JPH01210518A - Device for improving sludge ground and method of improving sludge ground utilizing said device - Google Patents

Abstract

PURPOSE:To drain water efficiently without deteriorating water quality by installing a treater with an absorption pipe onto a sludge ground partitioned by a water barrier sheet and draining water in the ground. CONSTITUTION:A plurality of water-barrier sheet stop piles 3 are driven so as to surround a specified region in a sludge ground 1, and a water barrier sheet 4 is mounted near the piles 3. A treater body 5 is set up to the upper section of the sludge ground 1, and water in the ground is extracted by using a water absorber 13. Accordingly, water can be drained efficiently within a wide range without deteriorating water quality.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a sludge ground improvement method and apparatus for purifying water quality by solidifying sludge deposited at the bottom of lakes, rivers, and shallow seas. It is something.

<Conventional technology> When fine soil particles or sludge from industrial waste or domestic wastewater flow into a river, lake, or shallow sea, some of them settle to the bottom of the river, forming a sedimentary layer. (hereinafter referred to as sludge). Sludge is a state in which particles tend to move and float in response to the flow and movement of water, leading to deterioration of water quality, which is undesirable in terms of deterioration of the natural environment, securing fishing grounds, securing water depth, and use for leisure purposes. .

On the other hand, (a) solidifying the sludge by mixing cement or lime, (b) removing the sludge by excavating or dredging the sludge ground, (c) covering the sludge ground by sprinkling earth and sand, ( d) Various methods have been proposed, such as laying a water-blocking sheet over the sludge.

<Problems to be Solved by the Invention> However, among the conventional methods for improving sludge soil, method (a) above involves operational difficulties and increases in cost, and method (b) This method not only causes water pollution during work, but also makes it difficult to secure a place to dispose of the sludge, and method (c) allows the soil to be mixed into the sludge, making it impossible to completely remove the sludge. It was technically similar to cover. In addition, these techniques are difficult to completely prevent the scattering of sludge, and it is necessary to use large-scale equipment to spread out the soil to a sufficient thickness. Problems such as storage arose. In addition, method (d) has the disadvantage that anaerobic methane fermentation occurs and hydrogen sulfide is also generated, which requires degassing and requires large-scale equipment.

This invention was made in view of these conventional problems, and provides a river that purifies the water quality by easily and reliably solidifying sludge without causing water pollution due to sludge scattering, and without shallowing the water depth. The purpose of the present invention is to obtain a method and device for improving sludge ground that can obtain the following properties.

Means for Solving the Problems> The sludge soil improvement device according to the present invention provides a water-blocking sheet around the periphery of the improvement device so as to isolate a predetermined area of the sludge soil, and a plurality of treatment device main bodies at the bottom. Consisting of a filter member with a protruding water-permeable water collection protrusion, an upper and surrounding water-blocking member, and a water suction pipe installed in a sealed chamber between these filter members and the water-blocking member, When this treatment device main body is installed on sludge ground, water in the sludge ground can be absorbed by the water absorption device through the water absorption pipe.

The sludge ground improvement method according to the present invention uses the above-mentioned sludge ground improvement device that floats on the water surface, can be towed, and can be sunk, and is sunk directly into the sludge ground, or if necessary, via a permeable sheet, After fixing a water-shielding sheet to the surrounding surface of the equipment to prevent lake water or seawater from flowing into the area where the treatment equipment body is in contact with the sludge ground surface, water inside the treatment equipment body subjected to atmospheric pressure and water pressure is removed. This method improves the ground by sucking up the sludge with a suction pump and dewatering the sludge from the ground. In addition, after ground improvement, the water-permeable sheet may be fixed to the surface of the sludge ground to prevent fine particles from floating.

<Function> When the improved device of the present invention is installed on sludge ground, the filter member comes into contact with the sludge ground directly or through a permeable sheet, and a water suction device such as a vacuum pump pumps the filter through the water suction pipe. When the gap between the member and the water shielding member is drawn in a negative pressure direction, atmospheric pressure and water pressure act on the sludge ground with a consolidation load, and the water in the sludge ground flows from the filter member into the improvement device through the filter. By suctioning this inflow water, the surface layer of the sludge ground is solidified by draining water quietly and quickly without stirring up sludge.

In addition, a filter member according to another object of the present invention has a plurality of protruding water collection protrusions, and by sinking these into the sludge ground, water in the sludge ground is drained from the sludge ground. This makes it possible to suction not only from the top surface but also from the inside of the protruding structure, increasing the efficiency of water absorption and assimilation of sludge ground.

