JP2019048280A - Purification method - Google Patents

Abstract

It is possible to purify contaminated soil at different depths in one plant. A step of injecting an injection solution to which a first indicator is added from one plant into a first contaminated soil in a first area and a second contaminated soil in a second area; From the plant, the injection liquid to which the second indicator agent is added has a third contaminated soil at a different depth from the second contaminated soil in the second area, and a different depth from the first contaminated soil in the first area. And a step of injecting into the fourth contaminated soil or the third contaminated soil and the fifth contaminated soil in the third area. [Selection] Figure 1

Description

  The present invention relates to a purification method for purifying contaminated soil.

  Patent Document 1 discloses a soil purification method that purifies contaminated soil using microorganisms. In this soil purification method, a nitrate solution, which is a nutrient for microorganisms, is injected into the contaminated soil, and the nitrate concentration is determined by measuring the concentration of nitrate in the groundwater of the contaminated soil. The contaminated soil is purified by controlling the amount of injection.

  On the other hand, there is a soil purification method that purifies contaminated soil by injecting into the contaminated soil an injection solution to which a purification agent, an activator, and an indicator such as a fluorescent paint are added. In this soil purification method, an injection solution containing a purification agent, an activator, and an indicator is injected into the contaminated soil, and the concentration of the indicator in the groundwater of the underground soil is measured to measure The concentration of the purifying agent and the activator is estimated, and the contaminated soil is purified by controlling the injection amount of the injected liquid based on this estimation.

  However, when using this soil remediation method to remediate contaminated soil at different depths, the concentration of the purifier or activator must be managed for each contaminated soil at different depths. Different types of indicators must be used for each soil. And since the plant which produces | generates an injection liquid is needed for every kind of index agent to be used, many installation expenses will start.

JP 2005-305282 A

  This invention considers the fact concerned, and makes it a subject to make it possible to purify the contaminated soil in different depths by one plant.

  The invention of the first aspect is a step of injecting, from one plant, an injection solution to which the first indicator is added to the first contaminated soil in the first area and the second contaminated soil in the second area; A third contaminated soil at a different depth from the second contaminated soil in the second area, and an infused liquid to which the second indicator agent is added from one plant, and the first contaminated soil in the first area And a step of pouring into the fourth contaminated soil at a different depth or into the third contaminated soil and the fifth contaminated soil in the third area.

  In the invention of the first aspect, contaminated soil (first to fifth contaminated soils) at different depths can be purified in one plant.

  The invention of the second aspect is the purification method of the first aspect, in the soaking period of the injection solution of the first contaminated soil and the second contaminated soil into which the injection solution to which the first indicator agent has been added is injected, An injection solution to which the second indicator is added is injected into the third contaminated soil and the fourth contaminated soil, or into the third contaminated soil and the fifth contaminated soil.

  In the invention of the second aspect, during the soaking period of the injected solution of the first contaminated soil and the second contaminated soil injected with the first injected solution, the third contaminated soil and the fourth contaminated soil, or the third contaminated soil. The plant can be operated efficiently by injecting the second injection liquid into the fifth contaminated soil.

  The invention of the third aspect is a first method in which an injection solution to which a first indicator is added is injected from one plant into the first contaminated soil in the first area and the second contaminated soil in the second area. And a third contaminated soil at a different depth from the second contaminated soil in the second area, and a fifth contaminated in the third area. A second step of injecting into the soil, and from the one plant, the infused solution to which the third indicator is added, the sixth contaminated soil at a different depth from the fifth contaminated soil in the third area, and And a third step of pouring into the fourth contaminated soil at a different depth from the first contaminated soil in the first area.

  In the invention of the third aspect, contaminated soil (first to sixth contaminated soils) at different depths can be purified by one plant. Further, the period in which the second step is performed is set as a soaking period of the injected solution in the first contaminated soil and the second contaminated soil in which the injection solution is injected in the first step, and the period in which the third step is performed is the second period. A plant can be efficiently operated by setting it as the immersion period of the injection liquid of the 3rd contaminated soil and the 5th contaminated soil which injected the injection liquid in the process.

  Since this invention was set as the said structure, the contaminated soil in a different depth can be purified in one plant.

It is front sectional drawing which shows the contaminated soil purification system which concerns on 1st Embodiment of this invention. It is front sectional drawing which shows the contaminated soil purification system which concerns on 1st Embodiment of this invention. It is a top view showing the impermeable wall concerning a 1st embodiment of the present invention. FIG. 4A and FIG. 4B are front views schematically showing a first area and a second area according to the first embodiment of the present invention. It is front sectional drawing which shows the contaminated soil purification system which concerns on 2nd Embodiment of this invention. It is front sectional drawing which shows the contaminated soil purification system which concerns on 2nd Embodiment of this invention. It is front sectional drawing which shows the contaminated soil purification system which concerns on 2nd Embodiment of this invention. It is a top view showing the impermeable wall concerning a 2nd embodiment of the present invention. FIG. 9A, FIG. 9B, and FIG. 9C are front views schematically showing the first area, the second area, and the third area according to the second embodiment of the present invention. FIG. 10A and FIG. 10B are front sectional views showing variations of the water injection well and the pumping well according to the first and second embodiments of the present invention. Fig.11 (a) and FIG.11 (b) are front sectional drawings which show the variation of the water injection well and pumping well which concern on 1st and 2nd embodiment of this invention. FIGS. 12A and 12B are front sectional views showing variations of the observation well according to the first and second embodiments of the present invention.

<First Embodiment>
In the purification method of the first embodiment, two areas (first area 14) formed by dividing the ground 12 by the contaminated soil purification system 10 shown in the front sectional view of FIG. 1 and the front sectional view of FIG. 2. Two contaminated soils present at different heights in the second area 16) (first contaminated soil 36 and fourth contaminated soil 42 in the first area 14, second contaminated soil 38 and third in the second area 16). The contaminated soil 40) is purified.

[Overall configuration of contaminated soil purification system]
The contaminated soil purification system 10 includes pumping wells 18A, 18B, 18C, 18D, water injection wells 20A, 20B, 20C, 20D, observation wells 22A, 22B, 22C, 22D, and a water shielding wall 24, which are constructed on the ground 12. The plant 26 and measuring devices 28A and 28B constructed on the ground surface 108 of the ground 12 are configured.

