JPH09276842A - Method for transporting bacteria into soil and method for purifying contaminated soil environment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the decomposition efficiency of a contaminant by mixing a compsn. containing bacteria with a fluid containing a gas phase and injecting the mixed fluid into soil to accelerate the transport of bacteria within soil to distribute bacteria over a wide range. SOLUTION: In purifying soil environment contaminated by the leakage of a hydrocarbon compd., a halogen type org. solvent and a chemical substance such as a metal or the like to environment by using the action of bacteria, bacteria are introduced into the soil environment along with a fluid containing a gas phase to treat the soil environment. The fluid containing the gas phase is one consisting of three phases containing a gas phase, a liquid phase and, according to circumstances, a solid phase and the solvent of the liquid phase is water and the gas phase in the liquid phase is present in such a state that air is dispersed in the liquid phase to float or a large number of air bubbles are gathered to be mutually brought into a closely contact state across liquid membranes. In this case, the gas phase ratio of the gas phase-containing fluid is set to 0.4-0.95.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention provides a method for promoting or controlling the mobility of microorganisms introduced into a soil environment. Furthermore, the present invention relates to a method for efficiently purifying the environment of soil, groundwater, etc. by transporting and introducing microorganisms into the soil environment polluted by pollutants using the method.

[0002]

[Prior Art] While the progress of science and technology and the development of industry,
Hydrocarbon compounds derived from crude oil, halogen-based organic solvents, and chemical substances such as heavy metals leak into the environment, causing environmental pollution, and there is a concern that human health and natural ecosystems may be adversely affected. Therefore, it is desired to establish a technique for preventing the spread of environmental pollution and restoring the polluted environment.

In recent years, pollution of soil and groundwater environments has become particularly clear, and various methods for repairing contaminated soil have been proposed and applied to restore the original environment by removing pollutants. . For example, physicochemical methods such as the method of digging up the soil at the contaminated site to volatilize and incinerate the pollutants, the method of pumping up contaminated groundwater, the method of extracting soil vapor, and the method of aeration are being repaired. . However, it is often the case that the conventional method is not appropriate because of the types and concentrations of pollutants, the geological environment of contaminated geological formations, costs, operability, and environmental impact.

In contrast to these physicochemical methods, a method (bioremediation) for purifying / restoring a polluted environment by utilizing the action of a microorganism capable of decomposing pollutants has been examined as an effective method. . Bioremediation is based on the condition that the repair process is mild compared to the conventional physicochemical method,
The advantage is that no large-scale civil engineering work or capital investment is required. Furthermore, it is said that it is possible to repair even low-level pollution, which is difficult by physicochemical methods.

[0005] A typical method of bioremediation is to collect the microorganisms that have accumulated in the environment due to the appearance of pollutant chemicals and have the activity of assimilating the pollutants. This is a method of purifying by using it. However, the application of this method is limited to the case where indigenous microorganisms that decompose the corresponding pollutants inhabit the polluted soil in advance.

[0006] Further, in soils contaminated with hardly biodegradable substances such as trichlorethylene, microorganisms capable of decomposing the pollutants are often not inhabited in the contaminated soil in advance. Furthermore, even when indigenous microorganisms capable of decomposing pollutants are present in the soil environment, they may not exhibit sufficient degrading activity due to the small number of such microorganisms.

[0007] As described above, when it is not possible to achieve the purification of the pollution by the indigenous microorganisms alone, an alien microorganism capable of decomposing the contaminant is artificially introduced into the contaminated soil, and further, if necessary. Bioremediation is carried out by supplying nutrients, oxygen, etc. to the degrading microorganisms.

[0008] When introducing microorganisms into the soil from the outside, some problems remain unsolved, which prevents the spread of bioremediation using this method. One of the features of bioremediation is that it is based on in situ treatment. In this treatment method, in order to decompose the pollutants in the ground by using the microorganisms introduced from the outside, in addition to maintaining the pollutant decomposition activity of the microorganisms, contacting the contaminants with the microorganisms, Moreover, it is necessary to efficiently and uniformly disperse and transport microorganisms to a large contaminated area in the ground.

