JP3037473B2 - Contaminant barrier material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to environmental protection, in particular, to the construction of a barrier around an area that is polluted or at risk of contamination by preventing the transfer of pollutants from that area to the surroundings. The present invention relates to a material for constituting a barrier wall of a pollutant used in an environmental protection method for preventing an influence on the environment.

[0002]

2. Description of the Related Art With the development of industry and the diversification of urban life, the problems of industrial waste and municipal waste have been greatly highlighted. In particular, in addition to an increase in the amount of waste treated, harmful substances contained in the waste, such as heavy metals such as mercury, cadmium, and chromium, flow out to living areas, for example, through groundwater.

[0003] For this purpose, it is a suitable solution to construct a blocking wall around a contaminated or at risk of contaminant to prevent the transfer of contaminants from that region to the surroundings. Indeed, it has been conventional to build concrete walls around the area, or even concrete impermeable walls at the bottom.

However, concrete walls have a high possibility of permeating heavy metals, and when cracks occur, they will intensively flow out therefrom.

On the other hand, Japanese Patent Application Laid-Open No. Sho 61-105500 proposes injecting a trapping substance having a high barrier property by adsorbing heavy metal ions into cracks in the barrier wall.

[0006]

However, when a material such as bentonite or cement containing calcium or sodium is used to form a mortar or concrete wall, the slurry before hardening is used. In the state, calcium or sodium in the material is present in the slurry in an ionic state, and the ionic component is adsorbed by the trapping substance. Often, they are substantially gone. As a result, there is a problem that the trapping substance has a result that the trapping substance has little expected trapping ability.

[0007] Therefore, a main object of the present invention is to prevent the material from being affected by other materials constituting the shielding wall and to exhibit an intended capturing property.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a contaminant barrier wall-forming material which surrounds a contaminated area or a region where there is a risk of contaminants. A solidifying building material selected from the group of mortar, concrete, and cement-bentonite for constructing a barrier wall for preventing the movement of the material, and a trapping material contained in the building material in a slurry state, The material has a coating on the surface of the trapping core material consisting of particles that adsorb or retain contaminants or pellets of the particles, and the building material is calcium or calcium that adsorbs to the trapping core material in a slurry state. A sodium ion component, wherein the coating blocks contact between the ionic component and the capture core material in a slurry state of a building material; And it is characterized in that the intended breaking or dissolved by contact with contaminants containing water through a blocking wall after construction.

[0009]

According to the present invention, a trapping material having a coating on the surface of a trapping core material composed of particles that adsorb or retain contaminants or pellets of the particles is selected from the group consisting of mortar, concrete and cement-bentonite. To form a barrier wall.

However, since the coating blocks the contact between the calcium or sodium ion component and the trapping core material in the slurry state of the building material, the calcium or sodium ion component is trapped before the solidification of the blocking wall. It is possible to reliably avoid a situation in which the core material is adsorbed and the original ability to adsorb contaminants almost disappears.

On the other hand, the coating made of gelatin or the like
After the barrier wall is constructed, it breaks or dissolves by contact with the contaminant-containing water passing through the barrier wall. The internal core capture material is exposed, demonstrating its ability to capture contaminants.

[0012]

The present invention will be described in more detail below. FIG. 2 is a conceptual diagram showing a construction target area according to the present invention, in which a blocking wall 2 is constructed so as to surround a waste dump site. A barrier 2 around an area contaminated by or at risk of being contaminated by waste to prevent the transfer of contaminants from that area to the surroundings.
Is preferably when the impermeable layer 3 is present at the bottom,
The structure is constructed by reaching the impermeable layer 3. When there is no water-impermeable layer 3 or there is a risk of infiltration by riding on groundwater downward, a bottom wall similar to the blocking wall 2 can be constructed below the contaminated area by appropriate means. . In this case, the bottom wall is desirably continuous with the blocking wall 2. If necessary, a liquid-impermeable sheet 5 can be provided inside the blocking wall 2 or the bottom wall.

