JP3332600B2 - Contaminated soil and groundwater purification methods - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil purification (repair) method for biologically decomposing a pollutant chemical substance, and more particularly, to a method for in situ treatment (IN SITU) remediation of soil contamination. More specifically, it relates to a method of supplying a liquid microbial contaminant decomposition material to a contaminated underground.

[0002]

2. Description of the Related Art In recent years, environmental pollution by hydrocarbons such as aromatic hydrocarbons, paraffins and naphthenes, and organic chlorine compounds such as trichloroethylene, tetrachloroethylene and tetrachloroethane has become a problem. Many of these penetrate into the soil and do not decompose, but gradually dissolve in the groundwater and expand the contaminated area through the groundwater.

[0003] It is strongly desired to establish a technique for preventing the reoccurrence of these serious environmental pollutions and for purifying the already-polluted environment to return it to its original state.

[0004] Examples of this environmental remediation technology include pumping contaminated groundwater to separate volatile organic matter, aerating it by adsorbing it on activated carbon, exposing contaminated soil to the sun or a heat source, and evaporating volatile organic matter by heat. Heat treatment, vacuum extraction in which contaminated soil is provided with a boring hole in a contaminated soil and a vacuum is used to suction contaminants, or vacuum pot treatment in which contaminated soil is heated in a vacuum pot and suctioned to extract the contaminated soil is performed.

[0005] These physicochemical treatments may be effective especially when the concentration is high and local contamination is severe.
When contamination is low and widespread, processing speed and cost become problems. Further, even if these organic substances can be recovered by activated carbon, there is a problem that many substances are usually hardly decomposable, and a treatment for further detoxifying the substances is required.

As a method for solving these problems of the physicochemical treatment, a soil remediation method using a biological treatment with a microorganism has recently been studied.

[0007] If microorganisms, especially microorganisms that can live in soil, decompose pollutants, purification is carried out by natural energy, the input energy is small, and the decomposition proceeds to water or carbon dioxide.

There are many known microorganisms that degrade hard-to-decompose compounds causing soil pollution, for example, aromatic hydrocarbons and organic chlorine compounds. However, when these microbial decomposed materials are sprayed as they are on actual contaminated soil, the supply of the materials usually becomes excessive, insufficient, or non-uniform, so that accurate purification may not be performed.

[0009] This is because there is a difference in time and a difference in physicochemical properties between "distribution of contaminants" and "dispersion of microbial decomposing materials", and it is difficult to make them identical.

In order to overcome these problems, a method of forcibly disposing the biodegradable material in the ground or a method of feeding the material by a pipe inserted into the soil layer has been used.

Conventional USP 5,120,160 and DE3,
839,093, USP5,080,782, USP
No. 5,032,042, US Pat. Nos. 4,401,569, etc., propose a method of supplying microorganisms and nutrients into the ground to biologically purify pollutants. However, these are techniques that do not guarantee a precise distribution of the biodegradable material, that is, a concentration distribution of depth and spread.

As described in US Pat. No. 4,442,895, a method of injecting a pressurized fluid into a stratum to generate cracks in fields such as oil and natural gas sampling and solidification of soft ground. Although it is known, it is not a technique completed as a means for supplying the decomposed material intended in the present invention into the formation.

US Pat. No. 5,133,625 proposes a method in which an injection port is provided at the tip of a pipe and liquid microbial decomposition material is sequentially injected while being inserted into the ground.
In order to inject liquid and gas sequentially, it is necessary to insert the liquid or gas that was previously injected at a certain depth while removing it, or to provide two injection pipes for liquid and gas, which is complicated. is there.

US Pat. No. 5,032,042 discloses a technique of having a pipe for introducing compressed air into the ground, holding a packer, and sequentially forming cracks in the depth direction. It is not suitable for sequentially injecting a liquid and a gas or two kinds of liquids or for injecting at a predetermined time interval, and has a drawback in that the injected substance moves toward the outer wall of the tube.

