JPH11319848A - Method and apparatus for treatment of muddy water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate muddy water containing soil and sands into a granular solid and clear reusable water without utilizing a dehydration apparatus. SOLUTION: This muddy water treatment system is equipped with a vibrating screen 14 for separating muddy water into muddy soil and a suspension water, a separation tank 20 wherein a flocculant is added to the suspension water for separating it into flocks and clear water, a biaxial mixer 16 wherein caking agent 28 and auxiliary caking agent 29 are added to the muddy soil and flocks and a stirring is carried out thereby a granular solid 30 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muddy water treatment technique for separating muddy water mixed with earth and sand generated in various civil works such as excavation of ground into granular solids and reusable clear water.

[0002]

2. Description of the Related Art Muddy water mixed with earth and sand generated in civil engineering works is difficult to transport and reuse as it is.
Since disposal in rivers and the like may cause environmental pollution, various techniques for treating such muddy water have been conventionally developed.

[0003] Conventional mud water treatment techniques include, for example, Japanese Patent Publication No. 6-62952, Japanese Patent Laid-Open Publication No. 7-1000, Japanese Patent Publication No. 7-100160, and Japanese Patent Publication No. 7-108.
There is one disclosed in, for example, Japanese Patent Publication No. 395.

According to the techniques disclosed in these publications, flocs and solids are formed by adding a predetermined chemical to muddy water generated in civil engineering work and the like, and moisture is generated from these flocs and solids. By removing, a non-fluid such as a dewatered cake having a water content ratio that can be transported, discarded, or reused can be obtained.

[0005]

In the case of the conventional muddy water treatment technology disclosed in the above-mentioned publications and the like, in order to reduce the water content of the finally obtained dewatered cake and the like, some type of dewatering means is used. A step of removing water from flocs and solids is required. For this reason, for example, a large-scale dewatering device such as a filter press or a centrifugal separator is often installed.

[0006] In addition, what is finally obtained by the muddy water treatment technology disclosed in the above-mentioned publications is clay-like and soil-like bodies such as dewatered cakes. Is inconvenient and its use when reused is limited. Further, since these dehydrated cakes and the like have water solubility, if they are so-called piled-up state, they may absorb rainwater and the like and may elute again as muddy water.

[0007] Furthermore, these dehydrated cakes and the like do not have the standard performance required for materials for civil engineering work, and thus cannot be reused as backfill materials or the like in this state. Further, even if these dewatered cakes are subjected to a specific treatment to reduce the water content, there is a problem that it is difficult to compact the compacts by compaction, so that they cannot be reused as backfill materials.

[0008] Therefore, dewatered cakes containing no harmful substances are dumped into a stable disposal facility, and dehydrated cakes containing harmful substances are dumped into a managed or shielded disposal facility. This is the actual situation.

Accordingly, an object of the present invention is to provide a muddy water treatment technique capable of separating muddy water mixed with earth and sand into granular solids and reusable clear water without using a dewatering device. To provide.

[0010]

In order to solve the above-mentioned problems, a muddy water treatment method according to the present invention comprises the steps of:
Alternatively, a solidifying material and a solidifying aid are added to a floc formed by adding a coagulant to muddy water, and the mixture is stirred to make the earth and sand and the floc into a granular solid. Here, the floc refers to a particle aggregate generated by aggregation and which can be regarded as independent particles. Also,
A granular solid is a granular material having a diameter of about 1 mm to 10 mm, having a performance equivalent to fine aggregate used as building aggregate, and having a property of not easily scattering by wind or the like in the outside air. Say.

The coagulant is added to earth and sand separated from the muddy water or muddy water, and a flocculant is formed. The solidified material and the solidification aid are added to the separated floc and agitated. The sediment and floc solidified by the action of the solidifying material gradually adhere to the surroundings, and the particle size gradually increases, so that the sediment and floc can be changed to a granular solid. In this case, a part of the water contained in the earth and sand or the floc is absorbed by the solidification aid, and the overall water content is reduced.
Muddy water mixed with earth and sand can be separated into clarified water and granular solids having a low water content, and reuse or disposal thereof becomes easy.

In the muddy water treatment method of the present invention, sodium alginate, polyacrylamide,
By using a material containing at least one of a polyacrylate and a polymethacrylate, muddy water can be efficiently separated into floc and clear water in a short time. In this case, EF-2 (trade name) which is a drug containing sodium alginate as a coagulant,
Alternatively, a polymer flocculant ED-1 (trade name), ED
-2 (trade name) (all distributors: DI Techno Co., Ltd.) and the like can be preferably used.

