JP2003094023A - Solidification treatment method for contaminated ground - Google Patents

Abstract

(57) [Summary] [Problem] Without requiring much cost as in the past,
Providing a solidification method for contaminated ground that can prevent the diffusion of pollutants more safely. SOLUTION: A cylindrical casing 10 having an upper end closed and a lower end opened is pressed into a land on the land or on the water floor containing pollutants while applying a static load to the casing.
The solidification material is added to and mixed with the ground in the casing 10 while the stirring blade 13 is rotated and moved upward and / or downward while rotating the stirring blade 13, and then the casing 10 is removed. Pull it out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pollutant prepared by in-situ solidification by injecting and mixing a solidifying material prior to the removal of land or water bottom soil containing organic or inorganic pollutants such as dioxins and heavy metals. The method of solidifying contaminated ground to prevent the diffusion of soil.

[0002]

2. Description of the Related Art Conventionally, when purifying land or water ground containing organic or inorganic pollutants such as dioxins and heavy metals, dredging or excavating the water bottom or contaminated ground on land and purifying the excavated soil. The method of processing is adopted.

As a method for preventing the diffusion of water-contaminated soil, there is a method of laying a cover sand on the surface of the water bottom to contain the contaminated soil.

In this type of environmental purification work, when dredging water bottom sediment, it is necessary to perform dredging without spreading the sand on the surface layer of the water bottom. Therefore, conventionally, as shown in FIG. In addition, a partition structure consisting of a solid anti-pollution film 1 is installed in water, and a dredger 2 using a large capacity pump is used to dredge with a large amount of surrounding water, and dehydration is performed by a dehydrator 3.

In addition, even in sand-covering / soil-covering work for containing pollutants on the bottom of the water and solidification work, in order to prevent the diffusion of pollution due to the hoisting of the bottom of the water, a solid anti-pollution film (partition structure) Had to use.

Further, when excavating the ground containing pollutants on land, if the surface is dry, soil particles containing the pollutants become dust and scatter to the surroundings. To prevent this, water is sprinkled on the ground surface. For example, the entire construction area is closed by a tent structure or the like and then excavated by an excavator such as a power shovel.

[0007]

Among these conventional methods, in the method of dredging the bottom of the ground together with a large amount of water, the surface layer of the bottom sediment is in an extremely soft floating mud state, which is easily disturbed. There were the following problems, and construction was extremely difficult. (1) Since it is necessary to dredge drastically together with a large amount of surrounding water so as not to diffuse sludge, the amount of dredged soil increases, and the labor and cost of subsequent treatment increase. (2) When dehydration treatment is performed after dredging, the wastewater generated at that time also contains toxic substances, so that the treatment also requires great cost. (3) In the case of a bottom sediment containing a problematic substance even in a small amount, it is necessary to make the pollution prevention structure extremely strong, and it is necessary to enclose it in a wide area, which causes a great cost.

Further, when excavating the ground containing pollutants on land, there is a problem that the pollutants permeate / diffuse with water into the deep part of the soil by sprinkling water to prevent scattering of the pollutants.

In view of the conventional problems as described above, the inventors of the present invention can insolubilize the pollutants and confine them in the in-situ by solidifying the ground containing the pollutants by adding and mixing the solidifying material. , Paying attention to the fact that diffusion can be prevented during dredging and excavation even when completely detoxifying is required, paying attention to the fact that the diffusion of pollutants can be prevented during dredging and excavation, and during solidification treatment, it is possible to reduce The present invention has been made for the purpose of providing a solidification treatment method for contaminated ground that can prevent the diffusion of pollutants more safely without requiring the above-mentioned cost.

[0010]

The feature of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose is that the upper end side is on the ground or the bottom of the ground containing pollutants. A cylindrical casing, which is closed and whose lower end side is opened, is press-fitted while applying a static load, the stirring blade is inserted into the ground in the casing, and the stirring blade is rotated to move upward and / or downward. The solidifying material is added to and mixed with the ground in the casing during the movement of the casing, and then the casing is pulled out.

In addition to the above-mentioned invention, when the casing is press-fitted into the ground or the ground at the bottom of the water, the upper end side of the casing is hermetically closed to apply a static load from the outside of the casing and It is preferable to press-fit the casing by drawing air or water with a pump.When the casing is press-fitted into the ground at the bottom of the water, the upper end of the casing is hermetically closed and a static load is applied from the outside of the casing. In addition, the casing is press-fitted by pulling out the air or water inside the casing with a pump, and all or part of the pulled-out water is returned to the ground in the casing from the bottom of the casing, and the water containing pollutants is mixed with the ground. It is preferable to confine it inside and solidify it. At this time, part of the drawn water is used to mix the water with the solidifying material. It is preferable to and use.

