JP3668967B2 - Solidification method for contaminated ground - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a contaminated ground which prevents the diffusion of pollutants by solidifying in situ by injecting and mixing a solidifying material prior to the removal of the ground or the bottom of the bottom containing organic or inorganic pollutants such as dioxins and heavy metals. Relates to the solidification processing method.
[0002]
[Prior art]
Conventionally, when purifying land or bottom soil containing organic or inorganic pollutants such as dioxin, heavy metals, etc., there is a method of dredging or excavating the bottom or land contaminated ground and purifying the excavated soil. It is taken.
[0003]
In addition, as a method for preventing the spread of water-bottom-contaminated soil, there is a construction method in which covered sand is laid on the surface of the water-bottom ground to contain the contaminated soil.
[0004]
In this type of environmental purification work, when dredging the bottom sediment, it is necessary to dred without spreading the soil on the surface of the bottom ground. For this reason, conventionally, as shown in FIG. A partition structure composed of a pollution prevention film 1 is installed in water, dredged with a large amount of surrounding water using a dredger 2 using a high-capacity pump, and dehydrated by a dehydrator 3.
[0005]
In addition, a solid anti-contamination membrane (partition structure) is used to prevent the spread of contamination due to the rolling up of the sediment at the bottom of the water in the sand-covering / soil-covering work and the solidification treatment work to contain the pollutants at the bottom of the water. There was a need.
[0006]
Furthermore, when excavating the ground containing pollutants on land, if the surface is dry, soil particles containing pollutants will be scattered as dust and scattered to the surroundings. For example, the entire construction area is closed with a tent structure, etc., and then excavated by an excavator such as a power shovel.
[0007]
[Problems to be solved by the invention]
In these conventional methods, the method of dredging the bottom of the ground with a large amount of water has the following problems because the surface layer of the bottom sediment is very easily disturbed, and has the following problems. It was very difficult.
(1) Since it is necessary to drown at a stretch with a large amount of surrounding water so that the sludge is not diffused, the amount of dredged soil increases, and the time and cost of subsequent treatment increase.
(2) When dehydration is performed after dredging, the wastewater generated at that time also contains harmful substances, and the treatment is very expensive.
(3) In the case of sediment containing substances that cause problems even in trace amounts, it is necessary to make the pollution prevention structure extremely strong, and it must be surrounded by a wide area, which entails tremendous costs.
[0008]
Further, when excavating the ground containing pollutants on land, there is a problem that the pollutants permeate and diffuse into the deep part of the soil together with water due to water spray for preventing the scattering of pollutants.
[0009]
In view of the conventional problems as described above, the present inventors can solidify the ground containing the pollutant by adding and mixing the solidifying material, so that the pollutant can be insolubilized and contained in its original position, and completely Focusing on the fact that diffusion can be prevented during dredging and excavation even when detoxification is required, and focusing on the prevention of diffusion of pollutants during dredging and excavation. The present invention has been made for the purpose of providing a method for solidifying a contaminated ground that can prevent the diffusion of pollutants more safely.
[0010]
[Means for Solving the Problems]
In order to solve the conventional problems as described above and achieve the intended purpose, the solidification method of the contaminated ground according to the present invention is characterized in that the upper end side is closed on the ground or the bottom of the ground containing the pollutant. a cylindrical casing lower end is released is, in a state of closing the upper end hermetically pressed while pulling by the casing inside air or water pump as well as adding the static load from the outside of the casing Then, a stirring blade is inserted into the ground in the casing, and the solidification material is added and mixed to the ground in the casing while the stirring blade is moved upward and / or downward while rotating. To pull out the casing.
[0011]
In addition, all or a part of the water extracted during the press-fitting of the casing into the ground at the bottom of the water may be returned to the ground within the casing from the bottom of the casing, and the water contaminated with contaminants may be contained in the ground and solidified. In this case, it is preferable to use a part of the extracted water as water for kneading the solidifying material.
[0012]
Further, when the casing is pulled out, it is preferable to apply a force in the pulling direction to the casing by press-fitting air or water into the casing.