In the muddy water treatment method of the present invention, a solidification material containing calcium oxide and a solidification aid containing at least one of calcium carbonate, dry sand, slag, and incinerated ash can be used. Calcium oxide contained in the solidified material generates heat when it reacts with water and changes to calcium hydroxide.When added to earth and sand or floc, it absorbs the water contained therein, and due to the heat generated at that time, the water generates heat. By evaporating and dehydrating, the water content of the earth and sand and the floc can be reduced, and the solidification reaction proceeds rapidly due to heat generation.

Further, by adding a solidifying aid such as calcium carbonate, dry sand, slag, and incinerated ash to soil and floc containing water, a part of the water in the soil and the floc is solidified. , The overall moisture content can be reduced. Furthermore, when the floc, which is an aggregate of fine particles, is granulated by adhering around these solidification aids as the central core, the coagulant in the floc functions as a binder, which results in efficient granulation. Progress.

In this case, as a solidifying material, quicklime or a calcium oxide-based drug, Staby P (trade name),
Stubby S (trade name), Stubby G (trade name) (all distributors: DCR System Co., Ltd.) and the like can be preferably used, whereby granules having a water content of about 30% to 50% can be used. A solid body can be obtained. In addition, when Staby P, Staby S, and Staby G are used, the fatty acids and the like contained therein cause hydrophobicity in the granular solid, so that there is no danger of elution of harmful substances due to rainwater or the like.

Further, in the muddy water treatment method of the present invention, by setting the moisture content of the solidification aid to 10% or less, the transfer of the water in the earth and sand or the floc to the solidification aid can be performed more efficiently. Therefore, a granular solid having a low water content and excellent reusability can be obtained.

On the other hand, the muddy water treatment apparatus of the present invention comprises a first separating means for separating muddy water into earth and sand and a suspension water, and a second separating means for adding a flocculant to the suspended water to separate it into floc and clear water. And a granulating means for adding a solidifying material and a solidifying aid to earth and sand and floc and stirring the solid content and floc to obtain a granular solid.

With this configuration, the muddy water is separated into earth and sand and suspended water by the first separating means, the suspended water is separated into floc and clear water by the second separating means, and these are separated by the granulating means. Can be granulated, so that muddy water mixed with earth and sand can be finally separated into clear water and granular solids. That is, a reusable granular solid and clear water can be obtained from muddy water mixed with earth and sand without using a dehydrating device.

Further, in the muddy water treatment apparatus of the present invention, as the first separating means, a mesh or a perforated plate for passing only the suspension water and a vibration mechanism for vibrating the mesh or the perforated plate can be provided. . With this configuration, the work of separating muddy water mixed with earth and sand into solids such as earth and sand and suspended water can be efficiently performed. In this case, a vibration sieve or the like can be suitably used.

Further, in the present invention, as the second separating means, a storage tank containing a suspension to which a flocculant is added,
A floc transfer mechanism for collecting floc settled in the storage tank and feeding the floc to the granulating means can be provided. With this configuration, the suspension is separated into flocs and clarified water in the storage tank, and the flocs are removed, so that clarified water that can be discarded or reused can be obtained.

Further, in the muddy water treatment apparatus of the present invention, as the flock transfer mechanism, a belt body circulating between a bottom portion of the storage tank, an upper space of the storage tank, and a flock inlet formed in the granulating means, A water-permeable container which is locked to the body and has a function of scooping the flocs at the bottom of the storage tank and discharging the flocs at the input port can be provided.

With such a configuration, the floc settling at the bottom of the storage tank can be continuously collected and charged into the granulating means, and the water-permeable container into which the floc has been scooped can be stored. When passing through the upper space of the flock, the water in the flock falls through the water-permeable container and can be fed into the granulation means with the water content of the flock reduced, thus increasing the efficiency of the granulation process. can do.

By mounting the muddy water treatment apparatus of the present invention on a movable trolley or automobile, it is possible to quickly move to an excavation site, move within the site, etc. This improves the workability, which can contribute to shortening the construction period of excavation work.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a configuration of a muddy water treatment device according to an embodiment.

The muddy water transferred from another device such as the suction device 10 or the muddy water mixed with earth and sand transferred from the excavator 11 or the like is accommodated in the water collecting tank 12, and the vibrating screen provided with the fine mesh mesh by the pump 13. After being sent to 14 and classified into solids and suspension water, the solids are fed into a mixer 16 via a measuring tank 15.