  The plant 26 passes from the water injection well 20A through the ground 12 to the pumping well 18A, from the water injection well 20B through the ground 12 to the pumping well 18B, from the water injection well 20C through the ground 12 to the pumping well 18C, or from the water injection well 20D. The groundwater is circulated from the ground through the ground 12 to the pumping well 18D. The measuring device 28A analyzes the groundwater collected from the observation wells 22A and 22B, and the measuring device 28B analyzes the groundwater collected from the observation wells 22C and 22D.

[Impermeable wall]
As shown in the plan view of FIG. 3, the water-impervious wall 24 surrounds the first area 14 and the second area 16 that are adjacent to each other and become a purification target area of the ground 12 in a plan view. It has water shielding walls 24A, 24B, 24C, 24D, 24E, 24F, and 24G made of steel sheet piles (sheet pile) (in FIG. 3, pumping wells 18A to 18D, water injection well 20A) To 20D, observation wells 22A to 22D, and measuring devices 28A and 28B are not shown). That is, the water shielding walls 24A, 24D, 24F, and 24C are disposed so as to surround the first area 14, and the water shielding walls 24B, 24E, 24G, and 24D are disposed so as to surround the second area 16. Accordingly, the flow of groundwater between the inside and outside of the first area 14 and between the inside and outside of the second area 16 is blocked.

[Contaminated soil]
The ground 12 includes aquifers 30 and 32 through which groundwater flows and an impermeable layer 34 through which groundwater does not flow. The aquifer 30 is formed in the upper layer portion of the ground 12 located above the impermeable layer 34, and the aquifer 32 is formed in the lower layer portion of the ground 12 located below the impermeable layer 34.

  The first contaminated soil 36 exists at a shallow depth (aquifer 30) of the ground 12 in the first area 14, and a second contamination is present at a deep depth (aquifer 32) of the ground 12 in the second area 16. The soil 38 is present, the ground 12 in the second area 16 is shallow, the third contaminated soil 40 is present at a depth different from the second contaminated soil 38 (aquifer 30), and the ground 12 in the first area 14 The fourth contaminated soil 42 exists at a deep depth (aquifer 32) different from the first contaminated soil 36.

  The first contaminated soil 36, the second contaminated soil 38, the third contaminated soil 40, and the fourth contaminated soil 42 are surrounded by the water shielding wall 24, so that the pollutants are in the first area 14 and the second area 16. Outflow to the outside is suppressed.

  The first polluted soil 36, the second polluted soil 38, the third polluted soil 40, and the fourth polluted soil 42 are equal to or higher than a reference value (for example, a value determined for each type of pollutant) in the ground 12. It is an included part. “Contaminants” is a concept that includes tetrachloroethylene, trichloroethylene, cis-1,2-dichloroethylene, vinyl chloride monomer, organic substances such as benzene and hexavalent chromium, inorganic compounds such as cyan, and mineral oils such as gasoline and light oil. is there.

  In FIG.1 and FIG.2, the groundwater levels 44 and 46 are illustrated with the dashed-dotted line, and the direction of the flow of the groundwater in the ground 12 is illustrated with the dashed-line arrow. This groundwater flow is generated by injecting an injection solution containing a purifier from the water injection wells 20A, 20B, 20C, and 20D into the ground 12 and further pumping the groundwater from the pumping wells 18A, 18B, 18C, and 18D. It is a flow.

[Pumping well]
The pumping wells 18 </ b> A, 18 </ b> B, 18 </ b> C, and 18 </ b> D are pumping means for pumping groundwater from the ground 12, and the groundwater in the aquifers 30 and 32 is sucked up by the pumping pump P and sent to the plant 26. 1 and 2, the pumping pump P is depicted as being installed outside the pumping wells 18A, 18B, 18C, 18D. This is for explaining the configuration, and the pumping pump P is used for pumping water. It is installed inside the wells 18A, 18B, 18C, 18D.

  Further, the pumping well 18A is disposed between the first contaminated soil 36 and the impermeable wall 24D, and is buried in the ground 12 so that the depth of the lower end is equal to or less than the depth of the first contaminated soil 36, and the pumped well 18D. Is disposed between the second contaminated soil 38 and the impermeable wall 24E and is buried in the ground 12 so that the depth of the lower end is equal to or less than the depth of the second contaminated soil 38. It is disposed between the soil 40 and the impermeable wall 24E and embedded in the ground 12 so that the depth of the lower end is equal to or less than the depth of the third contaminated soil 40. The pumping well 18B has the fourth contaminated soil 42 and the impermeable water. It is arranged between the wall 24D and embedded in the ground 12 so that the depth of the lower end is equal to or less than the depth of the fourth contaminated soil 42.

  1 and 2, for convenience of illustration, one pumping well 18A, 18B, 18C, 18D is shown, but the number and arrangement of the pumping wells 18A, 18B, 18C, 18D may be appropriately determined.

  The pumping well 18A is disposed in the first contaminated soil 36, the pumped well 18D is disposed in the second contaminated soil 38, the pumped well 18C is disposed in the third contaminated soil 40, and the pumped well 18B is disposed in the fourth contaminated soil 42. Also good. Moreover, what is necessary is just to use the conventional method for the concrete method of the pumping by the pumping well 18A, 18B, 18C, 18D.

[Water injection well]
The water injection wells 20A, 20B, 20C, and 20D are injection means for injecting the injection liquid generated in the plant 26 into the ground 12 and send the injection liquid into the ground 12 by a pump or the like (not shown).

  The water injection well 20A is a well disposed between the first contaminated soil 36 and the impermeable wall 24C, and is buried in the ground 12 so that the depth of the lower end is equal to or less than the depth of the first contaminated soil 36. The water injection well 20 </ b> D is a well disposed between the second contaminated soil 38 and the impermeable wall 24 </ b> D, and is buried in the ground 12 so that the lower end depth is equal to or less than the depth of the second contaminated soil 38. 20C is a well arranged between the third contaminated soil 40 and the impermeable wall 24D, embedded in the ground 12 so that the depth of the lower end is equal to or less than the depth of the third contaminated soil 40, and the water injection well 20B is The well is disposed between the fourth contaminated soil 42 and the impermeable wall 24C, and is embedded in the ground 12 so that the depth of the lower end is equal to or less than the depth of the fourth contaminated soil 42.

  1 and 2, for convenience of illustration, one water injection well 20A, 20B, 20C, and 20D is shown, but the number and arrangement of the water injection wells 20A, 20B, 20C, and 20D may be appropriately determined.