[0013]
In addition, the cylindrical cross-sectional shape of the casing may be a polygonal shape such as a regular triangle, a square, or a regular hexagon that can be arranged in a large number without gaps, and a plurality of casings are arranged side by side and press-fitted into the ground for construction. May be.
[0014]
Further, as the solidifying material, one of solidified materials such as cement-based solidified material, solidified material made of lime, neutral solidified material such as gypsum, solidified material mainly composed of water glass and organic polymer-based solidified material or A plurality of solidifying materials arbitrarily combined can be used.
[0015]
The wing that stirs the ground containing the pollutant and the solidified material has a wing expansion structure that can be opened and closed around the rotating shaft. After only the casing is press-fitted into the ground, the agitating blade is inserted and the solidified material is injected and stirred and mixed. Processing may be performed.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to FIGS.
[0017]
FIG. 1 shows an outline of an apparatus used in the present invention. Reference numeral 10 denotes a cylindrical casing which is press-fitted into the ground to be treated. The casing 10 has a lower end opened and an upper end hermetically closed by a top plate 11. A stirring blade spindle 12 for adding and mixing solidifying material is penetrated through the top plate 11 so as to be able to rotate and move in the vertical direction. The stirring blade support shaft 12 is rotationally driven and driven in the axial direction by a driving device 15 installed on the casing 10.
[0018]
A plurality of stirring blades 13 project radially from the stirring blade support shaft 12. Each of the stirring blades 13 is provided with a solidifying material discharge hole 14 at regular intervals so that the slurry-like solidifying material can be discharged through the stirring blade 13 and the stirring blade support shaft 12.
[0019]
A pressure increasing / decreasing conduit 16 is opened through the top plate 11 of the casing 10, and the inside of the casing 10 can be increased / decreased by pouring and draining with a pump 17.
[0020]
Next, the solidification process of the water bottom ground using the above-described apparatus will be described.
[0021]
First, as shown in FIG. 2, the casing 10 described above is installed on the water bottom ground 20 containing organic or inorganic pollutants such as dioxin and heavy metal, and the ground is statically prevented from being disturbed from the casing 10. And press-fitting into the ground 20 while applying a vertical load. At this time, water inside the casing 10 is drawn out by the pump 17 on the work support ship 21 on the water through the pressure increasing / decreasing pipe 16. As a result, the inside of the casing 10 is depressurized to facilitate press-fitting, and at the same time, scattering and diffusion of earth and sand containing contaminants are prevented.
[0022]
After press-fitting the casing 10 into the ground 20 in this way, as shown in FIG. 3, the solidification material plant 22 and the stirring blade support shaft 12 on the work support ship 21 on the water are connected via the solidification material injection hose 23. The stirring blades 13 provided in the casing 10 are lowered by a predetermined processing depth while being rotated by the driving device 15. Next, the stirring blade support shaft 12 is rotated while being pulled up, and a solidified material adjusted to a suspended slurry or solution is supplied from a solidifying material plant 22 from an arbitrary height position in the middle of the pulling up and is supplied from the solidifying material discharge hole 14 of the stirring blade 13. Discharge. As a result, the solidified material is uniformly injected into the contaminated ground in the casing 10 and mixed with stirring.
[0023]
In addition, when adjusting the solidified material slurry by the solidified material plant 22, the surplus contaminated water extracted from the casing 10 is used. The surplus contaminated water refers to water that may contain contaminants drawn from the inside of the casing, and is used for kneading or diluting when adjusting the solidified material to a suspended slurry or solution. By reusing as, it becomes possible to contain the contaminant inside the solidified body.
[0024]
In the casing 10 thus press-fitted into the water bottom ground 20, the solidified 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 drawing, the inside is pressurized by pouring water into the casing 10 through the pressurizing / depressurizing conduit 16 to facilitate the drawing. The solidified material mixed ground left in the water bottom ground 20 is solidified in a state left in place by the solidified material.
[0025]
The pulled-out casing 10 is moved to the next processing position and the same process as described above is repeated, and the contaminated water bottom ground having a desired area is solidified at the original position. The solidified ground may be excavated and removed for detoxification, or left as it is, and buried in the bottom of the water with sand cover or the like.