The suspended water that has passed through the vibrating screen 14 is stored in a regulating tank 17, where the concentration is checked by a concentration sensor 18 and the like.
To the coagulant tank 21 in the water supply path.
A polymer flocculant corresponding to the flow rate is added from the above. When the concentration of the suspension water in the adjustment tank 17 is high, the suspension 22 is sent to the wet cyclone 23 by the pump 22 to be separated into low-concentration suspension water and solids. It is also possible to adopt a configuration in which it is put on the screen 14. In this case, the suspension water in the adjustment tank 17 can be reused for excavation work by the excavator 11.

Here, the polymer flocculant is added in the water supply path, and the suspended water sent to the separation tank 20 via the line mixer 24 is converted into floc by the suspended substance forming flocs in the separation tank 20. And clear water. In this case, the floc settles at the bottom of the separation tank 20. Therefore, the net bucket 26 attached to the continuously rotating chain 25 continuously scoops the floc at the bottom of the separation tank 20. After the water in the floc is dropped while moving above the container, it is fed into the mixer 16 via the measuring tank 15. Separation tank 2
The clarified water within 0 can be reused in a high-pressure water drilling method or the like, and can be discharged to a river or the like after pH adjustment.

On the other hand, in the mixer 16, the solidifying material 28 containing calcium oxide and the solidifying aid 29 containing calcium carbonate are weighed in the measuring tank 27 and then charged. Separation tank 20
Is mixed with the floc, the solidifying material 28 and the solidifying aid 29 recovered from
Solidification and granulation are performed using the solidification aid 29 as a central core, and a granular solid 30 can be obtained. In this case, by setting the water content of the solidification aid 29 to 10% or less, the water content of the granular solid 30 becomes about 40%, and the reusability is excellent. In addition, as the solidification aid 29, in addition to calcium carbonate, dry sand, slag, incinerated ash, or the like can be used alone or as a mixture.

The granular solid 30 obtained by the muddy water treatment apparatus of this embodiment satisfies the JIS soil test, CBR test, and other necessary tests, and can be compacted by compaction or the like. In addition to the return material, it can be suitably used as a roadbed material, a roadbed material, and the like.
Here, the CBR test is a test in which a geosynthetic test piece is attached to a mold for CBR test with tension, a penetration rod is pushed in, and a penetration resistance is measured.

When the transferred muddy water is sludge-like muddy water 31, the liquid is directly charged into the measuring tank 15 without passing through the vibrating screen 14 to perform predetermined measurement, and then charged into the mixer 16. By kneading with the solidifying material 28 and the solidifying aid 29, granulation can be performed. In this case, since the transferred mud contains moisture from the beginning, no additional water is required in the solidification and granulation step, but the finally obtained granular solid 30 is used as a backfill material. When a predetermined water content is required, water can be adjusted by adding water during kneading.

In the present embodiment, EF-2 (trade name) which is a drug containing sodium alginate, ED-1 (trade name) which is a polymer flocculant, and ED-
2 (trade name) (all distributors: DI Techno Co., Ltd.) was able to obtain an excellent coagulation effect. In addition, as a solidifying material, a calcium oxide-based drug such as Stubby P (trade name), Stubby S (trade name), and Stubby G (trade name) (all sold by DCR System Co., Ltd.) When calcium carbonate and dry sand having a water content of 10% or less were used as the materials, a granular solid having a water content of about 40% was finally obtained.

Next, a muddy water treatment device mounted on a vehicle will be described with reference to FIGS. FIG. 2 is a partially cutaway right side view showing a muddy water treatment device mounted on an automobile, FIG. 3 is a plan view of the muddy water treatment device, and FIG. 4 is a partially cutout left side view of the muddy water treatment device.

In the muddy water treatment apparatus 40 of the present embodiment, muddy water mixed with earth and sand is introduced into a vibrating screen 42 via a receiving pipe 41 and separated into earth and sand and suspended water. The suspension water is supplied to a stirring tank 44. In the two-axis bag mill mixer 43, the solidified material storage tank 45 and the solidified auxiliary material storage tank 4
From step 6, a solidifying material containing calcium oxide and a solidifying aid containing calcium carbonate are added, and stirring is performed.