Although a method of pumping contaminated groundwater and treating it physicochemically or microbiologically has been attempted, this method requires energy for pumping and treatment,
There are many problems such as the need for ground facilities for purification, land subsidence, hindrance to the use of groundwater flow on the downstream side, and changes in underground water affecting downstream ecosystems.

[0016]

Conventionally, in a method of directly supplying microbial decomposing materials such as bacteria and nutrients to soil,
It was very difficult to artificially create a distribution corresponding to the distribution of pollutants on the ground surface. Under such insufficient control of the distribution of bacteria, it is disadvantageous in that the efficiency of decomposition is reduced and economic efficiency is increased, such as by supplying them in excess. On the other hand, it is physically difficult or costly to dig deep underground in a wide area to supply the decomposed material into the ground. In addition, when the decomposed material is naturally diffused simply by spraying from the ground surface, it is not possible to make the distribution state of both the same due to the time lag between the time when the contaminant began to diffuse and the time when the biological decomposed material was supplied. Have difficulty. In particular, a difference in diffusivity, in addition to the time difference, a difference in specific gravity between the two, a difference in chemical or biological affinity with soil, and the like also cause an increase in the difference in distribution. In particular, the conventional method does not show any solution to the problem of different supply conditions between the unsaturated zone and the saturated aquifer.

Therefore, a method has been proposed in which a boring hole is provided and these microbial degradation materials are injected from the hole. However, in a simple injection from the boring hole, the position, distribution range, concentration, etc. of the degrading material are as designed. Is difficult to expect.

This is due to the heterogeneous nature of the soil layer, the supply to only the water supply (water channel) formed by nature, and the flow down without any means for knowing the excess or deficiency of the supplied material.

Accordingly, an object of the present invention is to solve the above-mentioned problems in soil restoration, and to uniformly inject the decomposed material in the depth direction, inject into a predetermined area on a line or on a surface, and perform a predetermined injection. It is an object of the present invention to provide a method for reliably performing concentration injection, short-time injection, repeated injection, and injection of a plurality of materials.

[0020]

The above objects are achieved by the present invention described below.

That is, the present invention provides a method of polluting with a halogenated hydrocarbon.
Injection pipe inserted into the soil or groundwater area
Liquid microorganisms for decomposing halogenated hydrocarbons
Multiple inlets for pressure injection of material and pressure injection
Outer tube with multiple valves sometimes open to allow injection
And the depth of the soil or groundwater area, located inside the outer pipe
In the direction of the outer tube up and down to face the inlet of the outer tube
Injects liquid microbial material into the outer tube at a location
An injection pipe comprising an inner pipe having a spout;
And soil contaminated with liquid biodegradable material through the inlet
Soil contaminated by pressure injection into soil or groundwater areas
Purification method for purifying soil or groundwater
Inserting the pipe into the soil or groundwater area, and
To prevent microbial material from moving in the insertion direction
Filling process and filling the inner tube in the outer tube in the depth direction
Up and down so that the injection port and the injection port
Position adjustment process, and
The gap between the pipe and the outer pipe is located above and below the spout of the inner pipe.
And seal it with a packer without closing the spout.
Process and the liquid microbial material spouted from the spout
Pressure injection into the soil or groundwater area through the inlet
Process and pressurized injection process, the inner tube is in the depth direction inside the outer tube
And every time the ejection port faces a different injection port
This is a purification method characterized by performing an input step.

[0022]

Hereinafter, the present invention will be described in detail.

The route by which soil contamination substantially affects the environment varies depending on the nature of the pollutant and the state of pollution. However, in the case of soil contamination due to organic chlorine-based solvents, which has become a particular problem in recent years, the solvent that has leaked underground penetrates deep into the ground and gradually dissolves in groundwater. In the downstream area of the groundwater, problems often occur when the groundwater is directly used, or when flowing into the underground water flowing out from underground or into rivers.

If the contaminated soil is local and in the early stages of the contamination, the problem can be solved by treating the contaminated soil directly. However, many of the problems that arise today are that organic chlorine-based solvents have been widely used and more than 10 years have passed, and many have noticed the problem for the first time. Is dissolved in the groundwater passing through it little by little,
The above-mentioned groundwater pollution is affecting the environment.

