JP4359174B2 - Environmental purification method - Google Patents

Description

  The present invention relates to a method for purifying soil and groundwater contaminated with pollutants.

  In recent years, environmental pollution caused by organic halides such as trichlorethylene, tetrachloroethylene, and tetrachloroethane, which are included in industrial wastewater, has become a major problem. Many of these contaminants penetrate into the soil and enter the groundwater without being decomposed, expanding the contaminated area through this groundwater. It is strongly desired to establish a technique for preventing the spread of environmental pollution and purifying and repairing an already polluted environment.

In recent years, methods using biological treatment with microorganisms have been proposed as methods for purifying contaminated environments. This is a method of decomposing a pollutant into a harmless substance by microorganisms living in the contaminated area or introduced from the outside into the contaminated area. In this method, by introducing an active agent containing a substrate (carbon source), an inorganic nutrient salt such as nitrogen or phosphorus, a hydrogen donor, etc. into the contaminated area, the action of decomposing pollutants by microorganisms can be improved. It has been known. As the activator, compounds that are liquid at room temperature such as citric acid and methanol have been proposed (for example, Patent Documents 1 and 2). Patent Document 3 proposes the use of an activator that is solid at room temperature and contains fatty acids and alcohols having a specific carbon number.
JP-A-9-276894 Japanese Patent Application Laid-Open No. 11-90484 JP 2002-370085 A

  However, since the liquid activator is excellent in fluidity, even if it is injected into soil or groundwater, it will flow out of the contaminated area through groundwater in a relatively short time, and the effect of activating microorganisms is poor. was there. Therefore, when using a liquid activator, it was necessary to re-inject the activator into the soil in a relatively short cycle. On the other hand, in the case of a solid activator, the microbial activation effect is excellent and there is no need for frequent re-injection like a liquid activator. On the other hand, since the solid activator is difficult to diffuse in soil and groundwater, there is a problem that it is inferior in immediate effect. Thus, with conventional activators, it is difficult to achieve both the sustainability and immediate effect of the microbial activation effect, and there is a limit to the improvement in purification efficiency.

  Accordingly, an object of the present invention is to improve purification efficiency in an environmental purification method in which microorganisms are activated by an activator to decompose pollutants in soil and groundwater.

  In order to solve the above problems, the present invention provides a substance that activates the pollutant decomposing action of the microorganism in the presence of the microorganism that decomposes the pollutant in at least one of soil and groundwater containing the pollutant. An environmental purification method for purifying at least one of the soil and groundwater by introducing an activator comprising a liquid activator and a solid activator as the activator. .

  According to the environmental purification method of the present invention, by using a liquid activator, the activator is diffused in a contaminated area in a relatively short time, realizing an immediate microbial activation effect, and solid Use of the active agent can improve the durability of the effect and reduce the frequency of reinjection of the active agent. As a result, efficient environmental purification can be realized.

  The environmental purification method according to the present invention is particularly suitable for the purification of soil and / or groundwater containing organic halides as pollutants. Examples of the organic halide include tetrachloroethylene, trichloroethylene, dichloroethylene, vinyl chloride, dichloromethane, chloroform, carbon tetrachloride, chloroethane, dichloroethane, trichloroethane, dichloropropane, dichlorobroethylene, bromodichloromethane, chlorodibromomethane, and dioxin. . In particular, it is suitable for the purification of soil and / or groundwater containing at least one contaminant of tetrachlorethylene, trichlorethylene and carbon tetrachloride.

  In the environmental purification method of the present invention, as described above, a solid activator and a liquid activator are used in combination as activators for activating microorganisms.

  The solid activator contains a component that activates the microbial pollutant decomposing action, and can exist in a solid state in soil or groundwater. Examples of components that activate microorganisms include components that serve as nutrient salts (for example, phosphorus and nitrogen) of microorganisms, substrates (that is, organic substances as energy sources), and components that serve as hydrogen donors. The hydrogen donor is a substance that supplies hydrogen to microorganisms. The supplied hydrogen replaces, for example, halogens of organic halides that are pollutants, and promotes further biological degradation. used.

  As the solid activator, for example, at least one selected from carboxylic acid, alcohol, ester, amine and amide can be used. These substances function not only as substrates for microorganisms but also as hydrogen donors. In addition, amines and amides also function as nitrogen suppliers that supply microorganisms with nitrogen, which is a nutrient salt.