As a method for promoting the transport of microorganisms in the soil, a high pressure is generated in the soil to form a crack in the formation,
Attempts have been made to increase the permeability of fluids containing microorganisms. However, in this method, there are drawbacks such that the formation of cracks is locally limited and cannot cover a wide area, the transport of microorganisms remains around the cracks and does not disperse evenly, and disturbs the formation, which makes it practical. The effect is poor.

It is known that the coexistence of a surfactant in order to promote the contact between the microorganism and the fat-soluble pollutant improves the decomposition efficiency of the pollutant by the microorganism. However, in this case, the surfactant dissolves the pollutant in the aqueous phase and has the effect of promoting the utilization by the microorganism, but does not promote the transportation of the microorganism.

[0011]

Generally, even if a liquid containing microorganisms is directly introduced into the soil, the microorganisms are not transported together with the liquid and tend to remain around the injection point. One of the reasons for this is that the interaction between the microorganisms and the soil particles causes the microorganisms to adsorb to the soil particles and prevent them from moving, or that the microorganisms accumulate in the gaps between the soil particles and cause clogging. .

Further, since the microorganisms try to survive by adhering to the soil particles in the soil, even if the concentration of the microorganisms injected to prevent clogging is kept low, the microorganisms are trapped by the soil particles in the middle, It has been difficult to transport to a target contaminated area or to distribute microorganisms so as to cover the entire contaminated area. Depending on the geology, the pores are small due to the dense packing of soil particles, and even if the liquid injection itself resists, the microorganisms may not be able to be further transported and oxygen may not be supplied.

In addition to the above problems, in the bioremediation technique, the pollutants are decomposed by microorganisms, and the microorganisms and nutrients introduced into the soil are
Preventing unnecessary diffusion into the groundwater system is also an important issue. In light of environmental standards of soil and groundwater, the concentrations of phosphorus and nitrogen compounds used for the reproduction of microorganisms are not in a negligible range, which is an obstacle to the progress of bioremediation technology.

The microorganisms used here are required to have no pathogenicity or infectiousness to the human body, and to meet certain criteria for toxicity to the ecosystem. However, even if the microorganisms used are not pathogenic or environmentally toxic to the human body, inadvertent release of large amounts of foreign microorganisms into the environment may disturb the composition of the ecosystem. Is not preferable.

Conventionally, in order to limit the transportation range, there has been a means for preventing diffusion only by providing an impermeable barrier such as an impermeable wall. Furthermore, since the efficiency of transportation and diffusion of microorganisms and nutrients is low, it was necessary to send a large amount of microorganisms and nutrients into the soil. It has been difficult to prevent the spread of these excess microorganisms and nutrients to unnecessary areas.

The object of the present invention is to promote the transport of microorganisms in soil so that the microorganisms are uniformly distributed over a wide range.
The invention also aims to control the transport of microorganisms in the soil and to limit their distribution. In addition, the present invention is
When introducing microorganisms having the ability to decompose environmental pollutants into a contaminated soil environment, the object is to promote or control the transport of microorganisms in the soil to efficiently decompose the pollutants.

[0017]

[Means for Solving the Problems] The present invention for solving the above problems is a method for transporting microorganisms in a soil environment, which comprises introducing microorganisms into a soil together with a fluid containing a gas phase. . Furthermore, the present invention is a method for purifying a soil environment polluted with harmful substances by using the action of microorganisms, wherein the microorganisms are introduced into the soil environment together with a fluid containing a gas phase. It is a purification method.

In the present invention, a fluid forming a gas phase is used as a medium for transporting microorganisms. The present inventors have investigated the interaction between a fluid containing microorganisms and soil particles,
As a result of consideration from the aspect of the interfacial phenomenon, it was concluded that a fluid containing a gas phase acts as a transport medium for microorganisms by the following mechanism, and the present invention was completed.

