JP2004169322A - Method and apparatus for purifying contaminated groundwater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for purifying contaminated groundwater, which can reduce the number of recovery pits to be constructed, can shorten a period for recovery work, and can prevent a contaminated stock solution from being diffused around. <P>SOLUTION: The recovery pit 11, which reaches a contaminated stock solution area E in the ground and wherein a wall as high as the area E is formed of a water permeable screen 11a, is constructed; an impervious wall 12, which surrounds an outer periphery of the area E so as to guide the groundwater, flowing through the area E, to the recovery pit 11, is constructed; and a drainage treatment means for taking and treating the groundwater flowing into the recovery pit 11 is provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a purification method and a purification apparatus for purifying contaminated groundwater, and more particularly to a technique effective for recovering a contaminated undiluted solution (poorly water-soluble liquid) in a large amount in the ground. .
[0002]
[Prior art]
As a conventional method and apparatus for purifying contaminated groundwater, there is one disclosed in Japanese Patent Publication No. 6-104975 shown in FIGS. 7 and 8.
[0003]
As shown in FIGS. 7 and 8, the method and the apparatus 1 for purifying contaminated groundwater include a water-permeable wall 2 at a position downstream of the contaminated stock solution area E and intersecting with the flowing direction T of the groundwater. Is constructed to a depth that reaches the water-impermeable layer, and the purifying agent 3 is accommodated inside the wall 2.
[0004]
According to the purification method and the purification device 1, when the contaminated stock solution flows out together with the groundwater and flows into the purification device 1, the contaminated stock solution is treated by the purifying agent 3, and only the unpolluted groundwater is drained downstream. .
[0005]
However, in the conventional purification method and the purification apparatus 1, since the contaminated stock solution flowing out together with the groundwater is simply treated, the groundwater remains contaminated as long as the contaminated stock solution area E exists. That is, the contaminated stock solution area E cannot be positively purified.
[0006]
Further, as another conventional example, there is a construction in which a plurality of recovery pits reaching the contaminated undiluted solution area in the ground are constructed, and groundwater flowing into these recovery pits is recovered.
[0007]
According to this purifying device, the contaminated stock solution area itself can be positively purified.
[0008]
[Patent Document 1]
Japanese Patent Publication No. 6-104975 (FIGS. 1 and 2)
[0009]
[Problems to be solved by the invention]
However, in the above-mentioned conventional purification method and purification apparatus, a plurality of collection pits are generally constructed at appropriate places in the contaminated stock solution area in order to allow the natural flow of the groundwater to collect the contaminated stock solution after collecting it in the collection pit. And the recovery operation takes a long time. There is also a problem that the contaminated stock solution flows out from the contaminated stock solution area together with the groundwater and diffuses.
[0010]
Therefore, the present invention has been made to solve the above-mentioned problems, and the number of the construction of the recovery pit is small, and the recovery work can be shortened and the contaminated groundwater can be prevented from diffusing to the surroundings. It is an object to provide a purification method and a purification device.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, a collection pit which reaches the inside of the contaminated stock solution area in the ground and whose height is equal to the height of the contaminated stock solution area is formed by a water-permeable screen. And constructing an impermeable wall for guiding groundwater flowing in the contaminated stock solution area to the collection pit, and collecting the groundwater flowing into the collection pit.
[0012]
In this method of purifying contaminated groundwater, the flow of the groundwater flowing in the contaminated stock solution area is changed by the impermeable wall, and the groundwater is collected in the collection pits, and the contaminated stock solution can be efficiently collected by a small number of collection pits. In addition, groundwater passing through the contaminated stock solution area does not flow outside due to the impermeable wall.
[0013]
The invention according to claim 2 is the method for purifying contaminated groundwater according to claim 1, wherein the impermeable wall has an opening on the downstream side of the groundwater in the recovery pit. It is.
