Steel sheet pile with cleaning function and cleaning method for contaminated soil

The present invention relates to a steel sheet pile with a purification function and a method for purifying contaminated soil.

Conventionally, various plating materials, insulating oils, pigments, resins, solvents, pesticides, etc. have been used as materials for the metal industry, the electric industry, the electronic industry, the chemical industry, and the like. Water quality standards and environmental standards related to soil pollution have been established for these substances, but if the above substances mixed in the soil in the past are left as they are, they will penetrate deep underground over time and finally groundwater. Environmental pollution, which leads to pollution of the soil, has become a problem.

Against this background, various methods for removing pollutants such as volatile organic compounds, heavy metals, and oil mixed in the soil have been studied. It is classified into a method of purifying and backfilling at the site and a method of purifying in-situ without excavating contaminated soil. Although the method of excavating and removing contaminated soil is certain, it is difficult to apply when the excavated contaminated soil is complicated to dispose of, and there are buildings on the land in the contaminated area. The on-site excavation purification method requires a work space, is not applicable to operating factories, etc., and has problems such as purification costs. There are problems such as long time required and reliability of purification.

In-situ purification methods include a deep mixing method in which a purifying agent is mixed in a pile shape and a permeable purification wall method in which the soil mixed with a purifying agent is formed into a wall shape. There are problems such as the reliability of mixing due to the above, the difficulty of exchanging the purifying agent due to the underground mixing construction, and the restriction of applicable pollutants.

<p> Therefore, an object of the present invention is a steel sheet pile with a purification function and a contaminated steel sheet pile used for the purification of contaminated soil at low cost and high reliability, which can widely deal with the purification of pollutants eluted in groundwater such as volatile organic compounds and heavy metals. It is to provide a method of soil purification.</p>

<p> The above object is achieved by the following invention. That is, the present invention has a groove shape in which a steel sheet pile (1') provided with a water passage hole (3) in the abdominal plate (2) has a water passage hole (4) so as to cover the abdominal plate of the steel sheet pile. A steel sheet pile (1) with a purification function, characterized in that the steel (5) is fixed and a space (7) for holding the water purifying agent (6) is provided between the abdominal plate and the channel steel. )I will provide a.</p><p> Further, in the present invention, a water purifying agent (6) is filled in the space (7) of the steel sheet pile (1) of the present invention, and the steel sheet pile (1') containing at least the steel sheet pile (1) is provided. A continuous wall (12) is formed by placing it in the ground in or near the contaminated area of the soil, and the contaminated groundwater flowing from the contaminated area is collected from the channel steel (1) of the steel sheet pile (1). It is characterized by allowing water to pass through the water passage holes (4), purification agents (6) and abdominal plate water passage holes (3) of 5) to purify or adsorb pollutants contained in the contaminated groundwater. Provide a method for purifying contaminated soil.</p><p> In the purification method of the present invention, the purifying agent (6) is filled in a water-permeable bag body (10), and the shape of the bag body (10) is the same as or the cross-sectional shape of the space (7). Small and similar in shape and interchangeable in the space (7); an elastic tube (11) is inserted in the purifying agent (6). By expanding the tube, the contact between the surface of the bag body (10) containing the purifying agent (6) and the steel member around it is improved; the replacement of the purifying agent (6) is performed in the space (6). Only the purifying agent (6) is recovered by leaving the bag body (10) by water flow and suction from the upper surface of 7), and after the collection, a new purifying agent is put into the bag body (10); and groundwater. A wall (12) made of a steel sheet pile (1') including at least the steel sheet pile (1) of the present invention provided with a purifying agent (6) is constructed in the ground on the downstream side of the contaminated area where the flow of water is present. It is preferable to remove the pollutants in the flowing groundwater.</p>

<p> According to the present invention, a general method for placing a steel sheet pile by integrating a purifying agent having a purifying ability against pollutants such as volatile organic compounds and heavy metals eluted in water with a versatile steel sheet pile. In addition, by making it possible to easily replace the purifying agent having a purifying function, it is possible to purify groundwater at low cost and with high reliability.</p><p> Soil pollution is not a single substance pollution, but there are many complex pollutions such as volatile organic compounds and heavy metals, but in the present invention, purification agents that can deal with different pollutants are mixed or arranged in layers. By changing it, it is possible to deal with complex pollution.</p>

Next, the present invention will be described in more detail with reference to the drawings showing preferred embodiments. The steel sheet pile 1 with a purification function of the present invention is provided with a water passage hole 3 in the abdominal plate 2 of the normal steel sheet pile 1'as shown in FIGS. 1 and 2 which is a cross-sectional view taken along the line XX of FIG. A space for fixing a channel steel 5 having a water passage hole 4 so as to cover the abdominal plate 2 of the steel sheet pile 1', and holding a water purifying agent 6 between the abdominal plate 2 and the channel steel 5. It is characterized by the provision of 7.

The steel sheet pile 1'is a steel sheet pile widely used in conventional civil engineering or construction sites, and is not special in itself. In the present invention, the water passage hole 3 is formed in the abdominal plate 2 of the conventional steel sheet pile 1'. The size of the water passage hole 2 is not particularly limited, and may be any size and shape. The water passage hole 3 is preferably provided over the entire length of the steel sheet pile 1', but it is not essential to provide it over the entire length.

