JP2005028232A - Sediment cleaning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sediment cleaning method not exerting an adverse effect on the ecosystem of a sediment and unnecessary for reducing the depth of water by covering sand. <P>SOLUTION: This sediment cleaning method includes a process for sucking sludge (23h) containing a contaminant, a process for discharging the sludge (23h) into soil (27) at a place where a stirring means (17) is located and a process for kneading the discharged sludge (23h) with the surrounding soil (27) by the stirring means (17). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for purifying such polluted sediment when the pollutant is stored in the bottom of the sea, lake bed, river bed, or other region, that is, bottom sediment.
[0002]
[Prior art]
The sludge stored in the bottom of the seabed, lake bed, and riverbed contains a lot of pollutants. Among them, the inclusion of dioxin is attracting attention as being extremely dangerous for biological life.
Here, the dioxin treatment method is divided into a case where the dioxin concentration is higher than a reference value and a case where the dioxin concentration is lower than the reference value.
If the dioxin concentration is higher than the reference value, the pollutant is discharged from the sediment and solidified, but the cost is high.
On the other hand, sludge whose dioxin concentration is lower than the standard value is overwhelmingly larger than the amount of sludge whose dioxin concentration is higher than the standard value. In such cases, treatment at the sludge deposition site is possible. In-place processing is performed.
[0003]
There are two methods for treating sediment soil contaminated with dioxins at concentrations below the standard value.
One is “sand cover” and the other is “in-situ solidification”.
[0004]
“Sand covered sand” is about 3m thick and covered with high quality sand, etc., elution, winding up by waves and flow in the bottom chamber, and into the body of fish and shellfish through benthic organisms that ingest sediment. It is a method of blocking the accumulation path of the.
However, the problem with “sand cover” is that when contaminated sand is discharged, there is no place to take it. Moreover, the sand covered by the waves will be carried to other places. Therefore, it must be covered with sand, which will adversely affect the sediment ecosystem.
And in the case of rivers, sand cover is difficult to use. This is because when the sand is covered, the water depth of the river becomes shallow, which is inconvenient for ships operating the river.
[0005]
“In-situ solidification” means that the polluted sediment is solidified with toxic substances including sludge in-situ, thereby suppressing elution, rolling up sediment by waves and flow, and through benthic organisms that ingest sediment. This is a method of blocking the pathway of accumulation of seafood in the body.
This “in-situ solidification” also has an adverse effect on sediment ecosystems due to the use of solidification materials.
When the solidifying material is charged by a jet, the pollutant is diffused by the jet, resulting in an increase in contaminated soil, which is difficult to use. In addition, continuous monitoring for confirming the presence or absence of deterioration of the solidified layer with time is indispensable, leading to an increase in running cost.
[0006]
In addition, water bottom pollutant treatment technology has been proposed. For example, a technology has been developed in which the sludge part of the surface of the bottom of the water is pressed with a frame provided with a rotating blade, and a stabilizer is injected and stirred while suppressing the occurrence of pollution, and the sludge is instantly solidified and stabilized in a gel form. (See Non-Patent Document 1 and Non-Patent Document 2).
However, 2/3 or more of the sludge layer of pollutants including dioxins is water, and even if a large amount of stabilizer or solidifying material is added, the sludge-like pollutants are solidified and stabilized. It is difficult to do.
Further, if a large amount of stabilizer or solidifying material is added, the problem remains that the biological system in the layer immediately below the sludge is destroyed.
Furthermore, even if it can be solidified into a gelled state, as a result of erosion due to waves after solidification, sludge-like pollutants that have been solidified into a gelled state are exposed and subjected to the erosion action of waves, There is a possibility of diffusing pollutants. In order to prevent such a situation, sand cover is required, but the water depth becomes shallow.
[0007]
Thus, the technique effective for the bottom sediment purification mentioned above is not provided at present.
[0008]
[Non-Patent Document 1]
Construction communication newspaper dated May 21, 2003
[Non-Patent Document 2]
Construction industry newspaper dated May 21, 2003
[0009]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-mentioned problems of the prior art, and does not adversely affect the sediment ecosystem and does not reduce the water depth. The purpose is to provide.
