JPH0729119B2 - Solid-liquid separation method and apparatus for solid-liquid separation of dredging sludge - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a solid-liquid ionization device for aggregating and separating fine particles (microorganisms, algae, plankton, etc.) from a dredging liquid containing fine particles such as dredging liquid and dredged bottom mud. And a solid-liquid separation method.

[Prior Art] Since the particle size distribution of the fine particles in the dredged bottom mud and the dredging liquid accumulated in lakes and harbors is 50% in most cases, the particle size is several x 10 ^-3 mm or less. It is difficult to add and centrifuge and dehydrate it, and to concentrate and dehydrate it with a filter press or belt press, and environmental pollution cannot be avoided due to the addition of chemicals. Therefore, despite the fact that the sedimentation speed is less than 1 cm per day and it is difficult to acquire a vast land, the natural concentration pond method is adopted and no other effective treatment method is found.

The conventional settling tanks are too low in performance to remove dredging liquids, fine particles in lakes and seawater, and phytoplankton in vast areas, and their countermeasures cannot be taken.

[Problems to be Solved by the Invention] The present invention aims to improve solid-liquid separation performance by 1,000 times or more of the present, downsize and reduce weight, and to remove fine particles of lakes and seawater that have been difficult to remove in the past, such as phytoplankton. Etc.
It is an object of the present invention to provide a device with good performance for coagulation removal at a low cost.

[Means for Solving the Problem] In the solid-liquid separation device according to claim 1, a mixing pipe is formed by penetrating a wall of the dispersion chamber between the dispersion chamber for dispersing the supplied dredging liquid and the solid-liquid separation pond. One end of the mixing tube is opened into the dispersion chamber and the other end is opened into the solid-liquid separation basin. Insert the injection tube into the mixing tube,
The flow of injecting the injection liquid into the mixing pipe from the injection pipe discharge port,
The flow of the dredging liquid that flows into the mixing pipe single pipe portion comes into contact with the mixture, causing an electrolyte concentration difference between the fine particles at the interface,
Due to the decrease in the anti-power generation level, the violent collisions are repeated even between (1-5) × 10 ^-3 mm fine particles that are difficult to collide,
The mixed liquid that has formed huge flocs of 0.5 to 1 mm up to the mixing pipe discharge port is sent to the solid-liquid separation basin, and flocs of fine particles are separated.

A solid-liquid separation method according to claim 12 is an invention of a method for separating a dredging liquid into fine particles and a supernatant liquid by using the solid-liquid separation device according to claim 1, wherein the inside of the mixing pipe is Maintaining the flow rate of the mixed solution (dredging solution and injection solution) of 10 <Re <10 ⁵ and the flow rate of the injection solution in the injection tube of 5 <Re <10 ⁴ , contact both solutions in the mixing tube and aggregate. It almost completes the action.

The dredging liquid treated by the solid-liquid separation device of the present invention means dredging sludge [including algae (diatoms, cyanobacteria, green algae, flagellated algae) microorganisms and their dead bodies, and other organic and inorganic substances] The lake water is rich in phytoplankton, and the seawater, the actinomycetes that generate musty odor, the lake water that contains red tide flagellates, the seawater, and the settled sediment sludge of a fish farm.

Injection liquid is biological treatment supernatant, physicochemical treatment supernatant, low-concentration polluted industrial wastewater, seawater, tap water, distilled water, irrigation water and / or industrial water (lake water, river water, groundwater, etc.) To be Further, as the injection liquid, use an aqueous solution containing a coagulant, for example, a metal coagulant (aluminum salt, iron salt, activated silicic acid, magnesium salt, calcium salt) aqueous solution, an alkali metal salt aqueous solution, a polymer coagulant aqueous solution, or diatomaceous earth. You can also