<Embodiments of the invention> An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is sludge ground, which is located below the water surface 2, for example at the bottom of a river. In addition, a plurality of water-shielding sheet retaining piles 3 are driven in a predetermined area of this sludge ground 1 underwater so as to surround the area, and the sludge is placed near the water-shielding sheet retaining pile 3. A water-blocking sheet 4 is provided to separate a predetermined area of the ground 1 from each other. The lower part of this water-blocking sheet 4 is inserted to a predetermined depth into the sludge ground 1 from which water is to be drained, and the peripheral part 5a of the treatment equipment main body 5 is attached to the part facing the upper part of the sludge ground 1. It has become. This peripheral portion 5a is made of, for example, a water-impermeable frame member or a water-blocking member such as a water-blocking sheet. Moreover, the upper part of this peripheral part 5a, that is, the upper part of the processing apparatus main body 5,
It is covered with a water-shielding sheet 5b such as a geomembrane as a water-shielding member. Further, the bottom of the main body 5 of the processing device has a water collecting cone portion 6 as a plurality of water collecting protrusions.
The filter member 7a has the following characteristics. This filter member 7a is made of nonwoven fabric or the like. In addition, the water permeable sheet 7 installed between the improvement equipment and the sludge ground
b is made of a water-permeable sheet such as non-woven fabric or net to prevent soil particles such as sludge from being thrown up. 8
is a granular material such as sand or gravel that is housed in the water collection cone portion 6 and serves as a filter material that also serves as a weight. Reference numerals 9 and 10 indicate water collection layers made of non-woven fabric, which are provided in the sealed chambers 21 inside the water-blocking sheet 5b and inside the filter member 7a, respectively, and between these water collection layers 9 and 10, a water absorption pipe 11 is installed. It is laid down. This water suction pipe 11 has a large number of small holes in the water collection layer, and has a main pipe 11a and a plurality of branch pipes 1' connected to the main pipe 11a.
It consists of lb.

One end of the flexible hose 12 can be connected to a water collection port 11c provided in a part of the main pipe 11a. Reference numeral 13 denotes a water suction device capable of supplying air, which includes a separate tank 14 that connects the other end of the flexible hose 12, a gate valve 15.
Pump 16. It consists of a drive motor 17 for the pump 16, a drain hose 18, a compressor (not shown), and the like. This water absorption device 13 is installed, for example, on a ship or on land. Also,
The processing device main body 5 can connect a plurality of these in a row in a row and a row through connection members (not shown), and can also install them in parallel on the sludge ground l in a wide area at the same time, thereby allowing a plurality of flexible It is possible to simultaneously collect water from the sludge ground over a wide area using the water suction device from the hose 12. FIG. 2 shows an example of a piping pattern for the main pipe 11a and the branch pipe 11b. According to this, branch pipes 11b are branched and connected to a main pipe 11a having a water collection port 11C, and each branch pipe 11b is provided so as to be located above the water collection cone portion 6. Further, in this embodiment, each branch pipe 11b is enlarged by the water collection cone portion 6.

The water collecting cone portion 6 may be formed not only by a single protrusion but also by a long groove-shaped water collecting trench 19 as shown in FIG.

Next, a method for improving sludge ground using the improvement device of the above embodiment will be specifically explained.

First, the water-blocking sheet 4 separates the sludge ground 1 in a predetermined area from the inside and outside, thereby restricting the ingress and egress of water in the sludge ground 1 inside and outside this area. Next, the processing device main body 5 is installed on the sludge ground 1 within the predetermined area. Installation of the processing device main body 5 is performed as follows. First, air is supplied from a compressor (not shown) to the main pipe 11a and branch pipes 11b through the flexible hose 12, and then into the sealed chamber 21 in the processing device main body 5, which is surrounded by the peripheral part 5a, the water-blocking sheet 5b, and the filter member 7. The main body 5 of the processing device is moved above the water surface 2 using this buoyancy. Here, the water-permeable sheet 7b may be laid on the sludge ground in advance. Next, the vacuum pump 14 is operated in the predetermined area to remove the air, and the treatment device main body 5 containing the granular materials 8 is placed directly on the sludge ground 1 by its own weight or via the water-permeable sheet 7b. unload. Therefore, the water collection cone 6 is connected to this sludge ground 1.
It will settle into the state shown in Figure 1, where it has been inserted inside. Subsequently, the pump 16 is driven by the motor 17 to draw the space in the negative and positive directions through the flexible hose 12, the main pipe 11a, and the branch pipe 11b. As a result, atmospheric pressure and water pressure act on the sludge ground as consolidation loads. Therefore, through the filter member 7a including the water collecting cone 6, only the moisture in the filter ground 1 is dehydrated by compaction, and the water is transferred into the sealed chamber through the filtering granules 8 and water collecting 159, 10. 21, and the collected water is discharged to the drain hose 18 by the pump 16 through the branch pipe 11b and the main pipe 11a.