[0010]
[Means for Solving the Problems]
As a result of various studies, the inventor paid attention to the fact that sludge has a very high moisture content, and the ratio of components other than moisture in the sludge deposit layer is very small.
[0011]
In the purification method according to the present invention, the step (FIGS. 1 and 2) of installing the suction means (A1) in the layer (23) where sludge containing pollutants is deposited and the kneading means (A2) are accumulated A step of penetrating the layer (23) and causing the stirring means (stirring blade 17) provided in the kneading means (A2) to reach the soil under the bottom of the water (soil 27 about 3 to 5 m below the bottom of the water) (FIG. 1); The suction means (A1) sucks the sludge (23h) containing the contaminants and stores it in the storage means (tank T) (FIG. 2), and the sludge (23h) stored in the storage means (T). The step of discharging into the soil (27) where the stirring means (17) is located (FIG. 3), and the discharged sludge (23h) is kneaded into the surrounding soil (27) by the stirring means (17) And a step (FIG. 4). 1).
[0012]
Here, in the step of sucking the sludge (23h), the surrounding member (cover 3) provided in the suction means (A1) is covered with the sludge deposition layer (23), and the sludge (23) is enclosed in the surrounding member (cover 3). 23h) is sucked into the suction means (A1), and in the discharging step, sludge (23h) sucked from the injection port (19) provided in the kneading means (A2) is sprayed into the soil (27). (Claim 2).
[0013]
According to the bottom sediment purification method of the present invention having the above-described constituent means and steps, the bottom sediment (23, 25, 27) is only perforated by the kneading means (A2), and the bottom sediment (23, 25, 27) The impact on the ecosystem is extremely small.
[0014]
Contaminants are mixed and kneaded into the soil below the bottom of the water (soil 27 about 3 to 5 m below the bottom), and sludge (23h) is not recovered on the ground side, so the cost can be kept low.
[0015]
Because it is under the bottom of the water, the soil mixed with or kneaded with pollutants is not exposed even if it is eroded by waves. Therefore, there is no need for sand covering and there is no fear of shallow water depth.
[0016]
Only the rod-like kneading means (A2) penetrates the bottom sediment, and since no perforation using a jet jet is performed, there is no possibility that the contaminants deposited on the bottom sediment will diffuse.
[0017]
Furthermore, sediment sludge (compressed to less than 15 cm when crushed with a thickness of about 50 cm; 23 h) is kneaded into soil (27) in a region of about 5 m in the depth direction, for example, The soil of the containment layer 27) is diluted to about 3% as a whole. Therefore, for example, there is no inconvenience that the dioxin concentration increases beyond a predetermined level.
[0018]
In the purification method of the present invention, the excavating means (auger, rod, etc. 1) provided with the agitating means (stirring blade 17, excavating blade, etc.) is passed through the layer (23) in which sludge containing pollutants is deposited. A process (FIGS. 6 to 7) for reaching the soil under the bottom of the water (soil 27 about 3 to 5 m below the bottom), a process for sucking sludge (23h) containing the contaminants (FIG. 9), and aspiration The step of discharging the sludge (23h) into the soil (27) where the stirring means (17) is located (FIG. 10), and the discharged sludge (23h) by the stirring means (17) (27) including a step of kneading (FIG. 11).
[0019]
If comprised in this way, it is only necessary to transport the absorbed sludge below the same rod without storing it in the storage means (tank T). Moreover, it can implement only with a single apparatus called excavation means provided with the stirring apparatus and the mechanism which attracts sludge.
[0020]
Here, in the step of sucking the sludge (23h), the surrounding member (cover 3) provided in the excavating means (1) is covered with the sludge deposit layer (23), and the sludge ( 23h) is sucked into the excavating means (1) and discharged, the sludge (23h) sucked from the injection port (19) provided in the excavating means (1) is injected into the soil (27). (Claim 4).
[0021]
By using such a surrounding member (cover 3), the sludge (23h) can be easily collected.
Further, the collected sludge (23h) is injected into the soil (27) below through the inside of the excavating means (1).
