JP4572761B2 - In-situ containment method and in-situ containment device - Google Patents

Description

  The present invention relates to an in-situ containment method and an in-situ containment device that contain contaminated soil separately from the surroundings, and more particularly to an in-situ containment method and an in-situ containment device in which a water shielding wall is provided so as to surround a contaminated area. More specifically, the present invention relates to an in-situ containment method and an in-situ containment device that purify groundwater flowing out from the inside of the impermeable wall to the surroundings when the groundwater level inside the impermeable wall rises.

  An explanation of the technical method based on the Soil Contamination Countermeasures Law that prevents contaminated soil from eluting harmful substances from the contaminated soil and contaminating groundwater outside the area by containing the contaminated soil in situ (see Non-Patent Document 1 below) )It is described in. On page 111 of the commentary, “Specifically, the extent of contaminated soil and the depth of soil contamination within that range are confirmed by a boring survey, surrounding the extent of soil contamination, A water impervious wall such as steel sheet piles is driven into the impermeable layer to prevent soil contamination from spreading outside the range, and in order to prevent the rainwater from penetrating within the range and affecting the groundwater level inside the containment. In addition, the upper surface of the containment is covered with a material having a water-blocking function, and the upper surface is covered with a concrete layer having a thickness of 10 cm or more, or an asphalt layer having a thickness of 3 cm or more, as in the case of pavement measures. Measures will be taken to cover with soil accordingly. ”“ If an abnormal rise in water level is confirmed inside the containment, take appropriate measures such as lowering the water level due to pumping or reinforcing the water shielding structure. There is a necessity. Has been described as ".

As mentioned above, if the water level rises abnormally in the contaminated area surrounded by the impermeable wall, it overflows the impermeable wall and diffuses the contaminated groundwater, so measures such as lowering the water level due to pumping are necessary. It becomes. In JP-A-2003-53317, an in-situ containment method for constructing a water-impervious wall that reaches an impermeable layer so as to surround a contaminated area and contain contaminated soil in the contaminated area, along the inside of the impermeable wall. It is described that a drainage groove that reaches a predetermined depth is provided and pumping water from the drainage groove prevents the overflow of the contaminated groundwater level from the inside of the impermeable wall.
JP 2003-53317 A Explanation of technical methods for investigation and measures based on the Soil Contamination Countermeasures Law First edition published in September 2003 Supervision: Ministry of the Environment Edition / Issue: Soil Environment Center

  In the said Unexamined-Japanese-Patent No. 2003-53317, the water treatment equipment which purifies the sewage groundwater pumped up with the pump is needed separately. In addition, a pump is essential, which increases equipment costs and power costs.

  An object of the present invention is to provide an in-situ containment method and an in-situ containment device that can prevent the diffusion of contaminated groundwater from a containment area by simple means.

The in-situ containment method according to claim 1 is the in-situ containment method for constructing a water-impervious wall that reaches an impermeable layer or a hardly-permeable layer so as to surround the sewage area and contain the contaminated soil in the contaminated area. In addition, a groundwater outflow portion is provided in which the groundwater inside the impermeable wall flows out of the impermeable wall when the groundwater level inside the impermeable wall rises, and the impermeable wall passes through the groundwater outflow portion. In-situ containment method in which purification means for purifying groundwater flowing out to the outside is provided, and the purification means is disposed higher than the impermeable layer or the hardly permeable layer, wherein the purification means A water collecting channel is provided in the inner area of the impermeable wall to guide the groundwater inside the impermeable wall to the outflow portion of the groundwater, and the groundwater The outflow part is the same as the water collecting channel of the impermeable wall. Le or have it provided lower than,該地sewage outflow section is adapted from low-income recessed downward from the upper end of the shielding waterwall, the purifying means abuts the inner surface of the shielding waterwall And a part of the purification means enters the groundwater outflow portion, and the water collecting channel is disposed so as to contact an end surface of the purification means opposite to the groundwater outflow portion, and the impermeable wall It is provided so that it may circulate continuously along the inner surface .

Situ containment method of 請 Motomeko 2 Oite to claim 1, said population waterways is characterized in that made of water permeable material.

