JP5184225B2 - How to remove pollutants - Google Patents

Description

The present invention relates especially removal how contaminants can be efficiently removed even contaminants present over a wide range in the soil or the like in existing structures under.

  In recent years, in order to purify contaminated ground, methods for detoxifying pollutants at the current location by improving biostimulation and applying oxidizing agents such as hydrogen peroxide have been tried. However, there are improvements such as non-uniform drug diffusion and long reaction times. In particular, when there is a pollutant under the existing structure, it is difficult to bring the drug into contact with the pollutant.

Conventionally, the following methods have been taken as countermeasures against soil contamination at the current location.
For example, a ground and / or water quality improvement method by injecting gas-dissolved water has been proposed (see, for example, Patent Document 1). However, dissolved water mixed with bubbles has a drawback that the water permeability is lowered and the drug does not penetrate. Bubbles may be mixed in for the purpose of ground improvement, but in particular for the purpose of purification, penetration of the drug is necessary, and this is not an appropriate method.

  Moreover, the purification method and system which purify | clean a contaminated soil in the present position using a purification function material are proposed (for example, refer patent document 2). However, this method has a drawback that it is purified only in the vicinity of the installed well for injection. Therefore, if the contaminants existing under the existing structure are to be purified by the above method, it is necessary to install injection wells at a narrow interval such as 1 to 2 m, which is difficult in practice. Is the method.

Furthermore, in removing pollutants retained in the ground, a pollutant removal method has been proposed that makes it possible to remove pollutants by performing appropriate and reliable heating. A method for removing contaminants using an injection well having an inlet has been proposed (see, for example, Patent Document 3). However, the heating fluid used in the method does not have a clear purification effect, and therefore it is difficult to remove pollutants existing over a wide range, considering the thermal conductivity in the ground.
JP 2001-193048 A JP 2005-185981 A JP 2004-243229 A

In view of the above problems, the present invention improves the mobility of drugs in soil, and can efficiently remove even pollutants that exist over a wide range, for example, in soil under existing structures. and to provide a removal how the possible contaminants.

The above object is achieved by the present invention described below. That is, the method for removing contaminants according to the present invention includes:
<1> An injection well installation step in which an injection well having two or more injection ports including at least an upper injection port and a lower injection port is provided at one end of a pollutant existing region in soil, and at the other end of the pollutant existing region A recovery well installation step in which a recovery well having two or more recovery ports including at least an upper recovery port and a lower recovery port is provided, and a liquid containing a drug from two or more injection ports including the upper injection port and the lower injection port. Injecting, recovering the liquid containing the drug from two or more recovery ports including the upper recovery port and the lower recovery port, and pollutants from at least one recovery port selected from the upper recovery port and the lower recovery port And a pollutant collecting step for collecting the pollutant.

  Here, the “injection port” in the injection well is required to have a function of injecting or discharging a liquid containing the drug into the soil, and the “recovery port” in the recovery well is an agent. It is necessary to have a function of sucking and collecting the contained liquid. In addition, it is preferable to provide a filter at the inlet and the recovery port from the viewpoint of preventing the inlet and the recovery port from being blocked by soil.

  By injecting a liquid containing a drug from two or more inlets including an upper inlet and a lower inlet, a predetermined amount of the drug to be injected can be divided into two or more inlets, and an upper recovery port In addition, the drug mobility in the soil can be improved by sucking and collecting the liquid containing the drug from two or more recovery ports including the lower recovery port. By improving the mobility of the drug, the drug can easily reach the contaminant-existing region, and at least one or more selected from the upper recovery port and the lower recovery port is selected as the contaminant processed by the reaction with the drug. Contaminants are removed by sucking and collecting from the recovery port. Therefore, for example, even pollutants existing over a wide range in soil under existing structures can be efficiently removed.

The method for removing contaminants described in <1>, the contaminant mineral oil, Ru least one Der selected from volatile organic chlorine compounds and heavy metals.

The method for removing contaminants described in <1>, as the drug, Ru using at least one selected from surfactants and foaming agents.

The contaminant removal method according to <1> described above, in the contaminant recovery step, injects a liquid that contains a surfactant and does not contain a foaming agent from the upper inlet of the injection well, A liquid containing an effervescent drug and no surfactant is injected from the inlet.

When a surfactant and an effervescent drug are mixed and injected into the soil, there is a problem that the mobility in the soil of the mixture of the surfactant and the effervescent drug decreases due to bubbles generated from the effervescent drug. there were. However, it is possible to improve the mobility of the surfactant and the foaming agent in the soil by injecting the surfactant and the foaming agent into the soil divided into the upper inlet and the lower inlet. .
Further, by injecting the foaming agent from the lower inlet, bubbles generated from the foaming agent rise in the soil and are mixed with the surfactant, and the surfactant and the bubbles reach the pollutant existing region. . Contaminants are exfoliated from the soil particles in the soil by bubbles and solubilized in the liquid by the surfactant. Therefore, they are sucked from at least one recovery port selected from the upper recovery port and the lower recovery port. Can be recovered efficiently.
Thus, for example, even pollutants existing over a wide range in the soil or the like under existing structures can be efficiently removed.

< 2 > The contaminant removal method according to < 1 > described above is such that the depth at which the lower inlet is provided in the injection well is deeper than the contaminant existing region, and the lower recovery is performed in the recovery well. It is preferable that the depth at which the mouth is provided overlap with the depth at which the lower inlet is provided.

  Here, it is desirable that the inlet in the injection well and the recovery port in the recovery well have a width in the depth direction. Therefore, “the depth at which the lower inlet is provided is a depth deeper than the pollutant existing area” means that at least a part of the lower inlet having a width in the depth direction has the deepest depth in the pollutant existing area. It means that it is provided at a deeper depth than that. In addition, “to make the depth at which the lower recovery port is provided overlap the depth at which the lower injection port is provided” means that at least a part of the lower injection port having a width in the depth direction and a width in the same depth direction. It means that it is provided so as to overlap the depth of at least a part of the lower recovery port.

By setting the depth at which the lower inlet is provided to be deeper than the pollutant existing region, bubbles generated from the foaming agent rise in the soil, and the bubbles can reach from below the pollutant existing region. it can. In other words, the mobility of the surfactant and foaming agent in the soil should be made more favorable while maintaining the action of exfoliation from the soil particles due to air bubbles of the contaminants and solubilization of the surfactant in the liquid. Can do.
In addition, by making the depth at which the lower recovery port is provided overlap the depth at which the lower injection port is provided, the mobility of the effervescent drug injected from the lower injection port can be further improved. Furthermore, at the lower recovery port, the liquid containing the foaming chemical injected from the lower injection port is recovered, but the liquid recovered from the lower recovery port is unreacted effervescent that has not passed through the pollutant existing area. Since the drug is mainly contained, the liquid does not contain contaminants or contains very little contaminants. Therefore, for example, when post-processing such as separation processing of contaminants and liquid is performed after recovery, the post-processing only needs to be performed on the liquid recovered from the upper recovery port, and the burden of post-processing can be reduced.

< 3 > The contaminant removal method according to <1> or <2> is such that, in the injection well, the depth at which the upper injection port is provided is set to a depth where the concentration of the contaminant is the highest, and the recovery well In this case, it is preferable that the depth at which the upper stage recovery port is provided be the depth at which the groundwater level exists.

  Here, “the depth at which the upper stage inlet is provided is the depth where the concentration of the contaminant is the highest” means that at least a part of the upper stage inlet having a width in the depth direction has a depth in the pollutant existing region. It means that the concentration of pollutants in the direction is set at the highest depth. In addition, “the depth at which the upper stage recovery port is provided is the depth at which the groundwater level exists” means that the upper stage having a width in the depth direction when the groundwater exists in the soil to which the contaminant is removed according to the present invention. It means that at least a part of the recovery port is provided at a depth where the upper water surface exists in the depth direction of the groundwater.