[0022]
Alternatively, in the step of sucking the sludge, the sludge (23h) is sucked in a region separated from the location excavated by the excavating means (B), and a flexible (second) excavating means (for example, bent boring D) is used. ) From the sludge suction location to the location where the stirring means (17) is located, and during the discharging step, suction is performed via the inside of the flexible (second) excavation means (D). It is preferable to discharge the sludge (23h) at the location where the stirring means (17) is located (Claim 5).
[0023]
If comprised in this way, the agitation means (17) will be discharged | emitted by discharging | emitting the sludge (23h) sucked via the inside of the 2nd excavation means (D) in the location in which the agitation means (17) is located. It becomes possible to knead the sludge (23h) of the area | region separated from the excavation means (B) provided with in the soil (27) under a water bottom. As a result, the number of excavations by the excavation means (B) including the agitation means (17) can be reduced, and the influence on the sediment ecosystem can be minimized.
[0024]
In this invention, it is preferable to provide the process of supplying the pollutant purification material with respect to the soil of the location where the stirring means (17) is located (Claim 6).
[0025]
If the purification material (J) is added to the soil where the stirring means (17) is located, that is, the soil (27) in which sludge containing the pollutant is mixed, the purification of the bottom is further improved. It is.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0027]
1 to 4 show a first embodiment of the present invention.
In FIG. 1, there is a relatively strong ground 27 serving as a ground (containment layer) for containing sludge at the bottom lowermost layer of the water area 22 below the water surface 21, and a coating layer 25 on which sludge is accumulated above the containment layer 27. The upper part of the coating layer 25 is a sludge layer 23 containing a hazardous substance for dioxins.
[0028]
As shown in FIG. 1, the facility for carrying out the first embodiment includes a suction device (suction means) A1 that sucks and removes sludge accumulated on the sludge layer 23, and a tank that temporarily stores the sucked sludge ( The storage means) T and a kneading apparatus (kneading means) A2 for kneading the sludge into the ground 27 are roughly configured.
In FIG. 1, the tank T is installed on the ground G, but the tank T can be installed in a state where it floats on the water surface 21 by means such as a trolley (not shown).
[0029]
The suction device A1 has a hollow rod 1A.
The suction device A1 is configured such that a sludge 23h (a sludge collected to be distinguished from the sludge layer 23 has a symbol 23h) flows through the rod 1A.
Near the lower end of the rod 1, sludge suction holes 11 for sucking the sludge 23 h are formed at a plurality of locations in two upper and lower stages in the illustrated example.
[0030]
The rod 1A communicates with a tank (storage means) T for temporarily storing sludge through a line L1 through which sludge flows and a pump P1 interposed therein.
When the pump P1 is operated, the sludge 23h is sucked from the suction hole 11, and the sucked sludge 23h flows through the internal space of the rod 1A and the line L1 and is sent to the tank T.
The sludge 23h stored in the tank T (or the sludge 23h mixed with the solidified material by means not shown in the tank T) will be described later via a line L2 with the head added by the pump P2. It is sent to the kneading apparatus A2.
[0031]
In addition, a cover 3 that is a cylindrical member that covers the upper end of the suction device A1 on the outer periphery of the rod 1A of the suction device A1 and closes only the upper end and demarcates the region 23 in which the suction sludge accumulates is detachably provided. It has been.
[0032]
The kneading apparatus (kneading means) A2 has a hollow rod 1B that communicates with the tank T via a line L2.
The lower end portion of the rod 1B reaches a relatively strong ground 27 serving as a ground (containment layer) for containing sludge in the bottom bottom layer of the water area 22 below the water surface 21. A sludge ejection hole 19 is formed.
[0033]
A stirring blade 17 (stirring means) is formed above the sludge discharge hole 19 of the rod 1B so as to be orthogonal to the rod 1B, and the sludge 23h discharged from the sludge discharge hole 19 (or sludge mixed with a solidified material). 23h) is kneaded with the ground forming the containment layer in the containment layer 27.
Note that the stirring blade 17 may be configured so that a horizontally extending tip portion is folded upward as shown in FIG. 6 described later in relation to the second embodiment.
[0034]
Next, the steps of the first embodiment will be described with reference to FIGS.