That is, considering the formation of bubbles due to the presence of the surfactant, it can be considered as follows regarding the existence form of the microorganisms in the bubbles. In the fluid forming the bubbles, the bubbles are assembled and adjacent to each other. The point where those bubbles meet is called the plateau boundary and exhibits negative capillary pressure. Therefore, the liquid phase in the other part, where both surfaces of the foam film are parallel, tends to flow towards the plateau boundary. Surfactant molecules are present in the foam film with the hydrophobic groups facing the gas phase and the hydrophilic groups facing the liquid phase. Microorganisms existing in the liquid phase should have weak interaction with hydrophilic groups or tend to exist in the liquid phase away from the gas-liquid interface when they repel, so they should be concentrated at the center of the plateau boundary. Become. This protects the microorganisms from interacting directly with soil particles, prevents them from being trapped in the soil during transportation, and improves transportation efficiency.

In the present invention, the fluid containing the gas phase means
For example, it means a fluid consisting of two phases of a gas phase and a liquid phase or three phases including a solid phase in some cases, and a solvent of the liquid phase is water. In addition, as the existence form of the gas phase in the liquid phase, gas is dispersed in the liquid phase and floats (air bubbles), and a large number of air bubbles are aggregated and are in close contact with each other across a thin film of liquid ( Foam) is present. In the present invention, it is defined as a fluid containing both of them and containing a gas phase, and can be used in the present invention. Further, in the unsaturated layer where the formation is not saturated with groundwater, it is desirable that the vapor phase takes the form of foam. Further, it is desirable that the gas phase rate is as high as possible in the range where the foam is stably present, and more specifically, the gas phase rate of the fluid is preferably 0.4 to 0.95.

In the present invention, a surfactant is used to form a gas phase in the fluid. As a surfactant,
Strong foaming effect, low toxicity to microorganisms,
It is desirable to have properties such as low environmental toxicity or biodegradability. Among these properties, the charge of the hydrophilic group is the most important factor in the present invention.

Microorganisms interact with the hydrophilic groups of surfactants, the strongest of which is electrostatic interactions. The surface of the microorganism is generally negatively charged, and the strongest repulsive force is generated when the hydrophilic group of the surfactant is negatively charged. Therefore, an anionic surfactant,
Alternatively, a zwitterionic surfactant having a hydrophilic group in a negatively charged state is preferably used. The zwitterionic surfactant must be adjusted in pH so as to have a negative charge, but conversely, by adjusting the pH, the retention of the microorganism,
There is also an advantage that the ability to form bubbles can be controlled.

As the anionic surfactant, alkylbenzene sulfonate, α-olefin sulfonate,
An alkyl sulfate, an alkyl polyoxyethylene sulfate, etc. can be used. Nonionic surfactants have a structure that does not have an anionic group and are excellent in hard water resistance and suitable for use in soil environment, but when used alone, the foaming power is inferior to that of anionic surfactants. It is not suitable for single use because it has poor biodegradability such as alkyl polyoxyethylene ether. Fatty acid diethanolamide or the like is used as a foam stabilizing aid for an anionic surfactant. Cationic surfactants have a low foaming power and rather have a bactericidal effect, and are not suitable for the purpose of the present invention. Various surfactants satisfying the above conditions are added to the liquid phase in an appropriate concentration range to generate foam by a stirrer or the like,
Introduce gas phase.

In order to transport microorganisms over a wide area in soil, it is desirable that bubbles are stably present. For this purpose, a foam stabilizer can be added in addition to the surfactant. As the foam stabilizer, fatty acid mono- or diethanolamide, long-chain alcohol, amine oxide,
Carboxybetaine, sulfobetaine, hydroxyalkylamide, alkyl sulfoxide and the like can be used.

