JP3284824B2 - How to clean contaminated soil - 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 contaminated soil.

[0002]

2. Description of the Related Art Various types of wastes have been landfilled on landfill sites, sites of factories, etc., due to leakage of solvents used in factories, and disposal after use. The ground may be contaminated, creating contaminated soil in the ground. These contaminated soils may adversely affect the surrounding environment, and the ground containing such contaminated soils may not be reliable as the foundation ground for various structures. When planning the redevelopment of the site of a factory or the like, if it is found that such contaminated soil exists in the ground, it is desirable to immediately purify this.

[0003] The method of purifying such contaminated soil is generally classified into a method of treating the contaminated soil in situ using a chemical or a solidifying material, and a method of excavating the contaminated soil and then treating it. However, as an example of a method of purifying contaminated soil containing volatile contaminants and the like at the current position, in particular, toward a contaminated zone where contaminated soil in the ground exists,
By drilling a well from the ground surface and sucking the inside of the well with a vacuum pump or the like, air in a contaminated zone containing volatile contaminants is extracted, and the air containing the contaminated gas thus extracted is treated, for example. A method of purifying contaminated soil by sending it to a facility and treating it with activated carbon or the like has been considered.

[0004]

However, according to the above-mentioned conventional method for purifying contaminated soil at an in-situ location, fresh air for carrying the contaminated gas in the contaminated soil to clean the contaminated soil is provided. Since the air that has flowed into the ground from the ground surface through the gap between the soil particles will be used, the amount of air supplied to the ground is particularly small when the ground is a geological material with a small gap such as cohesive soil. In some cases, it is not possible to sufficiently clean and purify the contaminated soil due to a shortage, and there is a problem that such purification requires a great deal of time.

Therefore, the present invention has been made in view of such a conventional problem, and by inhaling air from a well formed in the ground while obtaining sufficient air for cleaning contaminated soil, It is an object of the present invention to provide a method for purifying contaminated soil that can efficiently and quickly purify the contaminated soil.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and its gist is to provide a viscous soil or the like.
Toward a contaminated zone where contaminated soil is present in the ground, which is a geology with a small gap, a permeable member is inserted from the ground surface into the ground to form a suction well, and the inside of the suction well is suctioned. Then, by causing a flow of air toward the suction well in the contaminated zone, carrying volatile contaminants in the air flow, and taking out and treating the air carrying the contaminants. A method for purifying contaminated soil, comprising: a vertical drain around the suction well so as to surround the contaminated soil.
It has air permeability that is driven into the ground from the ground surface by the construction method.
Forming a supply well of air by inserting and installing a drain material , and sucking air taken in from the supply well by a suction force from the suction well to generate a flow of air toward the suction well. To purify contaminated soil.

Here, for example, a perforated pipe as a member having air permeability may be inserted into a hole drilled in the ground by various boring devices, or a woven cloth or a quarry having a large porosity may be inserted into the suction well. a method of forming and filling a vertical drain cardboard drain implanted into the ground by method used for soil improvement, and a method of forming the de <br/> lane material such Sandodore down, members having air permeability Can be formed by various methods of inserting into the ground.

[0008]

In the method for purifying contaminated soil according to the present invention, the air supply well may be connected to an air supply device such as a blower, and air may be supplied from the air supply device to the supply well.

[0010]

According to the method for purifying contaminated soil of the present invention, the suction well inserted into the contaminated zone is sucked through, for example, a vacuum pump or the like. As a result, a sufficient amount of outside air is taken into the ground through the supply well, and this outside air passes through the contaminated soil sandwiched between the suction well and the supply well and travels toward the suction well. Flow down.
Therefore, it is possible to quickly and efficiently purify the contaminated soil while carrying the contaminant with a sufficient amount of air supplied from the supply well.

[0011] Further, since the supply well only needs to have a function for taking in air, it is known as a ground improvement method.
Using the vertical drain method, sand drains having air permeability, by implanting a drain material such as cardboard Dre down, can be easily and economically formed.

Further, if the supply well is connected to an air supply device such as a blower and the air is supplied from the air supply device to the supply well, the supply amount is adjusted and controlled.
A flow of air in an amount or direction suitable for carrying contaminants is generated in the contaminated zone, so that the contaminated soil can be more efficiently purified.

[0013]

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments.

According to the method for purifying contaminated soil according to this embodiment, as shown in FIG. 1, a suction well 11 is formed substantially at the center of an underground contaminated zone 10 where contaminated soil exists. The suction well 11 is substantially similar to the case of installing the conventional example well for construction, after drilling a hole in the ground from the ground surface by using a boring machine, in the hole made of vinyl chloride pipe It can be easily formed by inserting and installing a perforated tube 12 made of the above. In this embodiment, the perforated pipe 12 is inserted into the contaminated zone 10 located above the groundwater level, penetrates the contaminated zone 10 and is located just above the groundwater level, and the perforated pipe 1
The second, a large number of vent holes are formed perforated in a portion crossing mainly contaminated zone 10. Further, inside the perforated pipe 12, in order to prevent the earth and sand in the contamination zone 10 from flowing into the perforated pipe 12 through the ventilation hole due to the suction of air, the woven cloth or non-woven fabric is ventilated. The member having the property is appropriately filled.

