JP2007050314A - Method for optimizing how to decontaminate contaminated soil, and infiltration rate measuring instrument used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for optimizing how to decontaminate contaminated soil, in which a suitable condition can easily be decided with high precision when a liquid chemical is injected into contaminated soil at a site to decontaminate the contaminated soil while dispensing with the excavation/movement of the contaminated soil. <P>SOLUTION: The method for optimizing how to decontaminate the contaminated soil comprises: a sample collecting steps of digging the contaminated soil and collecting a sample of the contaminated soil to be decontaminated; an infiltration rate measuring step of packing the collected contaminated soil in a vessel having an injection port and a discharge port of the liquid chemical, injecting the liquid chemical to be used for decontamination in the predetermined pressure from the injection port and measuring a time and a flow rate to be taken since the liquid chemical is injected from the injection port until the injected liquid chemical is discharged from the discharge port to obtain the infiltration rate of the liquid chemical; and an optimization step of deciding at least one of what kind of the liquid chemical is used, how much of the liquid chemical is used and what pressure is applied to the liquid chemical on the basis of the obtained infiltration rate of the liquid chemical. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for optimizing contaminated soil repair for determining in advance conditions for efficiently repairing contaminated soil and an infiltration rate measuring apparatus used therefor.

  In recent years, as a solution to environmental pollution problems, various attempts have been made to remove soil pollutants contaminated with organic substances, etc., and repair the soil. A so-called on-site method has been widely used in which water and nutrients that are useful for microorganisms having a function of decomposing pollutants are injected, and the pollutants are decomposed and removed by the function of the microorganisms.

  However, in the on-site process, the soil must be excavated once and then post-processed to return it to its original state. In addition, although it is effective for the treatment of relatively shallow soil, the treatment of deep portions is difficult due to the time and labor required for excavating and moving the soil.

  For this reason, there is a method in which the chemicals required for treatment are directly injected into the contaminated soil in an amount determined by the amount of the pollutant and diffused into the soil to treat the pollutants present there. Yes. Conventionally, the soil in the field is collected and the soil quality, mainly the porosity, is measured, and the injection interval is determined from the hydraulic conductivity, the gap ratio, etc., and then the soil porosity, filling rate / injection rate and amount of drug used are determined. The method of determining and then injecting the drug at an empirically determined reference rate was common. If the drug injection is carried out on site according to the injection amount and injection rate determined in this way, and it is confirmed that the contaminants diffuse and affect the contaminated soil, the injection rate The measures such as lowering were taken.

The chemicals for treating the pollutants vary depending on the purpose. For example, insoluble agents such as cement that insolubilizes heavy metals, water glass, and other metal-based reducing agents for reductive dechlorination of VOCs. Hydrogen peroxide or the like is selected and injected into the soil. At this time, if the amount of the drug is excessive or the injection speed and pressure are higher than necessary, it will not only be disadvantageous in terms of cost, but it will affect other than the soil to be treated. There is also concern about causing environmentally unfavorable situations such as drug inflow.
Conventionally, when injecting chemicals into contaminated soil locally, in order to confirm whether the target soil has been repaired by standard construction determined in a model manner, the soil is subjected to check boring, excavation, etc. It is a complicated method, such as observing the state of the soil and feeding it back, and it is currently desired that a method for easily optimizing the contaminated soil using chemical injection is desired. .

  The object of the present invention in consideration of the above problems is contamination that can easily and accurately determine suitable conditions for repairing contaminated soil by injecting chemicals in the field without requiring excavation and movement of soil. It is to provide a method for optimizing soil remediation. Another object of the present invention is to provide an infiltration rate measuring device suitably used in the method for optimizing contaminated soil repair of the present invention.