[0014]
In this method of purifying contaminated groundwater, in addition to the effect of the first aspect, groundwater flows downstream of the recovery pit even if a purifying device is installed in the contaminated raw solution area. Groundwater can also flow into the recovery pit from the downstream side of the groundwater.
[0015]
A third aspect of the present invention is to construct a recovery pit that reaches the inside of the contaminated stock solution area in the ground, and has a wall at the height of the contaminated stock solution area formed of a water-permeable screen. And a drainage treatment means for taking up and treating groundwater flowing into the recovery pit by constructing a water impermeable wall for guiding groundwater flowing in the contaminated raw solution area to the recovery pit. Groundwater purification equipment.
[0016]
In this apparatus for purifying contaminated groundwater, the flow of the groundwater flowing in the contaminated stock solution area is changed by the impermeable wall, so that the groundwater is collected in the collection pits, and the contaminated stock solution can be efficiently collected by a small number of collection pits. In addition, groundwater passing through the contaminated stock solution area does not flow outside due to the impermeable wall.
[0017]
The invention of claim 4 is the apparatus for purifying contaminated groundwater according to claim 3, wherein the impermeable wall has an opening on the downstream side of the groundwater in the recovery pit.
[0018]
In the apparatus for purifying contaminated groundwater, in addition to the operation of the invention of claim 3, groundwater flows downstream from the recovery pit even if the purifier is installed in the contaminated stock solution area. Groundwater can also flow into the recovery pit from the downstream side of the groundwater.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
1 and 2 show a first embodiment of the present invention. FIG. 1 (a) is a side view of a purification device, FIG. 1 (b) is a plan view of the purification device, and FIG. FIG. 2B is a schematic plan view showing a flowing direction T of groundwater around the surrounding area. FIG.
[0021]
As shown in FIGS. 2 (a) and 2 (b), the ground is arranged from the ground surface in the order of a surface soil layer, an aquifer, and an impermeable layer. There is a place where a large amount of liquid is present (hereinafter, contaminated stock solution area E), and groundwater flows through the aquifer. The contaminated stock solution area E and the downflow direction T of the groundwater are specified by the investigation of the contaminated soil / groundwater.
[0022]
In such a case, as shown in FIGS. 1A and 1B, the contaminated groundwater purifying apparatus 10A includes a collection pit 11 constructed in a contaminated stock solution area E in the ground, and the collection pit 11. A water impermeable wall 12 is arranged so as to surround the outer periphery of the contaminated stock solution area E with the center at 11, and a wastewater treatment means (not shown) for taking in and treating groundwater flowing into the collection pit 11. .
[0023]
The recovery pit 11 has a cylindrical shape, reaches a water-impermeable layer deeper than the contaminated stock solution area E, and has a wall having a height of the contaminated stock solution area E formed of a water-permeable screen 11a.
[0024]
The impermeable walls 12 extend in directions orthogonal to each other with the collection pit 11 as a center, and are installed so as to guide the groundwater flowing in the contaminated stock solution area E to the collection pit 11. The upstream side of the groundwater flowing in the contaminated stock solution area E is largely open. Openings 12a are formed in the water impermeable walls 12 at mutually orthogonal portions, and the openings 12a open the downstream side of the collection pit 11 to the groundwater.
[0025]
The wastewater treatment means (not shown) is connected to a pipe (not shown) having a suction port in the collection pit 11, a suction pump (not shown) for sucking the inside of the pipe, and the other end of the pipe, And a wastewater treatment unit (not shown) for purifying and treating groundwater taken in by a suction pump.
[0026]
Next, a construction procedure of the purification device 10A will be briefly described.
[0027]
First, the contaminated stock solution area E and the flowing direction T of the groundwater are specified by investigating the contaminated soil and groundwater. Next, a recovery pit 11 reaching the impermeable layer is constructed in the contaminated stock solution area E, and a wastewater treatment means (not shown) is installed.
[0028]
Next, the impermeable wall 12 is constructed so as to surround the recovery pit 11 around the upstream side of the groundwater from the contaminated stock solution area E.