Further, at the time of pulling out the casing, it is preferable that a force in the pulling direction is applied to the casing by press-fitting air or water into the casing.

The tubular cross-sectional shape of the casing may be a polygonal shape such as a regular triangle, a square, or a regular hexagon that allows a large number of rows to be arranged without a gap. You may do it.

As the solidifying material, cement-based solidifying material,
1 of lime solidification material, gypsum neutralization material, water glass-based solidification material and organic polymer solidification material
It is possible to use different types of solidifying material or multiple solidifying materials in any combination.

A blade for stirring the soil containing the pollutant and the solidifying material has an expanding blade structure that can be freely opened and closed around the rotation axis, and after only the casing is press-fitted into the soil, the stirring blade is inserted to remove the solidifying material. You may make it perform injection stirring mixing processing.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to FIGS.
FIG. 11 will be described.

FIG. 1 shows an outline of an apparatus used in the present invention. Reference numeral 10 is a cylindrical casing which is press-fitted into the ground to be treated. The casing 10 has an open lower end and an upper end hermetically closed by a top plate 11. The top plate 11 has a stirring blade spindle 1 for adding and mixing the solidifying material.
2 is pierced so as to be rotatable and movable in the vertical direction. The stirring blade support shaft 12 is rotationally driven and axially driven by a drive device 15 installed on the casing 10.

A plurality of stirring blades 13 are radially provided on the stirring blade support shaft 12. The solidified material discharge holes 14 are opened at regular intervals in each of the stirring blades 13, and the slurry-like solidified material can be discharged through the stirring blades 13 and the stirring blade support shaft 12.

A pressure-increasing and depressurizing pipe line 16 is opened through the top plate 11 of the casing 10 so that the inside of the casing 10 can be pressurized and depressurized by pouring and draining water with a pump 17.

Next, the solidification treatment step of the water bottom ground using the above-mentioned apparatus will be described.

First, as shown in FIG.
The above-described casing 10 is installed on the water bottom soil 20 containing organic or inorganic pollutants such as heavy metals, and the casing 10 is press-fitted into the soil 20 while applying a static vertical load so as not to disturb the soil. Let This time,
The water inside the casing 10 is drawn out through the pressurizing / depressurizing conduit 16 by the pump 17 on the above-water work support ship 21. As a result, the inside of the casing 10 is decompressed to facilitate press-fitting, and at the same time, scattering and diffusion of earth and sand containing pollutants is prevented.

In this way, the casing 10 is converted into the ground 20.
After being press-fitted into the casing 10, as shown in FIG. 3, the solidifying material plant 22 on the work support vessel 21 on the water and the stirring blade support shaft 12 are communicated with each other through the solidifying material injection hose 23, and are provided in the casing 10. While rotating the stirring blade 13 being driven by the drive device 15, the stirring blade 13 is lowered to a predetermined processing depth. Then, the stirring blade support shaft 12 is rotated and pulled up, and the solidifying material adjusted to a suspension slurry or solution is supplied from the solidifying material plant 22 from an arbitrary height position on the way of raising, and the solidifying material discharge hole 14 of the stirring blade 13 is supplied. Discharge. As a result, the solidifying material is evenly injected into the contaminated ground in the casing 10 while stirring and mixing.

When the solidifying material slurry is prepared by the solidifying material plant 22, excess polluted water extracted from the inside of the casing 10 is used. The polluted surplus water refers to water that may contain contaminants extracted from the inside of the casing, and is used for kneading or diluting water when adjusting the solidifying material to a suspension slurry or solution. By reusing as a material, it becomes possible to further confine the pollutants inside the solidified body.

In the casing 10 thus press-fitted into the water bottom ground 20, the solidifying material is poured into the contaminated ground and mixed and stirred, and then the casing 10 is pulled out as shown in FIG. At the time of this withdrawal, water is injected into the casing 10 through the pressurizing / depressurizing pipe line 16 to pressurize the inside and facilitate withdrawal. The solidifying material mixed ground left in the water bottom ground 20 is solidified in the state left in the original position by the solidifying material.

The casing 10 that has been pulled out is moved to the next processing position, and the same steps as those described above are repeated to solidify the contaminated water bottom ground of a desired size in-situ. The solidified ground may be removed by excavating it to make it harmless, or may be left as it is at the current position and buried at the bottom of the water by covering with sand or the like.