  The method for optimizing a contaminated soil repair according to the present invention includes a sampling step for collecting a contaminated soil sample to be repaired, filling the collected contaminated soil into a container having a chemical solution inlet and a discharge port, The chemical solution used for restoration is injected from the injection port at a predetermined pressure, and the time and flow rate during which the chemical solution that has passed through the contaminated soil filled in the container is discharged from the discharge port is measured to determine the penetration rate of the chemical solution. An osmosis rate measuring step for measuring, and an optimization step for determining at least one of the type of chemical solution supplied to the contaminated soil, the supply amount, and the injection pressure at the time of supply from the penetration rate of the obtained chemical solution It is characterized by that.

In the present invention, the permeation rate measurement step may be performed once to determine a predetermined condition, but the permeation rate measurement step is performed a plurality of times while changing the injection pressure of the chemical solution to determine the optimal injection pressure of the chemical solution. You can also.
Moreover, prior to the permeation rate measurement step, the hydraulic conductivity of the contaminated soil can be measured in advance by performing a pre-water injection step of injecting water into the container filled with the collected contaminated soil. In the case of standard soil, this pre-water injection process can use a hydraulic conductivity determined in a model manner.
Furthermore, in the present invention, depending on the purpose, after the chemical solution injection test by the permeation rate measurement step is performed, a subsequent water injection step can be performed to predict changes in soil permeability due to the chemical solution permeation.

The penetration rate measuring device according to claim 7 of the present invention is provided on a side surface of the container, a container capable of storing the collected soil sample, a chemical liquid injection means for pumping the chemical liquid from the side surface of the container into the container, And a chemical solution collecting means for collecting the chemical solution which is pumped by the chemical solution injection means and permeates the soil sample in the lateral direction, and measures the amount of the chemical solution.
In such a permeation rate measuring device, the chemical solution injection means is connected to the side surface of the container and communicates with the inside of the container, and a pressure tank that pumps the chemical solution applied with pressure to the liquid supply tube, A pressure sensor that is provided in the liquid feeding pipe and detects the pressure of the chemical liquid pumped into the container, the liquid feeding pipe is branched and connected to the side surface of the container, or the inner wall of the container It is a preferred embodiment that a filter is provided between the soil sample and the soil sample, and a gap is formed between the inner wall and the filter.

  According to the method for optimizing contaminated soil repair according to the present invention, it is not necessary to excavate and move the soil. It can be determined with high accuracy.

  The method for optimizing a contaminated soil according to the present invention includes (1) a sample collecting step for collecting a contaminated soil sample to be repaired, and (2) the collected contaminated soil with a chemical injection port and a discharge port. Measure the time and flow rate of the chemical solution that is filled in the container, injects the chemical solution used for repair from the injection port at a predetermined pressure, and the chemical solution that has passed through the contaminated soil filled in the container is discharged from the discharge port. And at least one of the kind of chemical solution supplied to the contaminated soil, the supply amount, and the injection pressure at the time of supply, based on the penetration rate of the obtained chemical solution. And an optimization step for determining.

Hereinafter, the method of the present invention will be described in detail.
FIG. 1 is a flowchart showing an outline of the method of the present invention.
First, in the (1) sample collection step, a sample of contaminated soil is collected and, if desired, a soil survey is performed on site. A chemical injection test is performed using this soil sample [step (A) in the flow]. Based on this data, the mode of chemical movement in the soil sample is plotted [step (B) in the flow], the injection model formula is created and the injection pressure is determined [step (C) in the flow], and the injection interval [Step (D) in the flow] is performed, and final construction conditions are determined [Step (E) in the flow].