  By setting the depth at which the upper injection port is provided to the depth where the concentration of the contaminant is the highest, the drug can be efficiently reached the contaminant existing region. When the pollutant is a pollutant that is lighter than water, such as mineral oil, the pollutant treated with the chemical moves up in the ground water. Therefore, the pollutant lighter than water can be efficiently removed by setting the depth at which the upper stage recovery port is provided to the depth at which the groundwater level exists.

< 4 > In the method for removing contaminants according to < 3 >, it is preferable that the upper recovery port in the recovery well is movable in the depth direction.

  Since the upper recovery port in the recovery well is movable in the depth direction, the upper recovery port can be operated in response to fluctuations in the groundwater level, and pollutants that are lighter than water can be removed more efficiently. .

< 5 > In the contaminant removal method according to < 3 >, it is preferable that the upper injection port in the injection well is movable in the depth direction.

  When the upper inlet in the injection well is movable in the depth direction, the depth at which the upper inlet is installed can be easily adjusted to the highest contaminant concentration when the concentration of the contaminant changes with depth. And the medicine can efficiently reach the pollutant existing region.

In addition, the pollutant removal system of the present invention is
An injection well having two or more injection ports including an upper stage injection port and a lower stage injection port for injecting at least a liquid containing a drug, and an upper stage recovery port and a lower stage for recovering a liquid containing at least the drug injected from the injection well A pollutant having two or more recovery ports including a recovery port, and a recovery well for recovering contaminants from at least one or more recovery ports selected from the upper recovery port and the lower recovery port Removal system.

  By injecting a liquid containing a drug from two or more inlets including an upper inlet and a lower inlet, a predetermined amount of the drug to be injected can be divided into two or more inlets, and an upper recovery port In addition, the drug mobility in the soil can be improved by sucking and collecting the liquid containing the drug from two or more recovery ports including the lower recovery port. Therefore, by providing the injection well at one end of the pollutant existing area and the recovery well at the other end of the pollutant existing area, the drug can easily reach the pollutant existing area by improving the mobility of the drug. it can. The pollutant is removed by sucking and collecting the pollutant treated by the reaction with the drug from at least one recovery port selected from the upper recovery port and the lower recovery port. Therefore, for example, even pollutants existing over a wide range in soil under existing structures can be efficiently removed.

According to the present invention, to improve the mobility of the drug in the soil, for example, removal how contaminants that can be removed even effectively a contaminant that is present over a wide range in the soil or the like in existing structures under it is possible to provide a.

Hereinafter, a purification method and a contaminant removal system for contaminated soil according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing a contaminant removal method using the contaminant removal system of the present invention. The pollutant removal system of the present invention includes an injection well 2 having two or more inlets including a liquid containing at least a drug, an upper inlet 22 and a lower inlet 24 that inject in the directions of arrows A and B. And at least two recovery ports including an upper recovery port 42 and a lower recovery port 44 for recovering a liquid containing a medicine injected from the injection well, and selected from the upper recovery port 42 and the lower recovery port 44 And a recovery well 4 for recovering contaminants from at least one recovery port.
Further, in the method for removing contaminants of the present invention, an injection well in which an injection well 2 having two or more injection ports including at least an upper injection port 22 and a lower injection port 24 is provided at one end of a contaminant presence region 6 in soil. An installation step, a recovery well installation step in which a recovery well 4 having two or more recovery ports including at least an upper recovery port 42 and a lower recovery port 44 is provided at the other end of the pollutant presence region 6, and the upper injection port 22 A liquid containing a drug is injected from two or more inlets including the lower inlet 24 and in the direction of arrow A and arrow B, and two or more recovery including the upper recovery inlet 42 and the lower recovery outlet 44 are performed. Contaminant recovery for recovering a liquid containing a drug from the mouth and recovering contaminants from at least one recovery port selected from the upper recovery port 42 and the lower recovery port 44 And having a degree, the.

Types of contaminated soil purification method is subject to the process of applying the contaminated soil of the present invention are mineral oils, volatile organic chlorine compounds such as tetrachlorethylene, include heavy metals.

Further, the drug used is selected according to the pollutant, and examples thereof include surfactants, foaming drugs, oxidizing agents, metal-based reducing agents, microbial drugs, nutrient salts, and the like, and in particular, the pollutant is mineral oil. In some cases, it is preferable to use a surfactant and a foaming agent in combination. As the surfactant, an anionic (anionic) surfactant or a nonionic surfactant having an HLB value of 7 to 18 can be used. Specifically, as the nonionic surfactant, polyoxyethylene alkyl ether is used. , Glycerin fatty acid ester, propylene glycol fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, tetraoleic acid polyoxyethylene sorbitol, polyoxyethylene polyoxypropylene glycol, polyoxyethylene polyoxypropylene alkyl ether, polyethylene glycol fatty acid ester , Polyoxyethylene castor oil, polyglycerin fatty acid ester, alkylglycoside, etc., as anionic surfactant, fatty acid salt, polyoxyalkylene alkyl ether acetic acid , Alkyl sulfate, polyoxyalkylene alkyl ether sulfate, polyoxyalkylene alkyl amide ether sulfate, monoglyceride sulfate, olefin sulfonate, alkane sulfonate, acylated isethionate, acylated amino acid, alkyl phosphate And polyoxyalkylene alkyl ether phosphates.
As effervescent agents, hydrogen peroxide generators that dissociate into hydrogen peroxide and generate oxygen when dissolved in water (percarbonate, persulfate, perborate, peracetate, alkali metal sulfate peroxidation) Hydrogen adducts, alkaline earth metal sulfate hydrogen peroxide adducts, urea hydrogen peroxide adducts, melanin hydrogen peroxide adducts, amino acid hydrogen peroxide adducts, alkali metal peroxides, alkaline earth metal peroxides, etc.) And hydrogen peroxide.
Moreover, as a liquid containing the said chemical | medical agent, water etc. are mentioned, for example, It is preferable to use water especially.
In the present invention, a liquid containing a surfactant as a drug and not containing an effervescent drug is injected from the upper inlet of the injection well, and a surfactant containing an effervescent drug as a drug is injected from the lower inlet. Inject liquid that does not contain.

  In addition, it is preferable to adjust suitably the density | concentration of the chemical | medical agent in the liquid containing a chemical | medical agent by the chemical | medical agent to be used. For example, the concentration in the liquid when a surfactant is contained as a drug is preferably 0.01 to 1.0% by mass. Moreover, as a density | concentration in the liquid in the case of containing a foaming chemical | medical agent as a chemical | medical agent, it is preferable that it is 1-10 mass%.

  As shown in FIG. 1, the injection well 2 and the recovery well 4 are connected on the ground via a processing device such as a processing tank 10 or a chemical injection water tank 12, and the liquid containing the chemical and the recovery well 4 are connected. The recovered groundwater may be circulated. At this time, it is preferable that the groundwater collected from the viewpoint of underground infiltration is recharged from the chemical injection water tank 12 after being treated in the treatment tank 10. Examples of the groundwater treatment method include a method combining aeration treatment and activated carbon adsorption, a volatilization treatment method, a belt skimmer method, a floating oil recovery method, a centrifugal separation method, a membrane method, and a coagulation sedimentation method.

Hereinafter, the pollutant removal method of the present invention will be described in detail step by step.
<< First Embodiment >>
<Injection well installation process>
As shown in FIG. 1, the pollutant removal method according to the first embodiment includes two or more inlets including at least an upper inlet 22 and a lower inlet 24 at one end of a contaminant existing region 6 in soil. An injection well installation step of providing the injection well 2 is provided. In addition, when a groundwater flow exists in the soil in which a contaminant exists, it is preferable to provide the injection well 2 in the upstream in this groundwater flow.