Incidentally, in the process of pressing the casing 10 into the water bottom ground 20 in the above-mentioned treatment process, as shown in FIG.
Is installed, and the water extracted from the inside of the casing 10 is refluxed from the lower end opening of the casing 10 into the water bottom ground in the casing 10 to inject polluted water into the water bottom ground to solidify the contaminated ground and simultaneously contaminate it. It is preferred to contain the water in it.

Further, as shown in FIG. 6, the inside of the stirring blade is not installed in advance, and the inside of the casing 10 having the stirring blade inlet / outlet hole 25 at the top is used, and the stirring blade inlet / outlet hole 25 is closed by a cap. In the same manner as described above, press-fitting into the water bottom ground 20, and after completion of the press-fitting, the stirring blade 13 is inserted in the folded state along the stirring blade support shaft 12 through the stirring blade inlet / outlet hole 25, and inside the casing 10. Alternatively, the solidifying material may be injected and mixed and stirred.

Next, the solidification treatment step of the land ground will be described.

As shown in FIG. 7, the land ground 30 containing organic or inorganic pollutants such as dioxins and heavy metals.
The above-mentioned casing 10 is installed on top of the casing 10, and a static vertical load is applied from above the casing 10 while applying a static vertical load so as not to disturb the ground. At this time, the air inside the casing 10 is extracted through the pressurizing / depressurizing conduit 16 by the vacuum pump 31 installed adjacent to the land. As a result, the pressure inside the casing 10 is reduced to facilitate press fitting, and at the same time,
Prevent scattering and diffusion of sediment containing pollutants.

In this way, the casing 10 is replaced with the ground 30.
After being press-fitted into the casing 10, as shown in FIG. 8, the solidifying material plant 22 installed adjacent to the land and the stirring blade support shaft 12 are communicated with each other through the solidifying material injection hose 23, and are provided in the casing 10. While rotating the stirring blade 13 by the drive device 15, the stirring blade 13 is lowered to a predetermined processing depth.

Next, the stirring blade support shaft 12 is rotated and pulled up, and the solidified material adjusted to a slurry form is supplied from the solidification material plant 22 from an arbitrary height position during the lifting, and the solidified material discharge hole 14 of the stirring blade 13 is supplied. Discharge. As a result, the solidifying material is evenly injected into the contaminated ground in the casing 10 while stirring and mixing.

In the casing 10 thus press-fitted into the ground 30, the solidifying material is poured into the contaminated ground, mixed and stirred, and then the casing 10 is pulled out as shown in FIG. At the time of this withdrawal, air is pressure-injected into the casing 10 through the pressurizing / depressurizing conduit 16 to pressurize the inside, facilitating withdrawal. The remaining solidifying material-mixed ground is solidified by the solidifying material left in its original position.

The casing 10 that has been pulled out is moved to the next processing position, and the same steps as those described above are repeated to solidify the contaminated water bottom ground of a desired size in situ. The solidified ground may be subjected to various treatments such as industrial waste such as excavating and removing it to make it harmless, and if it is solidified so as to be completely insolubilized, It may be covered with soil and contained in situ.

In each of the various examples described above, the cylindrical casing 10 is used. However, according to this, the contaminated ground is sequentially solidified into a columnar shape.
As shown in 0 (a), an untreated portion B is generated between the adjacent solidification treated portions A. In order to prevent this, as shown in FIGS.
By making the cross-sectional shape of 0 a polygonal shape such as a regular triangle, a square, or a regular hexagon, the unprocessed portion can be eliminated.

In this case, as shown in FIG. 11, a metallic brush 40 is attached to the tip of the stirring blade 13 depending on the sectional shape of the casing 10, or as shown in FIG.
By using together with the agitating auxiliary blade 41 having the same structure as the No. 3 and having a small size, agitating can be performed without leaving an untreated portion even in the polygonal casing.

Although not shown in the drawing, it is also possible to improve a large range at once by combining a plurality of casings and constructing them simultaneously.

The solidifying material used is a cement-based solidifying material such as ordinary portland cement, blast furnace cement, solidifying material for special soil, neutralizing material such as b lime and c gypsum, and solidifying material containing d water glass as a main component. The material, e organic polymer-based solidifying material can be used alone or in any combination of the solidifying materials a to e.