  The type of contaminated soil to be treated by applying the method of the present invention is arbitrary, and examples thereof include organic halides such as oils, heavy metals, dioxins, PCBs, and VOCs, acidic substances, and alkaline substances. In addition, the chemical solution used in the restoration method is selected according to the pollutant. In addition to the method of immobilizing the pollutant in the soil by using an insolubilizing agent such as water glass as a chemical to suppress the diffusion of the contamination, Method for treating oil using magnesium, Fenton reagent, etc., hydrogen release agent (for example, HRC: trade name, manufactured by Regenesis), solid hydrogen donor (for example, Amteclean: trade name, manufactured by Matsushita Information Industrial Equipment Co., Ltd.) ), Microbial degradation promoter (for example, EDC: trade name, manufactured by Ecocycle Co., Ltd.), metal-based reducing agent (for example, special iron oxide fine particle-containing slurry or nano iron: trade name: RNIP, manufactured by Toda Kogyo Co., Ltd.), etc. Using a method for treating a volatile organochlorine compound (referred to as VOC as appropriate in this specification), the above-described Fenton reagent, metal-based reducing agent, etc. Pollutants in soil, such as methods for treating organic chlorine compounds such as oxine and PCB, and methods for neutralizing soil containing acidic or alkaline substances using hydrogen peroxide, oxidizing agents, alkaline agents, etc. It can be applied to any method that suppresses the effects on the environment and human body, such as detoxification and neutralization, but considering the effect of the treatment of the drug, a method using a chemical solution containing an undesired drug, solid fine particles, By using the optimization method of the present invention when using a chemical solution containing a thickener and the like and containing a chemical that may change the water permeability of the soil by penetrating into the soil, a remarkable effect is obtained. It can be said that

[(1) Sample collection process]
First, a soil sample to be repaired is collected. As a method for collecting a contaminated soil sample to be repaired, a known method such as soil excavation can be arbitrarily applied. In the sampling process, any well-known drilling device, for example, a geoprobe made by Koa Development Co., Ltd. can be used as long as drilling with a drill or the like and soil sampling at a predetermined depth are possible. Good.
Sampling may be performed at only one place in the processing target area, or may be performed at a plurality of places.

  If it is necessary to specify the contaminated area at the same time, samples may be taken at predetermined intervals, for example, 1 m or less, intervals 5 m, 10 m, 30 m, etc., depending on the accuracy of the survey. It is possible to identify the contaminated area by analyzing the target substance contained in the. The collected soil sample can then be used as a sample in step (2) described later.

[(2) Penetration rate measurement process]
FIG. 2 is a flowchart including the permeation rate measurement step, a water permeability test that is a preliminary test that is optionally performed, and a post-water permeability test that is optionally performed to detect the influence of chemical injection.
In the step (2), (2-1) a step of filling the sampled contaminated soil into a sample container having a chemical solution inlet and a discharge port; and (2-2) a chemical solution used for restoration at a predetermined pressure. And (2-3) measuring the time and flow rate during which the chemical solution that has passed through the contaminated soil filled in the container is discharged from the discharge port to measure the penetration rate of the chemical solution And a step of performing.

  (2-1) When filling a collected soil sample into a container, an average soil sample test can be performed by using a sample obtained by mixing soil collected from a plurality of locations. Moreover, when the location where the contaminated soil exists is detected in advance and more detailed data in the area is to be obtained, or when it is intended to accurately detect horizontal infiltration, as shown in FIG. The cylindrical soil sample collected by boring can be tested by filling a predetermined region of soil into a container as it is. In addition, when the area where the contaminated soil exists extends to a certain depth, as shown in FIG. 4, the container is filled with cylindrical soil (boring core sample) [FIG. 4 (A)] collected by boring. It is more realistic to measure the infiltration rate by using a shape suitable for that shape (Fig. 4 (B)) and filling a container suitable for that shape as a soil sample (Fig. 4 (C)). The penetration state can be observed [FIG. 4D]. In addition, the boring core sample as shown in FIG. 4A is usually collected every 1 m depth.

Here, prior to the step (2-2), it is preferable to perform a step of injecting water instead of a drug, and measure water permeability to know soil properties (such as a void coefficient).
In addition, the soil void coefficient can be predicted by replacing it with a predetermined model. In this case, the step of injecting this water (preliminary water injection test) may not be particularly performed.