  Suitable carboxylic acids for the solid activator include those containing a carboxylic acid having 10 or more carbon atoms. This is because such a carboxylic acid has a sufficiently high melting point, and an activator containing the carboxylic acid can easily maintain a solid state in soil or groundwater. The upper limit of the carbon number of the carboxylic acid is not particularly limited, but is preferably 22 or less because it is easily available industrially. Furthermore, the carbon number of the carboxylic acid is preferably 12-18, and most preferably 14-18.

  Further, the carboxylic acid is preferably a saturated carboxylic acid. This is because the presence of multiple bonds such as double bonds lowers the melting point of the carboxylic acid and it may be difficult to maintain the active agent containing the carboxylic acid in a solid state. The carboxylic acid is preferably a linear monocarboxylic acid, that is, a fatty acid. This is because the fatty acid is excellent in efficiency as a hydrogen donor.

  Examples of the carboxylic acid include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, lignoceric acid, behenic acid, and a mixture of these carboxylic acids. Myristic acid, palmitic acid and stearic acid are particularly preferred. Moreover, as a mixture, the fatty acid mixture extracted from natural products, such as a beef tallow fatty acid and a coconut oil fatty acid, besides the thing which artificially mixed multiple types of carboxylic acid may be sufficient.

  Suitable alcohols for the solid activator include those containing an alcohol having 12 or more carbon atoms. This is because such an alcohol has a sufficiently high melting point, and thus an activator containing the alcohol easily maintains a solid state in soil or groundwater. The upper limit of the carbon number of the alcohol is not particularly limited, but is preferably 20 or less because it is easily available industrially. Furthermore, the carbon number of this alcohol is preferably 12-18, and most preferably 14-18.

  Furthermore, the alcohol is preferably a saturated alcohol. This is because the presence of multiple bonds such as double bonds lowers the melting point of the alcohol and it may be difficult to maintain the active agent containing the alcohol in a solid state. The alcohol is preferably a linear primary alcohol. This is because it is excellent in efficiency as a hydrogen donor. The alcohol may be a polyhydric alcohol.

  Examples of the alcohol include lauryl alcohol, myristyl alcohol, stearyl alcohol, cetyl alcohol, behenyl alcohol, and a mixture of these alcohols. Among these, stearyl alcohol and myristyl alcohol are particularly preferable. Moreover, as a mixture, the alcohol mixture extracted from the natural product other than what artificially mixed multiple types of alcohol may be sufficient.

  Suitable esters for the solid activator include esters of carboxylic acids having 14 or more carbon atoms. Since such an ester has a sufficiently high melting point, an activator containing the ester easily maintains a solid state in soil or groundwater. The upper limit of the carbon number of the carboxylic acid group constituting the ester is not particularly limited, but is preferably 18 or less. Furthermore, it is preferable that carbon number of the carboxylic acid group which comprises ester is 16-18. The carboxylic acid group constituting the ester is preferably a linear saturated carboxylic acid group, that is, a fatty acid group.

  An example of the ester includes an ester having a chemical structure corresponding to the condensation product of the carboxylic acid and a monohydric alcohol. Examples of the monohydric alcohol include alcohols having 1 to 20, preferably 10 to 20, more preferably 14 to 18, and most preferably 16 to 18 carbon atoms. The monohydric alcohol is preferably a chain saturated alcohol.

  Examples of such esters include myristyl myristate, cetyl palmitate, stearyl stearate, methyl stearate, butyl stearate, cholesteryl stearate, batyl stearate, octyldodecyl behenate, behenyl behenate, and esters thereof. Among these, stearyl stearate, myristyl myristate, and methyl stearate are particularly preferable.

  Another example of the ester is an ester having a chemical structure corresponding to a condensation product of the carboxylic acid and a polyhydric alcohol. In this case, the ester may be a neutral ester or an alcoholic ester. Examples of the polyhydric alcohol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerin, sorbitol and the like. In the case of polyethylene glycol and polypropylene glycol, the average degree of polymerization is, for example, 50 to 800, preferably 80 to 200.

  Examples of such esters include sorbitan monomyristate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monobehenate, polyoxyethylene sorbitan monostearate, polyethylene glycol monostearate, polyethylene glycol distearate, Examples thereof include sorbitan sesquistearate, sorbitan tristearate, polyoxyethylene sorbitol hexastearate, and a mixture of these esters. Among these, sorbitan monostearate and polyethylene glycol monostearate are particularly preferable.

