JP2000236870A - Method for biologically recovering and cleaning polluted gas by tubular bioreactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a compact apparatus capable of cleaning a large amount of polluted gases by increasing solubility of the polluted gases into a culture solution. SOLUTION: This method for biologically recovering and cleaning polluted gases is characterized to have a process which alternately introduces a predetermined amount of a culture solution and a predetermined amount of polluted gases to one opening of a tubular bioreactor filled with fillers and discharges the waste liquid and the decomposed and treated gases from another opening. The apparatus for cleaning the polluted gases is characterized in that the bioreactor filled with the filler is tubular and has a means for alternately flowing in the culture solution containing microorganisms capable of decomposing polluting materials in the gases and the gases containing the polluting materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for biologically purifying polluted gases.

[0002]

2. Description of the Related Art When purifying gaseous contaminants in a bioreactor, the dissolution rate of the contaminant gas into a microorganism culture often affects the processing efficiency of the entire reactor. Therefore, to increase the amount of gas dissolved in the culture solution, increase the contact time between the gas and the culture solution, increase the contact area between the gas and the culture solution, and improve the solubility of the gas by applying pressure and additives. And so on.

[0003] For example, a sparger is installed in the lower layer of a reactor, and contaminant gas is spouted into the culture medium as fine bubbles from a large number of pores. A bubble tower type that dissolves contaminants in the liquid, or a stirrer in the reactor tank, stirs the culture solution to bubble the gas introduced into the culture solution, and further stabilizes the bubble residence time by stirring. Aeration and agitation type that dissolves contaminants into the culture solution by dispersing the culture solution into the reactor tank with a large gas-liquid ratio in the reactor tank filled with the filler, and simultaneously sprinkles the contaminant gas with the filler A packed tower type or the like in which a contaminant gas is dissolved in a culture solution attached to the surface of a filler by passing through the space between the fillers is generally used.

[0004]

When purifying gaseous pollutants, a large amount of low-concentration pollutant gases must be used.

For example, in recent years, soil and groundwater contamination has become serious, and aeration and vacuum extraction for extracting contaminants from soil and groundwater contaminated with volatile substances have been actively performed. Generates a large amount of polluting gas.

[0006] In addition, as the effects of pollutants on the human body and the environment are becoming more evident, the purifying concentration to be cleared is lower than ever before.
It has directly led to increased throughput.

[0007] In such a case, if the size of the reaction tank is scaled up in response to the large amount of pollutant gas, equipment and operation costs are required, and further, a culture cost for supplying a large amount of culture solution and a spent culture solution are required. Will also increase the disposal costs.

In order not to increase the size of the reaction tank, it is necessary to increase the efficiency of dissolving the contaminated gas in the culture solution, but the prior art is not sufficient for that purpose.

For example, in the bubble column type, even if fine bubbles are formed by a sparger or the like, if the introduction rate of the contaminant gas increases, the proportion of the bubbles in the culture solution increases, and the bubbles fuse to form a large bubble. And the contact area between the gas and the culture solution increases, so that the dissolved amount of the gas decreases.

[0010] Although the aeration and stirring type can cope with an increase in the amount of aeration to some extent by increasing the agitation speed, if the agitation speed is too high, the microorganisms will be damaged by the shearing force, so that there is a limit.

Further, in the case of the packed tower type, even if a porous material is used for the filler in order to increase the contact area between the gas and the culture solution, the culture solution can compare the unevenness of the filler surface when the filler is wetted by the culture solution. However, the contact area cannot be so large because the cover is too thick.

[0012] From the above, it is a major task to improve the dissolving efficiency of pollutant gas in the culture solution and to develop a device capable of purifying a large amount of pollutant gas with a compact device.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems.