First, a chemical solution is injected into a soil sample collected locally, and the travel distance is calculated. Predict the movement distance of the chemical solution at each pressure from the hydraulic conductivity, and obtain basic data in advance on the injection conditions at the site.
FIG. 5 is a model diagram showing an aspect of the permeation rate measuring apparatus 10 that can be used in the method of the present invention.
The permeation rate measuring apparatus 10 includes a chemical tank 12 having a pressurizing means, a water tank 14 for supplying water used for the water permeability test, a container 16 for filling a soil sample, and a chemical recovery tank 18. They are connected by a liquid feed pipe (pipe) 20.

  The container 16 for filling the soil sample is disposed in a state where the cylinder is placed sideways, that is, the end of the cylinder is on both sides, and the liquid is supplied from the container side surface in the horizontal direction. The container 16 includes a pair of filters 22A and 22B that allow liquid to pass through without passing through the soil in the vicinity of the inner side wall of the cylindrical container, and the soil is formed in the space formed by the pair of filters 22A and 22B. Is filled. In the cylindrical container, a gap is provided between the inner wall 24A and the filter 22A on the chemical solution injection side. When measuring the permeation rate of the chemical solution, when the chemical solution is pressurized and supplied from the chemical solution tank 12 to the container 16, the chemical solution first fills the space formed by the filter 22A, the side wall 24A, and the cylindrical outer wall, and then the filter It passes through 22A and penetrates into the soil with uniform pressure from the side of the cylindrical container. From the viewpoint that it is easy to check the state of penetration of the chemical solution in the soil, the cylindrical container is preferably formed of a light transmissive material such as glass or acrylic.

The injection direction of the chemical liquid into the container 16 is set laterally from the side, and injection is started. The injection pressure of the chemical liquid is maintained constant by the compressor 26 and the pressure adjustment valve 30 connected to the chemical liquid tank 12. Pressure adjustment can also be performed by supplying gas from a cylinder filled with pressurized gas. The pressure of the liquid is performed by a pressure detection sensor 32 attached to the pipe 20 connected to the container 16.
It penetrates into the soil filled with the chemical solution, passes through the filter 22B, and is discharged to the chemical solution recovery tank 18 through the liquid feed tube 20 communicated with the side wall 24B. The liquid in the chemical solution recovery tank 18 has a scale for measuring its volume. When the total amount of discharged chemical solution reaches a certain amount, for example, the injection is stopped when the total amount of discharged chemical solution reaches 1000 mL. The time from the start of injection to the stop and the amount discharged at each time are measured.

In this test, Q is the amount of drainage per unit time, i is the hydraulic gradient, and A is the cross-sectional area of the cylindrical case. From these values, the flow velocity v is calculated according to the following equation, and the permeability coefficient k is obtained.
In Q = k · A · i, from Q = A · v, v = k · i. Thus, the hydraulic conductivity k with respect to the said chemical | medical solution peculiar to a soil sample is calculated | required.
The hydraulic conductivity k for the chemical solution used is a constant for the soil when the flow is laminar.

Here, the penetration rate measuring apparatus of the present invention will be described.
The penetration rate measuring device of the present invention is provided with a container 16 capable of storing a collected soil sample, a chemical solution injection means for pumping a chemical solution from the side surface of the container into the container, a side surface of the container, and the chemical solution injection means And a chemical solution collecting means 18 for collecting the chemical solution that has been pumped in and passed through the soil sample in the lateral direction and measures the amount of the chemical solution.

  The chemical solution injection means is connected to the side surface of the container 16 and is provided in the liquid supply tube 20 that communicates with the inside of the container 16, the pressure tank 12 that pumps the chemical solution applied with pressure to the liquid supply tube, and the liquid supply tube. It is preferable to have a pressure sensor 32 that detects the pressure of the chemical liquid fed into the container. Further, from the viewpoint of making the permeation of the chemical solution from the side surface uniform, it is preferable that the liquid supply pipe for supplying the chemical solution to the container is branched and connected to the side surface of the container 16 as shown in FIG. For the same purpose, as shown in FIG. 5, it is also preferable to provide a filter 22A between the inner wall 24A of the container 16 and the soil sample, and to form a gap between the inner wall 24A and the filter 22A.