Conventionally, in order to transport microorganisms to the unsaturated layer, it was necessary to replace the gas phase in the unsaturated layer with water to form a continuous phase of water. However, according to this method, not only the above-mentioned problems occur in the transportation of microorganisms but also the ground changes due to an increase in the water content, which may adversely affect ground subsidence, liquefaction, and the like. According to the present invention, by including a large amount of gas phase in the fluid injected into the soil, it is possible to suppress the increase in the water content in the unsaturated layer to a small amount, and prevent the lack of oxygen and the adverse effect on the ground. You can

The volume of the total fluid required to transport a certain amount of microorganisms is increased by the volume of the gas phase when the fluid contains the gas phase. Therefore, when the same volume of liquid phase is introduced into soil, its transport range is expanded. Further, if the transport volume is limited to a certain range, the substantial volume of the microbial transport fluid excluding the gas phase can be significantly reduced, so that the required amount of microorganisms and nutrients can be saved, and not only the economic effect can be achieved. It also has the effect of reducing the burden on the environment.

The present invention is effective not only for facilitating the transportation of microorganisms in soil, but also for limiting the transportation range. According to the present invention, since microorganisms and nutrients are transported by a fluid containing a gas phase having a large volume ratio, transportation is stopped by providing a means for erasing the gas phase in any fluid. And the control of the transportation range can be performed. As a means for eliminating the gas phase in the fluid, it is convenient to use an antifoaming agent. As the defoaming agent, higher alcohol, fatty acid ester, polypropylene glycol, silicone oil emulsion and the like can be used. Since the defoaming agent acts only on the gas-liquid interface to destabilize the foam, the necessary amount can be suppressed to a small amount in consideration of the load on the environment.

Further, the present invention is characterized by purifying the environment by applying to the ecosystem an alien microorganism having a substance-converting ability for environmental purification, based on the above-mentioned alien microorganism survival method. It is the environmental purification method. According to the survival method, the substance converting ability of the foreign microorganisms can be efficiently utilized when decomposing pollutants and the like, so that the contaminated environment can be promptly purified with low labor.

The soil environment targeted by the present invention means an environment that includes all the elements that are under the surface of the earth and that form the stratum. Therefore, elements such as soil particles, soil microbes, humus, and groundwater are all included. Furthermore, in a soil environment contaminated with environmental pollutants, the pollutants and their degradative metabolites are also constituent elements.

Next, in the present invention, the foreign microorganisms include yeasts, fungi,
Mushrooms, bacteria, actinomycetes, single cell algae, viruses, protozoa, and animal or plant cell and tissue cultures are included, but bacteria, actinomycetes and the like are preferable from the viewpoint of practicality and action effects.

For example, in addition to bacteria of the genus Pseudomonas used for decomposing organic compounds (for example, petroleum hydrocarbons), Methylosinus, Methylomonas, Methylobacterium, which are known to have the ability to decompose various harmful substances, Al
kaligenes, Mycobacterium, Nitrosomonas, Xanthomona
s, Spirillum, Vibrio, Bacterium, Acromobacter, Aci
netobacter, Flavobacterium, Chromobacterium, Desul
fotomaculum, Micrococcus, Sarcina, Bacillus, Strep
tomyces, Nocardia, Corynebacterium, Pseudobacteriu
m, Arthrobacter, Bravibaterium, Saccharomyces, Lac
Microorganisms belonging to each genus of tobacillus can be used.

As the foreign microorganisms to be introduced, those already isolated or those screened according to the purpose from the environment can be used, and a mixed system of a plurality of strains may be used.
Furthermore, in the case of being separated by screening, it may be unidentified. Further, it may be a microbial strain different from the wild type due to mutation, fusion, gene recombination and the like.

The foreign microorganisms are not limited to the above-mentioned ones, and any microorganism may be used as long as it is a microorganism that originally does not survive in the soil environment to be introduced.
Further, the alien microorganisms in the present invention also include indigenous microorganisms existing in advance in the ecosystem to be introduced and having the ability to convert substances for environmental purification. It is known that microbial groups that assimilate the pollutants often accumulate in polluted ecosystems. When the number of individuals in the ecosystem is not sufficient to exert the ability of the microorganism, the microorganism is isolated, cultured and proliferated,
It will be introduced again into the ecosystem.