That is, the present invention provides a method for purifying a pollutant gas that decomposes the pollutant by introducing the gas containing the pollutant and a culture solution of the microorganism containing a microorganism capable of decomposing the pollutant into a bioreactor. , A predetermined amount of the culture solution and a predetermined amount of the contaminated gas are alternately introduced from one opening of a tubular bioreactor filled with a filler, and drainage and decomposed gas are discharged from the other opening. A method for purifying a pollutant gas, comprising the step of:

Further, in the apparatus for purifying a pollutant gas having a bioreactor filled with a filler, the bioreactor filled with the filler has a tubular shape, and the gaseous gas is removed from one opening of the tubular bioreactor. A contaminant gas purifying apparatus comprising an inflow means for alternately inflowing a culture solution of a microorganism containing a microorganism capable of decomposing a contaminant and a gas containing the contaminant.

[0016]

DETAILED DESCRIPTION OF THE INVENTION First, any degrading microorganism that can be used in the present invention may be any microorganism having a degrading ability, and is not limited to an isolated and identified microorganism at all. There is no problem even if the culture is performed in a culture solution or a culture solution containing contaminants. For example, the following isolates of TCE-degrading bacteria have been reported, and these can be used.

Welchia alkenophila sero 5 (USP
4877736, ATCC 53570), Welchia
alkenophila sero 33 (USP 4,877,736, A
TCC 53571), Methylocystis sp. Strain M
(Agric. Biol. Chem., 53, 2903 (1989), Biosci. B
iotech. Biochem., 56, 486 (1992) and 56, 736 (1992).
2)), Methylosinus trichosprium OB3b (Am.C
Hem. Soc. Natl. Meet. Dev. Environ. Microbiol., 2
9, 365 (1989), Appl. Environ. Microbiol., 55, 31.
55 (1989), Appl. Biochem. Biotechnol., 28, 877 (1
991), JP-A-2-92274, JP-A-3-2929
No. 70), Methylomonas sp. MM2 (Appl. Envir.
on. Microbiol., 57, 236 (1991)), Alcaligenes denit
rificans ssp.xylosoxidans JE75 (Arch.microb
iol., 154, 410 (1990)), Alcaligenes eutrophus.
JMP134 (Appl. Environ. Microbiol., 56, 1179)
(1990)), Mycobacterium vaccae JOB5 (J. Gen.
Microbiol., 82, 163 (1974), Appl. Environ. Micro
biol., 54, 2960 (1989), ATCC 29678), Pse
udomonas putida BH (Sewerage Association Journal, 24, 27 (198
7)), G4 strain (Appl. Environ. Microbiol., 52, 383 (19)
86), 53,949 (1987), 54,951 (1989), 56,27
9 (1990), 57, 193 (1991), USP 492580
2, ATCC 53617, Pseudomonas mendocina
KR-1 (Bio / Technol., 7,282 (1989)), Pseudomon
as putida F1 (Appl. Environ. Microbiol., 54,
1703 (1988), 54, 2578 (1988)), Pseudomonas flu
orescens PFL12 (Appl. Environ. Microbiol., 5
4,2578 (1988)), Pseudomonas putida KWI-9 (JP-A-6-70753), Pseudomonas cepacia
KK01 (Japanese Unexamined Patent Publication No. Hei 6-227770), Nitrosomo
nas europaea (Appl. Environ. Microbiol., 56, 1169)
(1990)), Lactobacillus vaginalis sp.nov (Int.
Syst. Bacteriol., 39, 368 (1989), ATCC 495.
40) If the pollutant is an organochlorine compound and requires an inducer, phenol,
There are aromatic compounds such as cresol and toluene, and methane and propane.

Next, the processing operation of the present reactor will be specifically described.

First, a filler that does not impregnate a liquid therein will be described. The culture solution and the contaminated gas are alternately introduced into the tube. First, the culture solution supplied into the tube adheres to the surface of the filler in the tube. Then, the contaminated gas supplied into the tube flows on the surface of the filler and dissolves in the culture solution on the surface of the filler. Contaminants dissolved in the culture solution are decomposed by microorganisms in the culture solution.

Thereafter, the culture solution supplied to the tube is mixed with the culture solution that has already adhered to the surface of the filler, and the culture solution having the water retention capacity of the filler is pushed out by the contaminant gas flowing next. And adhere to adjacent fillers. The flow of the gas keeps the culture solution in a thin film on the surface of the filler. The above steps are repeated, and after the culture solution is finally attached to all the fillers in the tube, the surplus culture solution is discharged out of the tube.

