JPH02164936A - Purifying method for underground contaminated water - Google Patents

Abstract

PURPOSE:To positively purify the underground contaminated water and utilize it as purified water by constructing a hollow wall body with water permeability reaching an underground water-impermeable layer and removably storing a purifying agent inside the hollow. CONSTITUTION:A hollow wall body 3 constituted of water-permeable members 14 and 14 and reaching an underground water-impermeable layer 2 is constructed, and a purifying agent 16 stored in a water-permeable storage container 18 is removably stored in the hollow inside of the wall body 8. This wall body 3 has at least a pair of porous plates 10 and 10, and structure materials 12 and 12 concurrently serving as spacers are arranged at a preset interval between them to support the porous plates 10 and 10. Porous hollow tubes may be arranged in parallel in the congested state, and a purifying agent may be removably stored in the hollow tubes in place of this constitution.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a method for purifying contaminated groundwater, and in particular, by building a permeable wall with a function of purifying contaminated groundwater, water passing through the wall is This is an attempt to purify contaminated water.

(Background of the Invention) In recent years, groundwater pollution has been caused by several solvents such as trichlorethylene used in the manufacture of semiconductors, the outflow of heavy metals from slag dumps, and seepage from industrial waste disposal sites. Groundwater pollution has become a problem.

By the way, if contamination of groundwater is discovered through a water quality test, it goes without saying that it cannot be used as domestic water, and various social problems arise due to groundwater contamination.

(Problem to be solved by the invention) In order to prevent this type of groundwater contamination, it is of course necessary to eliminate the causes of contamination and to prevent leakage as much as possible.

However, in reality, this type of accident cannot be completely prevented, and once these pollutants leak (and in some cases, the downstream or surrounding area becomes a contaminated area, and until the pollution-causing substances disappear) It is possible to use groundwater, but the current situation is that we are not doing anything about it for a long time until it disappears.

This invention was made in order to solve the above problem, and even in areas where this type of pollution has been recognized, the underground contaminated water can be actively purified and used as purified water. The purpose of this project is to provide a method for purifying underground contaminated water.

(Means for Solving the Problems) In order to achieve the above object, the present invention constructs a hollow wall body that has water permeability that reaches the underground water-impermeable layer (7. A purification agent is installed inside the hollow part of the wall body). It was made to be housed in a removable manner.

In addition, the wall body in this invention construction method consists of at least one pair of perforated plates and a plurality of spacer structures +A that support the perforated plates arranged at predetermined intervals between the perforated plates, and each structure is surrounded by each structural member and the perforated plates. A structure can be adopted in which the cleaning agent is removably housed in the hollow interior.

Further, the wall body may have a structure in which porous hollow tubes are densely arranged in a row, and the cleaning agent is removably housed inside the hollow tubes.

(Function) According to the above two methods, contaminated groundwater passes through the wall and is purified by the purifying agent housed inside the wall.

Since the purifying agent is removable, it can be replaced when its purifying ability is exhausted, making it possible to continuously purify underground contaminated water.

When the wall is made of at least one pair of perforated plates and a plurality of structural members that also serve as spacers and support the perforated plates arranged at predetermined intervals between the perforated plates, it can be constructed using the same construction method as the continuous underground wall construction method.

The continuous underground wall construction method can also be used when the wall has a structure in which porous hollow pipes are arranged closely in rows.

In addition, the conventional poling hole drilling method can also be used.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIGS. 1 and 2 show a first embodiment of the purification method of the present invention, which purifies underground contaminated water downstream of the location where the pollution occurs.

The figure shows an example where a contaminated spot 1 exists in a valley between mountains, and a water-permeable wall 3 is constructed downstream of the contaminated spot 1 at a depth that reaches the main permeable layer 2. There is.

This wall body 3 is constructed by a continuous underground wall construction method or the like.

Zunawaji, downstream of the contaminated site 1, an excavated trench 4 with a depth that reaches the impermeable layer is excavated in the left and right spreading direction and the depth direction while filling it with muddy water, and the wall 3 is
Construction is almost complete.

The wall 3 includes a pair of perforated plates 1 as shown in FIGS. 3 and 4.
0, a plurality of structural members 12 that also serve as spacers and support the perforated plates 10 and are arranged vertically between both perforated plates 10 at appropriate intervals, and between the outer surface of each perforated plate 10 and the excavated groove 4. A water-permeable part 14ε1 such as pea gravel that fills the formed voids and supports the perforated plate 0 from the outside.A purifying agent 16 is removably housed in a hollow interior surrounded by the structural material 12 and the perforated plate 10. It consists of

The perforated plate 10 may be, for example, a perforated steel plate or a concrete plate with a large number of holes formed therein, and a large number of water passage holes 1.0a smaller than the diameter of the water permeable part 140 are formed therein.

Further, the structural material 12 is made of H-beam steel, reinforced concrete, or the like.

The perforated plate 10 and the structural material 12 may be assembled from the beginning into the structure shown in the figure, and then built into the excavated trench 4.
The perforated plate 10 and the structural member 12 may be assembled inside the excavated groove 4.