The solid-liquid separation basin of the present invention is roughly divided into a settling solid-liquid separation basin 3) and a floating floating solid-liquid separation basin 26), and it is installed in the dredging liquid sampling basin 9) and on a ship separated from the dredging liquid sampling basin. Another example is the case where a pond is established on land. As an example, as shown in FIG. 2, a solid-liquid separation basin (sedimentable solid-liquid separation basin 3) is provided below the water surface in the dredging liquid collection basin, and the mixing pipe of the solid-liquid separation device or a connecting pipe connected to it is opened. The floc (dredge sludge) that has agglomerated in the solid-liquid separation basin is stored, and the supernatant liquid diffuses from the receiving port 22) on the upper surface of the solid-liquid separation basin into the dredging liquid collection basin.
As shown in the figure, there is a case where the solid-liquid separation pond and the dredging liquid collection pond are separated, and the dredging sludge aggregated in the solid-liquid separation pond is returned to the bottom of the tank and the supernatant liquid 8) is returned to the dredging liquid collection pond. . As shown in Fig. 3, a solid-liquid separation basin (floating solid-liquid separation basin 26) is installed in the dredging sampling basin. If the fine particles of the dredging liquid are buoyant, then the giant flocs agglomerated in the mixing pipe are also buoyant. The giant flocs sent from the connecting pipe to the bottom of the solid-liquid separation pond may be concentrated and floated and discharged as dredging sludge at the top of the cylinder, and the supernatant may diffuse from the bottom cylinder to the dredging sampling pond. An example of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the case where the solid-liquid separation device of the present invention (sedimentable solid-liquid separation basin 3) is isolated from the dredging liquid collection basin 9) and installed in the solid-liquid separation basin. In the solid-liquid separation device, dredging liquid 1)
A dispersion chamber 2) is provided in which is dispersedly supplied. Wall of dispersion chamber 12)
1 to a plurality of mixing pipes 4) penetrating through the pipe, and one end of the mixing pipe 4) having both ends opened in the dispersion chamber to form a dredging liquid supply port.
13), and the other end is a mixing pipe discharge port 15) that discharges the aggregate directly to the solid-liquid separation pond 3), and an injection pipe 5) for a plurality of mixing pipes.
FIG. 3 is a diagram of an apparatus in which the respective central axes are united and provided one by one. The injection pipe discharge port 14) opens toward the downstream of the mixing pipe. The flow of the injection liquid 6) supplied from the injection pipe discharge port and the flow of the dredging liquid flowing from the annular portion 17) into the single pipe portion 18) (see FIG. 4) flow in contact with each other, and at the interface, the dredging Violent collisions are repeated between the fine particles of the liquid, forming giant flocs while passing through the mixing tube. The giant flocs are prevented from being disturbed by the mixed liquid with a shielding plate 25) provided at the bottom of the solid-liquid separation pond 3), and the concentrated dredging sludge 10) is discharged and filtered out of the system. The supernatant plate 8) is sent to the dredging liquid sampling pond. The dredging liquid supply ports (13) of a plurality of mixing pipes are maintained at the same water level to equalize the inflow water amount of each mixing and the like. The number of mixing pipes is determined so that the total amount of the mixed liquid 7) of the dredging liquid amount and the injection liquid amount is maintained so that the flow velocity passing through each mixing pipe is 10 <Re <10 ⁵ . The flow rate of the injection liquid in the injection pipe is also maintained at 5 <Re <10 ⁴ .

FIG. 2 shows the solid-liquid separation device of the present invention (sedimentary solid-liquid separation basin 3).
Is installed in the dredging liquid collection pond 9). Dredging liquid 1)
A dispersion chamber 2) for supplying and dispersing is provided, and a mixing pipe is provided between the dispersion chamber and the solid-liquid separation basin 3) through the wall 12) of the dispersion chamber. The figure shows the case where the porous material 16) is loaded into the injection tube inserted into the mixing tube. The receiving port 22) of the solid-liquid separation pond 3) is
It has a cross-sectional area that accepts all of the mixed liquid 7) discharged from the mixing pipe for solid-liquid separation of the huge flocs discharged from the mixing pipe discharge port 15), and the water area load on the mixed liquid is 600 m ³ / m ² days or less is desirable. The supernatant liquid 8) diffuses from the receiving port 22) of the solid-liquid separation basin to the dredging liquid collection basin 9) and concentrates and stores the huge flocs that have settled and separated. Although it depends on the concentration and the treatment capacity of dredging sludge, the solid load per 1 m ^{3 of} solid-liquid separation basin is preferably 2500 kg / m ³ days or less. Concentrated sludge 10)
Is discharged from the bottom of the bag to the outside of the system by a discharge pipe. The arrangement of the mixing pipe (dredge liquid) and the injection pipe (injection liquid), the flow velocity in the mixing pipe, and the flow velocity in the injection pipe are in the same range as in FIG.

