low ratio side to high ratio gas introduction volume
Biological deodorization method comprising Rukoto. 2. The ceramic carrier has a calcium oxide content of 2 to 50%, an alumina content of 30% or less, a water absorption of 30% or more, and a firing temperature of the ceramic carrier of 800 to 1200 ° C. Item 2. The biological deodorization method according to Item 1. 3. The biological deodorization method according to claim 1, wherein the ceramic carrier has at least one through hole, and a filling porosity of the ceramic carrier is 0.8 or less. 4. The biological deodorizing method according to claim 3, wherein the ceramic carrier is a gear-shaped column. 5. The method according to claim 1, wherein the ceramic carrier has a pore diameter of 0.4 to 0.4.
100% occupancy of 50% or more and pore diameter of 4 to 20μ
The biological deodorization method according to any one of claims 1 to 4, wherein the occupancy of m is 2% or more. 6. A microorganism which contains calcium oxide and alumina and decomposes odor components on a fixed bed provided in the middle of a malodor gas passage in a deodorization tower provided with an inlet and an outlet for malodor gas. A large number of porous ceramic carriers of a predetermined shape for landing the body are filled, and a watering nozzle is arranged above the ceramic carriers in the deodorization tower,
A biological deodorizer with a drain port at the bottom of the deodorization tower , which has an inlet and an outlet for odorous gas, and has a odor gas passage in the tower.
Microorganisms that decompose odor components on a fixed bed
Woven made of natural cellulose or synthetic fibers for body implantation
Fills a large number of cloth, non-woven or sponge-like carriers
And a pressure gauge capable of measuring a static pressure loss across the fixed bed.
A sprinkling nozzle above the carrier in the preliminary tower,
Two preliminary deodorization towers each with a drain at the bottom
Installed on the upstream side of the deodorization tower, respectively, the gas outlet of each of the preliminary deodorization towers and the gas introduction of the deodorization tower
Mouth and pipe are connected respectively, and sulfur-based high concentration
An introduction pipe branched into two systems from a common source of odor gas
Odor gas through the gas inlet of each of the preliminary deodorization towers
Then, in each of the introduction pipes, gas is introduced into each of the preliminary deodorization towers.
Electric motor that switches the ratio with the control unit
And one of the two spare towers
A large amount of odorous gas is introduced, while a small amount of odorous gas is introduced.
Adjust the opening of each damper so that
Based on the value of the static pressure loss of the pressure gauge,
When the static pressure loss reaches the limit, the control
Switching the damper opening in the unit in the opposite direction
A biological deodorization device characterized in that it is controlled in such a manner as to be controlled in the following manner . 7. The ceramic carrier according to claim 1, further comprising calcium oxide.
Reduce the content to 2 to 50% and the alumina content to 30% or less
At least one through hole is formed in the ceramic carrier.
To reduce the porosity of the ceramic carrier to 0.8 or less.
The biological deodorizing device according to claim 6 .