  The water injection well 20A is disposed in the first contaminated soil 36, the water injection well 20D is disposed in the second contaminated soil 38, the water injection well 20C is disposed in the third contaminated soil 40, and the water injection well 20B is disposed in the fourth contaminated soil 42. Good. Moreover, what is necessary is just to use the conventional method for the specific method of injection | pouring by the water injection well 20A, 20B, 20C, 20D.

[Observation well]
Various sensors (not shown) are installed in the observation wells 22A, 22B, 22C, and 22D. The concentration of the purifier in the groundwater is measured by these sensors, and the measured value is provided in the plant 26. The electric signal is transmitted to the control unit 48.

  In addition, a pumping pump (not shown) is installed inside the observation wells 22A, 22B, 22C, and 22D, and the groundwater collected from the observation wells 22A, 22B, 22C, and 22D is pumped to the measuring devices 28A and 28B installed on the ground. To do.

  1 and 2, one observation well 22A, 22B, 22C, and 22D is shown for convenience of illustration, but the number and arrangement of the observation wells 22A, 22B, 22C, and 22D may be appropriately determined.

[plant]
The plant 26 is a facility for purifying the groundwater pumped from the pumping wells 18A, 18B, 18C, and 18D, adding a purifying agent and an indexing agent, and returning them to the ground 12. The water treatment device 50 and the heating device 52 And an addition tank 54 and a control unit 48.

[Water treatment equipment]
The water treatment apparatus 50 sends air into the groundwater pumped from the pumping wells 18A, 18B, 18C, and 18D, volatilizes volatile contaminants, and purifies the groundwater.

[Heating device]
The warming device 52 warms the groundwater purified by the water treatment device 50 with a heater (not shown) whose temperature is controlled by the control unit 48. By heating the groundwater by the heating device 52, it is possible to promote the growth of decomposing microorganisms that biodegrade the pollutants in the ground 12 or to increase the activity of the decomposing microorganisms.

[Addition tank]
The addition tank 54 adds a purifying agent and an indicator agent (hereinafter referred to as “first indicator agent”) to the groundwater purified by the water treatment device 50 to generate a first injection liquid, or An indicator agent (hereinafter referred to as “second indicator agent”) is added to produce a second injection solution. Specifically, the purifier and the first indicator agent or the second indicator agent are added to the groundwater stored in the addition tank 54 from the charging device (not shown) controlled by the control unit 48 and stirred. A first injection solution or a second injection solution is generated, and the first injection solution or the second injection solution is injected into the ground 12 from the water injection wells 20A, 20B, 20C, and 20D.

  “Purifying agent” is a substance that decomposes pollutants in the ground 12, and examples thereof include “decomposing microorganisms” such as dehalococcides and dehalosulfides that biodegrade pollutants, and contamination. There are "chemical decomposing agents" that chemically decompose substances. Specific examples of the chemical decomposing agent include “reducing agents” such as iron-based slurries, and “oxidizing agents” such as hydrogen peroxide, sulfates, Fenton reagents, permanganic acid, and percarbonates.

  “Decomposing microorganisms” are suitable for the purification of high molecular weight organic pollutants such as tetrachloroethylene, trichloroethylene and vinyl chloride monomer as pollutants, and low concentrations such as cis-1,2-dichloroethylene and hexavalent chromium as pollutants. “Chemical decomposition agents” are suitable for the purification of organic pollutants of molecular weight. In the first embodiment, a decomposing microorganism (dehalococcides) is used as a purification agent.

  The “indicator” is a substance that behaves in the same manner as the purifying agent in the ground 12 and can be easily measured in situ without using a large-scale facility even in a low concentration state. is there. Examples include fluorescent dyes (eosin, uranin, rhodamine, etc.), halogen ions, radioisotopes and the like. In the first embodiment, the first indicator agent is eosin, a fluorescent dye, and the second indicator agent is uranin, a fluorescent dye.

  Here, “showing the same behavior as the purification agent” specifically indicates that the density, viscosity, adsorption / decomposition characteristics, etc. of the indicator agent with respect to the groundwater are comparable to the purification agent. This “same degree” includes not only the case where they are completely matched, but also the degree to which a slight difference that can be measured by a test occurs.

  For this reason, the indicator agent (first indicator agent, second indicator agent) is used as a substance (tracer) for estimating the concentration of the purifier in the ground water of the ground 12. That is, the concentration of the purifier in the ground water of the ground 12 can be estimated by measuring the concentration of the indicator agent.

[Measuring instrument]
As shown in FIGS. 1 and 2, the measuring devices 28A and 28B include headers 56A and 56B and fluorescence measuring devices 58A and 58B.

  The groundwater inside the observation wells 22A, 22B, 22C, and 22D is pumped to a predetermined depth by a pump (not shown) installed inside each well, and fluorescent through the headers 56A and 56B of the measuring devices 28A and 28B. It is sent to the measuring devices 58A and 58B.

  The headers 56A and 56B are collective piping members for collecting a plurality of pipes into one, and ground water pumped from each of the observation wells 22A, 22B, 22C, and 22D by opening and closing solenoid valves and valves (not shown). Of these, it is possible to select which groundwater is sent to the fluorescence measuring devices 58A and 58B.

  The fluorescence measuring devices 58A and 58B measure the intensity of light emitted by the fluorescent dye as an indicator contained in the groundwater sent from the headers 56A and 56B. Specifically, when the excitation light is irradiated from the light source device to the groundwater, the light intensity C of the fluorescence generated by the fluorescent dye contained in the groundwater is measured.

  Then, an estimated concentration X of the purifier (decomposing microorganism) is obtained by the equation (1), where F (C) is the concentration of the fluorescent dye as a function of the light intensity C, and α is the coefficient. The coefficient α is derived from the difference in adsorption / decomposition characteristics measured by carrying out the adsorption / decomposition test for the cleaning agent (decomposing microorganism) and the fluorescent dye, respectively. In addition, although the adsorption / decomposition characteristics of the indicator agent with respect to the groundwater are approximately the same as those of the purifying agent, the difference may be such that the coefficient α can be calculated in this way.

[Control part]
The control unit 48 includes groundwater levels and ground measured by sensors installed in the observation wells 22A, 22B, 22C and 22D, the water injection wells 20A, 20B, 20C and 20D, and the pumping wells 18A, 18B, 18C and 18D. Information such as the internal temperature and the concentration of the purifier in the groundwater is received as an electrical signal. And according to the received information, the water treatment apparatus 50, the heating apparatus 52, the addition tank 54, and the pumping pump P are drive-controlled.