The number of foreign microorganisms to be introduced is appropriately determined depending on the substance conversion ability expected of the microorganism, the concentration of the decomposition target substance, and the like.
Just make a decision. For this reason, before actually introducing it, test introduction with a model system experimentally or experimentally,
It is advisable to calculate the required quantity. As a guideline, the number of foreign microorganisms introduced, depending on the kind of the microorganism, defining ecosystems per milliliter 10 ⁵ to 10 ¹⁰ cfu, preferably from 10 ⁷ to 10 about ¹⁰ cfu.

If the introduced amount is too small, foreign microorganisms can survive, but it is difficult to recognize the effect of decomposing the target substance.
On the other hand, if the amount introduced is too large, the nutrient source will be insufficient and a sudden anaerobic condition will occur, resulting in a large decrease in the introduced bacteria and a significant decrease in the effect.

By utilizing the above-mentioned method for surviving foreign microorganisms, environmental purification can be carried out efficiently and by selecting a means having a low environmental load. In this case, it is sufficient to select, as the alien microorganism, an effective microorganism having a substance converting ability particularly necessary for environmental purification, and it may be appropriately selected according to the target substance.

Examples of microorganisms preferably used in the practice of the present invention include J1 strain (FERM BP-5102) and its mutant strain JM1 strain (FERM BP-5352). The mycological characteristics of the J1 strain / JM1 strain are as follows.

Gram stainability and morphology: Gram-negative bacilli Growth in each medium BHIA: Good growth MacConkey: Viable Colony color: Cream Optimum temperature: 25 ° C> 30 ° C> 35 ° C Motility: Negative (semi-fluid medium) ) TSI (slant / butt): alkali / alkali, H ₂ S (−) oxidase: positive (weak) catalase: positive sugar fermentation glucose: negative sucrose: negative raffinose: negative galactose: negative maltose: negative urease: positive esculin Hydrolysis (β-glucosidase): Positive Nitrate reduction: Negative Indole productivity: Negative Glucose acidification: Negative Arginine dihydrolase: Negative Gelatin hydrolysis (protease): Negative β-galactosidase: Negative Assimilation of each compound Glucose: Negative L- Arabinose Negative D-mannose: Negative D-mannitol: Negative N-acetyl-D-glucosamine: Negative Maltose: Negative Potassium gluconate: Negative n-Capric acid: Positive Adipic acid: Negative dl-Malic acid: Positive Sodium citrate: Positive Acetic acid Phenyl: negative

[0039]

The present invention will be described below with reference to examples. Example 1 FIG. 1 is a device configuration diagram showing an embodiment of the present invention.
A bubble generator (1), a microbial transport liquid supply tank (2), a microbial supply tank (3), a liquid transfer pump at a point on the ground directly below the contaminated area
Install (4). Further, the injection well (5) is replaced with the contaminated area (6).
Excavate downwards to reach the lower end of the contaminated area. A portion of the injection well that penetrates the contaminated region has a porous wall, and the foam transport fluid is supplied to the contaminated region from that portion.

A microbial transportation liquid containing a foaming agent, a foaming auxiliary agent, a pH buffering agent, etc. is introduced into the foam generating apparatus. The bubble generating device generates a bubble containing air as a gas phase by a rotating disk mechanism. Foam formation and microbial mixing are done separately. Microorganisms may lose their activity due to elasticity and interfacial tension due to the operation of a foaming device such as high-speed stirring. Therefore, the microorganisms are added after foam formation. A culture solution containing microorganisms is added to the generated bubbles, and the microorganisms are mixed so as to spread over the entire fluid, and the mixture is pressure-fed to the injection well by a connected liquid feed pump.