In this embodiment, an air supply well 13 is formed around the suction well 11 with a contaminated soil interposed between the suction well 11 and the suction well 11 so as to surround the suction well 11 in a rectangular shape. It is formed while arranging many at intervals. That is, a large number of suction wells 11 are formed in the ground by using a drain construction method known as a ground improvement construction method, for example, a cardboard drain as a drain material 14 having air permeability, facing the suction well 11. By each driving, it can be formed easily and economically. The supply well 12 is also formed by driving the drain material 14 from the ground surface to just above the groundwater level.

Further, in this embodiment, a suction hose 17 communicating with a vacuum suction pump 15 is connected to an opening of the ground surface of the suction well 11 formed in the ground, and the vacuum suction pump 15 is Further, for example, a purification facility 1 equipped with a pollutant adsorption device or the like filled with activated carbon
6, the purification facility 16 purifies air containing contaminants sent from the vacuum suction pump 15 and then releases the air into the atmosphere.

According to this embodiment, after arranging the equipment such as the suction well 11 and the supply well 13 as described above,
When the inside of the suction well 11 is sucked by the vacuum suction pump 15, the suction force sucks the air in the contaminated zone 10 into the suction well 11, and a large number are provided so as to surround the suction well 11 with the contaminated soil interposed therebetween. A sufficient amount of fresh air is taken in from the supplied supply well 13, and an air flow uniformly flowing from the surrounding supply well 13 toward the central suction well 11 is generated in the contaminated soil. . Therefore, this sufficient amount of air flow increases the volatilization of volatile contaminants in the contaminated soil by the so-called Henry method, and carries the volatilized contaminants in the sufficient amount of air flow. Then, the water is sent to the purification facility 16 through the suction well 11 and the like, whereby the purification work of the contaminated soil is performed quickly and efficiently.

If the upper end of the supply well 13 is appropriately connected to an air supply device such as a blower, a sufficient amount of fresh air can be supplied to the contamination zone 10 and the supply well 13 can be supplied. It is possible to purify contaminated soil more efficiently by controlling the amount and location of air supply so that the flow of air in any amount and direction suitable for carrying contaminants is generated in the contaminated zone 10. Can also.

Furthermore, since the contaminated soil exists in a wide area in the ground, the suction well 11 and the supply well 13
Even if the distance between the contaminated zone 10 and the contaminated zone 10 is too large and it is difficult to generate an appropriate airflow between them, the region where the contaminated zone 10 exists is appropriately divided and divided as shown in FIG. If the suction well 11 and the supply well 13 are provided in combination in each area, it is possible to easily purify the contaminated soil spread over a wide area.

In the above embodiment, a large number of air supply wells 1 are provided around the suction well 11 and around the suction well 11.
3, the supply well 13 may be provided alone. In this case, the contaminated soil in the portion located between the suction well 11 and the supply well 13 is purified. Further, a plurality of suction wells 11 may be provided for one construction region, and a plurality of air suction wells 11 may be provided around the supply well 13 around the supply well 13.

Even when the suction well 11 is not used, the air supply well 13 functions as a ventilation path for poorly permeable soil, and serves as a vent for volatile contaminants to wash the soil. can do.

[0022]

As described [Effect Invention above in detail, according to the method of purifying contaminated soil of the present invention, enclose the contaminated soil around the suction wells formed in the ground to form a supply wells air,
Since the air taken in from the supply well is sucked by the suction force from the suction well to generate an air flow toward the suction well, the air is formed in the ground while obtaining sufficient air for cleaning the contaminated soil. By sucking air from the suction well, the contaminated soil can be purified efficiently and quickly.

Further, supply wells, by using the vertical drain method, known as ground improvement method, sand drains having air permeability, by implanting Dre <br/> down material such as cardboard Dre down, easily and It can be formed economically.

Furthermore, if the supply well is connected to an air supply device such as a blower and the air is supplied from the air supply device to the supply well, the contaminated soil can be more efficiently purified.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an implementation state of a method for purifying contaminated soil according to one embodiment of the present invention.

FIG. 2 is a plan view showing a situation where the purification method of the present invention is applied to the ground where contaminated soil exists over a wide area.

[Explanation of symbols]

 Reference Signs List 10 Contamination zone 11 Suction well 12 Perforated pipe 13 Supply well 14 Drain material 15 Vacuum suction pump 16 Purification facility

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-212366 (JP, A) JP-A-4-225887 (JP, A) JP-A-57-174103 (JP, A) JP-A-7-174 136631 (JP, A) JP-A-5-280034 (JP, A) JP-A-5-239823 (JP, A) JP-A-3-51417 (JP, A) US Patent Application Publication 5324137 (US, A) US Patent Application Publication 5553974 (US, A) US Patent Application Publication 5435666 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09C 1/04 E02D 3/10

Claims (2)

(57) [Claims] 1. A ground having a small gap such as a cohesive soil.
Toward the contamination zone in which the contaminated soil is present, a member having air permeability is inserted and installed from the ground surface into the ground to form a suction well, and the inside of the suction well is sucked, and A flow of air toward the suction well is generated, and a volatile contaminant is carried in the air flow, and the contaminated soil is purified by removing and treating the air carrying the pollutant. A method of cleaning, wherein a bag is provided around the suction well so as to surround the contaminated soil.
Driving from ground level into ground
A drain material having air permeability is inserted and installed to form an air supply well, and the air taken in from the supply well is sucked by the suction force from the suction well to flow the air toward the suction well. A method for purifying contaminated soil, characterized in that the method comprises the steps of: 2. The contaminated soil according to claim 1, wherein the air supply well is connected to an air supply device such as a blower, and air is supplied from the air supply device to the supply well. Purification method.