Situ containment method according to claim 3, in claim 1 or 2, wherein the cleaning means is characterized by comprising a treatment agent and water permeable material to remove or detoxify the contaminants in groundwater .

The in-situ containment method according to claim 4 is the in-situ containment method according to claim 3, wherein the purification means includes a container that contains the treatment agent and the water-permeable material, and an inflow portion of groundwater is provided at one end of the container. In addition, an outflow part of the treated groundwater is provided on the other end side.

The in-situ containment method according to claim 5 is the method according to claim 3 or 4, wherein the treatment agent is iron powder, activated carbon, hydrotalcite, rare earth compound, magnesium oxide, alumina, allophane, ion exchange resin, chelate resin, and clay mineral. It is one or a mixture of two or more selected from the group consisting of:

The in-situ containment method according to claim 6 is the method according to any one of claims 3 to 5 , wherein a plurality of the purification means are provided in multiple stages in a direction from the inner region to the outer region of the impermeable wall. The treatment agent for some of the purification means is different from the treatment agent for other purification means.

Situ containment method according to claim 7, in any one of claims 1 to 6, said population waterway, characterized in that the plurality of through holes is formed of perforated pipes provided in the tube wall is there.

The in-situ containment method according to claim 8 is the method according to any one of claims 1 to 7 , wherein the outflow portion communicates the inner region surrounded by the water shielding wall and the outer region of the water shielding wall. In addition, the inflow port is a drain pipe disposed in the inner region.

The in-situ containment method according to claim 9 is characterized in that, in claim 8 , the outer region is a sewer.

The in-situ containment device according to claim 10 , wherein a water shielding wall reaching the impermeable layer or the hardly permeable layer is constructed so as to surround the dirty water area, and the contaminated soil is contained in the contaminated area. In addition, a groundwater outflow portion is provided through which groundwater inside the impermeable wall flows out to the outside of the impermeable wall when the groundwater level inside the impermeable wall rises. A purification means for purifying groundwater flowing out of the impermeable wall is provided, and the purification means is an in-situ containment device disposed higher than the impermeable layer or the hardly permeable layer, wherein the purification The means is provided inside the impermeable wall with respect to the groundwater outflow portion, and a water collecting channel for guiding the groundwater inside the impermeable wall to the groundwater outflow portion is provided in an inner region of the impermeable wall. The outflow portion of the impermeable wall It is provided in the lower than or water collecting route the same level,該地sewage outflow section is adapted from low-income recessed downward from the upper end of the shielding waterwall, the purifying means, among shielding waterwall Provided in contact with the side surface, a part of the purification means has entered the groundwater outflow portion, the water collection channel is disposed in contact with the end surface of the purification means opposite to the groundwater outflow portion, It is provided so that it may circulate continuously along the inner surface of this water-impervious wall .

Situ containment device 請 Motomeko 11, in claim 10, said population waterways is characterized in that made of water permeable material.

  In the in-situ containment method and the in-situ containment device of the present invention, when the groundwater level inside the impermeable wall rises above a predetermined level, the groundwater inside the impermeable wall passes through the groundwater outflow portion provided on the impermeable wall. Although it flows out to the outside of the impermeable wall, since this outflow water is purified by the purification means, contamination outside the impermeable wall is prevented.

  As the purification means of the present invention, those containing a treating agent for removing or decomposing contaminants of groundwater and water-permeable materials such as sand and crushed stone are suitable.

  In the present invention, the purification means includes a container that contains the treatment agent and the water-permeable material, and an inflow portion of groundwater is provided on one end side of the container, and treated groundwater is provided on the other end side. It is preferable that the outflow part is provided. In this case, the flow of groundwater passing through the container is an extruded flow.

  Examples of the treating agent include iron powder, activated carbon, hydrotalcite, rare earth compound, magnesium oxide, alumina, allophane, ion exchange resin, chelate resin, clay mineral and the like. These treatment agents may be used alone or in combination of two or more depending on the type of pollutants in the groundwater.