Fig. 3 shows a floating solid-liquid separation pond as a solid-liquid separation pond when treating floating phytoplankton as dredging sludge.
Use 6). The arrangement of the mixing pipe 4) and the injection pipe 5), and the flow velocity in the mixing pipe and in the injection pipe are in the same range as in FIG. In order to separate the giant flocs from the mixed liquid 7) discharged from the mixing pipe, the mixed liquid supplied to the buoyant solid-liquid separation pond 26) is guided to the connecting pipe 24) and the outer cylinder of the solid-liquid separation pond. Supply tangentially to. Giant flocs are swirled and concentrated while being concentrated, and discharged from the system as a dredging sludge 10) from the top of the solid-liquid separation pond 26) and the supernatant 8) is discharged from the central cylinder at the bottom of the floating solid-liquid separation pond. Diffuse into the liquid sampling pond 9).

FIG. 4 is adopted when it is desired to process a large amount of dredging liquid.
FIG. 3 is a diagram in which two injection tubes are inserted in multiple stages in the mixing tube, and the mixing tubes and the central axes of the two injection tubes are united. The central axes of the injection liquid supply pipe central axis 19), the injection pipe central axis 20), and the mixing pipe central axis 21) are completely united, and the porous material 16) is provided in each of the injection pipes.
The figure which loaded is shown. When the central axes are perfectly united, the injection pipe length can be shortened and solid-liquid separation performance can be improved.

The aggregation effect is greater than when the injection tubes are inserted in parallel in the mixing tube.

FIG. 5 is a view in which two injection pipes are inserted in parallel to one mixing pipe and the injection liquid supply pipe central axis 19) and the injection liquid central axis 20) are completely united. Since the central axis of the mixing tube and the central axis of the injection tube are not completely united, the aggregating effect is greater than that in FIG. 4 in which the mixing tube central axis and the central axis of the injection tube are completely united. Hakui.

The solid-liquid separation performance is improved because the fine particles in the dredging liquid
In contact with the injection liquid, a difference in electrolyte concentration occurs between the fine particles of (0.1 to 50) × 10 ^-3 mm, and the reduction of the anti-power generation due to this causes a strong aggregating action between the fine particles, resulting in a mixed aggregating action. Repeatedly, huge flocs are formed downstream of the mixing tube. Therefore, even bulking sludge will form huge flocs. Generally, electrolytes (ions) of both solutions
When the concentration difference is large, the cohesive force between the agglomerated fine particles and the floc particles seems to be strong. Desirably, if the electrolyte concentration difference between the injection liquid and the dredging liquid is 0.1 mg / 1 or more, flocs are easily formed, and if it is 10 mg / 1 or more, the floc forming ability is strong. Flock is formed even at 2 × 10 ⁵ mg / 1 or more, but it is not economical because the drug cost increases. When dredging liquid is sea water, by using the polyvalent metal salt in the infusion solution polyvalent metal salt concentrations from can raise the same aggregation effect 1 / 10-1 / 200 of the alkali metal salts, 2 × 10 ⁵ Can be kept below mg / 1.

In general, when the dredging liquid is seawater, the solid-liquid separation performance is higher when the liquid to be injected has a lower electrolyte concentration than seawater (industrial water, river water, etc.).

If the flow rate of the mixed tract Re> 10 ^5, flocs are not formed. If Re <10 ⁵ , flock will form. 10> Re
In this case, the processing amount of the mixing tube per pipe is small and the processing cost is high. The flow velocity in the mixing tube of the formed floc is
Even if it is destroyed once it reaches 10 ⁴ <Re <10 ⁵ ,
If Re <10 ⁵ is maintained, flocs will form. If the discharge speed of the injection liquid in or from the injection pipe becomes Re> 10 ⁴ , no flocs are formed. If Re <10 ⁴ is maintained, flock growth will be promoted. If Re <5, the treatment amount of the injection pipe per one is small, and the treatment cost becomes large.

The injection volume is less than 200% of the dredging fluid, preferably 30
~ 1%. If it is less than 1%, the aggregating effect is low, and if it is more than 200%, the floc forming ability is not changed. If it exceeds 200%, the load on the solid-liquid separation basin is too large, and the effect of increasing the injection liquid is not recognized.