The microorganism-containing transport liquid injected into the unsaturated layer spreads radially from the point of injection into the stratum in accordance with the transport resistance of various parts of the stratum. When the contaminated region extends over the saturated aquifer, an injection point is provided at the lower end of the contaminated region, and the fact that the injected bubbles float up due to the difference in specific gravity is used to cover the contaminated region.

An antifoaming agent is used to limit the injection area and stop the transport of microorganisms. By injecting the defoaming agent from the injection well, the bubbles are defoamed and the transport fluid becomes only the liquid phase containing no gas phase. The transport is stopped because the effect of bubbles on the transport in soil disappears. Example 2 A soil column is used as a model experimental system in order to closely track the transport process of microorganisms transported by bubbles in soil. A borosilicate glass tube with an inner diameter of 3 cm and a length of 50 cm was filled with soil to form a soil column. The column is installed horizontally, and one end is connected to a device for injecting bubbles containing microorganisms,
At the other end, the concentrations of microorganisms and solutes in the liquid phase flowing out were measured. As a control, a microbial transportation solution and a microorganism in which the volume of the liquid phase was the same and only foaming was not performed were used.

Two types of columns were prepared using loam soil as soil. The gas phase ratio of the soil in the column was 0.24. As the surfactant, sodium dodecylbenzenesulfonate (anionic) was used at a concentration of 1 g / L. As for microorganisms, the applicant of the present invention
J1 strain (deposit number FERM BP-, which was isolated from sandy soil around 8 m and deposited at the Institute of Biotechnology, Institute of Biotechnology, Ministry of International Trade and Industry, was deposited.
5102) was used.

The J1 strain was added to 2 × YT medium (5% sodium glutamate added), cultured and grown. The bacterial concentration in the culture solution was 8 × 10 ⁸ cfu / ml. The microbial transport liquid was introduced into the foam generator to generate foam. A culture solution containing a microorganism was added to each and mixed, and the mixture was injected into the column by a liquid feed pump. The liquid transfer rate was 0.5 ml / s. Experimental Example The rotation of the disk of the foam generator was adjusted to prepare a microbial transport fluid having a gas phase ratio of 0 to 0.8, and the microbial transport fluid was injected into the column. The number of microorganisms in the microorganism transportation fluid distilled from the microorganism transportation fluid column was compared with the number of microorganisms injected into the column to determine the recovery rate of the microorganisms. The injection volume of the fluid was set to about 10 times the volume of the voids of the soil in the column so that the error due to the microorganisms remaining in the column could be ignored.

In FIG. 2, the horizontal axis represents the gas phase rate of the microbial transport fluid, and the vertical axis represents the microbial recovery rate. Recovery refers to the efficiency with which microorganisms pass through the column without being trapped by soil particles in the column. Therefore, it can be considered that the higher the recovery rate is, the farther the microorganisms are transported. FIG.
As shown in, almost no microorganisms were recovered from the transport fluid containing no gas phase. Therefore, it can be seen that most of the microorganisms are trapped in the column and the transportation is hindered, even though the fluid is flowing out from the column. On the other hand, the recovery rate improved drastically as the vapor phase rate of the transport fluid increased, and the recovery rate was about 90% at 80% vapor phase rate.
In this case, it is considered that the microorganisms are moving in the soil along with the flow of the transport fluid.

[0046]

As described above, the soil according to the present invention is characterized by mixing a composition containing a microorganism and a fluid containing a gas phase, and injecting the mixed fluid into the soil. According to the method for transporting microorganisms in the soil, it is possible to suppress the capture of the microorganisms in the soil particles and the gaps between the soil particles, and thus it becomes possible to transport the microorganisms to a wider range in the soil, and at the same time, transport the microorganisms. Since the resistance was reduced, the transport speed was also improved.

Further, by the same action, the fluctuation of the transportation efficiency is made uniform with respect to the soil in which the particle size and the water permeability of each part of the stratum vary, so that the microorganisms can be evenly dispersed and transported in the soil. Became. In addition, it has become possible to reduce the driving pressure for fluid transport by reducing the transport resistance to the formation, and as a result, the pressure on the formation is also reduced, preventing the formation of channels due to cracks, etc. It contributes to uniform distribution and transportation.

