JP2876358B2 - How to purify contaminated groundwater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying ground polluted groundwater.

[0002]

2. Description of the Related Art Due to the expansion of cities, the amount of industrial waste and household waste has increased, and landfill disposal sites have become indispensable. FIG. 5 is an example of the structure of a landfill. Generally, a landfill site is constructed by excavating the ground to form a pond 1 as shown in FIG. 5 or constructing a pond by embankment. A water-impermeable membrane 11 is formed on the surface of the pond 1 with rubber or asphalt to prevent harmful substances from dissolving from the waste 12 put into the pond 1 and flowing out to the surrounding ground.

[0003]

The prior art has the following problems. That is, in most cases, the pond constructed as described above cannot be sufficiently leveled, and the surface of the pond has a lot of water locally. Therefore, water accumulates under the rubber at the time of construction and cannot be laid evenly, and there is a case where asphalt cannot obtain continuity due to the influence of water. Therefore, as shown in FIG. 5, cracks 13 and the like are generated in an incomplete portion of the construction of the water-impermeable membrane 11, and contaminants may flow out therefrom to contaminate the groundwater and destroy the surrounding environment. .

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems, and purifies pollutants discharged from waste by passing them through a coal ash pile to purify the waste. It is an object of the present invention to provide a method for purifying contaminated groundwater that can suppress the influence on the surrounding environment of a landfill disposal site. That is, the present invention provides a method for constructing a pile with coal ash in the ground around a contaminant-containing area, and allowing groundwater contaminated with the contaminant flowing out of the contaminant-containing area to pass through the pile and filtering. Groundwater purification method. Also,
Pile is constructed with coal ash at the downstream peripheral part of the groundwater flow path in the pollutant-containing area, and the groundwater contaminated by the pollutant flowing out from the pollutant-containing area is transmitted through the pile and filtered, It is a purification method. Further, in the above-mentioned purification method, there is provided a method for purifying contaminated groundwater in which coal ash piles are continuously formed into a wall shape.

[0005]

An embodiment of the present invention will be described below with reference to the drawings. <A> Coal ash The present invention relates to a method for constructing a pile with coal ash in the infiltration ground of contaminated groundwater, and allowing the contaminated groundwater to pass through the coal ash pile and filtering.
It is a method of purifying contaminated groundwater. The coal ash used in the present invention is a residue of coal used as energy, and the characteristic of this coal ash is that its specific surface area is
It is as large as 0 to 8,000 cm ² / gr, and has good adsorptivity as seen in activated carbon. Therefore, it is effective as a filter material for filtering contaminated groundwater.

<B> Coal Ash Pile (FIGS. 1 and 2) The coal ash pile 2 is a pile body constructed by pouring coal ash into the ground. 1 and 2 show construction examples of the coal ash pile 2. In a place where the ground is soft, as shown in FIG. 1, when constructing a waste disposal site, a required number of coal ash piles 2 are constructed at the bottom of the pond 1 and are also used as reinforcing piles. If there is no particular problem in the ground, a coal ash pile 2 is built around the pond 1. In the disposal site where construction has already been completed, as shown in FIG. When building around the pond 1, it should be constructed at least on the downstream side of the groundwater in the pond 1.

<C> Method of Building Coal Ash Pile (FIGS. 3 and 4) The method of building the coal ash pile 2 is performed by various known methods such as a sand drain method and a sand compaction method.
For example, as shown in FIG. 3, the casing 3 is cast to a predetermined depth, and after the coal ash 21 is charged into the casing 3, the casing 3 is pulled out while applying air pressure, and the coal ash 21 is left in the ground. There is a method of constructing the coal ash pile 2 by using the method. As shown in FIG. 4, the casing 4 is driven to a predetermined depth, and is inserted through an inner pipe 41 in the casing 4.
A method is also conceivable in which the slurry-like coal ash 22 is charged, the casing 4 is pulled out while the coal ash 22 is charged, and the casing 4 is occasionally moved up and down to compact the coal ash 22.

[0008]

Next, the operation of the present invention will be described. <A> Adsorption Since coal ash has a large specific surface area, it effectively adsorbs contaminants B (for example, hydrogen sulfide, phosphorus which is one of the causes of eutrophication of water quality) contained in contaminated groundwater A. can do. Therefore, as shown in FIG. 2, the groundwater A contaminated by the pollutant B flowing out of the waste disposal site becomes the purified groundwater C after the pollutant B is adsorbed through the coal ash pile 2. Runs out of the area of waste disposal site.

<B> Water collection When the coal ash pile 2 has better water permeability than the surrounding ground,
Since the surrounding groundwater is collected on the coal ash pile 2, it can be effectively purified with a small number.

<C> Reinforcement The coal ash pile 2 can be expected to have a uniaxial compressive strength of about 2.0 kg / cm ² . Therefore, an effect as a reinforcing pile can be obtained, and soft ground can be reinforced.

[0011]

Since the present invention has been described above, the following effects can be obtained. <B> Groundwater contaminated by pollutants flowing out of the waste disposal site can be purified by passing it through coal ash piles. Therefore, the influence on the surrounding environment of the waste disposal site can be suppressed.

<B> After contaminated groundwater is permeated through coal ash piles and purified, it can be allowed to flow out of the area of the waste disposal site. Therefore, the flow of the natural groundwater in the existing area is not disturbed.

<C> By constructing the pile with coal ash, the function as a reinforcing pile can be obtained, and the soft ground can be reinforced.

[Brief description of the drawings]

[Fig. 1] Illustration of coal ash pile that also serves as reinforcement pile

FIG. 2 is an explanatory view of a case where a wall is constructed by continuously linking coal ash piles.

FIG. 3 is an explanatory diagram of a method for constructing a coal ash pile.

FIG. 4 is an explanatory diagram of a method for constructing a coal ash pile.

FIG. 5 is an explanatory view of a conventional technique.

Claims (3)

(57) [Claims] 1. A contaminated groundwater comprising: constructing a pile of coal ash in the ground around a contaminant-containing area; and permeating the groundwater contaminated by the contaminant flowing out of the contaminant-containing area through the pile and filtering the contaminated groundwater. Purification method. 2. A pile is constructed from coal ash at a downstream peripheral portion of a groundwater flow path in a pollutant-containing area, and groundwater contaminated by pollutant flowing out of the pollutant-containing area is transmitted through the pile and filtered. To purify the contaminated groundwater. 3. The method according to claim 1, wherein the coal ash pile is continuously formed into a wall shape.