Next, a filler for impregnating a liquid therein will be described. First, the culture solution supplied into the tube adheres to the surface of the filler in the tube. Next, the contaminant gas supplied into the tube pressurizes the culture solution adhering to the surface of the filler to impregnate the culture solution inside the filler. The impregnated culture solution adheres to the pore surface inside the filler. The contaminant gas is dissolved in the culture solution attached to the pore surface inside the filler, and the contaminants are decomposed by microorganisms in the culture solution.

Thereafter, the culture solution supplied to the tube adheres to the surface of the filler, and the contaminant gas supplied to the tube causes the culture solution adhering to the surface of the filler to pressurize the culture solution inside the filler. It is impregnated and mixed with the culture solution that has already adhered to the pore surface inside the filler. The culture solution exceeding the water retention capacity of the filler is then pushed out by the flowing contaminant gas and adheres to the adjacent filler. The flow of the gas keeps the culture solution in a thin film on the surface of the pores inside the filler. The above process is repeated, and after the culture solution is finally attached to all the fillers in the tube, the surplus culture solution is discharged out of the tube.

The present reactor is effective for solving the problems for the following reasons.

That is, the culture solution adheres thinly to the surface of the filler, and in the case of a filler impregnated with liquid, the culture solution also adheres thinly to the pore surface inside the filler, thereby greatly impairing the unevenness of the surface of the filler. The surface area of the culture solution that comes into contact with the contaminant gas can be increased without any problem. Since the surface area of the culture solution can be increased in this manner, the amount of the culture solution necessary for the decomposition reaction of the reactor can be minimized, and the culture cost and the disposal cost of the culture solution can be reduced.

Further, the pollutant gas moves while contacting the culture solution in the elongated tube, so that the contact time between the contaminant gas and the culture solution can be maintained for a long time, thereby increasing the efficiency of dissolving the pollutant gas into the culture solution. In addition, since the contaminated gas can be supplied into the tube in a laminar flow, unlike a normal reaction tank having a large cross-sectional area in the moving direction of the contaminated gas, when the supply speed of the contaminated gas is increased, the contaminated gas and the purified gas are removed. There is no possibility that the newly supplied pollutant gas is mixed and the diluted pollutant gas is discharged. Therefore, the inflow linear velocity of the pollutant gas can be increased as much as possible according to the tube diameter.

By realizing such a high dissolving efficiency, it is possible to treat a large amount of contaminated gas. In addition, in order to realize the required processing capacity, it is only necessary to adjust the length of the tube. Can respond flexibly to changes,
The equipment is simple and small. Next, the configuration of the tube reactor of the present invention will be specifically described.

[0027] First, the tube can be made of any material as long as it is capable of passing a contaminated gas or a culture solution, and is free of contaminant gas adsorption or erosion by the contaminant gas. Some are preferred. In particular, in the case of highly adsorbable contaminants such as trichlorethylene, flexible PFA made of fluororesin
Those made from are useful.

Although the tube may be of any size, in order to sufficiently realize the effects of the present invention, the tube has an inner diameter of 10 mm or less, more preferably 5 mm or less.
mm or less. This depends on the material of the tube and the supply speed of the contaminated gas and the culture solution.However, if the tube diameter is small, the culture solution fills the inner section of the tube due to surface tension, so it is pushed out by the subsequent contaminated gas and filled. This is because it is possible to infiltrate into the entire agent and further penetrate the surface of the filler or the pores inside the filler.

On the other hand, the inner diameter of the tube may be set so as to prevent the flow of the contaminated gas and the culture solution from being clogged on the way and to obtain a stable flow. For example, the inner diameter of the tube is 2 mm or more, more preferably 3 mm. The above can be considered.

The length of the tube is set so that the desired decomposition effect can be efficiently obtained in the gas from the exhaust and drain ports of the tube.