Here, an example of the structure of the injection well 2 will be described. FIG. 2A is a schematic configuration diagram showing the outside of an example of the injection well 2, and FIG. 2B is a schematic configuration diagram showing the inside of the injection well 2.
As shown in FIG. 2A, the injection well 2 has a casing pipe 20 having a plurality of upper injection holes 222 and a plurality of lower injection holes 242. The periphery of the upper injection hole 222 and the periphery of the lower injection hole 242 are covered with filter layers 220 and 240 formed of gravel, bean gravel, silica sand, sand, and the like, and the filter layer 220 contains a drug. It has a structure that allows liquid to pass through. The upper injection hole 22 and the filter layer 220 form the upper injection hole 22, and the lower injection hole 242 and the filter layer 240 form the lower injection hole 24. Further, peripheral portions other than the periphery of the upper injection hole 222 and the lower injection hole 242 of the casing pipe 20 are covered with a sealing material 30 formed of bentonite, mortar or the like, and the sealing material 30 does not transmit liquid. It has a structure.

  Inside the casing pipe 20, an upper stage injection pipe 224, a lower stage injection pipe 244 and a packer pipe 34 are arranged. The upper injection pipe 224, the lower injection pipe 244, and the packer pipe 34 may be made of, for example, a flexible and stretchable material. Specifically, the upper injection pipe 224, the lower injection pipe 244, and the packing pipe 34 may be made of rubber or synthetic resin. It is a hose. A pipe injection hole 226 is formed at the tip of the upper injection pipe 224, and the upper injection pipe 224 is installed so that the pipe injection hole 226 is disposed in the vicinity of the upper injection hole 222. In addition, a pipe injection hole 246 is formed at the tip of the lower injection pipe 244, and the lower injection pipe 244 is installed so that the pipe injection hole 246 is disposed in the vicinity of the lower injection hole 242. The

A cylindrical packer 32 is disposed above the region where the upper injection hole 222 of the casing pipe 20 is formed. The circumferential surface of the cylindrical packer 32 is made of a packer bag made of an elastic material such as rubber that expands and contracts, and the packer 32 is used for a packer that sends liquid or gas for inflating the packer 32 (packer bag). A pipe 34 is connected. By supplying liquid or gas from the packer piping 34 and applying pressure, the packer 32 (packer bag) expands and seals the inside of the casing pipe 20. The liquid containing the medicine injected from the upper injection pipe 224 by the packer 32 is prevented from leaking above the casing pipe 20.
Similarly, the packer 32 is arranged below the region where the upper injection hole 222 of the casing pipe 20 is formed and above the region where the lower injection hole 242 is formed. The packer 32 is expanded by the pressure from the service pipe 34 and seals the inside of the casing pipe 20. The liquid containing the medicine injected from the upper injection pipe 224 by the packer 32 leaks downward from the casing pipe 20, and the liquid containing the medicine injected from the lower injection pipe 244 passes through the casing pipe 20. Leaking upward is prevented. This prevents the liquid injected from the upper injection pipe 224 and the liquid injected from the lower injection pipe 244 from being mixed in the casing pipe 20.

  The formation of the injection well 2 shown in FIGS. 2A and 2B is performed as follows. First, a hole for inserting the injection well 2 is excavated by a method such as boring. The casing pipe 20 is inserted into the hole, and a material for forming the sealing material 30 (for example, bentonite, mortar, etc.) and a material for forming the filter layer 220 (for example, gravel stone) in the gap between the hole and the casing pipe 20. , Bean gravel, quartz sand, sand, etc.) are embedded to form the sealing material 30 and the filter layer 220. Thereafter, the upper stage injection pipe 224, the lower stage injection pipe 244, the packer 32 and the packer pipe 34 are inserted into predetermined positions in the casing pipe 20, and the packer 32 is expanded by applying pressure to the packer pipe 34 so that the casing pipe is expanded. The region in which the upper injection hole 222 in 20 is formed and the region in which the lower injection hole 242 is formed are sealed. Thereafter, the injection well 2 is formed by connecting the upper injection pipe 224 and the lower injection pipe 244 to the chemical injection water tank 12.

  In addition, it is good also as a structure by which the piping for exclusive use of a packer was connected with respect to each of the two packers 32, and the two packers 32 can be expand | swelled separately. By setting it as such a structure, the two packers 32 can be expanded more reliably.

<Recovery well installation process>
As shown in FIG. 1, the pollutant removal method according to the first embodiment is a recovery having two or more recovery ports including at least an upper recovery port 42 and a lower recovery port 44 at the other end of the contaminant presence region 6. It has a recovery well installation process in which the well 4 is provided. In addition, when a groundwater flow exists in the soil in which a pollutant exists, it is preferable to provide the recovery well 4 in the downstream in this groundwater flow.

Here, the structure of the recovery well 4 will be described with an example. FIG. 2C is a schematic configuration diagram showing the outside of an example of the recovery well 4, and FIG. 2D is a schematic configuration diagram showing the inside of the recovery well 4.
As shown in FIG. 2C, the recovery well 4 has a casing pipe 40 having a plurality of upper recovery holes 422 and a plurality of lower recovery holes 442. The periphery of the upper recovery hole 422 and the periphery of the lower recovery hole 442 are covered with filter layers 420 and 440 formed of gravel, bean gravel, silica sand, sand, etc., and the filter layer 420 contains a drug. It has a structure that allows liquids and contaminants to pass through. An upper recovery port 42 is formed by the upper recovery hole 422 and the filter layer 420, and a lower recovery port 44 is formed by the lower recovery hole 442 and the filter layer 440. Further, the peripheral portion other than the periphery of the upper recovery hole 422 and the lower recovery hole 442 of the casing pipe 40 is covered with a sealing material 30 formed of bentonite, mortar, or the like. The structure does not pass through.

  Inside the casing pipe 40, an upper stage recovery pipe 424, a lower stage recovery pipe 444 and a packer pipe 38 are arranged. As the packer pipe 38, for example, a flexible and stretchable material can be used, and specifically, a hose made of rubber or synthetic resin is used. On the other hand, since the upper recovery pipe 424 and the lower recovery pipe 444 are affected by negative pressure, it is preferable to use a material having high rigidity, for example, a metal pipe such as steel, cast iron, or aluminum. A pipe recovery hole 426 is formed at the tip of the upper recovery pipe 424, and the upper recovery pipe 424 is installed so that the pipe recovery hole 426 is disposed in the vicinity of the upper recovery hole 422. Further, a pipe recovery hole 446 is formed at the tip of the lower recovery pipe 444, and the lower recovery pipe 444 is installed so that the pipe recovery hole 446 is disposed in the vicinity of the lower recovery hole 442. The

A cylindrical packer 36 is disposed above the area where the upper recovery hole 422 of the casing pipe 40 is formed. The circumferential surface of the cylindrical packer 36 is made of a packer bag made of an elastic material such as rubber that expands and contracts. The packer 36 is used for a packer that sends liquid or gas for inflating the packer 36 (packer bag). A pipe 38 is connected. By supplying liquid or gas from the packer piping 38 and applying pressure, the packer 36 (packer bag) is expanded and the casing pipe 40 is sealed. The packer 36 prevents the liquid or contaminants containing the medicine recovered from the upper recovery hole 422 from leaking upward from the casing pipe 40.
Similarly, the packer 36 is disposed below the region where the upper recovery hole 422 of the casing pipe 40 is formed and above the region where the lower recovery hole 442 is formed. The packer 36 is expanded by the pressure from the service pipe 38 and seals the inside of the casing pipe 40. The liquid or contaminant containing the medicine recovered from the upper recovery hole 422 by the packer 36 leaks below the casing pipe 40, and the liquid or contaminant containing the medicine recovered from the lower recovery hole 442. Is prevented from leaking upward of the casing pipe 40. This prevents the liquid and contaminant collected from the upper recovery hole 422 and the liquid and contaminant recovered from the lower recovery hole 442 from being mixed in the casing pipe 40.