Here, a typical pollution mechanism of an organic chlorine-based solvent having a large specific gravity will be described.

FIG. 1 is a schematic diagram of a subsurface section of a typical organochlorine-contaminated soil.

First, the solvent that has permeated the soil I (top soil), H (loam layer), G (sand layer) and F (gravel layer) from the pollution source C is adsorbed by the soil, and the excess solvent that cannot be adsorbed flows into the lower soil one after another. And the adsorption proceeds. At this time, the distribution of the contaminants has a steep mountain shape, and the distribution in the horizontal direction does not progress so much as long as there is soil that can penetrate and adsorb.

Next, when the solvent reaches the formation E (silt clay layer) where the solvent cannot sufficiently penetrate or the aquifer in the dense soil layer, the solvent stays in the vicinity. Next, rainwater or groundwater supplied from the ground balances the adsorption of the solvent between the soil and the water, and the solvent dissolves in the water with a certain distribution coefficient. In many cases, the solubility of an organic chlorine-based solvent is as low as several thousand ppm or less. Although this value is low in terms of solubility physically, it is a large value as environmental pollution.

Further, when the adsorption equilibrium of the contaminants to the soil and the groundwater (a constant value is maintained by the distribution coefficient) is shifted to the re-equilibrium due to the newly introduced / supplied groundwater, the dissolved solvent is passed through the water. Spread the pollution. The groundwater flow J occurs below the groundwater level D, but the adsorption of the gravel layer has less solvent adsorption than the loam and silt layers. It will increase expansion.

The organic chlorinated solvent that has infiltrated into the ground evaporates in the ground together with the diffusion in the liquid state, causing contamination of the underground air. This pollution often contaminates a wide area at a low concentration. Become.

An object of the present invention is to provide an effective pollution control measure in a short time in consideration of such a pollution mechanism. That is, it is often difficult to dig up and remove the contaminant solvent that has penetrated deep into the soil, together with the soil. The depth of the infiltrated soil depends on the stratum, but can reach several meters to tens of meters. There are often active factories, facilities, houses, etc. above the contaminated area. Of course, the deeper, the wider the contaminated area. Slow groundwater migration takes a long time before contamination is detected, which also increases the area of contamination. Therefore, complete purification of the entire contaminated area may have to be impractical.

In the present invention, it is intended to carry out restoration by microbiological purification (bioremediation) in a short time in an appropriate position and arrangement with respect to the contamination mechanism of these aquifers and non-aquifers. .

Next, a method for decomposing biologically harmful chemical substances will be described.

The harmful chemical substances causing soil pollution which are problematic in the present invention are hardly decomposable compounds, such as halogenated hydrocarbons, for example, aromatic hydrocarbon compounds and organochlorine hydrocarbon compounds. Many microorganisms are known to decompose them, and some of them are known to have degrading enzymes. However, even if these microorganisms or enzymes are sprayed on actual contaminated soil as it is, a sufficient effect on harmful chemical substances in the soil cannot be expected.

One of the reasons is that the distribution characteristics of the microbial material and the chemical substance are different from each other, and that the time course of the distribution cannot be the same.

Another reason is that even if the decomposition activity is obtained under certain conditions such as an incubator on the ground, the same inhabiting conditions cannot be obtained in the ground.

When the microbial material is sprayed directly on the ground or in the ground, the microbial or enzyme concentration in the soil rapidly decreases with time, compared to the initial concentration at the time of normal application.

Although the reason for the decrease is not always clear, it is thought to be due to competition with conventional microorganisms in the soil, death from nutrition or other environmental incompatibility, predation by other organisms such as protozoa, and the like.

Therefore, it is necessary to take measures such as sowing the microorganism material frequently and in large quantities, which causes inconvenience in processing time, cost and the like. Therefore, there is a strong demand for a method for maintaining the activity of microorganisms in the soil where harmful substances are present. Similarly, in the case of enzymes, it is necessary to ensure conditions for maintaining the activity in the soil. Therefore, when supplying these microorganisms into the ground, it is necessary to simultaneously supply a microorganism active material, a surviving material, a propagation material, and the like.