Further, for the suspension water in the stirring tank 44,
After the polymer flocculant in the flocculant storage tank 47 is added by the flocculant metering pump 48, the polymer flocculant is sent to the separation tank 50, and the floc and the clarified water are separated in the separation tank 50,
Flock settles to the bottom. Here, the floating mixer 49 promotes floc formation by mixing and stirring the suspension water and the polymer flocculant, thereby adsorbing the polymer flocculant on the particles in the suspension water and adsorbing the floating particles. It has a function to make it work. The floc settled at the bottom of the separation tank 50 is scooped into a mesh bucket 52 that circulates by the rotation of the chain 51, and after the moisture in the floc drops while passing over the separation tank 50, the biaxial bag mill mixer 43. It is thrown.

Therefore, in the biaxial bag mill mixer 43, the above-mentioned solidified material containing earth and sand, calcium oxide,
Mixing of solidification aid and floc containing calcium carbonate,
The stirring causes a water-absorbing exothermic reaction of the calcium oxide-based component, and granulation with the solidification aid as the central nucleus is performed, whereby a granular solid body 58 can be obtained. The granular solid body 58 is discharged by a drawing screw conveyor 53, a vertical screw 54, and an upper screw conveyor 55. The upper screw conveyor 55
As shown in FIG. 3, since it is possible to rotate around the screw rotation fixing device 56, it is possible to change the discharge position of the granular solid body 58.

On the other hand, since the clarified water in the separation tank 50 can be discharged via a pH adjusting device (not shown) or the like, it can be reused as drilling water for a high-pressure drilling method or the like. . Further, the suspension water in the stirring tank 44 can also be discharged by the pump 57, and can be used for other excavators.

In the muddy water treatment apparatus 40, the EF
-2 (trade name), ED-1 (trade name), ED-2 (trade name) (all distributors: DI Techno Co., Ltd.)
By using, an excellent aggregation effect could be obtained.
In addition, as a solidifying material, Stubby P (trade name), Stubby S
(Trade name), Stubby G (trade name) (all distributors: DC System Co., Ltd.), and calcium carbonate and dry sand were used as solidification aids.
A granular solid body 58 having a water content of about 40% was obtained.

As described above, the muddy water treatment apparatus 40 can separate muddy water mixed with earth and sand into granular solids and clarified water without using a dehydrating apparatus. Reusable. In addition, the muddy water treatment device 40 is mounted on an automobile, and can be quickly moved to a digging work site, moved inside the site, etc., and has excellent mobility, contributing to shortening the construction period of the digging work. can do.

[0039]

According to the present invention, the following effects can be obtained.

(1) A solidifying material and a solidifying aid are added to earth and sand separated from muddy water or floc formed by adding a flocculant to muddy water, and the mixture is agitated to turn the sand and floc into a granular solid. As a result, muddy water mixed with earth and sand can be separated into clarified water and granular solids having a low water content, so that the granular solids can be reused as various civil engineering materials. Use or disposal becomes easy.

(2) By using a material containing calcium oxide as a solidifying material and a material containing at least one of calcium carbonate, dry sand, slag, and incinerated ash as a solidifying aid, the calcium oxide contained in the solidified material is reduced. Since it reacts with water and generates heat, the water contained in the earth and sand and floc is absorbed, and the heat generated at that time evaporates and dehydrates, lowering the water content of the earth and sand and floc, and the solidification reaction due to the heat generation It progresses rapidly. In addition, by adding a solidification aid such as calcium carbonate to soil and floc containing water, a part of the water in the soil and floc is transferred to the solidification aid and the overall moisture content is reduced. Granulation can proceed efficiently with these solidification aids as central nuclei.

(3) By setting the water content of the solidification aid to 10% or less, the water in the soil and flock can be more efficiently transferred to the solidification aid, so that the water content is low. Thus, a granular solid excellent in reusability can be obtained.

(4) First separating means for separating muddy water into earth and sand, suspended water, second separating means for adding flocculant to the suspended water to separate floc and clarified water, and solidifying into sediment and floc By adding a material and a solidification aid, and by providing a granulating means for granulating the sand and flocs by stirring, muddy water is separated into earth and sand and suspended water by the first separation means,
The suspension water is separated into floc and clear water by the second separation means,
Since these soils and flocs can be converted into granular solids by the granulating means, reusable clear water and granular solids can be obtained from muddy water without using a dehydrator.

(5) As a first separating means, by providing a mesh or perforated plate for passing only suspended water and a vibration mechanism for vibrating these meshes or perforated plates, muddy water mixed with earth and sand is removed. The work of separating into solids and suspension water can be performed efficiently.