First, as shown in FIG. 2, the suction device A <b> 1 is inserted into a region where the sludge 23 h to be removed is deposited until the lower ends of the rod 1 </ b> A and the cover 3 reach the surface of the coating layer 25. In other words, the suction device A1 is installed in the region 23 where the sludge 23h is deposited.
Here, the rod 1A may be lowered with the cover 3 attached, or, after processing only the rod 1A, the cover is moved from the water surface 21 along the rod 1A at a predetermined position (the sludge layer 23). It may be lowered to a position where the height direction is completely included in the cover height region.
[0035]
And as shown in FIG. 1, the kneading apparatus A2 provided with the stirring blade 17 (stirring means) is made to penetrate through the sludge layer 23 and the clothing layer 25, and the containment layer 27 (below the bottom of the water by about 3 to 5 m). (Soil reaching process).
Here, in the step of allowing the kneading device A2 to penetrate the sludge layer 23 and the clothing layer 25 and reach the containment layer 27 under the water bottom, the lower end of the rod 1A of the suction device A1 and the cover 3 reaches the surface of the coating layer 25. As such, it may be performed simultaneously with the installation step, or one of them may be preceded.
[0036]
After the rod 1A and the cover 3 are set at predetermined positions, the pump P1 (see FIG. 1; not shown in FIG. 2) is operated, and sediment containing sludge from the sludge layer 23 surrounded by the cover 3 (hereinafter referred to as sludge). 23h is sucked from the sludge suction hole 11 (step of sucking sludge).
The sucked sludge 23h flows through the rod 1A as indicated by an arrow in FIG. 2, and is stored in the tank T (see FIG. 1; not shown in FIG. 2) via the line L1.
[0037]
Next, as shown in FIG. 3, the kneading apparatus A2 is penetrated while excavating from the water surface 21 toward the containment layer 27 which is the lowermost layer with the stirring blade 17 folded. Then, as shown in FIG. 3, when the containment layer 27 is reached, or just before reaching, the stirring blade 17 is set horizontally (step of reaching the soil).
[0038]
And the pump P2 is driven, a head is added to the sludge 23h stored in the tank T, and it sends out toward the mixed apparatus A2 via the line L2. The sludge 23h to which the head is added flows through the space in the rod 1B (see the arrow in FIG. 3), and is discharged from the sludge discharge hole 19 toward the containment layer 27 (discharge process).
[0039]
When the sludge 23h is discharged to the containment layer 27, or after the sludge 23h is discharged to the containment layer 27, the stirring blade 17 is rotated, and the containment layer 27 contains a solidified material in the containment layer 27. 23h is kneaded (FIG. 4; kneading into soil).
[0040]
After kneading the sludge 23h into the containment layer 27, the excavator A is removed onto the water surface 21 to complete the bottom sediment purification method (not shown).
[0041]
According to the bottom sediment purification method of the first embodiment as described above, since only the sludge 23h is sucked by the suction device A1 and the bottom sediments 23, 25, 27 are perforated by the kneading device A2, the bottom sediment The impact on the ecosystem of 23, 25 and 27 is extremely small.
[0042]
Contaminants such as sludge 23h are mixed and kneaded into the containment layer 27, which is soil 3m to 5m below the bottom of the water, for example, and the sludge 23h is not disposed on the ground side. .
[0043]
Since the containment layer 27 into which sludge is kneaded exists under the bottom of the water, even when eroded by waves, soil containing mixed or kneaded pollutants such as sludge 23h is not exposed. Therefore, there is no need for sand covering and there is no fear of shallow water depth.
[0044]
Only the rod-shaped excavator A penetrates the bottom sediment, and since no jet is used, there is no risk of the contaminants diffusing.
[0045]
Furthermore, since the sediment sludge 23h that is compressed to less than 15 cm when crushed with a thickness of about 50 cm is kneaded into the soil (containment layer) 27 in a region of about 5 m in the depth direction, for example, after kneading the sludge However, as a whole soil of the containment layer 27, the concentration of the heddle is diluted to about 3%. Therefore, for example, there is no inconvenience that the dioxin concentration rises above a specified value.
[0046]
Next, a second embodiment will be described with reference to FIGS.
