JPH10328A - Biological deodorization method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively deodorize malodorous gases consisting of volatile org. carbon materials as malodorous components by using a dissolution accelerator in improving the dissolution rate of the malodorous components into water. SOLUTION: Microorganisms capable of decomposing the malodorous components, such as, Pseudomonas putida, are fixed to microorganism immobilizing carriers 2 packed in a biological deodorizing column 1. This biological deodorizing column 1 is internally provided with a spray nozzle 3 which sprays nutrient-salt contg. water to the microorganism immobilizing carriers 2 to supply the nutrients to the microorganisms. An org. solvent is added as the dissolution accelerator into this spraying water in order to improve the dissolution of the malodorous components into the water. As a result, the malodorous components in the malodorous gases are rapidly dissolved into the water and are migrated to the water phase, by which the decomposition by the microorganisms is effected. Consequently, an excellent deodorization effect is obtd. The sprayed water is recovered from the lower part of the biological deodorizing column 1 to a separating vessel 4. The org. solvent and the water are respectively-mixed by a mixer 5 and are sprayed again from the spraying nozzle 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for biological deodorization of malodorous gas using microorganisms that decompose malodorous components. More specifically, the present invention relates to volatile organic compounds such as toluene, xylene and benzene. The present invention relates to an effective biological deodorization method when the substance is a carbon substance.

[0002]

2. Description of the Related Art A biological deodorization method of passing a malodorous gas through a biological deodorization tower on which microorganisms that decompose malodorous components are immobilized includes:
For example, it is conventionally known as disclosed in Japanese Patent Application Laid-Open No. Hei 3-161019. The biological deodorization method described in this publication includes a packed bed supporting hydrogen sulfide decomposing microorganisms, a packed bed supporting methylmercaptan-decomposing microorganisms, and a packed bed supporting methyl sulfide decomposing microorganisms. This is a method for removing sulfur-based malodorous components such as hydrogen sulfide through gas.

[0003] Such a conventional biological deodorizing method has a certain effect in removing water-soluble malodorous components such as hydrogen sulfide. However, when the malodorous component is a volatile organic carbon substance such as toluene, xylene or benzene, a sufficient effect cannot be obtained. The reason is that the biological deodorization method is a method in which malodorous components in a malodorous gas are dissolved in an aqueous phase and decomposed and deodorized by microorganisms present in the aqueous phase. This is because it is limited by the dissolution rate and the concentration. For this reason,
For example, it cannot be applied to deodorization of malodorous gas containing a volatile organic carbon substance generated from an automobile painting booth or the like as a malodorous component.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and has an excellent deodorizing effect even on malodorous gas containing volatile organic carbon substances such as toluene, xylene and benzene as malodorous components. The purpose of the present invention is to provide a biological deodorizing method that can be mentioned.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a method for deodorizing a biodeodorant in which a malodorous component-decomposing microorganism is passed through a biological deodorization tower on which immobilized microorganisms are immobilized. The use of an agent improves the rate of dissolution of malodorous components in water. Specifically, octane, decane, or hexadecane is used as a dissolution promoter, and a method of adding to water spraying to a biological deodorization tower, or a cyclodextrin or polycyclodextrin is used as a dissolution promoter, and beads containing them are used. In a biological deodorization tower.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. FIG. 1 is a flow sheet showing a first embodiment of the present invention, wherein 1 is a biological deodorization tower, 2 is this biological deodorization tower 1
Is a microorganism-immobilized carrier filled in the inside. The microorganism-immobilized carrier 2 includes, for example, Pseudomonas putida
A microorganism capable of decomposing malodorous components such as (P. putida) is immobilized. The malodorous gas containing volatile organic carbon substances such as toluene, xylene and benzene as malodorous components flows upward from inside the biological deodorization tower 1 from below the biological deodorization tower 1 and passes through the gap between the microorganism-immobilizing carriers 2. During this process, the malodorous components are decomposed by the microorganisms, and are taken out from the upper end of the biological deodorization tower 1 as a processing gas.

A spray nozzle 3 is provided inside the biological deodorization tower 1.
Is provided, and the nutrient-containing water is transferred to the microorganism-immobilized carrier 2.
Water is supplied to the microorganisms to supply nutrients. In the embodiment of FIG. 1, an organic solvent for improving the dissolution rate of the malodorous component in water is added as a dissolution promoter to the water spray. This organic solvent is required to have the ability to dissolve bad odor components well, no toxicity to microorganisms, a high boiling point and low vapor pressure, so that it is difficult to volatilize by ventilation and difficult to be decomposed by microorganisms. Is done. When the malodorous component is a volatile organic carbon substance such as toluene, xylene or benzene, it is preferable to use any one of octane, decane and hexadecane as an organic solvent satisfying the above conditions. Silicon oil is also effective.

When the water to which the organic solvent is added is sprinkled from above the microorganism-immobilized carrier 2, the malodorous components in the malodorous gas are rapidly dissolved in water by the action of the organic solvent and transferred to the aqueous phase. Microbial degradation takes place. as a result,
As shown in the data of Examples described later, a very excellent deodorizing effect can be obtained as compared with the conventional method.
As shown in FIG. 1, the sprinkled water is collected from the lower part of the biological deodorization tower 1 to a separation tank 4, the organic solvent and the water containing nutrients are mixed at an appropriate ratio by a mixer 5, respectively, and then again from the spray nozzle 3. Sprinkled.

FIG. 2 is a flow sheet showing a second embodiment of the present invention. This embodiment corresponds to the fifth aspect of the present invention. In the invention according to claim 5, the beads 6 containing cyclodextrin or polycyclodextrin are packed inside the biological deodorization tower 1 together with the microorganism-immobilized carrier 2.