[Measuring method]
In the contaminated soil purification system 10 of the first embodiment, as shown in FIGS. 1 and 2, first, in the addition tank 54, decomposing microorganisms (dehalococcides) as a purification agent are added to the groundwater purified by the water treatment device 50. ) And a fluorescent dye (eosin) as a first indicator agent are added to produce a first injection solution. Alternatively, decomposing microorganisms (dehalococcides) as a purification agent and fluorescent dye (uranin) as a second indicator agent are added to the groundwater purified by the water treatment device 50 to generate a second injection solution. .

  Here, the concentration of the decomposing microorganisms in the injection solution (first injection solution, second injection solution) is made equal to the concentration of the indicator agent (first indicator agent, second indicator agent).

  Next, an injection solution (first injection solution, second injection solution) is injected from the addition tank 54 into the water injection wells 20A, 20B, 20C, and 20D. The injection liquids (first injection liquid and second injection liquid) injected into the water injection wells 20A, 20B, 20C and 20D are groundwater from the pumping wells 18A, 18B, 18C and 18D by the pumping pump P shown in FIGS. Is pumped into the ground 12 at a target speed to diffuse into the ground 12 and diffused to create contaminated soil (first contaminated soil 36, second contaminated soil). It diffuses into the soil 38, the third contaminated soil 40, and the fourth contaminated soil 42).

  At this time, the decomposing microorganisms (dehalococcides) and the indicator agents (first indicator agent, second indicator agent) as the purification agent have the same density, viscosity, adsorption / decomposition characteristics, etc. with respect to the groundwater as the purification agent. Because it is, it spreads at almost the same speed.

  However, the degrading microorganisms (dehalococcides) and the indicator agents (first indicator agent, second indicator agent) as a purification agent have a slight difference in adsorption / decomposition characteristics, so that in the process of diffusing to the ground 12 Difference in concentration in groundwater occurs. For this reason, the concentration of the purifying agent (decomposing microorganism) is assumed to be the estimated concentration X obtained by the equation (1) described above.

  Next, as shown in FIGS. 1 and 2, a pump (not shown) provided in the observation wells 22A, 22B, 22C, and 22D provided at locations away from the water injection wells 20A, 20B, 20C, and 20D. The groundwater inside the observation wells 22A, 22B, 22C and 22D is collected from the water and sent to the fluorescence measuring devices 58A and 58B. Then, by the fluorescence measuring devices 58A and 58B, the light intensity C of the fluorescent dye (eosin, uranin) constituting the indicator agent (first indicator agent, second indicator agent) is measured, and the indicator agent (first indicator agent, The concentration F (C) of the second indicator agent is calculated. Thereby, the concentration of the purifying agent (decomposing microorganism) is obtained as the estimated concentration X by the equation (1) described above.

[Purification method]
4 (a) and 4 (b) schematically show the first area 14 and the second area 16 in order to make it easy to understand which contaminated soil is being purified in the purification method of the first embodiment. Is shown. In the purification method of the first embodiment, first, in the first step, as shown in FIGS. 1 and 4 (a), the first injection liquid to which the first indicator agent is added is injected from one plant 26. It is injected into the wells 20A and 20D (arrows 60 and 62), and injected into the first contaminated soil 36 in the first area 14 and the second contaminated soil 38 in the second area 16 and diffused.

  In the first step, the groundwater inside the observation wells 22A and 22D is collected and sent to the measuring devices 28A and 28B, and the fluorescent dyes (eosin) constituting the first indicator agent are measured by the fluorescence measuring devices 58A and 58B. The light intensity C is measured. Further, the concentration F (C) of the first indicator agent is calculated from the measured light intensity C, and the estimated concentration X of the purifier (decomposing microorganism) is obtained from the concentration F (C) of the first indicator agent. Based on the estimated concentration X of the purification agent (decomposing microorganism), the amount of the first injection solution injected into the water injection wells 20A and 20D is controlled to purify the first contaminated soil 36 and the second contaminated soil 38. Do.

  That is, in the first step, as shown in FIG. 4A, the first injection solution to which the first indicator is added is transferred from one plant 26 to the first contaminated soil 36 and the second contaminated soil 38. inject.

  Next, in a 2nd process, as shown in FIG.2 and FIG.4 (b), the 2nd injection liquid to which the 2nd indicator was added from one plant 26 is inject | poured into the water injection wells 20C and 20B ( Arrows 66 and 64), injecting and diffusing into the third contaminated soil 40 in the second area 16 and the fourth contaminated soil 42 in the first area 14.

  In the second step, the groundwater inside the observation wells 22C and 22B is collected and sent to the measuring devices 28B and 28A, and the fluorescent dyes (uranin) constituting the second indicator agent are obtained by the fluorescence measuring devices 58B and 58A. The light intensity C is measured. Further, the concentration F (C) of the second indicator agent is calculated from the measured light intensity C, and the estimated concentration X of the purifier (decomposing microorganism) is obtained from the concentration F (C) of the second indicator agent. Based on the estimated concentration X of the purification agent (decomposing microorganism), the amount of the second injection solution injected into the water injection wells 20C and 20B is controlled to purify the third contaminated soil 40 and the fourth contaminated soil 42. Do.

  Further, the second step is performed during the soaking period of the first injection solution of the first contaminated soil 36 and the second contaminated soil 38 in which the first injection solution is injected in the first step. In FIG.2 and FIG.4 (b), the 1st contaminated soil 36 and the 2nd contaminated soil 38 of the state after inject | pouring the 1st injection liquid are shown in the 1st contaminated soil (36) and the 2nd contaminated soil (38). It is said.

  That is, in the second step, as shown in FIG. 4 (b), the second injection liquid to which the second indicator is added from one plant 26 is transferred to the third contaminated soil 40 and the second contaminated soil 42. inject.

[Action / Effect]
In the purification method of the first embodiment, as shown in FIGS. 1 and 2, at different depths, such as the first contaminated soil 36 and the fourth contaminated soil 42, and the second contaminated soil 38 and the third contaminated soil 40. A contaminated soil can be purified by one plant 26.

  In the purification method according to the first embodiment, the third contaminated soil 40 and the fourth contaminated soil are immersed in the first infusate period of the first contaminated soil 36 and the second contaminated soil 38 into which the first infused solution is injected. By injecting the second injection solution into the soil 42, the plant can be operated efficiently.