  The formation of the recovery well 4 shown in FIGS. 2C and 2D can be performed by the same method as the formation of the injection well 2. Here, a configuration in which dedicated packer piping is connected to each of the two packers 36 may be configured such that the two packers 36 can be individually expanded. By setting it as such a structure, the two packers 36 can be expanded more reliably.

<Contaminant recovery process>
The pollutant removal method according to the first embodiment injects a liquid containing a drug from two or more injection ports including the upper injection port 22 and the lower injection port 24, and sets the upper recovery port 42 and the lower recovery port 44. The method includes a contaminant recovery step of recovering the liquid containing the drug from the two or more recovery ports including and recovering the contaminant from at least one or more recovery ports selected from the upper recovery port 42 and the lower recovery port 44.

  The point that a predetermined amount of the medicine to be injected can be divided and injected into two or more injection ports by injecting the liquid containing the drug from two or more injection ports including the upper injection port 22 and the lower injection port 24, In addition, the mobility of the drug in the soil can be improved by sucking and collecting the liquid containing the drug from two or more recovery ports including the upper recovery port 42 and the lower recovery port 44. By improving the mobility of the drug, the drug can easily reach the pollutant existence region 6 and the pollutant treated by the reaction with the drug is selected from the upper recovery port 42 and the lower recovery port 44. Contaminants are removed by suction and recovery from at least one recovery port. Therefore, for example, even pollutants existing over a wide range in the soil under the existing structure 8 can be efficiently removed.

  When a surfactant and an effervescent agent are used in combination, a liquid containing a surfactant is injected from the upper inlet 22 of the injection well 2 and an effervescent agent is injected from the lower inlet 24. It is preferable to inject the contained liquid.

When a surfactant and an effervescent agent are used in combination, the mixture of the surfactant and the effervescent agent is mixed with the surfactant and the effervescent agent due to bubbles generated from the effervescent agent. There was a problem that the mobility in the inside decreased. However, it is possible to improve the mobility of the surfactant and the foaming agent in the soil by injecting the surfactant and the foaming agent into the upper inlet 22 and the lower inlet 24 and injecting them into the soil. Can do.
Further, by injecting the foaming agent from the lower injection port 24, the bubbles generated from the foaming agent rise in the soil and are mixed with the surfactant, and the surfactant and the bubbles enter the pollutant existing region 6. To reach. Here, as shown in FIG. 3, the contaminant 106 is separated from the soil particles 102 in the soil by the bubbles 108 and is solubilized in the liquid by the surfactant 110, so that the upper recovery port 42 and the lower recovery port 44. It is efficiently recovered by being sucked from at least one recovery port selected from.
Thus, for example, even pollutants existing over a wide range in the soil under the existing structure 8 can be efficiently removed.

  In addition, as described above, when the liquid containing the surfactant is injected from the upper injection port 22 of the injection well 2 and the liquid containing the foaming agent is injected from the lower injection port 24, it is shown in FIG. As described above, the depth at which the lower inlet 24 is provided in the injection well 2 is set to a depth deeper than the contaminant presence region 6, and the depth at which the lower recovery inlet 44 is provided in the recovery well 4 is It is preferable to overlap the provided depth.

As shown in FIG. 4, by setting the depth at which the lower inlet 24 is provided to a depth deeper than the contaminant presence region 6, the bubbles 108 generated from the effervescent drug 112 rise in the soil, and the bubbles 108 Can be reached from below the pollutant presence region 6. That is, as shown in FIG. 3, the surfactant 110 in the soil is further maintained while maintaining the action of the separation of the contaminant 106 from the soil particles 102 by the bubbles 108 and the solubilization in the liquid by the surfactant 110. In addition, the mobility of the foamable drug 112 can be made more suitable.
In addition, by making the depth at which the lower recovery port 44 is provided overlap the depth at which the lower injection port 24 is provided, the mobility of the effervescent drug 112 injected from the lower injection port 24 can be further improved. Furthermore, at the lower recovery port 44, the liquid containing the foamable drug 112 injected from the lower injection port 24 is recovered, but the liquid recovered from the lower recovery port 44 does not pass through the contaminant presence region 6. Since the unreacted effervescent drug 112 is mainly contained, the liquid does not contain contaminants or contains very little contaminants. Therefore, for example, when post-processing such as separation processing of contaminants and liquid is performed after recovery, the post-processing only needs to be performed on the liquid recovered from the upper recovery port 42, and the burden of post-processing can be reduced.

  In the contaminant removal method according to the first embodiment, as shown in FIG. 4, the depth at which the upper injection port 22 is provided in the injection well 2 is set so that the contaminant concentration in the contaminant presence region 6 is the highest. In addition to the high depth, it is preferable that the depth at which the upper recovery port 42 is provided in the recovery well 4 is a depth at which the groundwater level W exists.

  By setting the depth at which the upper injection port 22 is provided to the depth at which the concentration of the pollutant is the highest, the drug can efficiently reach the pollutant existence region 6. When the pollutant is a pollutant that is lighter than water, such as mineral oil, the pollutant treated with the chemical moves up in the ground water. Therefore, by setting the depth at which the upper stage recovery port 42 is provided to the depth at which the groundwater level W exists, it is possible to efficiently remove contaminants lighter than water.

<< Second Embodiment >>
<Injection well installation process>
The contaminant removal method according to the second embodiment includes an injection well installation step in which an upper injection port and a lower injection port are provided with injection wells that are movable in the depth direction. When the upper inlet is movable in the depth direction, the depth at which the upper inlet is provided can be easily adjusted to the depth with the highest pollutant concentration when the concentration of the contaminant changes with depth. It is possible to efficiently reach the pollutant existing area.

Here, an example of the structure of the injection well according to the second embodiment will be described. FIG. 5A is a schematic configuration diagram showing the outer side in an example of the injection well, and FIG. 5B is a schematic configuration diagram showing the inner side of the injection well.
As shown in FIG. 5A, the injection well has a casing pipe 20b having a plurality of upper injection holes 222b and a plurality of lower injection holes 242b. The periphery of the upper injection hole 222b and the periphery of the lower injection hole 242b are covered with filter layers 220b and 240b formed of gravel, bean gravel, silica sand, sand, and the like, and the filter layer 220b contains a drug. It has a structure that allows liquid to pass through. An upper injection port 22b is formed by the upper injection hole 222b and the filter layer 220b, and a lower injection port 24b is formed by the lower injection hole 242b and the filter layer 240b. Further, the peripheral portion other than the periphery of the upper injection hole 222b and the lower injection hole 242b of the casing pipe 20b is covered with a sealing material 30b formed of bentonite, mortar, etc., and the sealing material 30b does not transmit liquid. It has a structure.

  Inside the casing pipe 20b, an upper stage injection pipe 224b, a lower stage injection pipe 244b, a lower packer pipe 34b and an upper packer pipe 34c are arranged. The upper injection pipe 224b, the lower injection pipe 244b, the lower packer pipe 34b, and the upper packer pipe 34c can be made of, for example, a flexible and stretchable material. It is a hose made of rubber or synthetic resin. A pipe injection hole 226b is formed at the tip of the upper injection pipe 224b, and the upper injection pipe 224b is disposed in a region where the upper injection hole 222b is formed. Is installed. Further, a pipe injection hole 246b is formed at the tip of the lower injection pipe 244b, and the lower injection pipe 246b is disposed in the region where the lower injection hole 242b is formed. A pipe 244b is installed.