  From the viewpoint of confirming the state of penetration of the chemical solution, the container 16 is preferably formed of a light transmissive material, for example, glass or a transparent plastic plate. From this observation, it is preferable to select an injection pressure that penetrates uniformly from the viewpoint of a uniform repair process. If the pressure is too high for the sample soil, there will be a locally fast penetration part and a slow penetration part (pulse injection or split injection). There is a concern that a part of it may remain without being preferable. Specifically, as shown in FIG. 4D, there may be a case where there is a space where the chemical solution penetrates quickly locally. Such non-uniformity of infiltration can be mitigated by selecting the injection pressure of the chemical solution, but this is caused by local non-uniformity of the soil, for example, the presence of relatively large gravel. If it is difficult to relax due to pressure and finds a place where water is easily permeable due to unevenness in the soil, a solidifying agent or the like is injected in advance, and after filling the easily permeable space, an injection process is performed. It can also be taken. That is, the optimization method of the present invention can select conditions that are in line with the actual state of the soil.

In this step, it is preferable to measure the specific gravity, viscosity, and the like of the actually used chemical solution after measuring the amount of the active ingredient contained in the chemical solution in advance and determining the supply amount to the chemical solution.
In addition, when using a chemical solution whose viscosity changes with temperature, the chemical solution temperature is also an important factor for penetrability.

As described above with reference to the flowchart of FIG. 2, a water permeability test is performed as necessary before and after the injection test with the chemical solution. When conducting a water permeability test, the valve of the chemical liquid tank 12 is closed and water is supplied from the water tank 14 while maintaining the water pressure constant by the constant water level method, that is, by constantly maintaining the liquid level of the water tank. Otherwise, the water permeability coefficient k is obtained in the same manner as in the test using the chemical solution. By knowing the characteristics of the soil in advance by performing this water permeability test, the liquid supply conditions in the chemical liquid injection test can be predicted to some extent.
In addition, when the soil is uniform and close to a model environment, existing data related to water permeability of known model samples such as Toyoura standard sand and Asama mountain sand can be applied. In such a case, a prior water permeability test using a soil sample is not particularly necessary.

Performing a water permeability test after a chemical solution injection test is useful for predicting changes in physical properties of the soil after the chemical solution injection. In other words, when the chemical solution used contains solids such as metal fine particles, or when it contains a thickener, dispersant, etc., the water permeability characteristics of the soil may change due to their use, and this point is predicted in advance. it can. If this change is large and there is a concern that it may affect the environment, change the type of chemical solution used, or give up the method for remediating contaminated soil by injecting chemical solution, and replace it with another alternative method. It can happen.
The previous or subsequent water permeability test using these waters can be performed by the same method before and after the chemical solution injection test.

[(3) Optimization process]
Thus, by obtaining the permeation rate of the chemical solution, the water permeability coefficient k, etc., the type and supply amount of the chemical solution supplied to the contaminated soil can be optimized. In other words, depending on the amount of contaminated soil, the location where it is present, and the surrounding environment (for example, well use conditions) of the area to be repaired, it should be selected whether the chemical solution penetrates quickly or does not penetrate more than necessary. In other words, it accurately predicts and determines any or all of the types of chemicals to be used, the optimal amount of chemicals that match the volume of contaminated soil and the volume of the existing area, and the injection pressure at the time of supply. It becomes possible to do.
(2) Plotting the injection pressure and movement distance for each chemical solution obtained in the permeation rate measurement process, approximating the injection model, determining the optimal amount of chemical solution for contaminated soil, and securing the necessary movement distance Possible injection pressures can be determined.
In addition, it is possible to predict the optimal time when the chemical solution is injected in the contaminated soil restoration target region in consideration of the factors of the moving distance and time.
Furthermore, since this method can predict the chemical solution, the injection pressure, the boring interval for injection, etc., it has an advantage that optimization considering cost can be performed.