In FIG. 5, there is a ground (containment layer) 27 for containing sludge in the bottom lowermost layer of the water area 22 below the water surface 21, and a coating layer 25 in which sludge and the like are deposited above the containment layer 27. Above this is a sludge layer containing harmful substances for dioxins.
[0047]
On the other hand, the excavation means (excavator) A uses a double wound rod 1 having an inner pipe 2 as a whole, and the upper side uses a gap E between the double pipes to form a sludge 23h (a sludge layer). In order to distinguish from 23, the sludge collected is set to 23h).
In the middle of the double pipe (outer pipe), sludge suction holes 11 for sucking the sludge 23h are formed at a plurality of locations in two upper and lower stages in the illustrated example.
[0048]
A double pipe is modified below the double pipe, and a sand pump 13 is arranged at the uppermost stage, a mixing chamber 15 is provided below it, and a sludge discharge hole 19 is provided near the lower end thereof. A pressure chamber 16 is formed.
When the sand pump 13 is operated, the sludge 23h is sucked from the suction hole 11, and the sucked sludge 23h flows through the gap E and is sent to the mixing chamber 15. For example, when using a solidified material, The inside of the inner pipe 2 of the pipe is conveyed and mixed with a solidifying material (not shown) that has flowed into the mixing chamber 15.
The sludge 23h or the sludge 23h mixed with the solidified material is configured to be discharged out of the pipe from the sludge discharge hole 19 after the pressure is sufficiently increased in the pressure chamber 16.
[0049]
A stirring blade 17 is formed above the sludge discharge hole 19 so as to be orthogonal to the double tube rod 1. In the containment layer 27, the sludge 23 h discharged from the sludge discharge hole or the sludge 23 h mixed with the solidified material is contained in the containment layer 27. It is comprised so that it may knead | mix with the ground which forms a containment layer. In addition, you may comprise the said stirring blade 17 so that the front-end | tip part extended horizontally may be folded upward like FIG. 6 mentioned later.
[0050]
In addition, a cover 3 that is a cylindrical member that closes only the upper end of the double tube rod 1 and surrounds the upper end of the double tube rod 1 and demarcates a region 23 in which the sludge is accumulated is detachably provided. It has been.
[0051]
Next, the process of 2nd Embodiment is demonstrated with reference to FIGS.
First, in FIG. 6, the excavator A penetrates while excavating from the water surface 21 toward the containment layer 27, which is the lowest layer, with the stirring blade 17 folded. Then, as shown in FIG. 7, when the containment layer 27 is reached or just before reaching, the stirring blade 17 is set horizontally (the process of reaching the soil).
[0052]
In the step shown in FIG. 8, the cover is lowered from the water surface 21 along the double tube rod 1 to a predetermined position (a position where the height direction of the sludge layer 23 is completely included in the height region of the cover). . After the cover 3 is set at a predetermined position (indicated by a two-dot chain line in FIG. 8), in FIG. 9, the sand pump 13 is operated, and deposits containing sludge from the sludge layer 23 surrounded by the cover 3 (hereinafter, sludge is removed). 23h is sucked from the sludge suction hole 11 (step of sucking sludge).
[0053]
The sucked sludge 23h is mixed with a solidification material (not shown) conveyed from the inside of the inner tube 2 in the mixing chamber 15, and then the pressure is increased in the pressure chamber 16, and discharged from the sludge discharge hole 19 toward the containment layer 27. (FIG. 10; discharge process).
[0054]
When the sludge 23h is discharged to the containment layer 27 and / or after the discharge, the stirring blade 17 is rotated, and in the containment layer 27, the sludge 23h containing the solidified material is kneaded into the containment layer 27 (FIG. 11; soil). Kneading process).
[0055]
After kneading the sludge 23h into the containment layer 27, the excavator A is removed on the water surface 21, and the bottom sediment purification method is completed.
[0056]
In addition, as shown in FIG. 12, the re-diffusion of contaminants can be prevented more reliably by injecting the contaminant purification agent J into the soil where the stirring blades 17 are located.
It should be noted that the step of injecting the contaminant purification agent J can also be performed in the first embodiment shown in FIGS.