The purpose of the present invention is to supply the necessary amount of materials necessary for the decomposition by these microorganisms collectively or sequentially, and at appropriate time intervals to a target place.

When supplying the "required material" into the soil according to the present invention, an injection pipe having at least one or more multistage inlets is inserted into the "target place", and the target pipe is inserted from this pipe. The necessary amount of the material to be injected is injected only from the injection port of the depth, and then the same injection is performed from the injection port of the different depth to inject the required amount.

As a construction method capable of easily repeating these unit operations, a device similar to a cement or hardening agent injection device used in civil engineering work for solidifying soft ground can be used. It has been found that microbial material can be supplied underground with a similar configuration.

The difference between the injection agent in civil engineering work and the injection of microbial material in the present invention is that in the civil engineering work, the injection liquid stays in a relatively limited area and the injection material is introduced into the stratum so that the target portion is hardened. On the other hand, when supplying microbial material, it is often expected that the material permeates a wider area, and a material having a viscosity similar to that of water is used. For this reason, injection pressure and time, that is, restrictions on the injection amount are greatly different. In the civil engineering work for the purpose of hardening, there is a restriction for expecting rapid hardening at the same time as the injection in a state of good fluidity, but such a restriction does not occur for microbial materials. In civil engineering work, once the curing is completed, the purpose is achieved.However, purification by microorganisms requires introduction of multiple materials, especially materials having different physical properties such as liquid and gas, and injections are performed several times. May need to be repeated. These have basically similar structures of pipes and pumps used for injection, but have different structures and materials for managing and operating each.

Next, materials necessary for the injection will be described.

The microbial material for decomposing contaminant chemicals used in the present invention is a microbial material capable of decomposing chemical substances. As materials to be added thereto, materials having a growth function necessary for the growth of microorganisms and microorganisms can be used. An activity-maintaining functional material that exhibits decomposition and a surviving functional material that is a carrier that enables microorganisms to enter the ground and stably inhabit are used. The growth material corresponds to the culture medium of the microorganism. Microorganisms grow by nutrients and contribute to the breakdown of harmful substances. The activity sustaining material substantially promotes the decomposition of harmful substances, and may not be distinguished from nutrients. When a specific substance is not directly available as a nutrient, the microorganism produces a decomposing enzyme by an inducer (inducer) in order to decompose the specific substance, thereby promoting the decomposition. Degradation of the harmful substances is then made possible by enzymes produced by the microorganisms. In the present invention, a material necessary for producing this harmful substance-decomposing enzyme is used as an activity maintaining material.

This indicates that harmful chemical substances can be decomposed even by using enzymes which are metabolites of microorganisms without using microorganisms themselves. When an enzyme is used instead of a microorganism, a carrier holding the enzyme or a mineral or the like is required for the enzyme to exhibit a decomposition activity.

[0047] The surviving material provides, in part, a habitat for the microorganisms to be protected from other microorganisms and microbes when they are eaten or compete with each other in the ground. In some cases, it also serves as an immobilizing carrier in order to prevent effective microorganisms from diffusing and disappearing in groundwater. It is also possible that the growth material, the nutrient itself, can perform this function.

As the surviving material, various microorganism carriers conventionally used in bioreactors known in the pharmaceutical industry, the food industry, wastewater treatment systems, and the like are used as materials that provide a space for living microorganisms. For example, porous glass, ceramics, metal oxides, activated carbon, kaolinite, bentonite, zeolite, silica gel, alumina, particulate carriers such as anthracite, starch, agar,
Chitin, chitosan, polyvinyl alcohol, alginic acid, polyacrylamide, carrageenan, agarose,
Gel carrier such as gelatin, ion-exchange dendritic cellulose,
Examples include ion exchange resins, cellulose derivatives, glutaraldehyde, polyacrylic acid, and urethane polymers. Natural or synthetic polymer compounds are also effective, such as cotton, hemp, paper made of cellulose as a main component, or paper acetate made of natural materials or polymer acetate modified from natural products. Cloths made of synthetic polymers such as polyester and polyurethane can also be used. These have good adhesion of microorganisms,
Those having fine gaps are preferred. A fine material that can easily penetrate at the time of injection is preferably used.