  In the present invention, a plurality of purification means are provided in multiple stages in the direction from the inner region to the outer region of the water shielding wall, and the treatment agent of at least some of the purification means is different from the treatment agent of other purification means. It is good also as composition which has. By comprising in this way, the multiple types of contaminant in groundwater can be removed or detoxified efficiently, respectively.

  This purification means is provided inside the impermeable wall from the groundwater outflow part.

  Since the water collecting channel for guiding the ground water inside the water shielding wall to the ground water outflow portion is provided in the inner region of the water shielding wall, the ground water in the contaminated area can be collected smoothly.

  This water collecting pipe may be made of a water-permeable material, or may be made of a perforated pipe provided with a plurality of through holes in the pipe wall.

  In the present invention, the groundwater outflow portion is provided at the same level as or lower than the water collecting channel of the impermeable wall.

  In addition, the groundwater outflow portion may be a drain pipe that communicates the inner region and the outer region of the impermeable wall and has an inflow port disposed in the inner region. In this case, the outlet of the drain pipe is preferably connected to a sewer.

  The in-situ containment method and the in-situ containment apparatus of the present invention can be applied even to an artificially constructed one corresponding to an impermeable layer or a hardly permeable layer.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a cross-sectional perspective view showing an area to which the in-situ containment method according to the embodiment is applied, FIG. 2 is a plan view showing the underground structure in this area seen through the soil, and FIG. Fig. 3 (b) is a sectional view taken along the line IIIb-IIIb in Fig. 4, and Fig. 4 is a perspective view in the soil showing the water shielding wall, the purification means and the water collecting channel provided in the soil. FIG.

  As shown in FIG. 3A, the impermeable layer 3 or the hardly permeable layer is present at a predetermined depth from the ground surface 1, and the aquifer 2 is present on the upper side thereof.

  Since the contaminated soil 4 exists in all or a part of this area, the contaminated soil 4 is isolated from the surroundings 5 by the impermeable wall 10 and contained.

  The impermeable wall 10 has a lower end reaching the impermeable layer or the hardly permeable layer 3 and an upper end located near the ground surface 1 higher than the groundwater level 6. The upper end of the impermeable wall 10 may reach the ground surface 1.

  The impermeable wall 10 surrounds the entire circumference of the contaminated soil 4. In this embodiment, the planar view shape is a rectangular frame shape, but is not limited thereto.

  The water-impervious wall 10 can be constructed by applying a number of boreholes in the ground in a continuous row and pouring concrete into it, but may also be formed by driving a water-impervious steel sheet pile.

  As clearly shown in FIG. 4, this impermeable wall 10 is provided with one or a plurality of (three in this embodiment) rectangular groundwater outflow portions 11 each having a low portion recessed downward from the upper end. Yes. The lower edge of the groundwater outflow portion 11 is higher than the groundwater level 6 by a predetermined height (for example, about 0 to 100 cm).

  A purification unit 12 is provided on the inner side (contaminated soil 4 side) than the groundwater outflow unit 11. The purification unit 12 is made of a mixture of a water-permeable material such as sand and crushed stone and a treatment agent that exhibits a purification action by removing or decomposing contaminants such as iron powder and / or activated carbon. In addition, as the treating agent, hydrotalcite, magnesium oxide, alumina, allophane, ion exchange resin, clay mineral, or the like may be used.

  Plate members 13 made of steel sheet piles or the like are disposed on both sides and the lower portion of the purification unit 12. A waterproof concrete wall may be provided instead of the plate material 13.

  The upper surface of the purification unit 12 is preferably positioned higher than the lower edge of the groundwater outflow unit 11 by about 0 to 200 cm. Further, the lower surface of the purification unit 12 is preferably located 50 to 500 cm lower than the lower edge of the groundwater outflow unit 11. Although both side surfaces of the purification unit 12 are flush with the side edge of the groundwater outflow unit 11, the purification unit 12 may be provided wider than that.

  The purification unit 12 is provided so as to contact the inner surface of the water-impervious wall 10. Further, in this embodiment, a part of the purification unit 12 enters the groundwater outflow unit 11.