Further, the static vertical load applied when the casing 10 is press-fitted into the ground is described in, for example, FIG.
As shown in (a) to (c), on land, a press-fitting support member 50 fixed to a heavy machine such as a power shovel,
At the bottom of the water, a pressurizing shaft 51 for applying a vertical load is attached to a press-fitting support member 50 fixed to the work boat, and guides 52, 5 are provided.
13A so as to be movably supported in the axial direction via FIG.
13, the weight 54 is piled up on the pedestal 53 fixed to the pressing shaft 51, or the pedestal 53 is pushed down by the jack 55 as shown in FIG. 13B. As shown in FIG. 13C, this can be performed by moving the pressure shaft 51 downward by a gear or a roller 57 driven by a motor 56.

In the method for solidifying contaminated ground as described above,
By pressing the casing into the soil containing pollutants so that the pollutants in the soil do not diffuse, and stirring the solidifying material and the soil in the casing to create a solidified body, 1. 1. There is no diffusion of pollutants into the surrounding area. Since the solidifying material is added and stirred and mixed inside the casing, the solidifying material does not leak out, and there is little variation in the composition, and a homogeneous solidified body can be created. In-situ contaminated material can be contained 4. By removing and moving after solidification, it is possible to move and carry out to the treatment facility without diffusion of pollutants. In the case of subsoil, the amount of separated contaminated water is treated to the minimum necessary, so that construction cost can be reduced.

[0040]

As described above, in the method for solidifying contaminated ground according to the present invention, a cylindrical casing having an upper end side closed and a lower end side open to the land or water bottom ground containing pollutants, It is press-fitted while applying a static load, the stirring blade is inserted into the ground in the casing, and the solidifying material is added to the ground in the casing while moving the stirring blade in the upward and / or downward direction while rotating the stirring blade. By adding and mixing and then pulling out the casing, the contaminated ground can be injected, mixed, and mixed with the solidifying material in the closed casing.
Since the agitation process is performed, it is not necessary to install a strong pollution diffusion prevention curtain unlike the conventional burial process by dredging or sand cover of contaminated water bottom ground, and pollutants underground by sprinkling water during excavation of land ground The solidification treatment is performed in a state where the permeation and the diffusion due to the scattering of dust are completely prevented, and the contaminants can be treated at a low cost.

Further, according to the present invention, when the casing is press-fitted into the ground on the land or at the bottom of the water, the upper end side of the casing is hermetically closed, a static load is applied from the outside of the casing, and the air inside the casing is By pressing water into the casing by drawing it with a pump, the casing can be smoothly press-fitted, and the polluted air or polluted water in the casing generated by the press-fitting can be treated without being diffused.

Further, in the present invention, when the casing is press-fitted into the ground at the bottom of the water, the upper end of the casing is hermetically closed, a static load is applied from the outside of the casing, and the air or water inside the casing is removed. The casing is pressed into the casing by pulling it out with a pump, and all or part of the drawn water is returned to the ground in the casing from the bottom of the casing, and water containing contaminants is sealed in the ground and solidified, so that the casing A part of the treatment of polluted water generated inside is confined in the solidified ground and treated, so that the treatment of decontaminating polluted water generated is reduced.

Further, in the present invention, by using a part of the extracted water as the kneading water for the solidifying material, the detoxification process of the polluted water generated can be reduced.

Furthermore, in the present invention, when the casing is pulled out, air or water is press-fitted into the casing to exert a force in the pulling direction on the casing, so that the casing can be pulled out smoothly.

Further, in the present invention, the cylindrical cross-sectional shape of the casing is made into a polygonal shape such as a regular triangle, a square, a regular hexagon, etc., in which a large number can be arranged without a gap, so that the unsolidified portion is eliminated and the solidified treatment is efficiently performed. it can.

Further, according to the present invention, a plurality of casings are arranged side by side and press-fitted into the ground for construction, so that a wide area can be solidified at the same time.

Further, in the present invention, as the solidifying material, among the cement solidifying material, the solidifying material made of lime, the neutral solidifying material such as gypsum, the solidifying material containing water glass as a main component and the organic polymer solidifying material. By using one kind of solidifying material or a plurality of solidifying materials arbitrarily combined, solidifying processing suitable for the properties of the contaminated ground can be performed.

Further, in the present invention, the blade for stirring the soil containing the pollutant and the solidifying material has an expanding blade structure which can be freely opened and closed around the rotation axis, and only the casing is press-fitted into the soil, and then the stirring blade is inserted. By carrying out the process of injecting, stirring and mixing the solidifying material, the weight of the casing becomes light and the work such as press fitting and moving becomes easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an outline of an apparatus used in a method for solidifying contaminated ground according to the present invention.

FIG. 2 is a cross-sectional view showing a state of a casing press-fitting step in the method for solidifying a water bottom soil according to the present invention.

FIG. 3 is a cross-sectional view showing a state of the above solidifying material addition and mixing step.