As examples of materials that provide a habitat space and also use nutrients, many examples can be found in compost materials and the like known in the agriculture and forestry industry. That is, straws and sawdust of grains such as straw, rice bran, okara, dried plant remains such as squeeze of sugarcane, crabs and shrimp shells also have micropores and become microbial degradable nutrients,
In particular, a material that can be processed to a fine particle size is used.

Next, specific materials of microorganisms will be described. As the microorganism, a material whose decomposition activity is confirmed is used, and is selected from those belonging to the following genera.

Saccharomyces, Hanse
nula, Candida, Micrococcus,
Staphylococcus, Streptococ
cus, Leuconostoa, Lactobaci
lplus, Corynebacterium, Arth
robot, Bacillus, Clostri
Dium, Neisseria, Escherichi
a, Enterobacter, Serratia, A
chromobacter, Alcaligenes,
Flavobacterium, Acetobacter
r, Nitrosomonas, Nitrobacte
r, Thiobacillus, Gluconbact
er, Pseudomonas, Xanthomona
s, Vibria.

As the propagation material, those used in a culture medium for microorganisms can be used. For example, broth medium, M9 medium, L medium, Maltextrac
t, MY medium, nitrifying bacteria selection medium and the like are effective.

As the activity-maintaining material, those in which degrading bacteria are specified are known as inducers, but natural materials are usually in a mixed state, and cannot be specified. There are many things. Particularly in the case of microorganisms in a mixed state, a metabolite of one microorganism often becomes a symbiotic system that functions as an inducer of another microorganism. Therefore, when a mixed microorganism is used, natural organic substances in which various substances coexist are effective. Inducible substances that can be identified include methane in methane assimilating bacteria, toluene, phenol, o-, m- and p-cresol in aromatic assimilating bacteria, and ammonium salts in nitrifying bacteria. To date, as examples of bacteria known to be capable of degrading trichloroethane, dozens of species have been discovered and isolated. Of these, typical ones can be broadly divided into two types depending on the type of the substrate.

That is, it is a methane-utilizing bacterium or an aromatic compound-utilizing bacterium such as phenol. A representative of the former is Methylocytosis with methane monooxygenase.
sp. strain M (Agri. Biosci.
Biotech. Biochem. , 56, 486 (1
992), 56: 736 (1992)), Methy
losinus trichosporium OB
3b (Am. Chem. Soc. Natl. Meet.
Div. Environ. Chem. , 29,365
(1989), Appl. biochem. Biote
chnol. , 28, 877 (1991), the latter being the Acinetobacters having toluene monooxygenase or toluene dioxygenase.
p. strain G4 (Appl. Environ.
Microbiol. , 52, 383 (1986), 53, 949 (1987), 54, 951 (198).
9), 56, 279 (1990), 57, 1935
(1991)), Pseudomonas putid
a F1 (Appl. Environ. Microbi)
ol. , 54, 1703 (1988), 54, 257
8 (1988)). Of these,
With respect to aromatic compound-assimilating trichloroethane (TCE) degrading bacteria, the enzyme that decomposes TCE is an inducing enzyme induced by aromatic compounds such as phenol and toluene. A material containing an aromatic compound or decomposing into an aromatic compound is used.

When an enzyme material is used, a growth material such as a nutrient is unnecessary, but it is necessary to mix a mineral necessary for the enzyme to exhibit an activity, for example, a coenzyme such as Fe ²⁺ or NAPH. There is. Enzymes, in principle, should have a permanent degradation effect if present in the system, but in fact they are deactivated according to the conditions of use. Therefore, it is necessary to mix and integrate materials necessary for maintaining the activity of the enzyme for as long as possible.