As a method of filling the tube with the filler, it is desirable to use a method in which the filler is densely filled and the gap is reduced when the cross section of the tube is viewed. This prevents the culture medium and contaminated gas from preferentially passing through the unfilled area as a water supply or airway, and prevents culture medium and contaminated gas from permeating between and inside the packing material. To do that.

The material, structure and size of the filler may be selected so as to obtain a predetermined decomposition effect. It is desired that the material does not adsorb contaminants. Any shape may be used, but a granular or fibrous one has an advantage that it can be easily filled into a tube. As the size of the filler, for example, a filler having a size of 100 μm to 5 mm can be used.
In addition, if it is several tens of microns or less, the gap between the fillers is too small, so that it is difficult to transmit the contaminant gas and the culture solution.

With respect to the filler impregnating the liquid therein,
If the material of the filler is flexible and the inner wall of the tube and the filler or the filler are in close contact with each other and the gap between the tube and the filler or the filler can be eliminated, the permeation of the culture solution into the filler is prevented. Since it can be performed sufficiently, a high effect can be expected. The pore diameter inside the filler is desirably several tens of microns or more so as not to make it difficult for a contaminated gas or culture solution to pass through.

Specific examples of the filler that does not impregnate the liquid therein include glass beads, alumina beads, silica sand, and the like.

Examples of the filler that impregnates the liquid therein include zeolite, cellulose fiber, Teflon fiber, porous glass, chitopearl (manufactured by Fuji Boseki Co., Ltd.), and polyvinyl alcohol.

As a means for alternately supplying the culture solution and the contaminated gas to the tube reactor, any method and apparatus may be used. However, according to the method described below, the apparatus cost and operation cost can be reduced. Can be.

When an exhaust pipe connected to the outside is installed in an airtight tank, and a culture solution of microorganisms and a contaminated gas flow into the tank at the same time, an interface between the culture solution and the contaminated gas is naturally formed near the end of the discharge pipe. The culture medium and the contaminated gas which are formed and alternately flow out therefrom are introduced into a tubular bioreactor.

Specifically, in the reactor as shown in FIG. 1, a new culture medium 3 is supplied to the culture solution 2 from the bottom of the culture tank 1 of the reactor, and is directed upward. The exhaust pipe 8 is inserted from above or below the reactor, and the gas phase in the culture tank 1 is pressurized by passing the contaminant-containing gas 4 into the culture solution 2 as bubbles 7 using the diffuser 6. Then, the culture solution 2 exceeding the end 9 of the discharge tube is discharged. By determining the position of the terminal opening 9 of the discharge tube, the amount of the culture solution 2 to be stored is set.

When the culture solution that has passed through the end opening 9 of the discharge pipe is discharged, the contaminant-containing gas 4 is discharged from the discharge pipe 8. Since the supply speed of the fresh culture medium 3 is constant, the time when the culture medium 2 starts to be discharged next is almost the same, so that the culture medium 2 and the pollutant-containing gas 4 are connected to this at substantially constant intervals. To a tube reactor (eg, 230 in FIG. 2). The discharge pipe may be arranged not above the liquid surface but above as shown in FIG.

As a method of culturing the microorganism, any method may be used as long as the generated culture solution has a high decomposition activity. When the activity of decomposing microorganisms is reduced by the decomposition of contaminants, it is necessary to continuously supply a culture solution to the reactor.
Even in batch culture, there is no particular problem if equipment for alternately performing culture and supply to the reactor using two or more culture devices is provided.

If the growth of the microorganisms is not hindered by the decomposition of the contaminants, the microorganisms may be cultured by the apparatus itself that supplies the culture solution and the contaminant gas alternately.

The amount of microorganisms to be supplied to the tube reactor may be appropriately set depending on the concentration of the pollutant gas, the supply speed, and the resolution of the microorganisms. When the dissolution rate in the culture solution is the rate-limiting of the processing capacity of the tube reactor, it is advantageous to reduce the culture solution of the microorganism as much as possible in that the culture cost of the culture solution to be supplied and the disposal cost of the culture solution can be saved. is there.

Next, FIG. 2 shows the configuration of a typical purification device of the present invention.