The mixing pipe is placed between the dispersion chamber and the solid-liquid separation tank through the wall of the dispersion chamber, both ends of the mixing pipe are open to both chambers, and all the fine particles of the dredging liquid pass through the mixing pipe. Therefore, if it is always in contact with the injecting liquid discharged from one or a plurality of injecting pipes in the mixing pipe, collision between fine particles in the dredging liquid becomes easy, and flocs are easily formed in the mixing pipe. In the case where one or a plurality of injection pipe discharge ports are opened in the mixing pipe of the present invention, a case where a plurality of injection pipes are provided in parallel in one mixing pipe and a case where mixing pipes are mixed as shown in FIG. The case where the discharge port of the injection pipe provided in multiple stages in the pipe is opened may be mentioned. When a plurality of injection pipes are provided in multiple stages, as compared with the case where one mixing pipe is provided with one injection pipe, for example, an injection liquid containing a metal salt coagulant from the outermost upper discharge port of the injection pipe is As in the case of injecting the injection liquid containing the metal salt coagulant or the polymer coagulant from the injection port at the bottom of the section,
It is suitable for injecting different kinds of injecting liquids from different injection pipe outlets. When a plurality of injection pipes are provided in parallel, the injection liquid discharged from the adjacent injection pipes interferes with each other to cancel the difference in the concentration of the electrolytic chamber on the fine particles once formed, and the floc forming ability becomes low.

When the injection liquid supply pipe central axis 19) and the injection pipe central axis 20) are united with each other, two points of the injection pipe inlet and the injection pipe discharge port on the injection pipe central axis and two planes perpendicular to the center axis are provided. , Two points of intersection with the extension line of the injection liquid supply pipe center axis are within two circles drawn at 0.2 times the injection pipe inner diameter, centering on the two intersections of the injection pipe center axis and two planes, respectively. . When the center axis of the injection liquid supply tube and the center axis of the injection tube coincide with the intersection of the above-mentioned two planes perpendicular to the center axis of the injection tube (hereinafter referred to as complete unification), the length of the injection tube is shortened. it can. When the center axis of the injection tube and the center axis of the mixing tube 21) are united, the two points of the inlet and the outlet of the injection tube are centered on two intersection points between the two planes perpendicular to the center axis and the center axis of the injection tube. It means that there is an intersection of the central axis of the mixing tube and the above two planes in two circles drawn with 0.2 times the inner diameter of the injection tube. When the center axis of the injection tube and the center axis of the mixing tube coincide with the intersection of two planes perpendicular to the center axis of the injection tube (hereinafter referred to as “complete unification”), the agglomeration effect is large, and the length of the mixing tube is large. Can be shortened.

The length of the mixing pipe is the sum of the length of the annular part (17) where the dredging liquid contacts the injection pipe and the length from the injection pipe discharge port to the mixing pipe discharge port, that is, the length of the single pipe part (18). The pipe that connects the mixing pipe discharge port and the solid-liquid separation pond is called the connecting pipe, and is not included in the mixing pipe length. If the length of the annular part is 80 times or more the inner diameter of the mixing tube, and if the length of the single tube part is 65 times or more the inner diameter of the mixing tube, the shape of the mixing tube inlet, the viscosity of the dredging liquid, and the coefficient of friction of the tube Flock forming ability is exhibited, but the mixing tube becomes too long and not economical.

The longer the mixing pipe is, the less likely it is to be affected by the diameter of the mixing pipe, the shape of the inlet, the cohesive force of sludge, the water quality of the injection liquid, and the injection method. Desirably 0.1 to 10 m. The inner diameter of the mixing tube must be 0.01 m or less in order to be able to aggregate at 0.1 m or less.
If the inner diameter of the mixing pipe is less than this, the amount of treatment per pipe is small and the cost is high. Further, even if it is 10 m or more, it cannot be used for aggregation, but if it is 100 m or more, the solid-liquid separation device including the injection pipe length becomes huge, which is not economical. The length of this mixing tube is preferably a straight tube.

The inner diameter of the mixing tube is 0.01-5m. When the amount of water to be treated is 0.01 m or less, the pressure loss is large and the cost is high. If the length is 5 m or more, the length of the mixing pipe becomes too long and the device becomes large, which is not economical.

The mixing pipe installed between the dispersion chamber and the solid-liquid separation pond is horizontal,
Even if they are connected diagonally or vertically, the flocculating action of the present invention is greatly affected by the flow velocity in the mixing tube, but no difference in the floc forming ability in the mixing tube is observed even if the direction of the mixing tube is different. However, the dredging liquid contains fine particles that settle if they agglomerate, and fine particles that float if they agglomerate, and their characteristics do not change even if they flocculate into huge flocs.For example, blue-green algae sink in winter and surface in summer. Some of them change depending on the seasonal temperature. Even if it is dredged by suction, it is most efficient to suck up a large amount of water that is more than 10 times the amount of bottom mud, separate only the sludge on the spot, and discharge the supernatant liquid as it is to the dredging liquid collection pond. In order to enable this method to operate without causing secondary pollution, solid-liquid separation performance may be increased. For that purpose, it is necessary to provide two types of solid-liquid separation basins of sedimentation and floatability, which are suitable for the characteristics of the fine particles of the dredging liquid, and to use them alone or in combination in response to the changes in season and temperature.