FIG. 4 is a cross-sectional view showing a state of a casing pulling-out process of the above.

FIG. 5 is a cross-sectional view showing an outline of the state of sludge water recirculation in the casing press-fitting step of the above.

FIG. 6 is a cross-sectional view showing a state in which the stirrer is inserted when the expanding blade stirrer of the same is used.

FIG. 7 is a cross-sectional view showing a state of a casing press-fitting step in the method for solidifying land soil according to the present invention.

FIG. 8 is a cross-sectional view showing a state of a solidifying material adding and mixing step of the same.

FIG. 9 is a cross-sectional view showing a state of a casing extracting process of the above.

10 (a) to 10 (d) are plan views showing an outline of a ground treatment state according to casing shapes.

FIG. 11 is a cross-sectional view showing the outline of a stirring and mixing method for a polygonal casing.

FIG. 12 is a sectional view showing another embodiment of the above.

13 (a) to 13 (c) are side views showing different examples of the static load applying method at the time of press-fitting the casing in the present invention.

FIG. 14 is a side view showing an outline of a conventional dredging method for contaminated ground in water.

[Explanation of symbols]

10 casing 11 Top plate 12 Stirring blade support shaft 13 Stirrer 14 Solidified material discharge hole 15 Drive 16 Pressurizing / depressurizing pipeline 17 pumps 20 subsoil 21 Work Support Ship 22 Solidifying material plant 23 Solidifying material injection hose 24 Circulation canal 25 Stirring blade entry / exit hole 30 land ground 31 vacuum pump 40 metal brush 41 Stirring auxiliary blade 50 Press-fit support member 51 pressure shaft 52 Guide 53 cradle 54 Weight 55 jack 56 motor 57 gears (or rollers)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Yoneya             Tochigi Prefecture Nasu-gun Nishinasuno-cho 4 Ward-cho 1534-1             Goyo Construction Co., Ltd. Technical Research Center F-term (reference) 2D040 AB03 AC05 BA08 CA01 CA02                       CA03                 4D004 AA41 AB03 AB07 AC07 CA01                       CA13 CA15 CA45 CC13

Claims (9)

[Claims] 1. A cylindrical casing whose upper end side is closed and whose lower end side is open is press-fitted into a ground or water-bed ground containing pollutants while applying a static load, and is agitated into the ground in the casing. A polluted soil characterized by inserting a blade and adding and mixing a solidifying material to the ground in the casing while moving the stirring blade in an upward and / or downward direction while rotating the stirring blade, and then pulling out the casing. Solidification treatment method. 2. When the casing is press-fitted into the ground on the ground or at the bottom of the water, the upper end side of the casing is hermetically closed, a static load is applied from the outside of the casing, and the air or water inside the casing is pumped. The method for solidifying contaminated ground according to claim 1, wherein the casing is press-fitted by pulling out the casing. 3. When press-fitting the casing into the ground at the bottom of the water,
The upper end of the casing is hermetically closed, a static load is applied from the outside of the casing, and air or water inside the casing is pulled out by a pump to press-fit the casing and all or part of the drawn water. The method for solidifying contaminated ground according to claim 1, wherein water contaminated with pollutants is confined in the ground to be solidified by being refluxed from the bottom of the casing to the ground in the casing. 4. The method for solidifying contaminated ground according to claim 3, wherein a part of the extracted water is used as water for kneading the solidifying material. 5. The method for solidifying contaminated ground according to claim 2, 3 or 4, wherein when pulling out the casing, air or water is forced into the casing to exert a force in the pulling direction on the casing. 6. The solidification treatment of contaminated ground according to claim 1, wherein the cylindrical cross-sectional shape of the casing is a polygonal shape such as an equilateral triangle, a square, or an equilateral hexagon that allows a large number to be arranged without a gap. Construction method. 7. The method for solidifying contaminated ground according to claim 1, wherein a plurality of casings are arranged side by side and press-fitted into the ground for construction. 8. A cement-based solidifying material, a solidifying material made of lime, a neutral solidifying material such as gypsum, a solidifying material containing water glass as a main component, and an organic polymer solidifying material as the solidifying material. The method for solidifying contaminated ground according to claim 1, wherein a solidifying material or a plurality of solidifying materials arbitrarily combined is used. 9. A blade for agitating a soil containing contaminants and a solidifying material has an expanding blade structure which can be opened and closed about a rotation axis, and after only the casing is press-fitted into the soil, the agitating blade is inserted and solidified. The method for solidifying contaminated ground according to claim 1, wherein the material is subjected to mixing by stirring and mixing.