(6) As a second separating means, a storage tank containing a suspension to which a flocculant has been added, and a floc transfer mechanism for collecting floc settled at the bottom of the storage tank and feeding the floc to the granulating means. By disposing the suspension, the suspension is separated into flocs and clarified water in the storage tank, and the flocs are removed, so that clarified water that can be discarded or reused can be obtained.

(7) As a flock transfer mechanism, a belt body circulating between the bottom of the storage tank, an upper space of the storage tank, and a flock inlet formed in the granulating means, and a storage tank of the storage tank locked by the belt body By providing a water-permeable container having a function of scooping the flocs at the bottom and discharging the flocs at the loading port, it is possible to continuously collect the flocs settled at the bottom of the storage tank and to put the flocs into the granulating means. Yes, when the water-permeable container scooped the flock passes through the space above the storage tank, the water in the flock drops through the water-permeable container,
The floc can be fed to the granulation means in a state where the water content of the floc is reduced, and the granulation step can be made more efficient.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a muddy water treatment apparatus according to an embodiment.

FIG. 2 is a partially cutaway right side view showing the muddy water treatment apparatus according to the embodiment.

FIG. 3 is a plan view of the muddy water treatment device shown in FIG.

FIG. 4 is a partially cutaway left side view of the muddy water treatment apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Suction apparatus 11 Excavator 12 Water collecting tank 13, 19, 22, 57 Pump 14 Vibration screen 15, 27 Metering tank 16 Mixer 17 Adjusting tank 18 Concentration sensor 20, 50 Separation tank 21 Coagulant tank 23 Wet cyclone 24 Line mixer 25, REFERENCE SIGNS LIST 51 chain 26, 52 mesh bucket 28 solidifying material 29 solidifying aid 30 granular solid body 31 sludge muddy water 40 muddy water treatment device 41 receiving pipe 42 vibrating screen 43 biaxial bag mill mixer 44 stirring tank 45 solidifying material storage tank 46 solidifying auxiliary material storage Tank 47 Coagulant storage tank 48 Coagulant metering pump 49 Floating mixer 53 Extraction screw conveyor 54 Vertical screw 55 Upper screw conveyor 56 Screw rotation fixing device 58 Granular solid

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Uenaga 2-82 Watanabe-dori, Chuo-ku, Fukuoka City, Fukuoka Prefecture Inside Kyushu Electric Power Co., Inc. Kyushu Electric Power Co., Inc. (72) Inventor Takato Nakajima 1-19-19 Nabeshima, Saga City, Saga Prefecture DI Techno

Claims (8)

[Claims] 1. A method of adding a solidifying material and a solidifying aid to a sediment separated from muddy water or a floc formed by adding a flocculant to muddy water and stirring the sediment and the floc to form a granular solid. And a muddy water treatment method. 2. The method according to claim 1, wherein the coagulant is sodium alginate,
The muddy water treatment method according to claim 1, wherein the muddy water treatment contains at least one of polyacrylamide, polyacrylate, and polymethacrylate. 3. The solidification material contains calcium oxide, and the solidification aid contains at least one of calcium carbonate, dry sand, slag, and incinerated ash. Mud water treatment method. 4. The muddy water treatment method according to claim 1, wherein the water content of the solidification aid is 10% or less. 5. A first separating means for separating muddy water into soil and suspended water, a second separating means for adding a flocculant to the suspended water to separate floc and clear water, the sediment and the floc A muddy water treatment apparatus, comprising: a granulating means for adding the solidifying material and the solidifying aid to the mixture and agitating the soil and the floc to form a granular solid. 6. The muddy water treatment apparatus according to claim 5, further comprising, as the first separating means, a net or a perforated plate that allows only suspended water to pass through, and a vibration mechanism that vibrates the net or the perforated plate. 7. A storage tank containing the suspension water to which the flocculant has been added, and a floc transfer mechanism for collecting floc settled in the storage tank and putting the floc into the granulating means as the second separating means. The muddy water treatment apparatus according to claim 5, comprising: 8. A belt body that circulates between the bottom of the storage tank, the space above the storage tank, and a flock inlet formed in the granulating means, and is engaged with the belt body as the flock transfer mechanism. 8. The muddy water treatment apparatus according to claim 7, further comprising: a water permeable container having a function of scooping a floc at the bottom of the storage tank and discharging the floc at the input port.