Cylindrical packers 320b and 322b are arranged above and below the region where the upper injection hole 222b of the casing pipe 20b is formed, and the packers 320b and 322b are expanded by the pressure from the upper packer pipe 34c, and the casing pipe 20b. The inside is sealed. The packers 320b and 322b prevent the liquid containing the medicine injected from the upper injection pipe 224b from leaking upward and downward of the casing pipe 20b.
Similarly, cylindrical packers 324b and 326b are disposed above and below the region where the lower injection hole 242b of the casing pipe 20b is formed, and the packers 324b and 326b are expanded by the pressure from the lower packer pipe 34b. The casing pipe 20b is hermetically sealed. The packers 324b and 326b prevent the liquid containing the medicine injected from the lower injection pipe 244b from leaking upward and downward of the casing pipe 20b.
Note that the liquid injected from the upper injection pipe 224b by the packer 322b is prevented from leaking downward from the casing pipe 20b, and the liquid injected from the lower injection pipe 244b by the packer 324b is the casing pipe 20b. Is prevented from mixing in the casing pipe 20b with the liquid injected from the upper injection pipe 224b and the liquid injected from the lower injection pipe 244b. .

  Next, the packers 320b, 322b, 324b, and 326b will be described with reference to FIGS. Since the basic configurations of the packers 320b, 322b, 324b, and 326b are the same, the packer 320b will be described as a representative.

  FIG. 6A is a front view of the packer 320b in a state where the packer bag 212 is inflated, and FIG. 6B is a front view of the packer 320b in a contracted state. FIG. 7A is an enlarged view of a portion A of FIG. 6A (the disk portion 214 of the packer 320b), and FIG. 7B is a sectional view taken along the line BB of FIG. Here, the “axial direction” refers to the axial direction of each well, that is, in this embodiment, the vertical direction is the axial direction.

  The circumferential surface of the cylindrical packer 320b includes a packer bag 212 made of an elastic material such as rubber that expands and contracts. And the upper packer piping 34c which sends the liquid or gas for inflating the packer bag 212 is connected. By supplying liquid or gas from the upper packer pipe 34c and applying pressure, the packer bag 212 of the packer 320b expands (see FIG. 6A), and when the liquid or gas is extracted, the pressure decreases and the packer bag 212 contracts. (See FIG. 6B).

  As shown in FIG. 6, the packer 320b is provided with disc portions 214 and 216 at the upper end portion and the lower end portion. The packer bag 212 described above is provided between the disc portion 214 and the disc portion 216.

  As shown in FIG. 7, balls (balls) 260 as a plurality of rotating bodies are exposed from the peripheral wall 214 </ b> A of the disc portion 214 at predetermined intervals in the circumferential direction. The ball 260 as the rotating body functions as a means for reducing the resistance during the up and down operation (hereinafter referred to as “movement resistance reducing means”).

  As shown in FIG. 7, the disk portion 214 has recesses 213 formed at intervals in the circumferential direction. A hole 215 is formed at the bottom of the recess 213. A ball 260 is disposed in the hole 215, and a fitting portion 262 in which a hole 263 smaller than the diameter of the ball 260 is formed is fitted and joined to the recess 213. Note that in the cross-sectional view of FIG. 7B, the hatching indicating the cross section of the ball 260 is omitted (only the ball 260 is an external view).

  With such a configuration, the ball 260 is exposed without dropping from the disc portion 214, and the ball 260 is rotatable. The exposed ball 260 is much larger than a slit or hole formed in the casing pipe 20b.

  7B, the outer shape K of the disc portion 214 including the exposed ball 260 is the outermost portion of the packer 320b when the packer bag 212 is contracted. The diameter of the outer shape K is slightly smaller than the diameter of the casing pipe 20b. Note that the disc portion 216 has the same configuration and will not be described.

  The upper packer pipe 34c is connected to the packer 320b and also connects to the packer 322b through the packer 320b. The lower packer pipe 34b passes through the packers 320b and 322b and is connected to the packers 324b and 326b.

  Then, by sending liquid or gas from the upper packer pipe 34c and applying pressure, the packer bag (packer bag 212) of the packer 320b and the packer bag of the packer 322b expand, and the pressure is reduced by removing the liquid or gas. Shrinks down. On the other hand, by sending liquid or gas from the lower packer pipe 34b and applying pressure, the packer bag of the packer 324b and the packer bag of the packer 326b are expanded, and the pressure is lowered and contracted by extracting the liquid or gas.

The packer bags in the packers 320b, 322b, 324b and 326b shown in FIG. 5B are contracted as shown in FIG. 6B, so that the upper injection pipe 224b, the lower injection pipe 244b, The packer pipe 34b, the upper packer pipe 34c, and the packers 320b, 322b, 324b, and 326b can be integrally moved in the casing pipe 20b.
In addition, when operating (moving in the axial direction), the ball 260 as a rotating body comes into contact with the inner wall surface of the casing pipe 20b and rotates to reduce the movement resistance. At this time, since the exposed ball 260 is much larger than the slit or hole formed in the casing pipe 20b as described above, the ball 260 does not fit into the slit or hole.

  After operating (moving in the axial direction), the inside of the casing pipe 20b is sealed by inflating the packer bags in the packers 320b, 322b, 324b and 326b. Thereby, the injection well is partitioned by the packers 320b, 322b, 324b and 326b, and the upper injection port 22b and the lower injection port 24b are formed.

  Note that the packers 320b, 322b, 324b, and 326b are disposed inside the sealing material 30b.

  Further, a dedicated packer pipe is connected to each of the packers 320b, 322b, 324b, and 326b, and the packer bags of the packers 320b, 322b, 324b, and 326b can be individually expanded and contracted. It is good. By setting it as such a structure, the packer bag of each packer 320b, 322b, 324b, and 326b can be expanded and contracted more reliably.

  Next, a modified example of the disk portion having the movement resistance reducing means of another example will be described.

  First, the disc part 314 is demonstrated as a 1st modification using FIG. 8A is a partially enlarged view in which a main part of the disk portion 314 is enlarged, and FIG. 8B is a cross section taken along line BB (a direction orthogonal to the axial direction) of FIG. FIG.

  As shown in FIG. 8, recesses 313 are formed in the circumferential wall 314 </ b> A of the disk portion 314 with a gap in the circumferential direction. A fitting portion 372 in which a hemispherical (mountain-shaped) convex portion 370 is formed is fitted and joined to the concave portion 313. Therefore, a plurality of hemispherical (mountain-shaped) convex portions 370 protrude from the peripheral wall 314A of the disc portion 314 at predetermined intervals in the circumferential direction.

  Note that the fitting portion 372 in which the convex portion 370 is formed is preferably made of a material having better sliding properties than the peripheral wall 314A of the disc portion 314, for example, a fluororesin.

  With such a configuration, the apex portion of the convex portion 370 as the movement resistance reducing means abuts on the inner wall surface of the casing pipe 20b, thereby reducing the axial resistance of the packer and the rotational resistance around the axial direction. The

  Next, a disk portion 414 will be described with reference to FIG. 9 as a second modification. 9A is a partially enlarged view in which a main part of the disc portion 414 is enlarged, and FIG. 9B is a cross-sectional view taken along line BB (axial direction) of FIG. Therefore, the vertical direction in FIG. 9B is the axial direction.

  As shown in FIG. 9, recesses 413 are formed in the peripheral wall 414 </ b> A of the disc portion 414 with a gap in the circumferential direction. A wheel holding member 462 in which a rotating shaft 461 of the wheel 460 is rotatable is fitted and joined to the recess 413. A hole 415 is formed on the bottom surface of the recess 413 so that the wheel 460 does not interfere.