The culture tank 11 and the culture liquid / contaminated gas alternate supply tank 21 are connected in series, and the discharge pipe 28 of the latter 21 continues to the tube reactor 33 containing the filler, and the tip thereof is connected to the gas-liquid separation tank 31. I have.

In this case, the culture tank 11 is for purely culturing the culture solution 12 of microorganisms, and the ordinary air 14 is blown as bubbles 17 by the diffuser 16. Excess air is appropriately discharged from the exhaust port 15. The supply of the new culture medium 3 and the setting of the amount of the culture solution 12 to be stored by determining the position of the discharge pipe terminal opening 19 are the same as those in FIG.

In this figure, the discharge pipe 18 faces upward, and is supplied to the culture liquid / contaminated gas alternate supply tank 21 by the pressure of ventilation and suction by the motor 10 of the pump.

The system of the culture liquid / contaminated gas alternate supply tank 21 is basically the same as the culture tank 1 of FIG. The culture solution and the contaminated gas are subjected to sufficient gas-liquid contact and microbial decomposition in the tube reactor 33 via the discharge pipe 28, and then the gas-liquid separation tank 3
1 is supplied. Here, the gas to be treated 34 is separated from the treated culture solution 32 in the form of bubbles 37 and then discharged from the discharge pipe terminal opening 39.

In the present reactor, the supplied culture solution is spread thinly on the surface of the filler or the tube surface by the inflow pressure of the contaminant gas, and the surface area of the culture solution can be increased. Therefore, the amount of culture solution required for the decomposition reaction of the reactor is minimized. Thus, the amount of the culture solution to be supplied can be reduced.

The conventional packed tower reactor requires a relatively small amount of culture solution. However, in order to increase the contact area between the culture solution and the contaminant gas, the use of a filler having a large surface area or a very small one is required. The amount of the culture solution held between them increased, and the amount of contaminated gas dissolved in the amount of the culture solution decreased accordingly. In this reactor, for example, the volume ratio of the microorganism culture solution introduced into the tube to the total volume of the tube is set to 10% or less, preferably 1% to 10%, and the ratio of the amount of the culture solution in contact with the gas is set. To increase the decomposition efficiency.

If the decomposing activity of the culture discharged from the tube reactor can still be effectively used for treatment in this apparatus, as in the case where the decomposing activity of microorganisms does not decrease due to contaminants, the discharged culture can be used. It may be circulated again to the tube reactor to save the culture solution.

Although the contaminants to be treated in the tube reactor are intended to be those in the gas, even the contaminants present in the liquid or solid are transferred to the gas by aeration or heating to be treated by the tube reactor. Becomes possible.

Further, in the tube reactor, the contaminated gas can be supplied into the tube in a laminar flow. Therefore, unlike a normal reaction tank having a large cross-sectional area in the moving direction of the contaminated gas, when the supply speed of the contaminated gas is increased. There is no danger that the purified gas and the newly supplied contaminated gas are mixed and the diluted contaminated gas is discharged.

Therefore, the inflow linear velocity of the pollutant gas can be increased as much as possible according to the tube diameter. For example, 10 m / min or more with respect to the moving direction of the gas, the upper limit of which can be set within a range where the decomposition effect can be obtained,
Preferably, the inflow linear velocity of the pollutant gas can be set to 1 m / min or more and 10 m / min or less.

Hereinafter, the present invention will be described more specifically with reference to examples.

[0055]

[Example 1] [Example 1] Trichlorethylene purification test using a tube reactor using a liquid impervious filler J1 strain (FERM, FERM, Ministry of International Trade and Industry)
BP-5102, date of deposit: May 25, 1994). The J1 strain requires the presence of a chemical called an inducer to degrade trichlorethylene. That is, the target organic chlorine compound can be decomposed by the enzyme expressed to decompose the inducer. In this example, phenol was used as an inducer for the J1 strain.

The J1 strain was converted to phenol 200 in a Sakaguchi flask.
200 ml of an M9 medium containing ppm and minerals was inoculated, and shaking culture was performed at 23.5 ° C. for 24 hours. This culture solution 3 is placed in a culture tank 11 (46 mmΦ × 300) as shown in FIG.
mm), and aerated with a flow rate of 20 mL / min.
L / hr was supplied, and continuous culture was performed while controlling the temperature at 23.5 ° C.