When constructing such a blocking wall 2, it can be a mortar or concrete wall or a cement-bentonite wall. As shown in FIG. 1, the surface of the capture core material 10 </ b> A made of particles for adsorbing or retaining the contaminants in the waste 1 or pellets of the particles is formed in the barrier wall 2. The trapping material 10 having a coating 10B for preventing direct contact is contained.

When the continuous underground wall is used in the construction method when constructing the blocking wall 2, as shown in FIG. 2, a guide wall 11 is formed, and the excavation groove 12 is excavated while being filled with a bentonite stabilizing solution. After excavation, the solidifying material such as cement and the trapping material 1
0 can be added or stirred or replaced and stirred to achieve solidification.

The formed barrier wall 2 generally has a large water permeability at the beginning, and therefore a large percentage of water containing contaminants permeates through the barrier wall 2. At this time, the trapping material 1
In the case of No. 0, the coating 10B is partially or entirely dissolved by contact with the water, and the capturing core material 10A is exposed. Contaminants are adsorbed or held on the exposed core material 10A.

Eventually, with the passage of time after the formation of the blocking wall 2, the water permeability decreases, and a high liquid blocking property is exhibited. Even in this case, the contaminants containing the contaminant-containing water that penetrates into the blocking wall 2 through cracks or the like are captured.
A adsorbs or holds. As a result, it is possible to prevent the contaminant from flowing out around the blocking wall 2. The coating 10
By selecting a material or a film thickness of B, it is possible to control so that the coating 10B is dissolved by the time the solidification of the barrier wall is completed.

In the case where the excavation groove 12 is not filled with the bentonite stabilizing liquid, the trapping material 10 can be previously mixed with the constituent material of the blocking wall 2 and can be poured into the excavation groove 12.

On the other hand, the trapping material 10 according to the present invention can also be used when constructing the blocking wall 20 according to the embodiments shown in FIGS.

That is, first, as shown in FIG. 3, a guide wall 11 is constructed, and a long excavation groove 12 is excavated.
In this excavation, when excavation is performed using a stabilizing liquid 16A such as bentonite, the hole wall is stabilized. Then, FIG.
As shown in the figure, a hollow holder having a large number of through holes 13a,
For example, a hollow pipe 13 is inserted into the excavation groove 12.

In this case, as shown in FIG. 9, the hollow pipes 13 are inserted into the excavation groove 12 so that the capturing piles 6, 6 are finally arranged side by side in the longitudinal direction of the excavation groove 12. Place and insert. At the time of insertion, as shown in FIG.
When a spacer 14 for steadying for positioning is fixed around the hollow tube 13 in the excavation groove 12 and inserted, the centering is easy. The spacer 14 can be removed or buried later.

Thereafter, as shown in FIG. 5, a hollow space forming tube 15 with a bottom is inserted into the hollow tube 13. in this case,
The space forming pipe 15 may be inserted into the excavation groove 12 simultaneously with the hollow pipe 13. The space forming tube 15 is desirably bottomed so that the stabilizing liquid 16A does not enter from below. Instead of the space forming tube 15, a solid tube may be used.

When the insertion of the space forming tube 15 is completed,
A curing additive is added to the bentonite stabilizer 16A to stir and cure, or the bentonite stabilizer 16A is replaced with cement or mortar, for example.
As shown in FIG. 6, the solidifying material 16 is solidified.

After the flowability of the solidifying material 16 has been lost or solidified, the space forming tube 15 is pulled out to the ground,
As shown in FIG. 7, the extracted space is used as a filling space 1.
7 is assumed.

Thereafter, as shown in FIG. 8, the contaminant trapping material 10 is charged into the hollow tube 13 and filled therein, thereby completing the construction of the trapping piles 6, 6,... Shown in FIG.

In this case, the liquid-impervious blocking plate 1 such as a metal plate or a plastic plate straddles between the hollow tubes 13, 13.
The connection at 8 is more preferable because the liquid passing through the blocking wall 2 surely enters the hollow tube 13 and the contaminants are adsorbed or held by the captured core material 10A.