The dredging liquid supply ports 13) of the plurality of mixing pipes that open to the dispersion chamber,
If they are provided at the same water level (vertical type), the amount of liquid flowing into each mixing pipe becomes equal, the mixing pipe allowable flow rate is easily maintained, and the mixing pipe in which the solid-liquid separation performance deteriorates can be eliminated.

The injection pipe diameter is dm (outer diameter) and the mixing pipe diameter is Dm (inner diameter). When the width (D-d) m of the annular portion 17) is narrow, the amount of the dredging liquid flowing into the annular portion becomes non-uniform, which reduces the floc forming ability and the solid-liquid separation performance. The outer diameter of the injection tube that allows uniform inflow must be 0.97 times or less the inner diameter of the mixing tube. If the outer diameter of the injection pipe is 0.01 times or less of the inner diameter of the mixing pipe, the speed of the injection pipe discharge port 14) will be 300 times, and the Re will be> 10 ⁴ , even if the injection liquid amount to the dredging liquid amount is 3%. The floc forming ability is lowered and the solid-liquid separation performance is lowered.

The dispersion chamber and the solid-liquid separation pond can be connected by the mixing pipe and the connecting pipe even if the two chambers exist independently at a distance.

When the porous material 16) is loaded into the injection pipe 6), the rectifying effect is greater and the aggregating performance is better when the loading position is provided at a distance of 1 time or more of the injection pipe diameter on the upstream side of the injection pipe discharge port. Has a large impact on the improvement of. If a suitable porous material is provided at an appropriate position, it is not always necessary to unite the central axis of the injection liquid supply pipe with the central axis of the injection pipe, the amount of the injection liquid can be reduced, and the injection pipe length and the mixing pipe length can be shortened. . Further, when the flow rate in the mixing tube is made of a porous material, huge flocs are formed even if the flow rate is increased to 10 times Re when the porous material is not used, that is, Re = 10 ⁵ .

Porous material is made of antibacterial polymer fiber, inorganic fiber, 100-10,000g / m ² non-woven fabric at 10mm thickness, antibacterial polymer resin with 0.005-3mm cell diameter (continuous fine cells) Sponge, 0.005 to 5 mm diameter powder, 0.005 to 3 mm hole diameter metal, inorganic, polymer resin porous plate, woven fabric, knitted fabric, net, membrane, each of which is used alone or in combination in layers. Can be given. The loading height of the porous material
It is desirable that the pressure loss is 0.1 to 500 mm and the pressure loss is 10 to 10,000 mm when the average velocity of tap water in the pipe is 5 × 10 ⁻³ m / sec. If the pressure loss is 10 mm or less, there is no rectifying effect, and if it is 10,000 mm or more, the required power is large and it is uneconomical.

The material of the main body, dispersion chamber, mixing tube, and injection tube of the device is hard synthetic reinforced plastic and / or metal.

Using solid-liquid separation device of the same structure as the solid-liquid separator shown in FIG. 1 of the first embodiment present invention, brackish canal (C1 ^- 36.7mg / 1) saw solid sludge of riverbed as dredging solution Liquid separation was performed. Insert one injection pipe with a diameter of 0.025 m to a ring length of 0.6 m in a mixing pipe with a pipe length of 1 m and a diameter of 0.05 m, and set the water level of the dredging liquid supply port of the seven mixing pipes to 0.23 m on the floor wall of the dispersion chamber, The inflow rate of dredging liquid was made uniform. Seven mixing tubes were fixed on a solid-liquid separation pond having a diameter of 0.51 m, and the ratio of the injection liquid to the injection liquid 0.16 m ³ was supplied to the dredging liquid 1 m ³ . The injectate dredging process liquid / river water (C1 ^- 3.3mg / 1) =
A 7/3 mixture was used. The flow rate in the mixing tube is 0.0425-0.1
m / sec (Re = 2125 to 5000), injection pipe discharge speed of injection liquid
The treatment was performed at 0.0234 to 0.055 m / sec (Re = 585 to 1375). The load of dredging liquid on the solid-liquid separation basin was 10.3 to 24.2 m ³ / m ² hr, and the SS concentration in the supernatant was less than 10 mg / 1.