[0029]
Next, monitoring of contaminants and the like is performed using the observation well 13, various numerical analysis simulations are performed, and the drive content of the wastewater treatment means (not shown) is determined.
[0030]
Next, the purification operation of the purification device 10A will be described. Groundwater enters from the opening on the upstream side of the impermeable wall 12, and the entered underground water flows through the contaminated stock solution area E and its surroundings. However, the flow of the groundwater flowing out of the contaminated stock solution area E is changed by the impermeable wall 12. They gather at the collection pit 11 and flow into the collection pit 11. The groundwater flowing into the recovery pit 11 is taken in by a wastewater treatment means (not shown), and a predetermined wastewater purification treatment is performed.
[0031]
As described above, since the contaminated stock solution in the ground can be efficiently collected by the collection pit 11, the number of the collection pits 11 can be reduced as compared with the related art, and the collection work can be shortened. In addition, since the groundwater passing through the contaminated stock solution area E does not flow outside due to the impermeable wall 12, diffusion of the contaminated stock solution to the surroundings can be prevented.
[0032]
Further, in the conventional example, it is necessary to continuously operate the wastewater treatment means so that the contaminated groundwater is not diffused as much as possible. However, in the purification apparatus 10A, the diffusion can be prevented by the impermeable wall 12 as described above. Even if the wastewater treatment means (not shown) is operated intermittently, the contaminated stock solution can be recovered without worrying about diffusion.
[0033]
In the first embodiment, the collection pit 11 is provided only at one place. However, it is needless to say that the recovery pit 11 may be set at a plurality of places depending on the size of the contaminated stock solution area E and the flow of groundwater.
[0034]
In the first embodiment, since the impermeable wall 12 has the opening 12a on the downstream side of the groundwater of the collection pit 11, the groundwater flows downstream from the collection pit 11 even if the purification device 10A is installed. It can prevent groundwater disturbance to the side and land subsidence due to soft ground. Further, since groundwater can flow into the recovery pit 11 from the downstream side of the groundwater of the recovery pit 11, pollutants on the downstream side can also be recovered.
[0035]
FIG. 3 shows a second embodiment of the present invention. FIG. 3 (a) is a schematic plan view showing a contaminated stock solution area E and the flowing direction T of groundwater around it, and FIG. 3 (b) is a plan view of a purification device 10B. It is. As shown in FIGS. 3 (a) and 3 (b), in the purification device 10B of the second embodiment, the impermeable wall 20 surrounds almost the entire periphery except for one side on the upstream side of the contaminated stock solution area E. Are located in Other configurations are the same as those of the first embodiment, and thus the same components are denoted by the same reference numerals and description thereof will be omitted.
[0036]
Also in the second embodiment, similarly to the first embodiment, the contaminated stock solution in the ground can be efficiently collected by the collection pit 11, so that the number of the collection pits 11 can be reduced as compared with the related art, and the collection work can be performed in a short time. Can intervene. In addition, since the groundwater passing through the contaminated stock solution area E does not flow outside due to the impermeable wall 20, diffusion of the contaminated stock solution to the surroundings can be prevented.
[0037]
In addition, in the second embodiment, since the impermeable wall 20 surrounds three sides around the contaminated stock solution area E, the diffusion of groundwater can be further prevented.
[0038]
FIG. 4 shows a third embodiment of the present invention, FIG. 4 (a) is a schematic plan view showing a contaminated stock solution area E and the flowing direction T of groundwater around the area, and FIG. 4 (b) is a plan view of a purification device 10C. It is. As shown in FIGS. 4A and 4B, in the purification device 10C of the third embodiment, the impermeable wall 21 has one side on the upstream side of the contaminated stock solution area E, similarly to the second embodiment. It is arranged so as to surround almost the entire periphery except for. The difference is that the impermeable wall 20 of the second embodiment is arranged in a square shape, whereas the impermeable wall 21 of the third embodiment is arranged in a pentagonal shape. Other configurations are the same as those of the first embodiment, and thus the same components are denoted by the same reference numerals and description thereof will be omitted.