  The plate 13 preferably extends from 0 to 500 cm above the upper surface of the purification unit 12, and preferably extends from 0 to 500 cm below the lower surface of the purification unit 12. The plate material 13 is in contact with the inner surface of the water shielding wall 10. This abutting portion may be sealed if necessary.

  The plate material 13 covers the entire side surfaces and the lower part of the purification unit 12, and water is prevented from flowing into the purification unit 12 from the side surface and outflowing into the groundwater outflow unit 11 in a short circuit.

  A water collecting channel 14 is provided at a level parallel to the inner surface of the water shielding wall 10 and including the groundwater level 6. The water collecting channel 14 is made of a water permeable material such as sand or crushed stone. The water collecting channel 14 may be a perforated pipe.

  The water collecting channel 14 is disposed so as to be in contact with the end surface of the purification unit 12 opposite to the groundwater outflow unit 11. The water collecting channel 14 is provided so as to continuously circulate along the inner side surface of the impermeable wall 10, but the middle may be partially interrupted. Further, the water collecting channel 14 may be provided in a comb-teeth shape over the entire contaminated area.

  Although not shown in the figure, the ground surface 1 may be covered with asphalt, concrete, a water shielding sheet or the like to prevent underground penetration of rainwater.

  In the containment device configured as described above, the groundwater level inside the impermeable wall 10 is usually equal to or lower than the lower edge of the groundwater outflow portion 11. Will not leak.

  When the groundwater level inside the impermeable wall 10 rises for some reason such as rainfall, the groundwater flows into the purification unit 12 via the water collecting channel 14 or directly, and after being purified by the purification unit 12, the groundwater outflow unit 11 Out to the surroundings 5. This effluent water has been subjected to removal of heavy metals or decomposition or adsorption removal processing of contaminants such as halogenated organic substances in the purification section 12 and does not contaminate the surroundings 5.

  When the pollutant is a volatile organic chlorine compound, covering the ground surface 1 with asphalt or the like prevents (oxygen) from diffusing into the ground and improves the purification efficiency of the compound.

  When the pollutant is a heavy metal, the contaminated soil 4 or the water in the contaminated soil 4 may be brought into contact with air, thereby improving the heavy metal purification treatment efficiency.

FIG. 5 is a plan view of an area where the in-situ containment method according to the reference example is applied, FIG. 6 is an enlarged plan view of the vicinity of the groundwater outflow part in this area, and FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. is there.

In this reference example , a drain pipe 20 having a groundwater inflow port disposed in the inner region is provided so as to communicate the inner region surrounded by the impermeable wall 10 and the outer region.

As shown in FIG. 5, impervious wall 10 of the rectangular frame shape so as to surround the four sides of the contaminated soil (contaminated area) 4 is built. As described above, the impermeable wall 10 has a lower end that reaches the impermeable layer or the hardly permeable layer 3 and an upper end that is located near the ground surface 1 higher than the groundwater level 6. The upper end may reach the ground surface 1. In this embodiment, the outflow portion 11 composed of a low portion recessed downward from the upper end of the impermeable wall 10 is not provided.

Water collecting container 21 is installed in the vicinity of one corner of the inner region of the impervious wall 10. This water collection container 21 is a bottomed cylindrical container, the bottom part is located lower than the groundwater level 6, and the upper part is exposed on the ground surface 1. A lid 21 a is attached to the upper end of the water collection container 21. However, the upper portion of the water collecting container 21 may not be exposed on the ground surface 1.

  One end (groundwater inlet) of the drain pipe 20 is connected to the vicinity of the bottom of the water collection container 21 which is lower than the groundwater level 6. The drain pipe 20 extends from the inner area of the impermeable wall 10 to the outer area of the impermeable wall 10 through the impermeable wall 10. The drain pipe 20 is disposed so as to have a downward slope from the inner region to the outer region of the impermeable wall 10.

The other end of this drainage pipe 20 (outlet) is connected to the sewer through the outer region of the impervious wall 10 (not shown). In addition, when the sewer is arrange | positioned in the height which becomes higher than this drain pipe 20, you may connect the drain pipe 20 and a sewer via a pumping equipment (not shown).