[0010] Cyclodextrins and polycyclodextrins are cyclic polysaccharides, and have the property that various substances can be incorporated into the central part thereof.
Although the specific mechanism has not been fully elucidated, the present inventor has found that when beads 6 containing cyclodextrin or polycyclodextrin are filled inside the biological deodorization tower 1, volatile organic compounds such as toluene, xylene, and benzene can be used. It was confirmed that the solubility of the carbon material in water was improved. Although cyclodextrin or polycyclodextrin itself may be decomposed by microorganisms, it was also confirmed that when contained in beads prepared by the sol-gel method as shown in the examples, it was not degraded by microorganisms. .

In the flow sheet of FIG. 2 as well, the malodorous gas flows upward from inside the biological deodorization tower 1 from below the biological deodorization tower 1 and passes through the gap between the microorganism-immobilized carrier 2 and the beads 6. Then, the malodorous component is decomposed, and is taken out from the upper end of the biological deodorization tower 1 as a processing gas. Examples of each invention will be described below.

[0012]

[Example 1] (Example 1) Inside a 50 mL sealed container simulating a biological deodorization tower, 8 mL of a medium containing Pseudomonas putida (a commercially available product, ATCC-23973), which is a microorganism capable of decomposing malodorous components, is placed. , 100
Air containing m-xylene at a concentration of 00 ppm was sealed, and the temporal change in m-xylene concentration in the gas phase was measured. The results are shown by black circles in the graph of FIG. The data of this black circle means the conventional method. Next, the same measurement was performed when 1 mL of hexadecane, an organic solvent, was added to 7 mL of the medium, and when 1 mL of decane was added to 7 mL of the medium. The results are indicated by white circles and black squares in the graph of FIG. As is clear from these data, when hexadecane or decane was added, the m-xylene concentration in the gas phase rapidly decreased immediately after the start of the experiment, and it was confirmed that an excellent deodorizing effect was obtained.

Next, FIG. 4 shows the result of measuring the relationship between the amount of organic solvent added and the amount of Pseudomonas putida grown. In this experiment, the total amount of the medium and the organic solvent was kept at a constant value of 8 mL, and the addition amount of the organic solvent was changed from 0 to 3 mL. The vertical axis in FIG. 4 represents the growth ratio of Pseudomonas putida when the amount of Pseudomonas putida when the organic solvent is not added is 1. The sealed container was filled with air containing 2 μL of P-xylene.

As is apparent from FIG. 4, pseudomonas.
Putida grew significantly. Combining the data of FIG. 4 with the data of FIG. 3, it can be confirmed that Pseudomonas putida grew using the malodorous component as a nutrient source and sufficiently decomposed the malodorous component.

(Example 2) 7 mL of TMOS, 3 mL of distilled water, 0.1 M
0.1 mL of hydrochloric acid was put in a container, and after sonication, 10 mL of distilled water was added. To this, 10 mL of a solution containing polycyclodextrin at a concentration of 1 g / 10 mL and 10 mL of 0.1 M sodium borate were added, stirred, and allowed to stand at 27 ° C. for 24 hours. As a result, a bulk gel was obtained, which was pulverized and washed with a phosphate buffer to obtain beads containing polycyclodextrin and having an average particle diameter of 500 μm.

1 g of the obtained beads was put in a tightly sealed container together with 8 mL of a medium containing Pseudomonas putida in the same manner as in Example 1, and air containing m-xylene at a concentration of 10,000 ppm was sealed, and the change in the concentration was measured. As a result, 3
With time, the concentration of m-xylene decreased to 500 ppm, which was less than 1/10 that of the medium alone. By introducing beads containing polycyclodextrin in this manner, the same results as in the case where an organic solvent is added can be obtained.

[0017]

As described above, according to the biological deodorizing method of the present invention, the odorous gas containing volatile organic carbon substances such as toluene, xylene and benzene as the odorous component is rapidly decomposed by the microorganism. be able to. For this reason, according to the present invention, there is an advantage that the treatment equipment for a large amount of coating exhaust gas can be made much more compact than before.

[Brief description of the drawings]

FIG. 1 is a flow sheet showing a first embodiment of the present invention.

FIG. 2 is a flow sheet showing a second embodiment of the present invention.

FIG. 3 is a graph showing a temporal change in m-xylene concentration.

FIG. 4 is a graph showing the relationship between the amount of organic solvent added and the amount of Pseudomonas putida grown.

[Explanation of symbols]

Reference Signs List 1 biological deodorization tower, 2 microorganism-immobilized carrier, 3 spray nozzle, 4 separation tank, 5 mixer, 6 beads containing cyclodextrin or polycyclodextrin

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C12N 1/20 B01D 53/34 ZAB // (C12N 1/20 C12R 1:40)

Claims (5)

[Claims] In a biological deodorization method for passing a malodorous gas through a biological deodorization tower on which microorganisms that decompose malodorous components are immobilized, a dissolution promoter is used to improve the rate of dissolution of malodorous components in water. A biological deodorizing method characterized by the following. 2. The biological deodorizing method according to claim 1, wherein the malodorous component is a volatile organic carbon substance. 3. The biological deodorization method according to claim 2, wherein the dissolution promoter is an organic solvent and is used by being added to water sprayed on the biological deodorization tower. 4. The method according to claim 3, wherein one of octane, decane and hexadecane is used as the organic solvent. 5. The biological deodorization method according to claim 2, wherein the dissolution promoter is cyclodextrin or polycyclodextrin, and beads containing these are used by filling the biological deodorization tower.