  A rotation shaft 461 of the wheel 460 is set to a direction orthogonal to the axial direction. Therefore, the wheel 460 rotates in the axial direction.

  By setting it as such a structure, the wheel 460 (rotary body) as a movement resistance reduction means contact | abuts to the inner wall surface of the casing pipe 20b, and rotates, and the movement resistance of the packer's axial direction is reduced.

  In the second embodiment, as shown in FIG. 5, the intervals between the packers 320b, 322b, 324b and 326b are fixed, but the intervals between the packers 320b, 322b, 324b and 326b are variable (adjustable). A different configuration may be used. Therefore, a modification in which the intervals between the packers 320b, 322b, 324b, and 326b are variable (adjustable) will be described next.

  FIG. 10 is a perspective view showing a modified packer 322b. FIG. 11 is a front view schematically showing a main part of the modification. In FIG. 11, illustration of the packer pipes 34b and 34c is omitted.

  In the modification shown in FIGS. 10 and 11, the packer 322b is provided with a connecting rod 610 extending in the axial direction from the disk portions 218 and 219. Similarly, in the packer 320b, the disk portion 216 is extended in the axial direction. An extending connecting rod 610 is provided (see FIG. 11). In addition, the connecting rod 610 extending from the disk portion 218 of the packer 322 b and the connecting rod 610 extending from the disk portion 216 of the packer 320 b are connected via the adjustment rod 620 to form the rod 600. A male screw portion 602 is formed at the distal ends of the connecting rod 610 and the adjusting rod 620. There are different types of adjustment rods 620 having different overall lengths.

  Then, as shown in order in (1) to (3) of FIG. 12, an adjustment rod 620 is disposed between one connecting rod 610 and the other connecting rod 610, and the male thread portion 602 of the connecting rod 610 By screwing the high nut 650 into the male threaded portion 602 of the adjustment rod 620, the packers 320b and 322b are connected (the packer 320b, the connection rod 610, the adjustment rod 620, the connection rod 610, and the packer 322b are connected in this order). As a result, the entire rod 600 is variable (adjustable)).

  As described above, the adjustment rod 620 is of a type having a different overall length, and the interval between the packers 320b and 322b can be changed (adjusted) by exchanging the adjustment rod 620. Furthermore, the overall length of the rod 600 can be finely adjusted by adjusting the screwing allowance between the male screw portion 602 and the high nut 650.

  Although not shown, the packers 324b and 326b are also provided with the same rod 600, and the interval between the packers 322b, 324b and 326b can be adjusted by changing the length of the adjustment rod 620.

  In the present embodiment, three rods 600 are provided, but the present invention is not limited to this. One or more rods 600 are sufficient. Further, the steel rod 600 described above may be a single member, and the member corresponding to the other rod 600 may be a steel wire or the like.

  Further, the connecting rod 610 and the adjusting rod 620 may be connected by a member other than the high nut 650. For example, as shown in FIG. 13A, the connecting rod 610 and the adjusting rod 620 may be connected by a sleeve tube 660.

  In the sleeve tube 660, female screw holes 662 are formed in the peripheral wall 660 </ b> A at intervals in the axial direction (four female screw holes 662 are formed in this embodiment).

  As shown in FIG. 13B, the axis of the connecting rod 610 and the adjusting rod 620 are aligned with each other in a state where the sleeve tube 660 is inserted through the adjusting rod 620 in advance. As shown in FIG. 13C, in this state, the sleeve tube 660 is slid in the axial direction to be inserted through both the connecting rod 610 and the adjusting rod 620. Then, the connecting rod 610 and the adjusting rod 620 are connected by screwing and tightening a bolt 661 into each female screw hole 662 of the sleeve tube 660 (see FIG. 13A). Note that the total length can be finely adjusted by adjusting the insertion allowance in which the connecting rod 610 and the adjusting rod 620 are inserted into the sleeve tube 660.

  Note that the lower injection pipe 244b and the packer pipes 34b and 34c are flexible and stretchable materials, for example, rubber or synthetic resin hoses. The total length of each is set slightly longer than the assumed interval between the packers 320b, 322b, 324b and 326b. Therefore, even if the interval between the packers 320b, 322b, 324b, and 326b is changed (adjusted), it follows by bending. Note that the lower injection pipe 244b and the packer pipes 34b and 34c are preferably bellows because they are more easily bent. The entire tube (hose) may have a bellows shape or may have a partially bellows shape. Alternatively, only a part of the lower-stage injection pipe 244b and the packer pipes 34b and 34c may be formed of a hose made of a flexible and stretchable material (made of rubber or synthetic resin).

  The packer piping, the lower injection pipe, and the rod are formed of a material having high rigidity (for example, a metal pipe such as steel, cast iron, aluminum, etc.), similarly to the lower recovery pipe 644b in the recovery well described later. In addition, a flange portion may be formed at the tip, and a length adjustment packer pipe, a lower injection pipe, or a rod may be provided. The total length can be changed by exchanging with a length-adjusting packer pipe, a lower-stage injection pipe, or a rod having a different total length.

  This modification is an example of a configuration in which the intervals between the packers 320b, 322b, 324b, and 326b are variable (adjustable), and is not limited to such a configuration. As long as the intervals between the packers 320b, 322b, 324b, and 326b are variable (adjustable), any configuration may be used.

  As described above, by making the intervals between the packers 320b, 322b, 324b and 326b variable (adjustable), the optimum intervals and positions of the packers 320b, 322b, 324b and 326b can be obtained. In addition, even in the same contaminated soil, the optimal spacing and position of the packers 320b, 322b, 324b, and 326b may differ depending on the location of the well, but this configuration can easily cope with it. is there.

  Although not shown, the packers 320b, 322b, 324b, and 326b are hollow tubes that are disposed inside (specifically, inside the packer bag constituting the peripheral surface of the packer) with the axial direction as the longitudinal direction. In other words, the upper and lower disk portions 214 and 216 are connected by a hollow tube, and a portion corresponding to the hollow tube is opened, and a lower-stage injection pipe 244b and a packer are disposed in the hollow tube. It is good also as a structure which the piping 34b and 34c for service pass.

<Recovery well installation process>
The contaminant removal method according to the second embodiment includes a recovery well installation step in which the upper recovery port and the lower recovery port are provided with recovery wells that are movable in the depth direction. Since the upper stage recovery port is movable in the depth direction, the upper stage recovery port can be operated in response to changes in the groundwater level, and contaminants that are lighter than water can be removed more efficiently.
Note that the recovery well according to the second embodiment is an upper injection pipe made of a flexible and stretchable material in the injection well installed in the injection well installation process according to the second embodiment described above. It is possible to adopt a configuration in which the 224b and the lower-stage injection pipe 244b are replaced with an upper-stage recovery pipe and a lower-stage recovery pipe that are made of a material having high rigidity (for example, a metal pipe such as steel, cast iron, or aluminum). it can. This is because the recovery pipe is affected by negative pressure.

  In the following, in the recovery well according to the second embodiment, only a portion different from the above-described implantation well will be described, and the description of the same configuration as the above-described implantation well will be omitted.

FIG. 14 is a perspective view showing the packer 362b in a configuration in which the packer interval is variable (adjustable) in the recovery well. In the recovery well shown in FIG. 14, the lower injection pipe 244b shown in “Modification in which intervals between packers 320b, 322b, 324b and 326b are variable (adjustable)” in the above-described injection well installation step ( The pipe that is made of a flexible and stretchable material) is changed to a lower recovery pipe 644b made of a material having high rigidity (for example, a metal pipe such as steel, cast iron, or aluminum). Except for this, the same configuration is adopted.
FIG. 15 is a front view schematically showing the main part of the recovery well shown in FIG. In FIG. 15, the illustration of the packer pipes 38b and 38c is omitted.