[0057]
10-12, the discharge process which discharges the sludge 23h toward the containment layer 27 from the sludge discharge hole 19, the process in which the sludge 23h containing the solidification material is kneaded into the containment layer 27, and the contaminant purifier Although the step of injecting J is shown to be performed at a separate timing, the steps of FIGS. 10 to 12 or the discharging step of FIG. 10 and the step of kneading sludge in FIG. 11 are performed simultaneously. I can do it.
[0058]
The effects of the second embodiment shown in FIGS. 5 to 12 are the same as those of the first embodiment shown in FIGS.
However, according to the second embodiment of FIGS. 5 to 12, there is a merit that only one rod is used.
[0059]
Next, a third embodiment will be described with reference to FIG.
[0060]
In the second embodiment of FIGS. 5 to 12, a hazardous substance such as 23 h is enclosed by a cover provided around the excavator A, the harmful substance in the enclosed area is once sucked into the excavator A, and the suction is performed. In this embodiment, for example, a solidifying material or the like is mixed with the harmful substance and the harmful substance mixed with the solidifying material or the like is kneaded into the containment layer 27 again.
On the other hand, the third embodiment in FIG. 13 is an embodiment configured to suck the sludge 23h in a region separated from a location excavated by the excavator B. Less than. A third embodiment will be described with reference to FIG.
[0061]
In FIG. 13, the excavator B has a function of simply excavating under the water bottom and a function of kneading harmful substances into the containment layer 27 by the stirring blade 17 provided at the tip of the excavator B.
[0062]
First, boring is performed vertically toward the containment layer 27, which is an area where contaminants are finally processed by the excavator B. At that time, as shown in the second embodiment, the stirring blade 17 at the tip may be folded.
[0063]
On the other hand, the sludge 23h is sucked in a region separated from the location excavated by the excavator B of the sludge deposit layer 23, and is a second excavation means having flexibility, for example, the excavator from the sludge suction location by the bent boring D. Excavate to the point where the stirring blade 17 at the tip of B is located. In the discharging process, the sludge 23h sucked through the inside of the bent boring D is discharged at a place where the stirring blade 17 is located.
In addition, the code | symbol C in FIG.
[0064]
If comprised as mentioned above, the area | region separated from the excavator B provided with the stirring blade 17 by discharging | emitting the sludge 23h sucked via the inside of the bending boring D in the location in which the stirring blade 17 is located. The sludge 23h of 23b can be kneaded into the containment layer 27. As a result, the number of excavations by the excavator B equipped with the stirring blades 17 can be reduced, and the influence on the bottom ecosystem can be minimized.
[0065]
The illustrated embodiment is merely an example, and is not a description of the purpose of reducing the technical content of the present invention.
For example, in the first embodiment, the kneading means A2 may reach the containment layer 27 after the sludge is stored in the tank T.
In the second embodiment, the sand pump 13 and the mixing chamber 17 provided in the excavator A may be disposed upside down.
[0066]
【The invention's effect】
The effects of the present invention are listed below.
(1) The impact on sediment ecosystem is very small.
(2) Contaminants are mixed and kneaded into the soil below the bottom of the water (soil about 3 to 5 meters below the bottom), and the sludge is not treated on the ground side, so the construction cost can be kept low by that amount.
(3) Because it is under the bottom of the water, soil mixed with or kneaded with pollutants will not be exposed even if eroded by waves. Therefore, there is no need for sand covering and there is no fear of shallow water depth.
(4) Only the rod-shaped excavating means of the kneading means penetrates the bottom sediment, and since no jet is used, there is no possibility of the contaminants diffusing.
(5) Sediment sludge (compressed to less than 15 cm when crushed at a thickness of about 50 cm) is kneaded into the soil in a region of about 5 m in the depth direction, for example, 3% as a whole of the kneaded soil Diluted to a degree. Accordingly, there is no inconvenience such as an increase in dioxin concentration.
(6) Covering the sludge deposit layer with the surrounding member provided in the excavating means, sucking the sludge in the surrounding member into the excavating means, and injecting the sludge sucked from the injection port provided in the excavating means into the soil If it comprises, it will become easy to collect sludge.