Example-2 Using the same apparatus as in Example 1, the bottom mud and the water-bloom of the lake were treated. A. The concentration of the water-bloom liquid is 0.073 kg / m ³ , the water content of the bottom mud 80.3% is diluted to 1.87 kg / m ^3, and the mixed liquid of the water-bloom amount / bottom mud liquid = 10/1 is supplied. The flow velocity in the mixing tube is 0.04
m / sec (Re = 2000), injection pipe discharge speed of injection liquid is 0.05m / s
It was driven at ec (Re = 1250). B. The bottom mud 1.87 kg / m ³ is 0.0
Supply at a speed of 4 m / sec and the discharge port of the mixing pipe is below the sludge interface.
After reaching 0.5m, the supply of bottom mud was stopped and the water-bloom solution 0.073k
The supply of g / m ³ to the mixing tube was started at a rate of 0.04 m / sec, the injection rate of the injecting liquid was 0.05 m / sec, and the sludge interfacial meter extracted the rate at a rate commensurate with the deposition rate at the dredging sludge interface. As the injection liquid, a mixed liquid of treated water of A / tap water = 7/3 was used for both A and B. Load of water-blowing liquid of B to solid-liquid separation pond 9.7 m ³ / m ² hr,
Even if the amount of Aoko feed liquid of B is double that of A, SS of treated water is
It was 10 mg / 1, which was 14 times that of A, which was 4 times. The B dredged sludge sludge concentration was 4.3-6.7%.

Example-3 The blue-green algae of the lake were subjected to a floating treatment using a solid-liquid separation device of the same type as in FIG. In order to efficiently separate the blue-green algae that float at high temperature in summer, the sedimentation separation type solid-liquid separation pond in winter is not efficient, so the floating solid-liquid separation pond was adopted. The water-bloom that floated on the surface of the water was scraped with fluence and treated as a dredging liquid of SS180mg / 1 by a solid-liquid separation device. Mixing tube diameter 9 cm,
Pipe length 180 cm, injection pipe diameter 6 cm, pipe length 150 cm, upstream of the injection pipe discharge port 60 cm, porous propylene non-woven fabric thickness 10 mm, and basis weight 1560 gr / m ² 50 mm were loaded, and the central axes of the injection pipe and the mixing pipe were combined. Made one The dredging liquid supply port of the mixing tube was opened at a length of 120 cm of the annular portion of the mixing tube and at a water level of 25 cm on the floor wall of the dispersion chamber. The injection liquid used was seawater / treated water = 1/10. Injected liquid amount / dredging liquid amount = 1/10, mixed liquid processing amount of one mixing tube is 40
m ³ / day The water-bloom is washed with NaCl in the injection liquid discharged from the injection liquid discharge port, and a difference in the surface electrolyte concentration occurs between the unwashed water-bloom particles, and the collision effect is enhanced based on that difference, and the mixing pipe is discharged from the injection pipe discharge port. By the outlet, Aoko forms a huge floc. The mixed liquid discharged from the mixing pipe discharge port is tangentially supplied to the outer cylinder of the buoyant solid-liquid separation basin, and the huge flocs are concentrated as dredging sludge to 8 to 15.5 kg / m ³ or more. It is sent from the upper part of the separation pond to a pressure flotation device outside the system and further concentrated to 40 kg / m ³ or more. The amount of dredging liquid to be supplied is 450 m per 1 m ^{2 of} water surface of buoyant solid-liquid separation pond.
³ / day, solid load is 27.3 kg / day per 1 m ^{3 of} volume.
The supernatant liquid is discharged from the bottom cylinder of the floating solid-liquid separation pond. The SS concentration in the effluent was 6-12 mg / 1.