Next, the channel steel 5 that abuts on the abdominal plate 2 of the steel sheet pile 1'is not special in itself. In the present invention, the back plate 8 of the channel steel 5 is provided with a water passage hole 4, and the channel steel 5 provided with the water passage hole 4 is provided with the side plates 9, 9'and the abdominal plate 2 of the steel sheet pile 1'. The steel sheet pile 1 of the present invention is configured by fixing the steel sheet pile 1 toward the steel sheet by an appropriate means such as welding and providing a space 7 for storing the purifying agent 6. The size and shape of the water passage hole 4 are not particularly limited, but if the opening area of the water passage hole 4 is too large, a fine mesh (not shown) or the like is used to prevent earth and sand from flowing into the space 7. Can be installed.

The soil purification method of the present invention is characterized by using the steel sheet pile 1 and the purification agent 6. The purifying agent 6 used in the present invention is selected according to the contaminants, packed in a tubular and water-permeable bag body 10 and installed in the space 7. The bag body 10 needs to be water permeable, and is formed of, for example, a water permeable material such as a metal mesh of pores, a woven cloth, or a non-woven fabric. Further, the purifying agent 6 needs to be a purifying agent having a shape that does not leak from the eyes of the bag body 10, and for example, a purifying agent such as activated carbon granulated into granules, an ion exchange resin, or an oil absorbing agent is used. Alternatively, when the purifying agent is a fine powder, it is preferable to use the purifying agent as a child bag wrapped with a finer woven cloth or non-woven fabric.

The purifying agent 6 is filled in the water-permeable bag body 10 as described above, and the shape of the filling body has the same or slightly smaller similar shape than the cross-sectional shape of the space 7, and in the space 7. It is preferable to make it replaceable. Further, an elastic tube such as a rubber tube 11 is inserted in the bag body 10, and the rubber tube 11 is expanded after the on-site construction to bring the steel material and the bag body 10 into close contact with each other, so that the steel material and the bag are brought into close contact with each other. It is preferable to have a structure in which contaminated water does not leak from the gap with the body 10. Further, the bag body 10 containing these purifying agents 6 may be stored in the space 7 before the steel sheet pile 1 is driven into the ground, or after the steel sheet pile 1 is driven into the ground. Space 7 may be filled.

Specific examples of the soil purification method of the present invention will be described with reference to FIGS. 3 and 4. 3 and 4 are views showing a state in which the steel sheet pile 1 of the present invention containing the purifying agent 6 and the ordinary steel sheet pile 1'are driven into or near the contaminated ground to form a wall 12. .. That is, if necessary, pollutants in the soil, contaminated areas, ground composition, groundwater flow, ground permeability coefficient, etc. are investigated and analyzed by on-site boring surveys, and if groundwater flow is observed, pollution is observed. A wall 12 composed of the steel sheet pile 1 of the present invention and the ordinary steel sheet pile 1'is formed on the downstream side of the groundwater flow in the region. Although the use of ordinary steel sheet pile 1'is not essential, it is economical to use ordinary steel sheet pile 1'in combination with the steel sheet pile 1 of the present invention. The ratio of steel sheet pile 1 and steel sheet pile 1'is preferably determined by the flow rate of contaminated groundwater.

As shown in the figure, the steel sheet pile 1 of the present invention and the ordinary steel sheet pile 1'are driven into the downstream side of the flow of contaminated groundwater where the pollution is diffused, and are connected by using the joint portions 13 at both ends to form a wall. Form twelve. The driving depth of the steel sheet pile 1 and the steel sheet pile 1'is set to an appropriate driving depth according to the depth of the contaminated area in the ground. When groundwater is flowing in the direction of the arrow in the figure, the contaminated groundwater will pass through the channel steel water passage 4 of the steel sheet pile 1 constituting the wall 12, the purifying agent 6 and the steel sheet pile 1 water passage 3. The contaminated groundwater is purified or adsorbed by a purifying agent, and the purified groundwater flows downstream to purify the groundwater. In the case of purification of a contaminated area where there is no groundwater flow, either forcibly inject water from the ground to the upstream side of the wall 12, or pump up the groundwater on the downstream side to forcibly form a groundwater flow. You can also.

When groundwater purification is started as described above, the water quality before and after the passage of groundwater on the wall 12 consisting of steel sheet pile 1 and steel sheet pile 1'is monitored, and the purification function of the purification agent deteriorates or disappears. In order to replace the bag body from the upper surface of the space 7 shown in FIG. 1, only the purifying agent 6 is collected while leaving the bag body 10 by water flow and suction from the upper surface, and after the collection, a new purifying agent is applied to the bag body. It is also possible to replace the purifying agent by putting it in 10 or less. When the groundwater is purified in this way and the pollutant concentration in the groundwater on the upstream side of the wall 12 satisfies the environmental standard for groundwater, all the steel sheet piles with a purification function are removed, but this removal is easy. The removed steel sheet pile with purification function can be used repeatedly in other contaminated areas.

According to the present invention, a purifying agent having a purifying ability for pollutants eluted in a liquid such as volatile organic compounds and heavy metals is integrated into a versatile steel sheet pile, and a general method for placing a steel sheet pile is used. By making it possible to construct and easily replace the purifying chemical part having a purifying function, it is possible to purify groundwater at low cost and with high reliability.

<figref num="1">A partially cutaway perspective view illustrating the entire steel sheet pile with a purification function of the present invention.</figref><figref num="2">FIG. 1 is a cross-sectional view taken along the line XX.</figref><figref num="3">The figure explaining the purification method of this invention.</figref><figref num="4">The figure explaining the purification method of this invention.</figref>

Code description

1: Steel sheet pile with purification function 1': Normal steel sheet pile 2: Abdominal plate 3, 4: Water flow hole 5: Channel steel 6: Chemical 7: Space 8: Back plate 9, 9': Side plate 10: Bag body 11: Rubber tube 12: Wall 13: Joint part