Second Embodiment
As shown in the front sectional view of FIG. 5, the front sectional view of FIG. 6, and the front sectional view of FIG. 7, the second embodiment is divided into three areas (first area 14, Two contaminated soils (the first contaminated soil 36 and the fourth contaminated soil 42 in the first area 14, the second contaminated soil in the second area 16) existing at different heights in the second area 16 and the third area 68, respectively. The soil 38, the third contaminated soil 40, the fifth contaminated soil 70 and the sixth contaminated soil 72) in the third area 68 are purified. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

[Overall configuration of contaminated soil purification system]
Contaminated soil remediation system 74 is constructed in ground 12; pumping wells 18A, 18B, 18C, 18D, 18E, 18F, water injection wells 20A, 20B, 20C, 20D, 20E, 20F, observation wells 22A, 22B, 22C, 22D, 22E, 22F and the impermeable wall 76, and the plant 26 and the measuring devices 28A, 28B, 28C constructed on the ground surface 108 of the ground 12 are configured.

  The plant 26 passes from the water injection well 20A through the ground 12 to the pumping well 18A, from the water injection well 20B through the ground 12 to the pumping well 18B, from the water injection well 20C through the ground 12 to the pumping well 18C, and from the water injection well 20D. Groundwater is circulated through the ground 12 to the pumping well 18D, from the water injection well 20E through the ground 12 to the pumping well 18E, or from the water injection well 20F through the ground 12 to the pumping well 18F. The measuring device 28C analyzes groundwater collected from the observation wells 22E and 22F.

[Impermeable wall]
As shown in the plan view of FIG. 8, the water-impervious wall 76 is a first area 14, a second area 16, and a third area 68 that are adjacent to each other and are areas to be purified of the ground 12 in plan view. 8A, 24B, 24C, 24D, 24E, 24F, 24G, 24H, 24I, and 24J, which are made of steel sheet piles (sheet piles). The pumping wells 18A to 18F, the water injection wells 20A to 20F, the observation wells 22A to 22F, and the measuring devices 28A to 28C are not shown). That is, the impermeable walls 24A, 24D, 24F, 24C are arranged so as to surround the first area 14, and the impermeable walls 24B, 24E, 24G, 24D are arranged so as to surround the second area 16, and the third area 68 is arranged. The water shielding walls 24H, 24I, 24J, and 24E are disposed so as to surround the. Accordingly, the flow of groundwater between the inside and outside of the first area 14, the inside and outside of the second area 16, and the inside and outside of the third area 68 is blocked.

[Contaminated soil]
The fifth contaminated soil 70 exists at a deep depth (aquifer 32) of the ground 12 in the third area 68, and is different from the shallow depth of the ground 12 in the third area 68 (the aquifer). 30) there is a sixth contaminated soil 72.

  The fifth contaminated soil 70 and the sixth contaminated soil 72 are surrounded by the water-impervious wall 76, so that the contaminants are prevented from flowing out of the third area 68.

  The fifth contaminated soil 70 and the sixth contaminated soil 72 are portions of the ground 12 that contain the pollutant more than a reference value (for example, a value determined for each type of pollutant).

  In FIGS. 5, 6, and 7, the groundwater levels 44 and 46 are indicated by alternate long and short dash lines, and the direction of the flow of groundwater in the ground 12 is indicated by dashed arrows. In addition, the flow of this groundwater inject | pours the injection liquid containing a purification agent from the water injection well 20A, 20B, 20C, 20D, 20E, 20F to the ground 12, and also from the pumping well 18A, 18B, 18C, 18D, 18E, 18F It is a flow generated by pumping up groundwater.

[Pumping well]
The pumping wells 18 </ b> E and 18 </ b> F are pumping means for pumping up groundwater from the ground 12, sucking up groundwater in the aquifers 30 and 32 by the pumping pump P and sending it to the plant 26. 6 and 7, the pumping pump P is depicted as being installed outside the pumping wells 18E and 18F. This is for explaining the configuration, and the pumping pump P is used for the pumping wells 18E and 18F. It is installed inside.

  In addition, the pumping well 18E is disposed between the sixth contaminated soil 72 and the impermeable wall 24I and embedded in the ground 12 so that the depth of the lower end is equal to or less than the depth of the sixth contaminated soil 72. Is embedded between the fifth contaminated soil 70 and the impermeable wall 24 </ b> I and embedded in the ground 12 so that the lower end depth is equal to or less than the depth of the fifth contaminated soil 70.

  5, 6, and 7, for convenience of illustration, one pumping well 18 </ b> A, 18 </ b> B, 18 </ b> C, 18 </ b> D, 18 </ b> E, 18 </ b> F is shown, but each of the pumping wells 18 </ b> A, 18 </ b> B, 18 </ b> C, 18 </ b> D, 18 </ b> E, 18 </ b> F is shown. The number and arrangement may be determined as appropriate.

  The pumping well 18E may be disposed in the sixth contaminated soil 72, and the pumped well 18F may be disposed in the fifth contaminated soil 70. Moreover, what is necessary is just to use the conventional method for the concrete method of the pumping by the pumping wells 18E and 18F.

[Water injection well]
The water injection wells 20E and 20F are injection means for injecting the injection liquid generated in the plant 26 into the ground 12, and the injection liquid can be sent into the ground 12 by a pump or the like (not shown).

  The water injection well 20E is a well disposed between the sixth contaminated soil 72 and the impermeable wall 24E, and is buried in the ground 12 so that the depth of the lower end is equal to or less than the depth of the sixth contaminated soil 72. The water injection well 20 </ b> F is a well disposed between the fifth contaminated soil 70 and the impermeable wall 24 </ b> E, and is embedded in the ground 12 so that the depth of the lower end is equal to or less than the depth of the fifth contaminated soil 70.

  5, 6, and 7, one water injection well 20 </ b> E and 20 </ b> F is shown for convenience of illustration, but the number and arrangement of the water injection wells 20 </ b> E and 20 </ b> F may be appropriately determined.

  The water injection well 20E may be disposed in the sixth contaminated soil 72, and the water injection well 20F may be disposed in the fifth contaminated soil 70. Moreover, what is necessary is just to use the conventional method for the specific method of injection | pouring by the water injection wells 20E and 20F.

[Observation well]
Various sensors (not shown) are installed in the observation wells 22E and 22F, and the concentration of the purifier in the groundwater is measured by these sensors, and the measured value is transmitted to the control unit 48 provided in the plant 26. It is transmitted with an electrical signal.