  Suitable amines for the solid activator include amines containing hydrocarbon groups having 12 or more carbon atoms. This is because such an amine has a sufficiently high melting point, and an activator containing the amine can easily maintain a solid state in soil or groundwater. The upper limit of the carbon number of the hydrocarbon group constituting the amine is not particularly limited, but is preferably 24 or less. Furthermore, the hydrocarbon group preferably has 12 to 18 carbon atoms, and most preferably has 16 to 18 carbon atoms.

  Further, the amine is preferably a fatty amine. This is because the presence of multiple bonds such as double bonds lowers the melting point of the amine and may make it difficult to maintain the active agent containing the amine in a solid state. The amine is preferably a linear primary or secondary amine. This is because it is excellent in efficiency as a hydrogen donor. The amine may be a polyamine such as diamine.

  Examples of the amine include laurylamine, myristylamine, stearylamine, dipalmitylamine, distearylamine, dimethylbehenylamine, palmitylpropylenediamine, stearylpropylenediamine, and mixtures thereof. Of these, distearylamine and stearylamine are particularly preferable.

  Suitable amides for the solid activator include acid amides having 10 or more carbon atoms. Since such an amide has a sufficiently high melting point, an active agent containing the amide tends to maintain a solid state in soil or groundwater. The upper limit of the carbon number of the acid amide is not particularly limited, but is preferably 22 or less. Furthermore, the carbon number of the acid amide is preferably 10-18, and most preferably 16-18. The hydrocarbon group constituting the acid amide is preferably a linear alkyl group. The acid amide is preferably a primary amide.

  Such amides include, for example, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, erucic acid amide, ethylene bis-threaric acid amide, and mixtures thereof. Of these, palmitic acid amide and stearic acid amide are particularly preferable.

  In addition, as the solid activator, it is possible to use a component in which a component for activating microorganisms is supported on a solid carrier. In this case, the form of the active ingredient itself is not particularly limited, and may be liquid or solid at room temperature. As the carrier, it is preferable to use a substance that is substantially harmless to the environment such as soil and groundwater. For example, cellulose, silica gel, silica sol, alumina, clay, talc, mica, calcium carbonate, bentonite, boehmite, activated carbon, Wood flour or the like can be used. Also, the supporting method is not particularly limited. For example, in addition to a method of simply attaching the above components to the surface of the carrier, a method of filling the above components in the pores using a porous carrier, etc. Can be adopted.

  The shape of the solid activator is not particularly limited, and can be any shape such as a particle shape, a rod shape, a plate shape, or a net shape. In particular, since the surface area can be increased, it is preferably particulate. In this case, the particle size is not particularly limited, but may be, for example, 0.1 to 10 mm, preferably 0.5 to 2 mm.

The amount of the solid activator used is not particularly limited, and can be appropriately set according to the type of the activator, the area of the contaminated area, the amount of the contaminant, and the like. For example, analyze and identify the types and amounts of pollutants contained in contaminated soil and groundwater sampled from surface surveys, shallow surveys, and deep surveys of contaminated areas, and geological conditions (such as permeability). , indexing the concentration from the mass of contaminants contained on the mass of contaminated soil and ground water, type of contaminant, the concentration, inter-phase of the diffusivity and chlorine solid active agent and a necessary amount for replacing the hydrogen Thus, the purification efficiency can be improved by using 0.1 to 20 times, preferably 1 to 12 times as much solid activator as the amount of contaminants in the contaminated area. As a specific example, for example, in the case of contamination of 10 ppm of tetrachlorethylene on a soil area of 200 m ² , use of a solid activator of about 600 kg is exemplified.

  The liquid activator includes a component that activates the microbial pollutant decomposing action and can exist in a liquid state in soil or groundwater. Examples of components that activate microorganisms include, for example, components that serve as nutrient salts and substrates of microorganisms and hydrogen donors, in the same manner as solid activators.

  Preferable examples of the liquid activator include those containing at least one selected from carboxylic acids, alcohols, esters and amines. These substances function not only as substrates for microorganisms but also as hydrogen donors. The amine also functions as a nitrogen supplier that is a nutrient salt of microorganisms.

  Suitable carboxylic acids for the liquid activator include, for example, saturated or unsaturated carboxylic acids having 4 to 18, preferably 8 to 18, and more preferably 10 to 18 carbon atoms. In particular, a linear carboxylic acid is preferable. Specific examples of such carboxylic acids include oleic acid, linoleic acid, linolenic acid, decanoic acid and the like.