Example-4 Using the same type of flocculation device as in Fig.-2, the sludge on the marsh floor was treated. One injection tube diameter (6 cm) was inserted into one mixing tube (diameter 7.5 cm), and the mixing tube central axis and the injection tube central axis were completely united. A) A porous material [propylene non-woven fabric (thickness 10 mm, basis weight 1080 g / m ² ) 15 mm thick 4
The total thickness is 60 mm in a layered form] upstream from the injection port discharge port
A rectifying layer was provided by filling 50 cm. B) There was no rectifying layer in the injection tube. Both AB had an injection pipe length of 160 cm, the mixing pipe had a single pipe length of 80 cm, an annular length of 120 cm and a total length of 200 cm, and a mixing pipe with a water level of 25 cm was provided on the floor wall of the dispersion chamber. The solid-liquid separation pond is a bag made of synthetic fiber woven cloth, one end of which opens upward, and serves as a receiving port for the giant flocs formed by the mixing tube. The water area load was 6 m ³ / m ² hr. A metal ring was used to hold the receiving port in the form of a bag, and the bag was suspended on a fixed buoy above the surface of the water. The bottom of the bag was fixed to the bottom of the lake and concentrated sludge was pulled out from the tip of the bottom. Dredging sludge [moisture (dry basis) 520%,
Ignition loss 19%, TOC 86mg / g dry mud, COD25.8mg / 1, filtrate C1
^- 3.6 mg / 1] and a mixture of the infusion liquid, mixing tube 55 per one
m ³ / day (Re = 1.1 × 10 ⁴ ) was supplied to the dispersion chamber, and 6 m ³ / day per injection pipe was used as injection water for river water (COD 2 mg / 1) Fe.
(Trivalent) 5 mg / 1 was added and supplied. C) Fe (trivalent) 25 mg /
Add 0.11 of injection liquid to 0.61 with dredging sludge and 90G / s in coagulation tank
Ec force was applied for 4 minutes and flocs were removed by filtration. Filtration was performed at a filtration rate of 18 m / hr on a filter bed packed with sand particles having a particle diameter of 0.8 mm to a thickness of 12 cm. Concentration of SS in filtrate, concentration of dredging sludge concentrated in solid-liquid separation basin, and concentration of overflow supernatant
The SS concentration is shown in Table-1.

[Effects of the Invention] The present invention is configured as described above. When the dredging liquid comes into contact with the injection liquid flowing out from the injection pipe discharge port in the mixing tube, collision agglomeration occurs between the fine particles having a particle size of (1 to 5) × 10 ⁻³ mm, which are difficult to collide at the interface, After further collision, a huge floc of 0.5 to 1 mm is formed in the mixing tube within a few seconds. Its solid-liquid separation performance is large, and the sedimentation speed of conventionally dredged bottom mud natural dehydration basin is 1 cm / day or less, and the solid-liquid separation device of the present invention can perform solid-liquid separation treatment in 300 m ³ / m ² days or more. Further, since the solid-liquid ionizer of the present invention is small and lightweight, it can be installed easily and installed in an existing dredging boat to improve the solid-liquid separation performance by several tens of times.

Since the solid-liquid separation device of the present invention can use the electrolyte in the dredging liquid as an aggregating liquid of the fine particles in the dredging liquid, the cost of the aggregating agent can be reduced.

Since an injection liquid containing an alkali metal salt as a coagulant can be used in the solid-liquid separation device of the present invention, it is possible to perform coagulation separation of microorganisms in lakes and mares that hate polyvalent metal salts and microorganisms that are difficult to settle.

Furthermore, when using an injection liquid containing a polyvalent metal salt as an aggregating agent, the concentration of the injection liquid to be injected into the mixing tube is the same as about a fraction of the concentration of the aggregating liquid added by the aggregating liquid adding method of the conventional aggregating apparatus. The solid-liquid separation performance is demonstrated, and the coagulant cost is low.

The conventional aggregating device requires a high-speed stirring chamber for collision between fine particles, but the solid-liquid separation device of the present invention only causes the injection liquid and the dredging liquid to come into contact with each other in the mixing pipe, so that the collision of the fine particles is prevented. Offensive and forming huge flocs, power for collision,
No high-speed agitation room or flock growth room is required.

A mixing pipe between the dispersion chamber and the solid-liquid separation pond is used in the lateral direction, diagonal direction,
Even if they are connected in the vertical direction, or if the dispersion chamber and the solid-liquid separation basin that are separate from each other are connected by the mixing pipe and the connecting pipe, the formation of huge flocs in the mixing pipe will be completed. ,
If the flow velocity in the connecting pipe is Re <10 ^5, there is no difference in solid-liquid separation performance regardless of the connection direction and connection method because the flocs are not destroyed. A floating solid-liquid separation basin may be provided for the floating flocs, and a sedimentary solid-liquid separation basin may be provided for the settling flocs.

Since the interface between the sludge in the solid-liquid separation pond and the supernatant liquid is distinct, it is possible to detect the inflowing sludge with an optical sensor for its sedimentation (floating) deposition rate and automatically extract it according to that rate. Because it can be done, operation management is easy.