[0039]
In the third embodiment, the same operation and effect as those of the second embodiment can be obtained. In the third embodiment, groundwater can be collected in the collection pit 11 more quickly than in the second embodiment.
[0040]
FIG. 5 shows a fourth embodiment of the present invention. FIG. 5 (a) is a schematic plan view showing a contaminated stock solution area E and the flowing direction T of groundwater around it. FIG. 5 (b) is a plan view of a purification device 10D. It is. As shown in FIGS. 5 (a) and 5 (b), in the purification device 10D of the fourth embodiment, the impermeable wall 22 is located on the upstream side of the contaminated stock solution area E, as in the second and third embodiments. Are arranged so as to surround almost the entire periphery except for one side. The difference is that the impermeable wall 20 of the second embodiment is arranged in a square shape, whereas the impermeable wall 22 of the fourth embodiment is arranged in an arc shape. Other configurations are the same as those of the first embodiment, and thus the same components are denoted by the same reference numerals and description thereof will be omitted.
[0041]
In the fourth embodiment, the same operation and effect as those of the second embodiment can be obtained. Further, the fourth embodiment can collect groundwater into the collection pit 11 more quickly than the second embodiment.
[0042]
6A and 6B show a fifth embodiment of the present invention. FIG. 6A is a schematic plan view showing a contaminated stock solution area E and a flowing direction T of groundwater around the area, and FIG. 6B is a plan view of a purification device 10E. It is. As shown in FIGS. 6 (a) and 6 (b), in the purification device 10E of the fifth embodiment, unlike the second embodiment, the impermeable wall 23 is smaller than one side on the upstream side of the contaminated stock solution area E. It is arranged so as to surround almost the entire periphery except for a part. The impermeable wall 23 of the fifth embodiment is arranged in a square shape. Other configurations are the same as those of the first embodiment, and thus the same components are denoted by the same reference numerals and description thereof will be omitted.
[0043]
In the fifth embodiment, the same operation and effect as those of the second to fourth embodiments can be obtained.
[0044]
In the fifth embodiment, since the impermeable wall 23 surrounds substantially four sides around the contaminated liquid solution area E, it is possible to almost completely prevent the diffusion of groundwater.
[0045]
【The invention's effect】
As described above, according to the first aspect of the present invention, a recovery pit that reaches the inside of the contaminated stock solution area in the ground and has a wall at the height of the contaminated stock solution area is formed by a water-permeable screen. At the same time, a water barrier that surrounds the outer periphery of the contaminated stock solution area and guides the groundwater flowing in the contaminated stock solution area to the collection pit is collected, and the groundwater that flows into the collection pit is collected. In addition, the flow of the groundwater flowing in the contaminated stock solution area is changed by the impermeable wall, so that the groundwater collects in the collection pits, and the contaminated stock solution can be efficiently collected by a small number of collection pits. Therefore, the number of collection pits can be reduced, and the collection work can be shortened. In addition, since the groundwater passing through the contaminated stock solution area does not flow outside due to the impermeable wall, diffusion of the contaminated stock solution to the surroundings can be prevented.
[0046]
According to the second aspect of the present invention, in the method for purifying contaminated groundwater according to the first aspect, the impermeable wall has an opening on the downstream side of the groundwater in the recovery pit. In addition to the effects of the first aspect of the present invention, groundwater flows downstream from the recovery pit even if a purification device is installed in the contaminated stock solution area, so that groundwater disturbance on the downstream side and land subsidence due to soft ground can be prevented. Also, since groundwater can flow into the recovery pit from the downstream side of the groundwater in the recovery pit, contaminants on the downstream side can also be recovered.