  Moreover, a pumping pump (not shown) is installed inside the observation wells 22E and 22F, and the groundwater collected from the observation wells 22E and 22F is pumped to the measuring device 28C installed on the ground.

  5, 6, and 7, one observation well 22 </ b> E and 22 </ b> F is shown for convenience of illustration, but the number and arrangement of the observation wells 22 </ b> E and 22 </ b> F may be appropriately determined.

[plant]
The plant 26 is a facility for purifying the groundwater pumped from the pumping wells 18A, 18B, 18C, 18D, 18E, and 18F, adding a purifying agent and an indicator agent, and returning them to the ground 12. The water treatment device 50, A heating device 52, an addition tank 54, and a control unit 48 are included.

[Water treatment equipment]
The water treatment device 50 sends air to the groundwater pumped from the pumping wells 18A, 18B, 18C, 18D, 18E, and 18F, and volatilizes volatile pollutants to purify the groundwater.

[Addition tank]
The addition tank 54 adds the purifying agent and the second indicator agent to the groundwater purified by the water treatment device 50 to add the cleaner and the first indicator agent, and adds the cleaner and the second indicator agent. An injection solution is generated, or a purification agent and an indicator agent (hereinafter referred to as “third indicator agent”) are added to generate a third injection solution. Specifically, the purifier and the first indicator agent, the second indicator agent, or the third indicator agent are added to the groundwater stored in the addition tank 54 from the charging device (not shown) controlled by the control unit 48. The first injection solution, the second injection solution, or the third injection solution is generated by adding and stirring, and the first injection solution, the second injection solution, or the third injection solution is added to the water injection wells 20A, 20B, 20C, 20D, and 20E. , 20F is injected into the ground 12. In the second embodiment, the first indicator agent is fluorescent dye eosin, the second indicator agent is fluorescent dye uranin, and the third indicator agent is fluorescent dye rhodamine. Rhodamine is a substance that exhibits the same behavior as the purification agent in the ground 12.

[Measuring instrument]
As shown in FIGS. 5, 6, and 7, the measuring device 28C includes a header 56C and a fluorescence measuring device 58C.

  The groundwater inside the observation wells 22E and 22F is pumped to a predetermined depth by a pump (not shown) installed inside each well, and sent to the fluorescence measuring device 58C via the header 56C of the measuring device 28C.

  The header 56C is a collective piping member for collecting a plurality of pipes into one. By opening and closing a solenoid valve or a valve (not shown), which groundwater is pumped from each of the observation wells 22E and 22F. Whether to send to the fluorescence measuring device 58C can be selected.

  The fluorescence measuring device 58C measures the intensity of light emitted from the fluorescent dye as an indicator contained in the groundwater sent from the header 56C. Specifically, when the excitation light is irradiated from the light source device to the groundwater, the light intensity C of the fluorescence generated by the fluorescent dye contained in the groundwater is measured.

  Then, an estimated concentration X of the purifier (decomposing microorganism) is obtained by the equation (1), where F (C) is the concentration of the fluorescent dye as a function of the light intensity C, and α is the coefficient.

[Control part]
The control unit 48 provides information such as the groundwater level, ground temperature, and the concentration of the purifier in the groundwater measured by the sensors installed in the observation wells 22E and 22F, the water injection wells 20E and 20F, and the pumping wells 18E and 18F. Are received as electrical signals. And according to the received information, the water treatment apparatus 50, the heating apparatus 52, the addition tank 54, and the pumping pump P are drive-controlled.

[Measuring method]
In the contaminated soil purification system 74 of the second embodiment, as shown in FIGS. 5, 6, and 7, first, in the addition tank 54, decomposing microorganisms (dehydrates) as a purification agent are added to the groundwater purified by the water treatment device 50. Halococcides) and a fluorescent dye (eosin) as a first indicator agent are added to produce a first injection solution, a fluorescent dye (uranin) as a second indicator agent is added, and a second injection solution is added Or a fluorescent dye (rhodamine) as a third indicator is added to produce a third injection solution.

  Here, the concentration of decomposing microorganisms in the injection solution (first injection solution, second injection solution, third injection solution) and the concentration of indicator agent (first indicator agent, second indicator agent, third indicator agent) Make equal.

  Next, an injection solution (a first injection solution, a second injection solution, and a third injection solution) is injected from the addition tank 54 to the water injection wells 20A, 20B, 20C, 20D, 20E, and 20F. The injection liquids (first injection liquid, second injection liquid, and third injection liquid) injected into the water injection wells 20A, 20B, 20C, 20D, 20E, and 20F are the pumps P shown in FIGS. Pumps groundwater from pumping wells 18A, 18B, 18C, 18D, 18E, and 18F to generate a groundwater gradient, thereby creating groundwater from the wells 20A, 20B, 20C, 20D, 20E, and 20F. 12 and diffused to diffuse contaminated soil (first contaminated soil 36, second contaminated soil 38, third contaminated soil 40, fourth contaminated soil 42, fifth contaminated soil 70, sixth contaminated soil 72). .

  At this time, the decomposing microorganism (dehalococcides) as the purifying agent and the indicator agent (first indicator agent, second indicator agent, third indicator agent) have the same density, viscosity, adsorption / decomposition characteristics, etc. with respect to groundwater. It spreads at almost equal speed.

  However, since there are slight differences in adsorption / decomposition characteristics between decomposing microorganisms (dehalococcides) and indicator agents (first indicator agent, second indicator agent, third indicator agent) as purification agents, the ground 12 In the process of diffusing, the concentration in the groundwater is different. For this reason, the density | concentration of a purifier (decomposing microorganisms) is set to the estimated density | concentration X calculated | required by Formula (1).

  Next, as shown in FIGS. 5, 6, and 7, observation wells 22 </ b> A, 22 </ b> B, 22 </ b> C, 22 </ b> D, 22 </ b> E, 22 </ b> F provided at locations away from the water injection wells 20 </ b> A, 20 </ b> B, 20 </ b> C, 20 </ b> D, 20 </ b> E, 20 </ b> F. The groundwater inside the observation wells 22A, 22B, 22C, 22D, 22E, and 22F is collected from a pumping pump (not shown) provided inside the groundwater, and the groundwater is sent to the fluorescence measuring devices 58A, 58B, and 58C. Then, the light intensity C of the fluorescent dyes (eosin, uranin, rhodamine) constituting the indicator agents (first indicator agent, second indicator agent, third indicator agent) is measured by the fluorescence measuring devices 58A, 58B, 58C. The concentration F (C) of the indicator agent (first indicator agent, second indicator agent, third indicator agent) is calculated. Thereby, the density | concentration of a purifier (decomposing microorganisms) is calculated | required as the estimated density | concentration X by Formula (1).