[0026]
In the above-described processing step, in the step of press-fitting the casing 10 into the water bottom ground 20, as shown in FIG. 5, a reflux water channel 24 is installed in the wall thickness of the casing 10 and extracted from the casing 10. It is preferable that the polluted water is injected into the bottom bottom ground by refluxing the water from the lower end opening of the casing 10 into the bottom bottom ground in the casing 10, and the polluted water is contained in the ground simultaneously with the solidification of the contaminated ground.
[0027]
In addition, as shown in FIG. 6, without using a stirring blade in the interior, the inside of the casing 10 with the stirring blade access hole 25 opened in the center of the top is used, and the stirring blade access hole 25 is closed with a cap. In the same manner as described above, it is press-fitted into the water bottom ground 20, and after completion of the press-fitting, the stirring blade 13 is inserted in a state of being folded along the stirring blade support shaft 12 through the stirring blade inlet / outlet hole 25, and is expanded in the casing 10. Then, the solidifying material may be poured and mixed and stirred.
[0028]
Next, the solidification process of the land will be described.
[0029]
As shown in FIG. 7, the casing 10 described above is installed on the land ground 30 containing organic or inorganic contaminants such as dioxin and heavy metal, and the static vertical from the casing 10 so as not to disturb the ground. Press fit while applying a load. At this time, the air inside the casing 10 is drawn out through the pressure-reducing pipe line 16 by the vacuum pump 31 installed adjacent to the land. As a result, the inside of the casing 10 is depressurized to facilitate press-fitting, and at the same time, scattering and diffusion of earth and sand containing contaminants are prevented.
[0030]
After the casing 10 is press-fitted into the ground 30 in this way, as shown in FIG. 8, the solidifying material plant 22 installed adjacent to the land and the stirring blade support shaft 12 communicate with each other via the solidifying material injection hose 23. The stirring blade 13 provided in the casing 10 is lowered to a predetermined processing depth while being rotated by the driving device 15.
[0031]
Next, the stirring blade spindle 12 is rotated while being pulled up, and the solidified material adjusted in a slurry form is supplied from the solidifying material plant 22 from an arbitrary height position during the pulling up and discharged from the solidifying material discharge hole 14 of the stirring blade 13. As a result, the solidified material is uniformly injected into the contaminated ground in the casing 10 and mixed with stirring.
[0032]
In the casing 10 thus press-fitted into the land ground 30, the solidified 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 drawing, air is pressurized and injected into the casing 10 through the pressurizing / depressurizing pipeline 16 to pressurize the inside, thereby facilitating the drawing. The remaining solidified material mixed ground is solidified in a state left in place by the solidified material.
[0033]
The pulled-out casing 10 is moved to the next processing position and the same process as described above is repeated, and the contaminated water bottom ground having a desired area is solidified at the original position. The solidified ground may be subjected to various treatments as industrial waste, such as excavating and removing it, and detoxifying it.When solidified to completely insolubilize, It may be soiled and sealed in place.
[0034]
In the various examples described above, the cylindrical casing 10 is used, but according to this, the contaminated ground is sequentially solidified into a columnar shape, so that as shown in FIG. An unprocessed portion B is generated between the respective solidified processing portions A. In order to prevent this, an unprocessed portion can be eliminated by making the cross-sectional shape of the casing 10 a polygonal shape such as a regular triangle, a square, or a regular hexagon as shown in FIGS.
[0035]
In this case, as shown in FIG. 11, a metal brush 40 is attached to the tip of the stirring blade 13 depending on the cross-sectional shape of the casing 10, or the stirring assist with the same structure as the stirring blade 13 as shown in FIG. By using the blades 41 together, stirring can be performed so as not to leave an untreated portion even in the polygonal casing.
[0036]
Although not shown in the figure, a large range can be improved at a time by combining a plurality of casings and constructing them simultaneously.
[0037]
Solidifying materials to be used are: a normal portland cement, a blast furnace cement, a cementitious solidifying material such as a special soil solidifying material, b a neutral solidifying material such as lime and c gypsum, d a solidifying material mainly composed of water glass, e The organic polymer solidifying material can be used alone or in any combination of the above solidifying materials a to e.