As a result of such water drainage work, the sludge ground 1 in the area separated by the water-blocking sheet 4 is gradually dehydrated and hardened, thereby preventing water from entering from other sources and preventing the sludge from easily dissolving in water. become.

After the solidification work is completed, the water permeable sheet 7b
The sludge is separated from the improvement equipment and left on the solidified sludge ground 1 to act to prevent the sludge from dissolving and scattering. Note that the remaining water permeable sheet 7b is fixed with fixed stakes.

Further, the improvement device including the filter member 7a is moved onto the sludge ground 1 to be improved next using the buoyancy. Even in this case, the water-permeable sheet 7b can be laid in advance on the sludge ground before the improvement device is submerged. Next, by removing air by operating the vacuum pump 14, the treatment device body 5 is lowered onto the ground 1 to be treated, and the same treatment operations as described above are repeated. In this way, by solidifying the sludge ground 1 over a wide area and preventing it from becoming powdery or colloidal and dissolving and scattering, river water quality can be purified.

In the above embodiment, the treatment device main body 5 is made of a flexible material such as a water-shielding sheet or a non-woven fabric, but this is because the bottom surface of the treatment device main body 5 lies in the sludge ground 1.
This is to make it easier to adapt to the unevenness of the surface.

Further, when the improvement device is floated above the water surface 2 after the solidification treatment of the sludge ground 1, a cone-shaped hole 20 is formed in the sludge ground 1 as shown in FIG. By doing so, the fine particles that have subsequently flowed in can be allowed to fall into the cone-shaped hole 20 and be deposited therein, and can be prevented from rising again.

Water purification effect is performed more effectively. In addition, in FIG. 4, 21 is a fixing pile for fixing the permeable sheet 7b on the sludge ground.

<Effects of the Invention> As described above, according to the present invention, an improvement device is installed on the sludge ground in a predetermined area separated by a water-shielding sheet, and the moisture in the sludge ground is absorbed by the water absorption device through the improvement device. Since we have adopted a method for draining water from sludge soil, it is possible to drain water from sludge ground over a wide area by simply transferring the improved equipment to the sludge ground one after another, or by joining multiple devices together.
It has the effect of being able to be carried out efficiently without causing water pollution.

Further, according to another invention of the present invention, floating on the water surface,
An improved device having a water-shielding sheet that can be towed and sunk to consolidate sludge ground using atmospheric pressure and water pressure and that separates sludge ground in a predetermined area, a filter member, a water-shielding member, and a water suction pipe, and the filter member as described above. The sludge ground improvement device is composed of a water absorbing device that extracts water from the sludge ground through a water suction pipe, so the device can be installed at low cost and easily without the need for conventional earth and sand sprinkling equipment or gas venting equipment. There are effects that can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing the sludge ground improvement device according to the present invention, Fig. 2 is a piping pattern diagram of the main pipe and branch pipes of the water suction pipe, and Fig. 3 shows another embodiment of the water collection protrusion. A plan view showing,
Figure 4 is a cross-sectional view showing the improved sludge ground. 1...Sludge ground, 4...Water shielding sheet, 6...Water collection protrusion, 7a...Filter member, 11...Water intake pipe, 13...
Water absorption device.

Claims (1)

[Scope of Claims] 1) A water-blocking sheet that separates a predetermined area of sludge ground, and a filter member that is installed on the sludge ground in the predetermined area and has a bottom protruding from a plurality of water-permeable water collection protrusions. The processing equipment main body has a water intake pipe in a sealed chamber formed between the filter member and the water intake pipe, and the sludge ground is formed through the filter member and the water intake pipe. A sludge soil improvement device equipped with a water absorption device that extracts the moisture inside. 2) Separate the sludge ground in a predetermined area with a water-blocking sheet,
A treatment equipment main body is installed on the sludge ground in this predetermined area, the bottom part of which is permeable and the other parts of which are water impermeable, and a water suction pipe is installed inside. A method for improving sludge soil by removing moisture from it. 3) The method for improving sludge ground according to claim 2, wherein water in the sludge ground is removed by installing a treatment device main body on the sludge ground via a water-permeable sheet.