  As shown in FIG. 15, the lower recovery pipe 644 b has a flange 632 at the tip, and the adjustment lower recovery pipe 629 has a flange 632 at both ends. An adjustment lower-stage recovery pipe 629 is disposed between the upper lower-stage recovery pipe 644b and the lower lower-stage recovery pipe 644b, and the flanges 632 are joined to each other (for example, bolted). In other words, the upper and lower lower recovery pipes 644b are connected by the adjustment lower recovery pipe 629. Note that the lower recovery pipe 644b and the adjustment lower recovery pipe 629 are affected by negative pressure, and thus are made of a material having high rigidity, for example, a metal pipe such as steel, cast iron, or aluminum.

  The adjustment lower stage recovery pipe 629 is of a different type and can be replaced. In addition, as in the above-described modification in the implantation well installation process, the rod 600 (more precisely, the adjustment rod 620) is of a different type and can be replaced. Therefore, the interval between the packers 360b and 362b can be changed (adjusted) by exchanging the adjustment lower-stage recovery pipe 629 and the adjustment rod 620.

  As described above, even in the recovery well, by making the packer interval variable (adjustable), it is possible to obtain the optimum packer interval and position. Moreover, even in the same purification site, the optimal interval and position of the packer may differ depending on the location of the well, but such a configuration can be easily handled.

  As shown in FIG. 15, the adjustment lower-stage recovery pipe 629 does not connect the upper and lower lower-stage recovery pipes 644b, but connects the flanges 632 of the upper and lower lower-stage recovery pipes 644b. May be. In this case, the lower-stage recovery pipe 644b is of a type that has a different total length from the joint portion (root portion) to the disk portion to the flange 632, and is replaceable. The intervals between the packers 360b and 362b can be changed (adjusted) by exchanging the lower-stage collection pipes 644b with different lengths and joining the lower-stage collection pipes 644b to each other.

<Pollutant removal process>
Using the injection well and the recovery well according to the second embodiment installed as described above, it is possible to efficiently remove contaminants by the method described in the first embodiment.

«Third embodiment»
<Injection well installation process>
In the contaminant removal method according to the third embodiment, the injection well installed in the injection well installation step has the same configuration as the injection well installed in the first embodiment or the second embodiment described above. Can be adopted.

<Recovery well installation process>
The contaminant removal method according to the third embodiment includes a recovery well installation step in which an upper recovery port is provided with a recovery well that is movable in the depth direction. Since the upper stage recovery port is movable in the depth direction, the upper stage recovery port can be operated in response to changes in the groundwater level, and contaminants that are lighter than water can be removed more efficiently.

Here, the structure of the recovery well according to the third embodiment will be described. FIG. 16A is a schematic configuration diagram showing the outside of the recovery well, and FIG. 16B is a schematic configuration diagram showing the inside of the recovery well.
As shown in FIG. 16A, the recovery well has a casing pipe 40d having a plurality of upper recovery holes 422d and a plurality of lower recovery holes 442d. The periphery of the upper recovery hole 422d and the periphery of the lower recovery hole 442d are covered with filter layers 420d and 440d formed of gravel, bean gravel, silica sand, sand, and the like. It has a structure through which the contained liquid permeates. An upper recovery port 42d is formed by the upper recovery hole 422d and the filter layer 420d, and a lower recovery port 44d is formed by the lower recovery hole 442d and the filter layer 440d. Further, the peripheral portion other than the periphery of the upper recovery hole 422d and the lower recovery hole 442d of the casing pipe 40d is covered with a sealing material 30d formed of bentonite, mortar, etc., and the sealing material 30d does not transmit liquid. It has a structure.

  An upper stage recovery pipe 424d, a lower stage recovery pipe 444d, and a packer pipe 38d are disposed inside the casing pipe 40d. A pump 426d is installed at the tip of the upper recovery pipe 424d, and the upper recovery pipe 424d is installed so that the pump 426d is disposed in the region where the upper recovery hole 422d is formed. Is done. Further, a pumping pump 446d is installed at the tip of the lower-stage recovery pipe 444d, and the lower-stage recovery pipe 444d is disposed in the region where the lower-stage recovery hole 442d is formed. Is installed.

  A cylindrical packer 36d is disposed in the lower direction of the region where the upper recovery hole 422d is formed in the casing pipe 40d and in the upper direction of the region where the lower recovery hole 442d is formed. The peripheral surface of the cylindrical packer 36d is made of a packer bag made of an elastic material such as rubber that expands and contracts, and the packer 36d is for a packer that sends liquid or gas for inflating the packer 36d (packer bag). A pipe 38d is connected. By supplying liquid or gas from the packer piping 38d and applying pressure, the packer 36d (packer bag) is expanded, and the inside of the casing pipe 40d is sealed. The packer 36d prevents the liquid containing the medicine recovered from the pump 446d through the lower recovery pipe 444d from leaking above the casing pipe 40d, and the liquid to be recovered by the upper recovery pipe 424d is from the upper stage. The liquid to be recovered by the lower-stage recovery pipe 444d is reliably recovered from the lower stage.

  The upper recovery port can be moved in the depth direction by operating the upper recovery pipe 424d with the pump 426d at the tip in the vertical direction. Therefore, the depth of the upper recovery port can be adjusted according to the groundwater level, and by setting the depth at which the groundwater level exists, it is possible to efficiently remove contaminants lighter than water.

In the pollutant removal method of the present invention described above, the total amount of the liquid containing the chemical to be injected into the soil from the injection well 2 is usually 5 to 20 L / min. When the diameter is increased, an injection rate exceeding 30 L / min is also possible. In addition, when the injection well 2 has two injection ports, the upper injection port 22 and the lower injection port 24, each of the injection amounts may be half of the total amount, or the upper injection port 22 and the lower injection port. The injection amount condition may be changed between the inlet 24 and the inlet 24.
Moreover, the moving speed | velocity | rate of the chemical | medical agent in soil is 0.2 m / day-20 m / day as an actual flow rate. The higher the moving speed of the drug is, the higher the moving effect of the pollutant is. However, the higher the moving speed is, the larger the recovery amount is.

  As mentioned above, although this invention was demonstrated, this invention is not limited to said embodiment. For example, in the embodiment, the removal of soil pollutants under the existing structure 8 has been described, but the place where the removal is performed is not limited, for example, the ruins of buildings such as factories and warehouses where the pollutants were handled, The present invention can be suitably applied to a waste disposal site or the like.

  Hereinafter, the effects of the present invention will be verified using examples. In addition, this invention is not limited to a following example.

[Evaluation of drug mobility in the horizontal direction]
(Comparative Example 1)
As shown in FIG. 17, a ground containing a layer 80 of sand 80 cm (5 cm × 16) in the depth direction and 70 cm (5 cm × 14) in the lateral direction is used as a model to inject and collect a liquid containing a drug. Then, a diffusion simulation was performed on how the drug moved. The ground is provided with an upper inlet 22e and a lower inlet 24e assuming an injection well, and an upper pumping (recovery) inlet 42e and a lower pumping (recovery) 44e assuming a pumping (recovery) well. : 2.1 × 10 ⁻³ cm / sec, head in injection well: +3.0 m, head in pumping (recovery) well: −3.0 m (note that head 1 m = 0.1 kgf / cm ² ) . Moreover, the used sand is K = 2.122 * 10 < ^-8 > m < ² >, n = 0.37.

In the above diffusion simulation, no injection is performed from the upper injection port, and an aqueous solution containing 0.1% by mass of surfactant and 5.0% by mass of foaming agent is supplied from the lower injection port at 40 L / min. Injected. In addition, no pumping was performed from the upper pumping port, and pumping was performed from the lower pumping port under the above conditions.
The chemical | medical agent was inject | poured on said conditions, the chemical | medical agent density | concentration in the soil 24 hours after was measured, and it plotted in FIG.