  In the inner region of the impermeable wall 10, a water purification unit 12 </ b> A is installed adjacent to the water collection container 21. As shown in FIG. 6, the water purification unit 12 </ b> A accommodates water-permeable materials such as sand and crushed stone, treatment agents that perform purification action by removing or decomposing contaminants, and these water-permeable materials and treatment agents. And a container 24.

As shown,該収receptor 24 is disposed substantially U-shape so as to surround three sides of the water purification unit 12A, 3 sheets of plate members 24a made of steel sheet piles, etc., 24b, are constructed by 24c. Seals are applied to the joints between the plate members 24a to 24c as necessary. Of the container 24, the side that is not blocked by the plate members 24 a to 24 c is an inflow portion 24 d of groundwater into the container 24. A treated groundwater outlet 24e is provided in the plate 24b that closes the inflow portion 24d and the opposite side. The outflow port 24 e communicates with the inside of the water collection container 21 through a pipe 25. In addition, you may construct the container 24 with a concrete wall instead of the said board | plate materials 24a-24c.

  Each of the plate members 24a to 24c of the container 24 extends from 0 to 500 cm above the groundwater level 6 and preferably extends from 0 to 500 cm below the groundwater level 6. The outlet 24e and the pipe 25 are disposed substantially horizontally at a level including the groundwater level 6.

The yield condition 24, in the direction toward the outlet 24e from the inlet 24d, the layer 22a of the first water permeable material, the first treatment agent layer 23a, the layer 22b of the second water permeable material, a second The treatment agent layer 23b and the third water-permeable material layer 22c are formed in this order in multiple layers.

  Each of the layers 22a to 22c, 23a, and 23b is fully extended from one inner surface to the other inner surface of the plate members 24a and 24c facing each other, and from the inflow portion 24d to the inner surface of the opposite plate member 24b. Filled. Each of the layers 22a to 22c, 23a, and 23b has a lower surface that reaches 50 to 500 cm below the groundwater level 6 and an upper surface that preferably reaches 0 to 200 cm above the groundwater level 6.

Each layer 22 a to 22 c, 23a, but the upper and lower surfaces of 23b and upper and lower sides of each plate 24a~24c are positioned at the same level substantially respectively, each plate 24a~24c are layers 22 a to 22 c, It may extend below the lower surface of 23a, 23b, and may extend above the upper surface of each layer 22a-22c, 23a, 23b.

The first treatment agent layer 23a and the second treatment agent layer 23b are composed of different kinds (or blends) of treatment agents. As described above, examples of the treating agent include iron powder, activated carbon, hydrotalcite, rare earth compound, magnesium oxide, alumina, allophane, ion exchange resin, chelate resin, and clay mineral. The treatment agent is appropriately selected according to the contaminant contained in the groundwater. At this time, as the first and second treatment agent layers 23a and 23b, different kinds of treatment agents may be used alone (without mixing), or two or more kinds of treatment agents may be mixed. May be used.

  The first to third water-permeable material layers 22a to 22c may be made of the same type of water-permeable material, or may be made of different types of water-permeable materials.

By surrounding the three sides of the purification unit 12A of a plate material 24a-24c, the water is prevented from flowing out to short to the water collecting container 21 flows into the purifier 12A. If necessary, a plate material may also be provided on the bottom surface and top surface of the purification unit 12A to prevent water from flowing into the purification unit 12A from the bottom surface and top surface of the purification unit 12A.

The level containing the groundwater level 6, the water collecting route 14A is provided in a comb-like across the contaminated areas of the inner impervious wall 10. In this embodiment as well, the water collecting channel 14A is made of a water-permeable material such as sand or crushed stone, but may be constituted by a perforated pipe or the like.

Specifically , as shown in FIG. 5, the main water collection channel 14 a is extended so as to cross the square contaminated area 4 surrounded by the water shielding wall 10 diagonally from the corner portion where the water collection container 21 is installed. ing. The proximal end side of the main water collecting channel 14a is disposed so as to be in contact with the end surface of the first water-permeable material layer 22a facing the inflow portion 24d of the water purification unit 12A.