[0038]
Further, the static vertical load applied when the casing 10 is press-fitted into the ground is fixed to a heavy machine such as a power shovel on land as shown in FIGS. 13 (a) to 13 (c), for example. The pressurizing shaft 51 for applying a vertical load can be moved in the axial direction via the guides 52 and 52 with respect to the press-fitting support member 50 and the press-fitting support member 50 fixed to the work ship at the bottom of the water. As shown in FIG. 13A, the weight 54 is stacked on the cradle 53 fixed to the pressure shaft 51, or the cradle 53 is jacked as shown in FIG. 13B. The pressing shaft 51 can be pushed down by 55, or the pressing shaft 51 can be moved downward by a gear or roller 57 driven by a motor 56, as shown in FIG.
[0039]
In the solidification method for contaminated ground as described above, the casing is pressed into the ground containing the pollutant so that the pollutant in the local ground does not diffuse, and the solidified material and the ground are agitated and solidified. By creating a body: 1. There is no diffusion of pollutants to the surroundings. 2. Since the solidifying material is added and stirred and mixed inside the casing, the solidifying material does not leak out, so that a uniform solidified body can be created with little variation in the composition. 3. Contain contaminated materials in situ. After solidification, it can be moved and taken out to the treatment facility without removing the pollutants by removing and moving. In the case of submerged ground, the construction cost can be reduced because the amount of separated contaminated water treated is minimized.
[0040]
【The invention's effect】
As described above, in the solidification treatment method for contaminated ground according to the present invention, a static load is applied to a cylindrical casing whose upper end side is closed and lower end side is released to the ground or the bottom of the ground containing the pollutant. The stirring blade is inserted into the ground in the casing, and the agitation blade is inserted into the ground in the casing, and the solidification material is added and mixed to the ground in the casing while the stirring blade is moved upward and / or downward while rotating. After the casing is pulled out, the contaminated ground is injected, mixed and stirred in the closed casing, so that the contaminated ground bottom is buried by dredging or covering sand. It is no longer necessary to install a strong anti-diffusion curtain as in the case of treatment, and solidification treatment is performed in such a way that the diffusion of pollutants into the ground due to water spraying and the diffusion of dust during the excavation of land is completely prevented. Become a Rukoto, it can handle pollutants at a low cost.
[0041]
Further, in the present invention, when the casing is press-fitted into the ground or the bottom of the water bottom, the upper end side 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 pumped By press-fitting the casing by pulling out, it is possible to smoothly press-fit the casing, and it is possible to perform processing without diffusing contaminated air or contaminated water in the casing caused by the press-fitting.
[0042]
Further, in the present invention, when the casing is press-fitted into the ground of the bottom, 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. The casing is pressed into the casing and all or part of the extracted water is returned to the ground in the casing from the bottom of the casing, and contaminated water is contained in the ground and solidified. Since a part of the contaminated water treatment is contained in the solidified ground and treated, the detoxification treatment of the generated contaminated water is reduced.
[0043]
Furthermore, in this invention, the detoxification process of the polluted water which generate | occur | produces is reduced by using water as kneading | mixing water of a solidification material using some extracted water.
[0044]
Further, in the present invention, when the casing is pulled out, the casing can be pulled out smoothly by applying a force in the pulling direction to the casing by press-fitting air or water into the casing.
[0045]
Furthermore, in the present invention, the cylindrical cross-sectional shape of the casing is a polygonal shape such as a regular triangle, a square, or a regular hexagon that can be arranged in a large number without gaps, so that an unsolidified portion can be eliminated and the solidification process can be performed efficiently.
[0046]
Further, in the present invention, a plurality of casings are arranged side by side, press-fitted into the ground, and then constructed, whereby a wide range can be simultaneously solidified.
[0047]
Furthermore, in the present invention, as the solidifying material, cement solidified material, solidified material made of lime, neutral solidified material such as gypsum, solidified material mainly composed of water glass, and organic polymer solidified material. By using a solidified material or a plurality of solidified materials arbitrarily combined, a solidification treatment can be performed in accordance with the properties of the contaminated ground.