When the amount of the culture solution stored in the culture tank 11 is 380
The position of the outlet end 19 was set to be mL. The culture medium 12 produced in excess of the set culture medium volume is supplied to the culture medium / contaminated gas alternate supply tank 2 as shown in FIG.
1 (46 mmΦ × 100 mm, stored culture solution volume 90 mL).

A gas 24 in which trichlorethylene was mixed with air was introduced from a permeator (not shown) into the culture solution / contaminated gas alternate supply tank, and was blown out as bubbles 27 into the culture solution 24 by a diffuser 26. At this time, the introduced concentration of trichlorethylene is about 5 pp as a gas phase concentration.
m, and the supply speed was 50 mL / min.

A tube-like reaction tank 33 (4 mmΦ × 160) filled with glass beads having a particle diameter of 1 mm as shown in FIG.
000 mm, and the volume of the stored culture solution is 200 mL). The gas-liquid separation tank 31 (46) separates the culture solution 32 discharged from the reaction tank 33 and the treated gas 34 into a gas and a liquid as shown in FIG.
mmΦ × 100 mm, and the volume of the stored culture solution was 90 mL).

The total amount of the culture solution during the contact between the culture solution and the contaminated gas from the culture solution / contaminated gas alternate supply tank 21 to the gas-liquid separation tank 31 via the reaction tank 33 was 380 mL.

Twenty-four hours after the start of the supply of trichlorethylene, the gas 34 in the gas phase of the gas-liquid separation tank 31 is sampled from the sampling port 30 using a syringe (not shown), and is sampled by gas chromatography (not shown). It was measured as the concentration of trichlorethylene discharged from the reactor.

Further, the supply rate of the trichlorethylene contaminated gas was set to 100, 150, 200, 250, 300 mL / m
The concentration was gradually increased to in, and the concentration of trichlorethylene discharged from the reactor was measured in the same manner.

FIG. 5 shows the above measurement results.

[Comparative Example 1-1] The J1 strain was continuously cultured in the same manner as in Example 1, and the produced culture solution 12 was used in a bubble column type reaction vessel 41 (46 mmΦ × 300 mm, stored culture solution) as shown in FIG. (380 mL).

The reaction tank has the same configuration as the culture tank 11 (same as in Example 1) except that the size of the reaction tank is the same as that of the culture tank 11 (Example 1). This is equivalent to one culture tank. That is, trichlorethylene was introduced into the reaction tank as a gas 24 mixed with air from a permeator (not shown), and was blown out as bubbles into the culture solution 22 by the diffuser 26. At this time, the introduction concentration of trichlorethylene was about 5 ppm as a gas phase concentration,
The supply speed was 50 mL / min.

Twenty-four hours after the start of the supply of trichlorethylene, the gas 34 in the gas phase of the reaction tank 41 is sampled from the sampling port 30 using a syringe (not shown), and is sampled from the reactor by gas chromatography (not shown). It was measured as the concentration of trichlorethylene discharged.

Further, the feed rate of the trichlorethylene contaminated gas was set to 100, 150, 200, 250, 300 mL / m
The concentration was gradually increased to in, and the concentration of trichlorethylene discharged from the reactor was measured in the same manner.

FIG. 5 shows the above measurement results.

[Comparative Example 1-2] The J1 strain was continuously cultured in the same manner as in Example 1.
packed into a reaction vessel 51 (46 mmΦ × 1200 m
m, 200 mL of the adherent culture solution in the 53 parts of the filler, 180 mL of the culture solution in the liquid collection portion, and 380 mL of the total culture solution stored in the tank. Trichlorethylene is introduced into the reaction vessel 51 from a permeator (not shown) as a gas 24 in which air is mixed with air.
As a result, bubbles were spouted into the culture solution 22 at the liquid collection portion. At this time, the introduction concentration of trichlorethylene was about 5 ppm in gas phase concentration, and the supply rate was 50 mL / min.