[0047]
According to the invention of claim 3, a recovery pit which reaches the inside of the contaminated stock solution area in the ground and whose height is equal to the height of the contaminated stock solution area is formed by a water-permeable screen. A contaminated wall surrounding the outer perimeter and guiding the groundwater flowing in the contaminated stock solution area to the recovery pit was provided, and a wastewater treatment means for collecting and treating the groundwater flowing into the recovery pit was provided. In the purification device of the above, the flow of the groundwater flowing in the contaminated stock solution area is changed by the impermeable wall, the groundwater is collected in the collection pit, and the contaminated stock solution can be efficiently collected by a small number of collection pits. Therefore, the number of collection pits can be reduced, and the collection work can be shortened. In addition, since the groundwater passing through the contaminated stock solution area does not flow outside due to the impermeable wall, diffusion of the contaminated stock solution to the surroundings can be prevented.
[0048]
According to the invention of claim 4, the contaminated groundwater purifying apparatus according to claim 1, wherein the impermeable wall has an opening on the downstream side of the groundwater in the recovery pit. In addition to the effect of the third aspect of the present invention, groundwater flows downstream from the recovery pit even if the purification device is installed, so that groundwater obstruction to the downstream side and land subsidence due to soft ground can be prevented. Further, since groundwater can flow into the recovery pit from the downstream side of the groundwater in the recovery pit, pollutants on the downstream side can also be recovered.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of the present invention, in which (a) is a side view of a purification device, and (b) is a plan view of the purification device.
FIGS. 2A and 2B show a first embodiment of the present invention, wherein FIG. 2A is a schematic plan view showing a contaminated stock solution area and the flow of groundwater around the contaminated stock solution, and FIG. FIG.
3A and 3B show a second embodiment of the present invention, in which FIG. 3A is a schematic plan view showing a contaminated stock solution area and the flow of groundwater around it, and FIG. 3B is a plan view of a purification device.
4A and 4B show a third embodiment of the present invention, in which FIG. 4A is a schematic plan view showing a contaminated stock solution area and the flow of groundwater around it, and FIG. 4B is a plan view of a purification device.
5A and 5B show a fourth embodiment of the present invention, wherein FIG. 5A is a schematic plan view showing a contaminated stock solution area and the flow of groundwater around it, and FIG. 5B is a plan view of a purification device.
6A and 6B show a fifth embodiment of the present invention, wherein FIG. 6A is a schematic plan view showing a contaminated stock solution area and the flow of groundwater around the area, and FIG. 6B is a plan view of a purification device.
FIG. 7 is a plan view of a conventional purification device.
FIG. 8 is a sectional view of a conventional purification device.
[Explanation of symbols]
10A, 10B, 10C, 10D, 10E Purification device 11 Recovery pit 11a Screen 12, 20, 21, 22, 23 Impermeable wall E Contaminated stock solution area T Flowing direction of groundwater

Claims (4)

A recovery pit that reaches the inside of the contaminated stock solution area in the ground, and the wall of the height of the contaminated stock solution area is formed by a water-permeable screen, surrounds the outer periphery of the contaminated stock solution area, and A method for purifying contaminated groundwater, comprising constructing a water impermeable wall for guiding flowing groundwater to the collection pit, and collecting the groundwater flowing into the collection pit. The method for purifying contaminated groundwater according to claim 1,
The method for purifying contaminated groundwater, wherein the impermeable wall has an opening on the downstream side of the groundwater in the recovery pit. A contaminated stock solution area in the ground is reached, and a wall at the height of the contaminated stock solution area forms a collection pit formed by a water-permeable screen, and the outer periphery of the contaminated stock solution area is surrounded by the contaminated stock solution area. A contaminated wall for guiding groundwater flowing through the collection pit, and wastewater treatment means for collecting and treating the groundwater flowing into the collection pit. The apparatus for purifying contaminated groundwater according to claim 3,
The contaminated groundwater purification device, wherein the impermeable wall has an opening on the downstream side of the groundwater in the recovery pit.

Images