[0048]
Furthermore, in the present invention, the wing for stirring the ground containing the pollutant and the solidified material has a wing expansion structure that can be opened and closed around the rotation shaft, and after pressing only the casing into the ground, the stirring wing is inserted and solidified. By performing the injection stirring and mixing process of the material, the casing becomes light in weight, and operations such as press-fitting and movement become easy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an apparatus used in a method for solidifying a 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 solidified ground bottom processing method according to the present invention.
FIG. 3 is a cross-sectional view showing a state of a solidifying material addition mixing step as described above.
FIG. 4 is a cross-sectional view showing a state of the same casing pulling-out process.
FIG. 5 is a cross-sectional view showing an outline of a circulating state of sludge water in the casing press-fitting step.
FIG. 6 is a cross-sectional view showing a state in which a stirrer is inserted when the above-described wing-type stirrer is used.
FIG. 7 is a cross-sectional view showing a state of a casing press-fitting process in the solidification method for land according to the present invention.
FIG. 8 is a cross-sectional view showing a state of the solidifying material addition mixing step same as above.
FIG. 9 is a cross-sectional view showing a state of the same casing pulling-out process.
FIGS. 10A to 10D are plan views showing an outline of a ground treatment state according to casing shape.
FIG. 11 is a cross-sectional view schematically showing a stirring and mixing method for a polygonal casing.
FIG. 12 is a sectional view showing another embodiment of the above.
FIGS. 13A to 13C are side views showing different examples of a method for applying a static load at the time of casing press-fitting according to the present invention.
FIG. 14 is a side view showing an outline of a conventional dredging method for underwater contaminated ground.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Casing 11 Top plate 12 Agitation blade spindle 13 Agitation blade 14 Solidification material discharge hole 15 Drive device 16 Pressure-reduction pipe line 17 Pump 20 Submarine ground 21 Work support ship 22 Solidification material plant 23 Solidification material injection hose 24 Recirculation flow path 25 Stirring Blade inlet / outlet 30 Land ground 31 Vacuum pump 40 Metal brush 41 Stirring auxiliary blade 50 Press-in support member 51 Pressure shaft 52 Guide 53 Receiving base 54 Weight 55 Jack 56 Motor 57 Gear (or roller)

Claims (8)

On land or sea bed of ground containing contaminants, the cylindrical casing lower end upper side is closed has been released, while closing the upper end airtight, adding static load from the outside of the casing In addition, the air or water inside the casing is press-fitted while being pulled out by a pump , the stirring blade is inserted into the ground in the casing, and the inside of the casing is moved while moving the stirring blade upward and / or downward. A solidification treatment method for contaminated ground, characterized in that a solidification material is added to and mixed with the ground and then the casing is pulled out. The whole or part of the water extracted during the press-fitting of the casing into the ground of the bottom is returned to the ground in the casing from the bottom of the casing, and the contaminated water is contained in the ground and solidified. Solidification method for contaminated ground as described. The method for solidifying a contaminated ground according to claim 1 or 2 , wherein a part of the extracted water is used as kneaded water for the solidified material . The method for solidifying a contaminated ground according to claim 1, 2 or 3 , wherein a force in the pulling direction is applied to the casing by press-fitting air or water into the casing when the casing is pulled out . 5. The method for solidifying a contaminated ground according to claim 1, wherein the cylindrical cross-sectional shape of the casing is a polygonal shape such as a regular triangle, a square, or a regular hexagon that can be arranged in a large number without gaps . The solidification processing method for contaminated ground according to claim 1, wherein a plurality of casings are juxtaposed side by side and press-fitted into the ground for construction. As a solidifying material, a cement-based solidified material, a solidified material made of lime, a neutral solidified material such as gypsum, a solidified material mainly composed of water glass, and an organic polymer-based solidified material, or optionally The method for solidifying a contaminated ground according to claim 1, wherein a plurality of combined solidifying materials are used . The wing that stirs the ground containing the pollutant and the solidified material has a wing expansion structure that can be opened and closed around the rotating shaft. After only the casing is press-fitted into the ground, the agitating blade is inserted and the solidified material is injected and stirred and mixed. The solidification processing method of the contaminated ground of Claims 1-6 or 7 which performs a process.

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