24 hours after the start of the supply of trichlorethylene, the gas 34 in the gas phase of the reaction tank 51 is sampled from the sampling port 30 using a syringe (not shown), and is sampled from the reactor by gas chromatography (not shown). It was measured as the concentration of trichlorethylene discharged.

Further, the supply rate of the trichlorethylene contaminated gas was set to 100, 150, 200, 250, 300 mL / m
The concentration was gradually increased to in, and the concentration of trichlorethylene discharged from the reactor was measured in the same manner.

FIG. 5 shows the results of the above measurement.

In Example 1, Comparative Examples 1-1 and 1-2, the same amount of culture solution was used for the decomposition, but the residual trichlorethylene concentration in the exhaust gas was lowest in Example 1, and the decomposition efficiency was the lowest. It can be said that it is high. This indicates that the reactor of the present invention can efficiently decompose trichlorethylene contaminated gas.

[Example 2] Purification test of trichlorethylene by a tube reactor using a liquid permeable filler Pseudomonas cepacia KK01 strain as a microorganism that decomposes trichlorethylene
(Ministry of International Trade and Industry, National Institute of Advanced Industrial Science and Technology
RM BP-4235, accession date: March 11, 1992). The KK01 strain requires an inducer to decompose trichlorethylene, and in this example, phenol was used.

The experiment was performed in a tubular reaction tank 33 (4 mmΦ).
The same procedure as in Example 1 was carried out except that Teflon fiber (manufactured by DuPont, fiber diameter: 0.02 mm) was filled in × 80000 mm and the volume of the stored culture solution was 200 mL.

FIG. 6 shows the results.

[Comparative Example 2-1] The same experiment as in Comparative Example 1-1 was performed except that the KK01 strain was used as a trichloroethylene-degrading microorganism.

FIG. 6 shows the results.

[Comparative Example 2-2] Using a KK01 strain as a trichloroethylene-degrading microorganism, a packed-tower type reaction vessel (46 mmΦ × 1000 mm, filled with Teflon fiber (manufactured by DuPont, fiber diameter: 0.02 mm)) filled with 1000 mL, filler part 200 mL of the attached culture solution, 180 mL of the culture solution in the collection part
Comparative Example 1-2 except that 380 mL of the culture solution stored in the tank was used.
The same experiment was performed.

FIG. 6 shows the results.

Although the same amount of culture solution is used for decomposition in both the examples and comparative examples, the concentration of residual trichlorethylene in the exhaust gas is the lowest in the examples and the decomposition efficiency is the highest.
This indicates that the reactor of the present invention can efficiently decompose trichlorethylene contaminated gas.

[0082]

According to the present invention, the efficiency of purifying pollutant gas by the bioreactor can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a basic configuration of a culture tank used in a purification apparatus of the present invention and an operation principle of the apparatus.

FIG. 2 is a diagram showing a purification device according to an embodiment of the present invention.

FIG. 3 is a diagram showing, as a comparative example, a purification apparatus having a configuration using a bubble column without using a tubular bioreactor filled with a filler, unlike the present invention.

FIG. 4 is a diagram showing, as a comparative example, a purifying apparatus having a configuration using a conventionally used packed tower instead of a tubular bioreactor, which is further different from the present invention.

FIG. 5 is a graph showing measurement results in Example 1 together with Comparative Examples.

FIG. 6 is a graph showing a measurement result in Example 2 together with a comparative example.

[Explanation of symbols]