Examples of the enzyme include toluene monooxygenase, toluene oxygenase, ammonia monooxygenase, methane monooxygenase and the like.

The biodegradable material of the present invention uses all or a part of the above substances as an aqueous solution or suspension.

FIG. 2 is a sectional view of each unit of the injection pipe used in the present invention.

An outer tube 22 for injection having a multistage inlet 23 used in the present invention is inserted into at least one portion of the contaminated region 20, and the outer periphery of the outer tube 22 is surrounded by the filler 30. The inner tube 21 having the ejection port 28 is inserted inside the outer tube 22. Packers 29 are provided above and below the ejection port 28 of the inner tube 21 so that liquid and gas do not move to the adjacent injection port. The inner pipe 21 is connected to a flexible pipe 32 and an extendable connection pipe (not shown) so as to be movable up and down. The end of this pipe is connected to a liquid feed pump 24 or a compressor via a valve 25,
The liquid in the microbial decomposition material tank 27 is sent, or a separate fluid is sent through the valve 26.

Each injection port is provided with a valve 33 that can pass only in the direction in which the fluid of the jet port is sent out. The outer pipe 22 is connected to each stage, and has a structure in which the length can be appropriately changed according to the depth of the destination layer. The pitch of the inlet is arbitrarily set by changing the length of one pipe, but a pipe having a preset pitch is used. Normal 30cm
A pitch of about 1 m is used. After the injection port is positioned at the target injection port, the packer is inflated to seal the inner wall of the pipe. For the expansion of the packer, a confidential seal is obtained by feeding the injection fluid itself into the rubber-like body or by providing a separate mechanism for feeding a fluid for expanding the packer.

[0061]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 A 1.5 m fine sand layer, a 1.5 m Kanto loam layer, a 1 m Kanuma soil, and a 0.5 m Kuroboku soil were laminated as model test soil in a 5 m square concrete container from below, and the surface was compacted. Covered with about 20 cm of clay layer. Each layer of fine sand layer, loam layer, and Kanuma soil contains about 10 mg of trichlorethylene (TCE) /
It is adjusted to have a Kg contamination concentration. In addition, each stratum is pressed at the time of laminating construction so as to have a hydraulic conductivity close to that of actual soil.

A drilling hole is provided in the center of the vessel as an injection well, and an outer tube having an outer diameter of 80 mm is inserted so that the tip is 25 cm from the bottom. The injection port of the outer tube was arranged in three stages of 0.5 m, 2.0 m, and 3.25 m from below so as to be at the center of each layer, and each stage was provided with a hole having a diameter of 8 mm in four directions. A rubber tube smaller than the outer diameter of the outer tube was fitted into each inlet so as to close the inlet. The gap between the borehole and the outer pipe was sealed with a caking material mixed with fine sand and water glass. The inner tube having an outer diameter of 40 mm had a spout at a position of 20 mm from the tip, and rubber tubes serving as a packer were arranged vertically. The upper and lower portions of each rubber tube are fixedly attached to the outer wall of the inner tube, and have a mechanism that expands from the center by the pressure of the injected fluid.

The other side of the inner pipe is connected to a rubber hose at the above-ground portion, and further connected to a liquid feed pump via a valve. Each pipe is provided so that the microbial decomposition material in the tank can be pressure-fed to the inlet by this liquid sending pump. The microbial decomposition material is supplied to each layer by pressure injection into the fine sand layer from the lowest injection port, and then the spout is set to 2.0 m of the loam layer.
And then pressurized and injected into the vicinity of the inlet, and similarly supplied to the uppermost inlet, Kanuma soil.

The microbial decomposition material solution was prepared by culturing strain KK01 (deposited with the Research Institute of Microorganisms, Ministry of International Trade and Industry on March 11, 1992, deposit number FERM P-12869) in M9 medium, and having a bacterial concentration of 10%. ^A decomposed liquid was prepared so as to have a concentration of ⁸ cells / ml, and Edible Red No. 106 was added thereto at a rate of 1 g / l as an indicator substance for confirming injection.