Branch water collecting channels 14b extend from a plurality of locations along the extending direction of the main water collecting channel 14a in parallel with each side in two orthogonal directions of the water shielding wall 10 (vertical direction and horizontal direction in FIG. 5). Yes. (Note that six branch catchment channels 14b extend from the main catchment channel 14a at intervals in the left-right direction and the up-down direction in FIG. 5).

Although not shown, the earth Table 1 asphalt, concrete, covered by water barrier sheet or the like, so as to prevent underground infiltration of rainwater.

  Even in the containment device configured as described above, when the groundwater level 6 inside the impermeable wall 10 rises for some reason such as rainfall, the groundwater flows into the purification unit 12A via the water collecting channel 14A or directly. At this time, groundwater flows into the container 24 from the water collecting channel 14A through the inflow portion 24d, and the first water-permeable material layer 22a, the first treatment agent layer 23a, and the second water-permeable material By sequentially passing through the layer 22b, the second treatment agent layer 23b, and the third water-permeable material layer 22c, contaminants in the groundwater are removed or detoxified.

  This groundwater is purified by the purification section 12A, and then flows out from the outlet 24e to the sewer flowing through the outer region of the impermeable wall 10 through the pipe 25, the water collection container 21 and the drain pipe 20. This effluent has been subjected to the decomposition or adsorption removal processing of the pollutant in the purification unit 12A, and does not contaminate the sewer.

In this reference example , since the water collecting channel 14 </ b> A is disposed over substantially the entire contaminated area 4, groundwater can be collected evenly over substantially the entire contaminated area 4 .

In the reference example of FIG. 8, (the inlet of the discharge pipe 20) the water collecting container 21 is disposed near the center of the contaminated area 4.

Also in FIG. 8, the water collecting route 14B is disposed over substantially the entire contaminated area 4.

Substantially U-shaped current waterways 14c along the inner surface of the impervious wall 10 surrounding the dirty three sides of the dye region 4 is extended, slightly smaller generally U-shaped current waterway 14d is extended on the inside, on the inside A substantially U-shaped water collecting channel 14e that is a little smaller is extended, and a substantially U-shaped water collecting channel 14f that is a little smaller is extended inside. In addition, a water collecting channel 14g is extended along the inner side surface of the remaining one water-impervious wall 10 so as to short-circuit the vicinity of both ends of the substantially U-shaped water collecting channels 14c to 14f, and the substantially U-shaped water collecting channel 14c to 14f. A water collecting channel 14h is extended toward the center of the contaminated area 4 so as to cross the vicinity of the intermediate portion in the extending direction of the water collecting channels 14c to 14f.

  A water collection container 21 and a purification unit 12A are arranged inside the innermost substantially U-shaped water collection channel 14f. The end of the water collecting channel 14h is connected to the purification unit 12A.

Even in this reference example , since the water collecting channel 14B is disposed over substantially the entire contaminated area 4, groundwater can be collected evenly over substantially the entire contaminated area 4.

Form of implementation described above are only an example of the present invention, the present invention is not limited to the above embodiment.

It is a perspective view which shows the area where the in-situ containment construction method which concerns on embodiment was applied. It is a top view which shows the underground structure of this area. 3A is a cross-sectional view taken along line IIIa-IIIa in FIG. 1, and FIG. 3B is a cross-sectional view taken along line IIIb-IIIb in FIG. It is a perspective view which shows a water-impervious wall, a purification means, and a water collection channel. It is a top view of the area where the in-situ containment construction method concerning a reference example was applied. FIG. 6 is an enlarged plan view of the vicinity of a groundwater outflow portion in the area of FIG. It is sectional drawing which follows the VII-VII line of FIG. It is a perspective view which shows the area where the in-situ containment construction method which concerns on another reference example was applied.