 1 Culture tank (direct introduction of gas containing contaminants) 2, 22 Culture solution 3 Supply medium 4, 24 Gas containing contaminants 5 Exhaust / Drainage 6, 26 Diffuser (for gas containing contaminants) 7, 27 Bubbles (contains contaminants) Gas) 8, 28 Drain pipe (for exhaust / drainage containing pollutants) 9, 29 Drain pipe opening (for exhaust / drainage containing pollutants) 10 Motor 11 Culture tank (for culture / induction) 12 Culture solution (culture)・ Induction only 14 Air 15 Exhaust port 16 Diffuser (For air) 17 Bubbles (Air) 18 Discharge pipe (For exhaust / drainage containing air) 19 Opening of exhaust pipe (For exhaust / drainage containing air) 21 Culture solution ・Contaminated gas alternate supply tank 30 Sampling port 31 Gas-liquid separation tank 32 Culture solution 33 Tube reactor 34 Gas to be treated 35 Exhaust / drainage (pollutant decomposed) 37 Bubbles (gas to be treated) 38 Discharge pipe (exhaust after pollutant decomposed)・ Drainage ) 39 discharge pipe opening (for pollutant degradation already exhaust-drain) 41 bubble column 50 water spray device 51 packed tower 53 filler

Continued on front page F-term (reference) 4B029 AA02 AA05 BB01 CC01 CC02 CC10 CC13 DA05 DA06 DB11 DF01 DF03 DF04 DF05 DF09 DF10 DG06 4B065 AA01X AA57X AC20 BB01 BC01 BC03 BC05 BC12 BC20 BC23 BC41 BC42 BC50 CA56

Claims (14)

[Claims] 1. A method for purifying a pollutant gas, which comprises introducing a gas containing a pollutant and a culture solution of the microorganism containing a microorganism capable of decomposing the pollutant into a bioreactor to decompose the pollutant, A step of alternately introducing a predetermined amount of the culture solution and a predetermined amount of the contaminated gas from one opening of a tubular bioreactor filled with an agent, and discharging the drainage and the decomposed gas from the other opening. A method for purifying a pollutant gas, comprising: 2. The method according to claim 1, wherein the inner diameter of the tube is 10 mm or less. 3. The method according to claim 1, wherein a linear velocity of the gas moving in the reactor is 10 m / min or more with respect to a moving direction of the gas. 4. The reactor according to claim 1, wherein the volume ratio of the microorganism culture solution in the reactor to the volume of the reactor is 10% or less.
4. The method according to any one of claims 3 to 3. 5. A step of forming a liquid phase of a culture solution of the microorganism holding the degrading microorganism in an airtight tank and a gas phase in contact with the liquid phase, and culturing the microorganism in the liquid phase. The gas containing the liquid and the contaminant is further introduced, and the culture pressure containing the microorganism and the gas containing the contaminant alternately flow out of the discharge pipe having an opening near the interface between the liquid phase and the gas phase due to the inflow pressure. The method according to any one of claims 1 to 4, further comprising the step of: introducing the mixture into the tubular bioreactor. 6. The method according to claim 1, wherein the filler is a porous body.
6. The method according to any one of claims 1 to 5. 7. The method according to claim 1, wherein the contaminant is trichloroethylene. 8. An apparatus for purifying contaminated gas having a bioreactor filled with a filler, wherein the bioreactor filled with the filler is tubular, and the gaseous gas is removed from one opening of the tubular bioreactor. An apparatus for purifying a polluted gas, comprising an inflow means for alternately flowing a culture solution of the microorganism containing a microorganism capable of decomposing a pollutant and a gas containing the pollutant. 9. The apparatus according to claim 8, wherein the inner diameter of the tube is 10 mm or less. 10. The linear velocity of gas moving in the reactor is at least 10 m / min with respect to the direction of gas movement.
Apparatus according to claim 8 or claim 9, wherein: 11. The apparatus according to claim 8, wherein a volume ratio of the microorganism culture solution in the reactor to the volume of the reactor can be 10% or less. 12. The inflow means includes means for forming a liquid phase comprising a culture solution of the microorganisms holding the microorganisms in an airtight tank, and a gas phase in contact with the liquid phase; Means for introducing a culture solution of a microorganism and a contaminated gas into the inside thereof, and an opening positioned near an interface between the liquid phase and the gas phase due to the inflow pressure, and an outlet pipe for allowing a culture solution of the microorganism and a contaminated gas to flow out alternately The device according to any one of claims 8 to 11, comprising: 13. The apparatus according to claim 8, wherein the filler is a porous body. 14. The apparatus according to claim 8, wherein the pollutant of the pollutant gas is trichlorethylene.