After the completion of the three injection cycles, the mixture was left for two days, half of the diagonal soil on which injection was performed was removed, and the distribution of indicator substances and the distribution of microorganisms were observed. Up to 20-50cm in the vertical direction, about 4 in the radial direction
A distribution of 0 to 70 cm was recognized, while the distribution was 15 cm in the depth direction and 60 cm in the radial direction in the Kanto loam layer. When the ratio of TCE content in the distribution region to the non-distribution region of the biodegradable material was examined in each of these layers, it was confirmed that the TCE content was attenuated to 1/3 to 1/7 in the distribution region.

Example 2 After the same injection as in Example 1 was performed, the distribution of microbial degradation products and the degradation of TCE were examined by supplying compressed air from each injection port. In both directions, an increase from the same to a maximum of 50% was confirmed as compared with the liquid microbial decomposition material alone, and it was confirmed that the decomposition was attenuated to 1/4 to 1/10.

Example 3 After the same injection as in Example 1, the indicator substance was replaced with edible red No. 106 from blue No. 106 after standing for 2 days, and re-injection was performed under the same conditions as in Example 1. Distribution after 2 days and T
When the decomposition of CE was examined, the distribution was similar to that of the first injection, but the distribution of the first injection was slightly larger and tended to diffuse in the direction of gravity. The TCE attenuation ratio at the point where the microbial decomposition solution was supplied twice was 1/50 at the maximum, and was 1/2 in most cases.
0 or less.

[0069]

According to the method of the present invention, it is possible to supply a uniform, large amount and a rapid biodegradable material. In addition, one injection pipe can easily inject injection materials with different physical properties, and can be supplied economically and in a short period of time. And the effect of ensuring quick and reliable restoration of the target contaminated soil was obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the spread of contaminants in a stratum.

FIG. 2 is a diagram for explaining the method of the present invention.

Continuation of the front page Examiner Koichi Nakano (56) References JP-A-5-231086 (JP, A) JP-A-7-265898 (JP, A) JP-A-6-218355 (JP, A) JP-A Sho64 -34380 (JP, A) JP-A-4-68109 (JP, A) Table 7-501005 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09C 1/00- 1/10 C02F 3/00 C02F 11/02

Claims (3)

(57) [Claims] Claims: 1. A soil contaminated with halogenated hydrocarbons.
Or an injection pipe inserted into the groundwater area,
Add liquid microbial material to decompose
A plurality of injection ports for pressure injection, and at the time of pressure injection
Outer tube with a plurality of valves that are open to allow said injection
And the soil or groundwater area located inside the outer pipe.
Moving up and down in the outer tube in the depth direction of the
The liquid microorganism material at a position facing the injection port
And an inner pipe having a jet port for jetting the material into the outer pipe.
Equipped with an injection tube, through the injection port and the injection port
And transferring said liquid microbial degradation material to said contaminated soil or
Contaminated soil or ground by pressure injection into the groundwater area
Is a purification method for purifying a groundwater area, wherein the injection pipe is inserted into the soil or the groundwater area.
The microbial material is transferred around the outer tube in the insertion direction.
A step of filling a filler for preventing movement, and moving the inner pipe up and down in the depth direction within the outer pipe,
A position where the injection port and the injection port face each other in the depth direction.
A positioning step of the location, within the gaps of the outer tube and the inner tube while the opposite
Close the spout at the upper and lower positions of the spout of the pipe
Sealing with a packer without blocking, and opposing the liquid microorganism material ejected from the ejection port.
Pressurized injection into the soil or groundwater area through the inlet
And pressurizing and injecting, wherein the inner pipe has a depth inside the outer pipe.
In the direction, and the spout faces the different spout.
Cleaning step, wherein the pressure injection step is performed every time
Law. 2. The purification method according to claim 1, wherein the liquid microbial material , nutrient, and microbial carrier are injected simultaneously or individually. 3. The purification method according to claim 1, wherein the liquid microbial material and the gas are injected using the same injection tube.