  Suitable alcohols for the liquid activator include, for example, saturated or unsaturated alcohols and polyhydric alcohols having 1 to 12, preferably 2 to 8, more preferably 4 to 8 carbon atoms. Specific examples of such alcohol include propyl alcohol, polyethylene glycol, glycerin, sorbitol and the like.

  Suitable esters for liquid activators include, for example, those having a chemical structure corresponding to the condensation product of the carboxylic acid and the alcohol. Specific examples of such esters include stearyl triglyceride and stearyl sorbite.

  Suitable amines for the liquid activator include, for example, amines having a saturated or unsaturated hydrocarbon group having 6 to 20, preferably 8 to 16, and more preferably 8 to 12 carbon atoms. In particular, a linear primary amine is preferable. Specific examples of such amines include coconut amine, decanamine, laurylamine and the like.

  Moreover, what contains polylactic acid ester as another preferable example of a liquid activator is mentioned. Polylactic acid ester can release hydrogen by a hydration reaction of lactic acid in its decomposition step, and functions as a hydrogen donor for microorganisms. It also functions as a substrate for microorganisms. As such an active agent containing a polylactic acid ester, for example, “HRC (trade name)” manufactured by Regenesis, USA can be exemplified.

  Further, as the liquid active agent, it is possible to use a component obtained by dissolving, dispersing or suspending a component for activating microorganisms in a liquid base agent. In this case, the form of the active ingredient itself is not particularly limited, and it may be liquid at room temperature or solid. As the base material, it is preferable to use a substance that is substantially harmless to the environment such as soil and groundwater. Examples of such a base material include water, glycerin, sorbitol, mannitol and the like.

  In addition, the viscosity of the liquid active agent is not particularly limited, but it is room temperature (20 ° C.) from the viewpoint of suppressing rapid outflow from the soil while ensuring sufficient diffusibility in the soil. Is preferably 2000 to 80000 centipoise, more preferably 4000 to 10000 centipoise.

The amount of liquid activator used is not particularly limited, and can be set as appropriate according to the type of activator, the area of the contaminated region, the amount of contaminant, and the like. For example, analyze and identify the types and amounts of pollutants contained in contaminated soil and groundwater sampled from surface surveys, shallow surveys, and deep surveys of contaminated areas, and geological conditions (such as permeability). the mass of contaminated soil and ground water, indexing the concentration from the mass of pollutant containing against competitor (oxidants), type of contaminant, the concentration, the diffusivity and chlorine solid active agent is replaced with hydrogen The purification efficiency can be improved by using 0.1 to 20 times, preferably 1 to 12 times as much liquid activator as the amount of pollutants in the contaminated area, depending on the phase required it can. As a specific example, for example, in the case of contamination of 10 ppm of tetrachlorethylene in a soil area of 200 m ² , use of about 300 kg of liquid activator is exemplified.

  Hereinafter, an example of the environmental purification method according to the present invention will be described with reference to the drawings.

  FIG. 2 is a schematic diagram showing an example of soil and groundwater contamination. In the example of this figure, the soil in the contaminated area has a stratum structure in which the top soil 2, the upper silt layer 3, the sandy soil layer 4 and the lower silt layer 5 are accumulated in order from the ground surface. The sandy soil layer 4 is a layer containing groundwater, that is, an aquifer.

  In the soil having such a stratum structure, as shown in FIG. 2, the pollutant 6 penetrates from the ground pollution source 1 to the topsoil 2 and is adsorbed by the soil. Excess contaminant 6 that is not adsorbed penetrates the soil further downward. When the contaminant 6 reaches the upper silt layer 3, the layer 6 is impermeable or hardly permeable, and therefore stays on the surface of the layer. However, the excess contaminant 6 further penetrates the upper silt layer 3 and reaches the sandy soil layer 4 (aquifer). And it is diffused by groundwater, and the contamination range is expanded. In order to effectively suppress the spread of contamination from such a contamination mechanism, suppression and purification of groundwater is particularly important.

  FIG. 1 is a schematic diagram for explaining an example of an environmental purification method according to the present invention. In particular, this figure illustrates a purification method for suppressing and purifying groundwater contamination.