Another feature of the present invention is a method of mixing a composition containing microorganisms with a fluid containing a gas phase and injecting the mixed fluid into soil in a method for transporting microorganisms into soil. And a means having a defoaming action on the fluid injected into the soil. This has made it possible to limit and control the range in which microorganisms are transported. In addition, since not only the microorganisms but also the region where phosphorus and nitrogen compounds contained in nutrients in the microorganism transport fluid diffuse can be limited and controlled at the same time, it is possible to prevent secondary pollution of soil and groundwater environment.

As described above, according to the present invention, when a microorganism is transported into the soil, it can be transported over a wider area in the soil, the transport speed can be improved, and the dispersion can be evenly dispersed. Since the civil engineering work such as the formation of cracks in the formation, the formation of complex shapes and the formation of many wells as in the technique of injecting into soil is not required, the cost and the construction period can be shortened. Furthermore, because the scale of the equipment will reduce the constraints of repair work due to the presence of above-ground buildings, it is necessary to apply the repair technology by injecting microorganisms into the soil for contaminated sites in a wider range of site conditions. To realize.

In the present invention, in addition to the above-mentioned effects on the transport characteristics of microorganisms, there are economic and environmental protection effects.
Since the fluid injected into the soil contains the gas phase, the volume of the transport region per unit mass of the fluid increases, and the fluid mass required to secure the same transport region is reduced. This not only reduces the cost but also reduces the injection amount of microorganisms and nutrients including phosphorus and nitrogen compounds accompanying it, and contributes to preventing secondary pollution of the soil environment. In addition, the presence of the gas phase suppresses an increase in the water content in the injection region when the fluid is injected into the unsaturated layer, and therefore has the effect of not causing fluctuations in the ground or liquefaction.

[Brief description of drawings]

FIG. 1 is a device configuration diagram illustrating an embodiment according to a first example of the present invention.

FIG. 2 is a graph showing a recovery rate of microorganisms from a column according to an experimental example of Example 2 of the present invention.

[Explanation of symbols]

 1 Bubble generator 2 Microbe transport liquid supply tank 3 Microbe supply tank 4 Liquid feed pump 5 Injection well 6 Contaminated soil area

Claims (9)

[Claims] 1. A method for transporting microorganisms into soil, which comprises mixing a composition containing microorganisms with a fluid containing a gas phase and injecting the mixed fluid into soil. 2. A process of mixing a composition containing a microorganism and a fluid containing a gas phase and injecting the mixed fluid into soil, and defoaming the fluid injected into the soil. A method for transporting a microorganism into soil, which comprises providing a means having an action. 3. The vapor phase ratio of the fluid containing the vapor phase is 0.4 or more.
The method for transporting microorganisms into the soil according to claim 1 or 2, which is 0.95 or less. 4. The method for transporting microorganisms into the soil according to claim 1, wherein the fluid containing a gas phase comprises foam. 5. A polluted soil environment comprising mixing a composition containing a microorganism capable of decomposing environmental pollutants with a fluid containing a gas phase and injecting the mixed fluid into the soil. Purification method. 6. A process of mixing a composition containing a microorganism capable of decomposing environmental pollutants and a foam-forming fluid, and injecting the mixed fluid into soil, and a process of injecting the mixed fluid into the soil. A method for purifying a contaminated soil environment, characterized in that means for defoaming a fluid is provided. 7. The vapor phase ratio of the fluid containing the vapor phase is 0.4 or more.
The method for purifying a contaminated soil environment according to claim 5, wherein the method is 0.95 or less. 8. The method for purifying a contaminated soil environment according to claim 5, wherein the fluid containing a gas phase comprises foam. 9. A composition containing a microorganism is moved in the soil while containing a gas phase,
Method of transporting microorganisms into soil.