DESCRIPTION OF SYMBOLS 10 Impermeable wall 11 Groundwater outflow part 12,12A Purification | purification part 13 Board | plate material 14,14A, 14B Catchment path 20 Drain pipe 21 Catchment container 22a-22c Permeable material layer 23a-23b Treatment agent layer 24 Container 24d Inflow part 24e outlet

Claims (11)

In the in-situ containment method of building a water-blocking wall that reaches an impermeable layer or a hardly permeable layer so as to surround the sewage area and contain the contaminated soil in the contaminated area,
Provided in the impermeable wall is a groundwater outflow portion through which groundwater inside the impermeable wall flows out to the outside of the impermeable wall when the groundwater level inside the impermeable wall rises. Purifying means for purifying groundwater flowing out of the impermeable wall is provided,
An in-situ containment method in which the purification means is disposed higher than the impermeable layer or the hardly permeable layer,
The purifying means is provided inside the impermeable wall from the groundwater outflow part,
In the inner area of the impermeable wall, a water collecting channel for guiding the groundwater inside the impermeable wall to the groundwater outflow portion is provided,
The groundwater outflow portion is provided at the same level as or lower than the water collecting channel of the water shielding wall ,
The groundwater outflow part is composed of a low part recessed downward from the upper end of the impermeable wall,
The purification means is provided so as to contact the inner surface of the impermeable wall, and a part of the purification means enters the groundwater outflow portion,
The water collecting channel is disposed so as to be in contact with the end surface of the purification means opposite to the groundwater outflow portion, and is provided so as to continuously circulate along the inner surface of the water shielding wall. In-situ containment method. Oite to claim 1, said population waterway situ containment method characterized by comprising from water permeable material. 3. The in-situ containment method according to claim 1 or 2 , wherein the purification means includes a treatment agent for removing or detoxifying contaminants in groundwater and a water-permeable material. The purifying means according to claim 3 , further comprising a container that contains the treatment agent and the water-permeable material, wherein an inflow portion of groundwater is provided on one end side of the container, and the other end side is treated. An in-situ containment method characterized by a groundwater outflow. According to claim 3 or 4, wherein the treating agent, iron powder, activated carbon, hydrotalcite, rare earth compound, magnesium oxide, alumina, allophane, ion exchange resins, one selected from the group consisting of chelating resin and clay mineral or 2 An in-situ containment method characterized by being a mixture of more than seeds. In any one of Claims 3 thru | or 5 , the said some purification | cleaning means is provided in multiple stages in the direction which goes to an outer side area | region from the inner area | region of the said water-impervious wall,
An in-situ containment method characterized in that the treatment agent of at least some of the purification means is different from the treatment agent of other purification means. The in-situ containment method according to any one of claims 1 to 6 , wherein the water collecting channel is formed of a perforated pipe having a plurality of through holes provided on a pipe wall. In any one of claims 1 to 7, wherein the outlet section, so as to communicate the outer region of the inner region surrounded by the impervious wall and shielding waterwall, the inlet is in the inner region In-situ containment method characterized by being a drainage pipe arranged. 9. The in-situ containment method according to claim 8, wherein the outer region is a sewer. In-situ containment device that constructs a water-impervious wall that reaches the impermeable layer or the hardly permeable layer so as to surround the sewage area and contains the contaminated soil in the contaminated area.
The water shielding wall is provided with a groundwater outflow portion through which groundwater inside the water shielding wall flows out of the water shielding wall when the groundwater level inside the water shielding wall rises. Purification means for purifying groundwater flowing out of the impermeable wall through the water is provided,
An in-situ containment device in which the purification means is disposed higher than the impermeable layer or the hardly permeable layer,
The purifying means is provided inside the impermeable wall from the groundwater outflow part,
In the inner area of the impermeable wall, a water collecting channel for guiding the groundwater inside the impermeable wall to the groundwater outflow portion is provided,
The outflow portion is provided at the same level as or lower than the water collecting channel of the impermeable wall ,
The groundwater outflow part is composed of a low part recessed downward from the upper end of the impermeable wall,
The purification means is provided so as to contact the inner surface of the impermeable wall, and a part of the purification means enters the groundwater outflow portion,
The water collecting channel is disposed so as to be in contact with the end surface of the purification means opposite to the groundwater outflow portion, and is provided so as to continuously circulate along the inner surface of the water shielding wall. In-situ containment device. The in-situ containment device according to claim 10, wherein the water collecting channel is made of a water-permeable material.

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