[Purification method]
FIGS. 9A, 9B, and 9C schematically illustrate the first area 14 in order to make it easy to understand which contaminated soil is being purified in the purification method of the second embodiment. The second area 16 and the third area 68 are shown. In the purification method of the second embodiment, first, in the first step, as shown in FIG. 5 and FIG. 9A, the first injection liquid to which the first indicator is added is injected from one plant 26. It is injected into the wells 20A and 20D (arrows 78 and 80) and injected into the first contaminated soil 36 in the first area 14 and the second contaminated soil 38 in the second area 16 and diffused.

  In the first step, the groundwater inside the observation wells 22A and 22D is collected and sent to the measuring devices 28A and 28B, and the fluorescent dyes (eosin) constituting the first indicator agent are measured by the fluorescence measuring devices 58A and 58B. The light intensity C is measured. Further, the concentration F (C) of the first indicator agent is calculated from the measured light intensity C, and the estimated concentration X of the purifier (decomposing microorganism) is obtained from the concentration F (C) of the first indicator agent. Based on the estimated concentration X of the purification agent (decomposing microorganism), the amount of the first injection solution injected into the water injection wells 20A and 20D is controlled to purify the first contaminated soil 36 and the second contaminated soil 38. Do.

  That is, in the first step, as shown in FIG. 9A, the first injection solution to which the first indicator is added is transferred from one plant 26 to the first contaminated soil 36 and the second contaminated soil 38. inject.

  Next, in a 2nd process, as shown in FIG.6 and FIG.9 (b), the 2nd injection liquid to which the 2nd indicator was added from one plant 26 is inject | poured into the water injection wells 20C and 20F ( Arrows 82 and 84) are injected and diffused into the third contaminated soil 40 in the second area 16 and the fifth contaminated soil 70 in the third area 68.

  In the second step, ground water inside the observation wells 22C and 22F is collected and sent to the measuring devices 28B and 28C, and the fluorescent dyes (uranin) constituting the second indicator agent are obtained by the fluorescence measuring devices 58B and 58C. The light intensity C is measured. Further, the concentration F (C) of the second indicator agent is calculated from the measured light intensity C, and the estimated concentration X of the purifier (decomposing microorganism) is obtained from the concentration F (C) of the second indicator agent. Based on the estimated concentration X of the purifying agent (decomposing microorganism), the amount of the second injected liquid injected into the water injection wells 20C and 20F is controlled to purify the third contaminated soil 40 and the fifth contaminated soil 70. Do.

  Further, the second step is performed during the soaking period of the first injection solution of the first contaminated soil 36 and the second contaminated soil 38 in which the first injection solution is injected in the first step. In FIG. 6, FIG. 7, FIG. 9 (b) and FIG. 9 (c), the first contaminated soil 36 and the second contaminated soil 38 in the state after the first infusion solution is injected into the first contaminated soil (36 ) And second contaminated soil (38).

  That is, in the second step, as shown in FIG. 9 (b), the second injection liquid to which the second indicator is added from one plant 26 is transferred to the third contaminated soil 40 and the fifth contaminated soil 70. inject.

  Next, in a 3rd process, as shown in FIG.7 and FIG.9 (c), the 3rd injection liquid to which the 3rd indicator was added from one plant 26 is inject | poured into the water injection wells 20E and 20B ( Arrows 86 and 88), injecting and diffusing into the sixth contaminated soil 72 in the third area 68 and the fourth contaminated soil 42 in the first area 14.

  In the third step, the groundwater inside the observation wells 22E and 22B is collected and sent to the measuring devices 28C and 28A, and the fluorescent dyes (rhodamine) constituting the third indicator agent are obtained by the fluorescence measuring devices 58C and 58A. The light intensity C is measured. Further, the concentration F (C) of the third indicator agent is calculated from the measured light intensity C, and the estimated concentration X of the purifier (decomposing microorganism) is obtained from the concentration F (C) of the third indicator agent. Based on the estimated concentration X of the purifying agent (decomposing microorganism), the amount of the third injected liquid injected into the water injection wells 20E and 20B is controlled to purify the sixth contaminated soil 72 and the fourth contaminated soil 42. Do.

  Further, the third step is performed during the soaking period of the second injection solution of the third contaminated soil 40 and the fifth contaminated soil 70 into which the second injection solution has been injected in the second step. In FIG.7 and FIG.9 (c), the 3rd contaminated soil 40 and the 5th contaminated soil 70 of the state after inject | pouring a 2nd injection liquid are changed into the 3rd contaminated soil (40) and the 5th contaminated soil (70). It is said.

  That is, in the third step, as shown in FIG. 9 (c), the third injection solution to which the third indicator is added from one plant 26 to the sixth contaminated soil 72 and the fourth contaminated soil 42. inject.

[Action / Effect]
In the purification method of the second embodiment, as shown in FIGS. 5, 6 and 7, the first contaminated soil 36 and the fourth contaminated soil 42, the third contaminated soil 40 and the second contaminated soil 38, and the sixth contaminated soil are obtained. Like the soil 72 and the fifth contaminated soil 70, contaminated soil at different depths can be purified by one plant 26.

  Moreover, in the purification method of 2nd Embodiment, the period when a 2nd process is performed is immersed in the 1st injection liquid of the 1st contaminated soil 36 and the 2nd contaminated soil 38 which inject | poured the 1st injection liquid at the 1st process. By setting the period during which the third step is performed as the storage period, the immersion period of the second injection solution of the third contaminated soil 40 and the fifth contaminated soil 70 into which the second injection solution has been injected in the second step, The plant 26 can be operated efficiently.

<Modification>
Variations of the first and second embodiments will be described.

  In 1st and 2nd embodiment, as shown in FIG.1, FIG.2, FIG.5, FIG.6 and FIG. 7, in the ground water purified by the water treatment apparatus 50, a purification | cleaning agent and an indicator agent (1st indicator agent, 1st indicator agent). 2 indicator agent, 3rd indicator agent) and the injection solution (the 1st injection solution, the 2nd injection solution, the 3rd injection solution) produced | generated by adding contaminated soil (1st contaminated soil 36, 2nd contaminated soil 38, Although the example injected into the 3rd contaminated soil 40, the 4th contaminated soil 42, the 5th contaminated soil 70, the 6th contaminated soil 72) was shown, the contaminated soil (the 1st contaminated soil 36, the 2nd contaminated soil 38, the 3rd The injection solution to be injected into the contaminated soil 40, the fourth contaminated soil 42, the fifth contaminated soil 70, and the sixth contaminated soil 72) is generated by adding an activator and an indicator to the groundwater purified by the water treatment device 50. Alternatively, it may be generated by adding a purifier, an activator, and an indicator to the groundwater purified by the water treatment device 50. It may be.