The purifying agent 16 may be, for example, various filter media, activated carbon, ion exchange resin, other chemical or biological catalysts depending on the purpose of purification, or combinations thereof.
These are filled in a water-permeable bag-shaped, cylindrical, or plate-shaped storage container 18 and housed in the hollow interior.

According to this embodiment, rainwater permeates through the soil of the polluted location 1 in the valley through the slopes of the mountains, becomes groundwater, and flows downstream. Pass through and flow ■.

By passing through this wall 3, the groundwater contaminated at the contaminated site 1 comes into contact with the purifying agent 16, and by passing through this, it is rendered harmless.

Note that the purifying agent 16 loses its purifying ability as it adsorbs pollutants, so depending on the degree of staining and the service life, the storage container 18 is sometimes taken out and a new purifying agent 16 is filled into the hollow interior. Continuous purification is possible.

For example, as shown in FIG. 5, a partition plate 20 made of a perforated plate is arranged in the middle between the perforated plate 10 and the structural material 12, and the housing space is divided into two in the thickness direction. The cleaning agent 16 and the storage container 18 may be removably housed inside each container.

With this configuration, the type of purifying agent 16 can be varied along the direction of underground water passage, and more effective purification can be achieved.

FIG. 6 shows still another embodiment of the wall body 3, in which a perforated hollow pipe 3o, such as a hollow steel pipe, in which a large number of holes are bored inside the excavated groove 4, is arranged so that the outer periphery thereof is mutually connected. A water-permeable material such as pea gravel] 4 is filled in the outer periphery of the hollow tube 3 [-] in a cylindrical shape, and a purifying agent 16 is placed in a cylindrical shape inside the hollow tube 3 [-]. It houses a storage container 18 that is filled and water permeable.

In this embodiment, the storage space is cylindrical, so the cleaning agent 16 is replaced and replaced.

Next, FIGS. 7 and 8 show a second embodiment in which the present invention is applied within the contaminated area 1, where ground water is pumped in a purified state and this is used as industrial water. It shows.

In the figure, a water-permeable wall 3 is built in the area of the G-dyed area 1 at a depth that reaches the impermeable layer 2 to form a rectangular shape.
A rectangular area surrounded by this wall 3 is a groundwater pumping area 40, and a well 42 is provided in the center of the area 4o,
Ground water is pumped up through a pump 44.

The wall body 3 has a structure similar to that of the first embodiment, and contains a cleaning agent inside the wall.

Therefore, when pumping up contaminated water existing underground at contaminated site 1, the contaminated water always passes through wall 3 and is purified by the purifying agent inside, so the pumped water is This means that it can be used normally, and even in contaminated areas it is possible to supply it as normal groundwater.

(Effects of the Invention) As explained in detail in each of the embodiments above, in the underground contaminated water purification method according to the present invention, the contaminated ground water passes through the wall and the purification agent stored in the hollow interior of the wall. purified by.

Since the purifying agent is removable, it can be replaced when its purifying ability is exhausted, making it possible to continuously purify underground contaminated water. Therefore, as shown in the first embodiment, even if there is a source of contamination in the flow, the groundwater can be rendered harmless by passing through this wall. Further, as shown in the second embodiment, even in a contaminated area, groundwater can be pumped up in a harmless state.

If the wall consists of at least one pair of perforated plates and a plurality of structural shrines that also serve as spacers and support the perforated plates arranged at predetermined intervals between the perforated plates, the above method can be used in the same way as the conventional continuous underground wall construction method. It can be constructed, and there is no need to use difficult construction methods.

Even if the wall has a structure in which porous hollow tubes are arranged in a dense row, the continuous underground wall method and the poling hole drilling method can be used, and the cylindrical shape makes it easier to replace the purifying agent. .

[Brief explanation of the drawing]

Figures 1 and 2 show a first embodiment of the purification method according to the present invention for purifying underground contaminated water downstream of lη-dyed soil. Fig. 3 is a vertical sectional view showing the detailed structure of the wall, Fig. 4 is a horizontal sectional view taken along the IV-IV line in Fig. 3, and Fig. 5 shows another implementation of the wall. FIG. 6 is a horizontal sectional view showing another embodiment of the wall body, and FIG. 7 is a horizontal sectional view showing another embodiment of the wall body. FIG. 8 is a plan view showing a second embodiment applied to the use of the present invention, and FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 1...Contaminated area 2...Impermeable layer 3...Water permeable wall 10...Porous plate 12/Spacer/structural material 14...Water permeable member 16...Purifying agent 30... Perforated Hollow Tube Patent 1 Acquaintance Agent Jindo Co., Ltd. Obayashi Corporation

Claims (3)

[Claims] (1) A method for purifying underground contaminated water, which is characterized by constructing a hollow wall that allows water to pass through to an impermeable layer underground, and removably storing a purifying agent inside the hollow wall. (2) The wall body consists of at least one pair of perforated plates and a plurality of structural members that also serve as spacers and support the perforated plates arranged at predetermined intervals between the perforated plates. 2. The underground contaminated water purification method according to claim 1, wherein the purification agent is removably housed. (3) The wall body is formed by closely arranging porous hollow tubes, and a cleaning agent is removably housed inside the hollow tubes. The described underground contaminated water purification method.