  In addition, by determining the chemical solution to be used, the injection pressure, the boring interval for injection, etc. by the method of the present invention, considering the amount of soil to be treated, the area of the construction site, the device to be used, etc., in advance, It is also possible to predict an accurate cost.

  There is no particular limitation on the method of injecting the chemical solution in the region where the contaminated soil exists under the construction conditions optimized by the method of the present invention. Double tube double packer, double tube strainer, Geoprobe (manufactured by Koa Development Co., Ltd.) Well-known injection methods such as single tube rod injection and triple tube rod injection can be used.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
Example 1
The example of the method of optimizing the kind of chemical | medical solution to be used using the method of this invention is shown.
First, a sample soil is collected and a chemical permeability test is performed to determine the movement speed of the chemical on the ground, and a suitable chemical is selected.

The permeation rate measuring device used is the device shown in the model diagram of FIG.
The chemical tank 12 provided with a pressurizing means is made of stainless steel and has a diameter of 97.6φ and a height of 200 mm. After filling the chemical liquid, it is pressurized from above by a compressor to ensure a predetermined injection pressure. The main body of the container 16 filled with the soil sample is a transparent cylinder made of acrylic resin, and has a diameter of 90 mm and a length of 113 mm. The filter 22A disposed on the inlet side is formed by laminating a lead ball having a diameter of about 1 to 10 mm and a perforated plastic plate, and does not prevent the penetration of the chemical solution, but cannot pass through the soil. The filter 22B disposed on the discharge port side is also produced using a lead ball having a diameter of about 1 to 10 mm.
The chemical tank 12 and the container 16 are connected by a stainless steel pipe 20. The injection pressure was measured using a pressure gauge [Pressure Transducer PA-850 (trade name: manufactured by Nidec Copal Electronics)] 32 and connected to a data logger Thermic Model 2300A (trade name: manufactured by Eto Denki Co., Ltd.). Measure continuously.

In this case, an injection test was performed using three types of chemical solutions having different permeability (a high-penetration type chemical solution A, a normal osmotic type chemical solution B, and a low-penetration type chemical solution C). Details of each chemical solution are as follows.
High penetration type chemical solution A: Dispersion in which α-Fe · Fe ₃ O ₄ composite particles having an average particle size of 70 nm are dispersed in an aqueous solution of 20% by mass of polyaspartic acid sodium salt, 25% by mass Normal osmotic type chemical solution B: Average particle size A dispersion obtained by dispersing 25% by mass of 70 nm α-Fe · Fe ₃ O ₄ composite particles in a 5% by mass aqueous solution of polyaspartic acid sodium salt;
Low penetration type chemical C: Dispersion in which α-Fe · Fe ₃ O ₄ composite particles having an average particle diameter of 70 nm are dispersed in water by 25% by mass

The calculation results of the moving speed of each chemical solution at a predetermined pressure injection are shown in Table 1 below. FIG. 7 is a graph plotting the calculation results. The water permeability coefficient of the sample soil before injecting the chemical solution is in the range of 8 × 10 ⁻³ to 23 × 10 ⁻³ cm / sec, and substantially reproduces the water permeability of the target ground.
From an economic point of view, it is desirable that the influence radius per injection well be wider, and the planned target value is to secure a moving distance of 100 cm or more.

As is apparent from the graphs in Table 1 and FIG. 7, the high penetration type chemical solution A can be expected to have a moving speed of 51.2 cm / hr at an injection pressure of 300 kPa, but the low penetration type chemical solution C, the normal penetration type chemical solution. In B, it was confirmed that the moving speed remained at 4.7 cm / hr and 12.5 cm / hr. For this reason, when the movement distance is taken into consideration, it is understood that it is preferable to select the highly osmotic chemical A as the chemical used.
As the injection conditions in this ground, the injection pressure is 300 kPa, the injection time is 1 hour, and the moving distance is 51.2 cm. In order to achieve the planned target value, the high penetration type chemical solution A is used, and the injection pressure is 600 kPa. By doing this, it can be seen that a moving distance of 100 cm can be secured, and the interval and number of installed wells can be set according to this moving distance.