  When adding an activator and an indicator to groundwater purified by the water treatment device 50 to generate an injection solution, an indicator for estimating the concentration of the activator is added, and the water treatment device 50 In the case of generating an infusion by adding a purifier, an activator and an indicator to groundwater purified by the above, an indicator for estimating the concentration of the purifier and an agent for estimating the concentration of the activator An indicator is added.

  The “active agent” refers to a substance that activates biodegradation of degrading microorganisms, and examples include yeast extract substances, hydrogen sustained-release agents (polylactic acid esters), high fatty acid esters, and lactose. Since these activators have the same density, viscosity, adsorption / decomposition characteristics, etc. with respect to the groundwater as the indicator, the concentration is estimated using the indicator as in the case of the purifier in the first and second embodiments. can do.

  In the first and second embodiments, examples have been shown in which the indicator agent is the fluorescent dye eosin, uranin, or rhodamine. However, other fluorescent dyes may be used as the indicator agent, and halogen ions, radioactive substances may be used. An isotope or the like may be used.

  Further, in the first and second embodiments, in the first area 14, the second area 16, and the third area 68, two water injection wells (water injection well 20A and water injection well 20B, water injection well 20C and water injection well 20D, Water well 20E and water well 20F), water well (pump well 18A and water well 18B, water well 18C and water well 18D, water well 18E and water well 18F) and observation well (observation well 22A and water well 22B, water well) 22C and observation well 22D, observation well 22E and observation well 22F), two contaminated soils (first contaminated soil 36 and fourth contaminated soil 42, third contaminated soil 40 and second contaminated soil 38, sixth contaminated soil) Although the example which purified the soil 72 and the 5th contaminated soil 70) was shown, in the 1st area 14, the 2nd area 16, and the 3rd area 68, one each A water injection well, a pumping well and an observation well are provided and two contaminated soils (first contaminated soil 36 and fourth contaminated soil 42, third contaminated soil 40 and second contaminated soil 38, sixth contaminated soil 72 and fifth contaminated soil). The soil 70) may be purified.

  For example, as shown in the front sectional view of FIG. 10A and the front sectional view of FIG. 11A, one water injection well 90 is provided in the first area 14, the second area 16, and the third area 68. Two water well pipes 92A and 92B may be disposed in the water injection well 90.

  In the water injection well 90 located at the depth of the impermeable layer 34, a water blocking material layer 94 is provided. Further, the well steel pipe 92A is disposed so that the tip portion is positioned above the water-stopping material layer 94, and the well steel pipe 92B is disposed so that the tip portion is positioned below the water-stopping material layer 94. Yes. Furthermore, the end portions of the well steel pipes 92A and 92B are perforated pipes that can inject the injected liquid into the ground 12.

  Further, for example, as shown in the front sectional view of FIG. 10B and the front sectional view of FIG. 11B, one pumping well 96 in the first area 14, the second area 16, and the third area 68. And two pumped steel pipes 98A and 98B may be disposed in the pumped well 96.

  In the pumping well 96 located at the depth of the impermeable layer 34, the water blocking material layer 100 is provided. Further, the pumped steel pipe 98 </ b> A is disposed so that the tip portion is positioned above the water blocking material layer 100, and the pumped steel pipe 98 </ b> B is disposed so that the tip portion is positioned below the water blocking material layer 100. Further, the ends of the pumped steel pipes 98A and 98B are perforated pipes capable of pumping groundwater from the ground 12.

  Further, for example, as shown in the front sectional view of FIG. 12A and the front sectional view of FIG. 12B, one observation well 102 is formed in the first area 14, the second area 16, and the third area 68. And two pumped steel pipes 104 </ b> A and 104 </ b> B may be disposed in the observation well 102.

  A water blocking material layer 106 is provided in the observation well 102 located at the depth of the impermeable layer 34. Further, the pumped steel pipe 104 </ b> A is disposed so that the tip end is positioned above the water blocking material layer 106, and the pumped steel pipe 104 </ b> B is disposed so that the tip end is positioned below the water blocking material layer 106. Furthermore, the ends of the pumped steel pipes 104 </ b> A and 104 </ b> B are perforated pipes capable of pumping ground water from the ground 12.

  Although the first and second embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can be implemented in various modes without departing from the gist of the present invention. Of course.

14 First Area 16 Second Area 26 Plant 36 First Contaminated Soil 38 Second Contaminated Soil 40 Third Contaminated Soil 42 Fourth Contaminated Soil 68 Third Area 70 Fifth Contaminated Soil 72 Sixth Contaminated Soil

Claims (3)

A step of injecting, from one plant, an infusion solution to which the first indicator has been added to the first contaminated soil in the first area and the second contaminated soil in the second area;
From one said plant, the 3rd contaminated soil in the depth different from the said 2nd contaminated soil of the said 2nd area, the said 1st contaminated soil of the said 1st area with the injection liquid with which the 2nd indicator was added Injecting into a fourth contaminated soil at a different depth or into the third contaminated soil and a fifth contaminated soil in a third area;
A purification method.   During the soaking period of the injection solution of the first contaminated soil and the second contaminated soil into which the injection solution to which the first indicator agent has been added is poured, or to the third contaminated soil and the fourth contaminated soil, or The purification method according to claim 1, wherein an injection solution to which the second indicator agent is added is injected into the third contaminated soil and the fifth contaminated soil. A first step of injecting, from one plant, an infusion solution to which the first indicator has been added, into the first contaminated soil in the first area and the second contaminated soil in the second area;
From one said plant, the injection solution to which the second indicator is added is transferred to the third contaminated soil at a different depth from the second contaminated soil in the second area and the fifth contaminated soil in the third area. A second step of injecting;
From one said plant, the 6th contaminated soil in the different depth from the said 5th contaminated soil of the said 3rd area, the said 1st contaminated soil of the said 1st area with the injection liquid with which the 3rd indicator was added A third step of injecting into a fourth contaminated soil at a different depth;
A purification method.