( Reference Example 1)
In the diffusion simulation, an aqueous solution containing 0.05% by mass of a surfactant and 2.5% by mass of an effervescent drug was injected at 40 L / min from both the upper and lower injection ports. In addition, water was pumped under the above conditions at both the upper pumping port and the lower pumping port.
The drug was injected under the above conditions, and the drug concentration in the soil after 24 hours was measured and plotted in FIG.
FIG. 19 shows the diffusion under the condition that the water permeability is reduced to ½ by the foaming agent.

(Example 1 )
In the diffusion simulation, a 0.1% by mass aqueous surfactant solution was injected at 40 L / min from the upper stage inlet. Moreover, 5.0 mass% foaming chemical | medical agent aqueous solution (sodium percarbonate) was inject | poured from the lower stage injection port at 40 L / min. In addition, water was pumped under the above conditions at both the upper pumping port and the lower pumping port.
The drug was injected under the above conditions, and the drug concentration in the soil after 24 hours was measured and plotted in FIG.
From FIG. 20, it can be seen that the drug from the upper inlet is easily diffused, but the diffusion of the drug from the lower inlet is not changed.

It is a schematic block diagram which shows the removal method of the contaminant of this invention. (A) is a schematic block diagram which shows the outer side in an example of the injection well which concerns on 1st embodiment of this invention, (B) is a schematic block diagram which shows the inner side of an injection well, (C) is a schematic block diagram of this invention. It is a schematic block diagram which shows the outer side in an example of the collection | recovery well which concerns on 1st embodiment, (D) is a schematic block diagram which shows the inner side of a collection | recovery well. It is the schematic for demonstrating the effect | action in the soil of a bubble and surfactant. It is a schematic block diagram which shows the depth of the depth direction of an upper stage inlet, a lower stage inlet, an upper stage collection port, and a lower stage collection port. It is a figure which shows typically the injection well which concerns on 2nd embodiment of this invention. (A) is a figure which shows the state which the packer of the injection well which concerns on 2nd embodiment of this invention expanded, (B) is a figure of the state which the packer contracted. (A) is the elements on larger scale which expanded the A section of Drawing 6 (A), and (B) is a sectional view which met the BB line of (A). (A) is the elements on larger scale which expanded the principal part (part corresponding to Drawing 7 (A)) of the disk part of the first modification, and (B) is along the BB line of (A). FIG. (A) is the elements on larger scale which expanded the principal part (part corresponding to FIG. 7 (A)) of the disc part of a 2nd modification, (B) is along the BB line of (A). FIG. It is a perspective view which shows the packer of a modification. It is a front view which shows typically the principal part of the packer of a modification. It is explanatory drawing explaining the connection of an adjustment rod and a connection rod to (1)-(3) in order. (A) is a perspective view which shows the other example of the connection part of an adjustment rod and a connection rod, (B) and (C) are explanatory drawings explaining connection of an adjustment rod and a connection rod in order. It is a perspective view which shows the packer of the modification in a collection | recovery well. It is a front view which shows typically the principal part of the packer of the modification in a recovery well. It is a figure which shows typically the collection | recovery well which concerns on 3rd embodiment of this invention. It is a schematic sectional drawing which shows the two-dimensional soil tank test apparatus used for the Example. 5 is a graph plotting the drug concentration in soil in Comparative Example 1. 2 is a graph plotting drug concentrations in soil in Example 1. FIG. It is the graph which plotted the chemical | medical agent density | concentration in the soil in Example 2. FIG.

Explanation of symbols

2 Injection well 4 Recovery well 6 Pollutant existence area 8 Existing structure 10 Treatment tank 12 Chemical injection water tank 20 Casing pipe 20b Casing pipe 22 Upper injection port 22b Upper injection port 22e Upper injection port 24 Lower injection port 24b Lower injection port 24e Lower inlet 30 Sealing material 30b Sealing material 32 Packer 34 Packer piping 34b Lower packer piping 34c Upper packer piping 36 Packer 36d Packer 38 Packer piping 38b Packer piping 38d Packer piping 40 Casing pipe 40d Casing pipe 42 Upper stage recovery Port 42d Upper stage recovery port 42e Upper stage pumping (recovery) port 44 Lower stage recovery port 44d Lower stage recovery port 44e Lower stage pumping (recovery) port 80 Sand layer 102 Soil particle 106 Pollutant 108 Bubble 110 Surfactant 112 Foaming agent 212 Packer -Bag 213 Concave 214 Disc 214A Peripheral wall 215 Hole 216 Disc 218 Disc 219 Disc 220 Filter layer 220b Filter layer 222 Upper injection hole 222b Upper injection hole 224 Upper injection pipe 224b Upper injection pipe 226 Pipe injection hole 226b Pipe injection hole 240 Filter layer 240b Filter layer 242 Lower injection hole 242b Lower injection hole 244 Lower injection pipe 244b Lower injection pipe 246 Pipe injection hole 246b Pipe injection hole 260 Ball 262 Insertion part 263 Hole 313 Concave part 314 Disc part 314A Peripheral wall 320b Packer 322b Packer 324b Packer 326b Packer 360b Packer 362b Packer 370 Convex part 372 Insertion part 413 Concave part 414 Disc part 414A Peripheral wall 415 Hole 420 Filter layer 422 upper recovery hole 422d upper recovery hole 424 upper recovery pipe 424d upper recovery pipe 426 pipe recovery hole 426d pumping pump 440 filter layer 440d filter layer 442 lower recovery hole 444d lower recovery hole 444 lower Recovery pipe 444d Lower recovery pipe 446 Pipe recovery hole 446d Pumping pump 460 Wheel 461 Rotating shaft 462 Wheel holding member 600 Rod 602 Male thread 610 Connecting rod 620 Adjustment rod 629 Adjustment lower recovery pipe 632 Flange 644b Lower recovery pipe 650 High nut 660 Sleeve tube 660A Perimeter wall 661 Bolt 662 Female screw hole W Groundwater level

Claims (5)

An injection well installation step of providing an injection well having two or more inlets including at least an upper inlet and a lower inlet at one end of a pollutant existing region in the soil;
A recovery well installation step of providing a recovery well having two or more recovery ports including at least an upper recovery port and a lower recovery port at the other end of the contaminant presence region;
A liquid containing a medicine is injected from two or more inlets including the upper inlet and the lower inlet, and a liquid containing a drug is recovered from two or more outlets including the upper and lower outlets. And a pollutant recovery step of recovering the pollutant from at least one recovery port selected from the upper recovery port and the lower recovery port;
Have
The pollutant is at least one selected from mineral oil, volatile organochlorine compounds and heavy metals,
In the pollutant recovery step, a liquid containing a surfactant and not containing an effervescent drug is injected from the upper inlet of the injection well, and an effervescent drug is added as the drug from the lower inlet. A method for removing contaminants comprising injecting a liquid containing no surfactant .   In the injection well, the depth at which the lower injection port is provided is set to be deeper than the contaminant existing region, and the depth at which the lower recovery port is provided in the recovery well overlaps the depth at which the lower injection port is provided. The pollutant removal method according to claim 1, wherein:   In the injection well, the depth at which the upper stage inlet is provided is the depth where the concentration of the contaminant is the highest, and the depth in which the upper stage inlet is provided in the recovery well is the depth at which the groundwater level exists. The method for removing a pollutant according to claim 1 or 2.   The method for removing contaminants according to claim 3, wherein the upper recovery port in the recovery well is movable in the depth direction.   The contaminant removal method according to claim 3, wherein an upper stage inlet in the injection well is movable in a depth direction.