It is a flowchart which shows the outline | summary of the optimization method of the contaminated soil repair of this invention. It is a flowchart which shows the outline | summary of an osmosis | permeation rate measurement process among the optimization methods of the contaminated soil repair of this invention. It is a model figure which shows the aspect which extract | collects the soil sample applied to an osmosis | permeation rate measuring apparatus from the cylindrical soil (boring core sample) extract | collected by boring in the horizontal direction. (A) to (C) show a mode of preparing a soil sample to be applied to a permeation rate measuring device in order to measure a permeation rate measurement in the depth direction from a cylindrical soil (boring core sample) collected by boring. It is a model figure to show, (D) is a model figure which shows the nonuniformity of the chemical | medical solution osmosis | permeation in a container. It is a model figure which shows the one aspect | mode of the osmosis | permeation rate measuring apparatus used for the optimization method of the contaminated soil repair of this invention. It is a model figure which shows the aspect connected to the container into which the liquid feeding pipe which supplies a chemical | medical solution branches and is filled with a soil sample. 4 is a graph showing the relationship between the injection pressure of the chemical liquid and the movement distance of the chemical liquid in Example 1.

Explanation of symbols

10 Penetration rate measuring device 12 Chemical tank (pressure tank)
16 Container filled with soil sample 18 Discharge tank (chemical solution recovery means)

Claims (10)

A sampling process for collecting contaminated soil samples to be repaired;
The collected contaminated soil is filled into a container having a chemical solution inlet and outlet, the chemical solution used for repair is injected from the inlet at a predetermined pressure, and the chemical solution passes through the contaminated soil filled in the container. A permeation rate measurement process for measuring the time and flow rate during which the liquid is discharged from the discharge port and measuring the permeation rate of the chemical solution;
An optimization method for remediating contaminated soil, comprising: an optimization step for determining at least one of the type of chemical solution supplied to the contaminated soil, the supply amount, and the injection pressure at the time of supply from the penetration rate of the obtained chemical solution.   The method for optimizing a contaminated soil according to claim 1, wherein the permeation rate measurement step is performed a plurality of times while changing the injection pressure of the chemical solution to determine the optimal injection pressure of the chemical solution.   The contaminated soil remediation according to claim 1 or 2, wherein a pre-water injection step of injecting water into the container filled with the collected contaminated soil is performed prior to the infiltration rate measuring step. Optimization method.   The contaminated soil remediation according to claim 1 or 2, wherein the contaminated soil contains a volatile organochlorine compound (VOC) as a contaminant, and the injected chemical is a dispersion of a metal-based reducing agent. Optimization method.   The method for optimizing a contaminated soil according to claim 1 or 2, wherein the contaminated soil contains a volatile organic chlorine compound (VOC) as a contaminant, and a chemical to be injected is a Fenton reagent.   The method for optimizing a contaminated soil according to claim 1 or 2, wherein the contaminated soil contains oil as a contaminant, and a chemical solution to be injected is a Fenton reagent. A container that can store the collected soil sample;
Chemical injection means for pumping the chemical from the side of the container into the container;
An osmotic rate measuring device, comprising: a chemical solution collecting means for collecting a chemical solution which is provided on a side surface of the container and is pumped by the chemical solution injecting means and permeates the soil sample in a lateral direction, and measures the amount of the chemical solution. .   The chemical solution injecting means is connected to a side surface of the container and communicates with the inside of the container, a pressure tank for pumping a chemical solution applied with pressure to the liquid supply tube, and a liquid supply tube. The osmotic velocity measuring device according to claim 7, further comprising a pressure sensor that detects a pressure of the chemical liquid pumped to the surface.   The permeation rate measuring device according to claim 7 or 8, wherein the liquid feeding pipe is branched and connected to a side surface of the container.   The permeation rate measurement according to any one of claims 7 to 9, wherein a filter is provided between the inner wall of the container and a soil sample, and a gap is formed between the inner wall and the filter. apparatus.

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