In the above example, the hollow tube 13 and the space forming tube 15 can be a metal tube or a plastic tube such as vinyl chloride. In order to facilitate removal of the space forming tube 15, an oil-based release agent can be applied to the inner surface of the hollow tube 13 or the outer surface of the space forming tube 15 or both. Sand or the like may be poured between them.

In the present invention, regarding the core material for trapping, those which adsorb or retain pollutants such as activated carbon, coal, charcoal, zeolite, vermiculite, kaolin, sodium bentonite, silica, blast furnace slag, and other clay minerals are used. They can be used alone or in a mixed state. This type of ion exchange capacity,
This is used because it has an adsorbing ability or a holding ability in the pores by a porous material.

In addition, one or more of the materials disclosed in the above publication can be used in combination. When the contaminants are ammoniacal nitrogen or the like, trapping materials corresponding to these can be used. Waste disposal sites may have many types of pollutants. Therefore, the types of the core material for capturing can be made different for the capturing piles 6, 6,.... In addition, the trapping core material may be unit particles as they are, but may be used by being aggregated or agglomerated using an appropriate binder like pellets.

Further, as the coating 10B covering the surface of the core capturing material 10A, a material soluble in water may be used, and for example, a gelatin, a cellulose-based material, and a vinyl acetate-based material can be used.

When constructing the blocking wall 2, as shown in FIG. 10, the trapping material 10 of the present invention can be added to the material for forming the continuous pile 2A. The continuous pile can be formed by a so-called injection stirring mixing method. In addition, the trapping material 10 can be similarly added to the case where the blocking wall is formed only by grout injection or the like.

[0031]

As described above, according to the present invention, it is possible to prevent the construction material constituting the barrier from being affected by the calcium or sodium ion component, and to exhibit the desired trapping property after the construction of the barrier. Can be done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a capture material of the present invention.

FIG. 2 is a cross-sectional view of a state where a blocking wall is constructed according to the present invention.

FIG. 3 is a schematic sectional view of a first step of a construction example of the present invention.

FIG. 4 is a schematic sectional view of a second step of a construction example of the present invention.

FIG. 5 is a schematic sectional view of a third step of a working example of the present invention.

FIG. 6 is a schematic sectional view of a fourth step of a working example of the present invention.

FIG. 7 is a schematic sectional view of a fifth step of a working example of the present invention.

FIG. 8 is a schematic sectional view of a sixth step of the working example of the present invention.

FIG. 9 is a horizontal sectional view of a blocking wall showing a completed state of the present invention.

FIG. 10 is a sectional view of another example of a blocking wall according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Waste, 2, 2A ... Blocking wall, 3 ... Water-impermeable layer, 5 ... Liquid-impermeable sheet, 6 ... Capture pile, 10 ... Capture material, 10A ...
Capture core material, 10B ... coating, 11 ... guide wall,
12: excavation groove, 13: hollow holder, 13a: through hole, 14
... spacer, 15 ... space forming tube, 16 ... solidifying material,
16A: stable liquid, 17: space, 18: blocking plate, 20: blocking wall.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI C04B 14/36 C04B 14/36 20/10 20/10 (58) Investigated field (Int.Cl. ⁷ , DB name) C04B 28/02 ZAB B09B 1/00 E02D 5/18 102 E04B 1/62 C04B 20/10

Claims (1)

(57) [Claims] A group of mortar, concrete and cement-bentonite for constructing a barrier around a contaminated or at-risk area to prevent the transfer of contaminants from that area to the surroundings. And a capture material to be contained in the build material in a slurry state, wherein the capture material comprises particles that adsorb or retain contaminants or pellets formed by granulating the particles. A coating on the surface of the core material, wherein the building material has a calcium or sodium ion component adsorbed to the trapping core material in a slurry state, and the coating has the ionic component and the calcium component in a slurry state of the building material. Blocks contact with captured core material and breaks or dissolves due to contact with contaminant-containing water through the constructed barrier. Blocking wall material constituting the contaminants, characterized in that the.