(7) The sludge is sucked in a region separated from the position excavated by the excavating means, and excavated from the sludge sucking position to the position where the kneading means is located by a flexible second excavating means (for example, bent boring). If the sludge sucked through the inside of the second excavation means is discharged at the location where the kneading means is located, the sludge in the region separated from the excavation means provided with the kneading means It can be kneaded into the soil. As a result, the number of excavations by the excavating means provided with the kneading means can be reduced, and the influence on the sediment ecosystem can be minimized.
(8) If the purification material is added to the soil where the kneading means is located, that is, the soil containing sludge containing the pollutants, the degree of bottom sediment purification is further improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall configuration of a first embodiment of the present invention.
FIG. 2 is a process diagram showing a process of sucking sludge in the first embodiment of the present invention.
FIG. 3 is a process diagram showing a process of discharging sludge to the ground in the first embodiment of the present invention.
FIG. 4 is a process diagram showing a process of kneading sludge discharged to the ground into the ground in the first embodiment of the present invention.
FIG. 5 is a sectional view showing an overall configuration of a second embodiment of the present invention.
FIG. 6 is a process diagram showing an initial state in which the excavator reaches the soil in the second embodiment of the present invention.
FIG. 7 is a process diagram showing a state in which the excavator reaches the soil in the second embodiment of the present invention.
FIG. 8 is a process diagram showing a process of installing a cover at a predetermined position in the second embodiment of the present invention.
FIG. 9 is a process diagram showing a process of sucking sludge in a second embodiment of the present invention.
FIG. 10 is a process diagram showing a process of discharging sludge to the ground in the second embodiment of the present invention.
FIG. 11 is a process diagram showing a process of kneading sludge discharged to the ground into the ground in the second embodiment of the present invention.
FIG. 12 is a cross-sectional view showing another embodiment of the second embodiment of the present invention and showing a state in which a contaminant purifier is discharged onto the ground.
FIG. 13 is a cross-sectional view showing the overall configuration of a third embodiment of the present invention.
[Explanation of symbols]
A ... Excavator
1 ... Double tube rod
2 ... Inner pipe
3 ... Cover
11 ... Sludge suction hole
13 ... Sand pump
15 ... Mixing chamber
16 ... Pressure chamber
17 ... stirring blade
19 ... sludge discharge hole
21 ... Water surface
22 ... Water area
23 ... Sludge layer
23h ... sludge
25 ... Coating layer
27 ... Containment layer / ground

Claims (6)

A step of installing suction means in a layer in which sludge containing pollutants is deposited, a step of allowing the kneading means to penetrate the layer in which sludge is accumulated, and agitating means provided in the kneading means to reach the soil under the water bottom; , Sucking sludge containing contaminants by suction means and storing it in the storage means, discharging the sludge stored in the storage means into the soil where the stirring means is located, and discharged A bottom purification process comprising kneading sludge into the surrounding soil by stirring means. In the step of sucking the sludge, the surrounding member provided in the suction means is covered with the sludge deposition layer, the sludge in the surrounding member is sucked into the suction means, and in the step of discharging, the jet provided in the kneading means The sediment purification method according to claim 1, wherein sludge sucked from the mouth is sprayed into the soil. Drilling means equipped with agitation means through the layer containing sludge containing contaminants to reach the soil below the bottom of the water, sucking sludge containing contaminants, and kneading the sucked sludge A bottom purification method comprising a step of discharging the soil where the means is located into the soil and a step of kneading the discharged sludge into the surrounding soil by the kneading means. In the step of sucking the sludge, the surrounding member provided in the excavating means is covered with the sludge deposit layer, the sludge in the surrounding member is sucked into the excavating means, and in the step of discharging, the jet provided in the excavating means The sediment purification method according to claim 3, wherein sludge sucked from the mouth is sprayed into the soil. In the step of sucking the sludge, the sludge is sucked in a region separated from the position excavated by the excavating means, and excavated from the sludge sucking position to the position where the kneading means is located by the flexible excavating means, The bottom sediment purification method according to any one of claims 1 to 4, wherein in the discharging step, sludge sucked through the inside of the flexible excavating means is discharged at a location where the kneading means is located. The bottom sediment purification method according to any one of claims 1 to 5, further comprising a step of supplying a contaminant purification material to the soil where the kneading means is located.

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