  In this environmental purification method, a liquid activator and a solid activator are introduced into soil and / or groundwater in a contaminated area. In soil and / or groundwater, there are microorganisms that can degrade pollutants. Examples of such microorganisms include Saccharomyces genus, Hansenula genus, Candida genus and the like. In addition, the microorganism may be an indigenous microorganism in the soil and / or groundwater, or may be a microorganism artificially introduced from the outside into the soil and / or groundwater.

  The method of introducing the liquid activator is not particularly limited. For example, a method of spraying on the ground surface by a sprinkler, a method of mixing with soil, a method of simply injecting (without pressurization) into an injection well, a pump, etc. A method of injecting using the above pressurizing means (pressure injecting method) or the like can be employed, but it is particularly preferable to employ the pressure injecting method. In the pressure injection method, the injection well may be injected using a pressurizing means, or may be directly injected into the soil without using the injection well.

  FIG. 3 is a process diagram for explaining the pressure injection method. First, as shown in FIG. 3A, an injection hole 10 is formed in soil in a contaminated area by a method such as boring, and a pipe 20 having an injection hole at the tip is inserted into the injection hole 10. At this time, the inlet at the tip of the pipe 20 is not particularly limited, but since it can effectively purify the contamination of the groundwater, it reaches the aquifer (sandy soil layer 4 in FIG. 1), that is, It is preferable to reach deeper than the groundwater level. Furthermore, it is preferable to reach the impermeable layer (lower silt layer 5 in FIG. 1) immediately below the aquifer. Subsequently, as shown in FIGS. 3B and 3C, the liquid activator is injected from the pipe 20 while being pressurized with a pump or the like. The injected liquid active agent diffuses into the soil from the inlet of the pipe 20. In order to inject the liquid active agent over a wider range, the injection of the active agent is preferably performed while the pipe 20 is pulled out.

  The method of introducing the solid activator is not particularly limited. For example, the method of directly burying in the soil, the method of replacing the contaminated soil with soil containing the solid activator (excavation and replacement method), boulding, etc. Although the method etc. which supply to the formed injection well can be employ | adopted, it is preferable to employ | adopt especially the excavation replacement method.

  FIG. 4 is a process diagram for explaining the excavation and replacement method. First, as shown in FIG. 4A, soil in a region where contamination occurs is excavated. The excavation area is not particularly limited, but it is preferable that the excavation area reaches directly above the aquifer (sandy soil layer 4 in FIG. 1) because it can effectively purify the contamination of groundwater. Then, as shown in FIG. 4B, soil replacement is performed by refilling the excavated region with soil mixed with a solid activator. At this time, the refilled excavation replacement region can be configured with a single layer, but as shown in FIG. 4C, it is preferable to configure with a plurality of layers according to the original geological structure. In the example of FIG. 4C, the excavation and replacement area includes, in order from the bottom, a crushed stone layer 11 containing a solid activator, a protective sandy soil layer 12, an impermeable or hardly permeable layer 13, and a sandy soil. Although it is comprised by five layers, the layer 14 and the crushed stone layer 15, a layer structure is not limited to this.

  In the excavation replacement region, the solid active agent may be contained uniformly, but may be localized only in a part. As such a form, as shown in FIG. 1, a form in which the excavation area is refilled with a plurality of soil layers and a solid activator is contained in at least one of them is included. In this case, the layer 11 containing the solid activator effectively suppresses the contamination of the groundwater, so as shown in FIG. 1, directly above the aquifer (sandy soil layer 4 in FIG. 1), that is, It is preferable to provide near the groundwater level.

  In addition, when an impermeable or hardly permeable layer on the aquifer such as the upper silt layer 3 is removed by excavation, when the excavation area is refilled, the impervious or hardly permeable property is changed. The layer 13 is preferably provided. This is because the impermeable or hardly permeable layer on the aquifer has a role of suppressing the penetration of contaminants into the groundwater. The impermeable or hardly permeable layer 13 is not particularly limited, but can be formed of a material containing clay such as bentonite, for example.

  According to the environmental purification method, the microorganisms present in the soil and / or groundwater are activated by the introduction of the liquid activator and the solid activator. And by the effect | action of this microorganism, a pollutant is decomposed | disassembled into a harmless substance, and purification | cleaning of soil and / or groundwater can be implement | achieved. In particular, since the liquid active agent is excellent in fluidity, when it is introduced into soil or groundwater, it quickly diffuses to the surroundings. Therefore, the microorganism activation effect can be expressed at a relatively early stage after the introduction of the active agent. On the other hand, since the solid active agent gradually releases the active ingredient, it can exert a microorganism activation effect over a relatively long period. In the above purification method, since these two kinds of activators are used in combination, it is possible to achieve both immediate effect and sustainability of the microorganism activation effect, and it is possible to efficiently purify soil and groundwater.

  Further, according to the above method, the environment can be purified only by the operation of introducing it into the soil and / or groundwater, so that the purification process at the place where the contamination occurs, that is, the in-situ process can be performed.

  The contaminated soil having a geological structure as shown in FIG. 2 was used to purify groundwater using a solid activator and a liquid activator in combination. In this soil, the depth of about 1.8 m from the ground surface is the topsoil layer 2, the range of depth of about 1.8 to 2.8 m is the upper silt layer 3, and the depth of about 2.8 to 5 is the same. The range of .4 m was the sandy soil layer 4 and the depth of about 5.4 m or more was the lower silt layer 5. The sandy soil layer 4 is a layer containing groundwater (that is, an aquifer), and the groundwater level was about 2.3 m deep from the ground surface.

  Further, when groundwater was pumped from the sandy soil layer and the concentration of the pollutants contained therein was analyzed, the tetrachlorethylene (PCE) concentration was about 25 mg / L, the trichlorethylene (TCE) concentration was about 18 mg / L, and cis-dichloroethane. The (c-DCE) concentration was about 11 mg / L.

An excavation hole having a depth of about 10 m from the ground surface was provided as an injection well for the contaminated soil. The number of injection wells was 10 with respect to the area of contaminated soil of 200 m ² . Of these, 4 were administered solid active agent and 6 were injected with liquid active agent. In addition, as a solid activator, the thing which has a stearic acid as a main component was used, and the usage-amount was set to 600 kg in total. Further, as the liquid active agent, a mixture of stearic acid and glycerin in a weight ratio of 1: 9 was used, and the amount used was 400 kg in total.

  Every three months after the introduction of the activator, groundwater was pumped from the contaminated soil, and the concentrations of pollutants (TCE, PCE and c-DCE) contained therein were measured. The results are shown in FIG.

  As shown in FIG. 5, according to the present example, a significant decrease in pollutants can be confirmed within an early period of 3 months after the introduction of the active agent. Further, after 12 months, all three types of pollutants are observed. The concentration in the ground water could be reduced to 0.001 mg / L or less. From this result, according to the present Example, it was confirmed that the immediate effect of the pollutant decomposition effect was excellent. Further, such a decrease in the pollutant concentration to a reference value (0.001 mg / L) or less can be realized by only one injection operation without requiring reinjection of the active agent. Thus, according to this example, it was confirmed that the durability of the pollutant decomposition effect was excellent.

  The environmental purification method of the present invention includes, for example, soil contaminated with the pollutant around a place where a substance that can become a pollutant is used or discharged, such as an electronic parts factory, a metal product factory, a dry cleaning site, and a garbage incineration site. It is extremely useful as a method for purifying groundwater.

It is a schematic diagram for demonstrating an example of the environmental purification method of this invention. It is a schematic diagram which shows an example of the contamination mechanism of soil and groundwater. It is process drawing for demonstrating an example of the introduction method of a liquid activator. It is process drawing for demonstrating an example of the introduction method of a solid activator. It is a graph which shows the pollutant reduction effect of groundwater in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pollution source 2 Topsoil 3 Upper silt layer 4 Sandy soil layer 5 Lower silt layer 6 Pollutant 10 Liquid activator injection hole 11 Solid activator containing layer 12 Protective layer 13 Impermeable or hardly permeable layer 14 Sandy soil layer 15 Crushed stone layer 20 Pipe

Claims (3)

Introducing an activator containing a substance that activates the pollutant decomposing action of the microorganism in the presence of a microorganism that decomposes the pollutant into at least one of soil and groundwater containing an organic halide as the pollutant, An environmental purification method for purifying at least one of the soil and groundwater in situ ,
As the active agent, a liquid active agent and a solid active agent are used in combination ,
The liquid activator comprises a mixture of glycerin and stearic acid and has a viscosity of 2000-80000 centipoise at 20 ° C .;
The environmental purification method , wherein the solid activator contains stearic acid . The environmental purification method according to claim 1 , wherein the introduction of the liquid activator is performed by pressurizing and injecting the liquid activator into soil. The environmental purification method according to claim 1 or 2 , wherein the introduction of the solid activator is performed by replacing soil in a contaminated area with soil containing the solid activator.

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