Since the sludge interface is distinct in the sedimentation solid-liquid separation pond, if you control the sludge interface with an optical sensor, you can simply set up a simple room or bag that does not allow huge flocs to flow under the surface of the dredging liquid collection pond. It is possible to obtain a concentrated dredged sludge because a sufficient residence time can be taken for the solid-liquid separated dredged sludge. The room and bag may be constructed of cloth, synthetic resin film, wood and / or metal plate, and the supernatant liquid may be diffused from the upper surface of the solid-liquid separation basin to the dredging liquid collection basin.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the solid-liquid separation tank of the present invention provided with a solid-liquid separator (sedimentary solid-liquid separation tank). FIG. 2 is a cross-sectional view of a case where a solid-liquid separation device (sedimentary solid-liquid separation basin) is provided in the dredging liquid collection basin of the present invention. FIG. 3 is a cross-sectional view of a case where a solid-liquid separation device (floating solid-liquid separation pond) is provided in the dredging liquid collection pond of the present invention. FIG. 4 is a cross-sectional view in which the injection liquid supply pipe central axis, the injection pipe central axis and the mixing pipe central axis of the present invention are completely united, and the injection pipe discharge port in which the porous material is loaded in the mixing pipe is opened in multiple stages. Is. FIG. 5 is a cross-sectional view in which the discharge ports of two injection pipes are opened in parallel in the mixing pipe. 1: Dredging liquid, 2: Dispersion chamber, 3: Solid-liquid separation tank (sedimentary solid-liquid separation tank) 4: Mixing tube, 5: Injection tube, 6: Injection solution, 7: Mixed solution, 8: Supernatant solution 9 : Dredging liquid collection pond, 10: Dredging sludge, 11: Injection liquid supply pipe, 12:
Wall 13: Dredging liquid supply port, 14: Injection pipe discharge port, 15: Mixing pipe discharge port 16: Porous material, 17: Annular part, 18: Single pipe part, 19: Injection liquid supply pipe central axis 20: Injection pipe Central axis, 21: mixing tube central axis, 22: receiving port, 2
3: Lake (sea) bottom 24: Connection pipe, 25: Shield, 26: Solid-liquid separation pond (floating solid-liquid separation pond)

Claims (16)

[Claims] 1. A dispersion chamber 2) for dispersing a dredging liquid 1) and a solid-liquid separation basin 3) for separating fine particles and a supernatant liquid, one end of which is a dispersion chamber and the other is between them. Disperse one or more mixing tubes 4) whose ends open into the solid-liquid separation tank 4) into the dispersion chamber wall 12).
From the dredging liquid containing fine particles, characterized in that it has a structure in which one or a plurality of injection pipes 5) for injecting the injection liquid 6) are provided in the mixing pipe. Solid-liquid separator that separates into and. 2. A solid-liquid separator having a structure in which a mixing pipe 4) is provided between a dispersion chamber 2) and a solid-liquid separation basin 3) and the two are connected to each other. The solid-liquid separation device according to claim 1, wherein the solid-liquid separation device is arranged in any one of a vertical direction and a vertical direction. 3. The solid-liquid separation device according to claim 1, wherein the dispersion chamber 2) and the solid-liquid separation basin 3) are connected by a mixing pipe 4) and a connecting pipe. 4. A supply pipe for supplying an injection liquid 6) to the injection pipe 5).
11. The solid-liquid separation device according to claim 1, which further comprises 11). 5. The solid-liquid separator according to claim 4, wherein the central axes of the injection liquid supply pipe 11) and the injection pipe 5) are unified. 6. The solid-liquid separation device according to claim 1, wherein the central axes of the injection pipe 5) and the mixing pipe 4) are united. 7. The solid-liquid separator according to claim 1, which has a structure in which a porous material 16) is loaded in the injection pipe 5). 8. The injection pipe diameter (outer diameter) is the same as the mixing pipe diameter (inner diameter).
The solid-liquid separation device according to claim 1, wherein the amount is 0.01 to 0.97 times. 9. A dredging liquid supply port 13) which flows into a plurality of mixing pipes.
The solid-liquid separator according to claim 1, wherein the water levels are the same. 10. The solid-liquid separation device according to claim 1, wherein the solid-liquid separation tank comprises a sedimentable solid-liquid separation tank 3) and / or a floating solid-liquid separation tank 26). 11. The solid-liquid separation device according to claim 1, wherein the solid-liquid separation pond has a structure in which a room or a bag is provided in the dredging sampling pond 9). 12. The solid-liquid separation device according to claim 1, wherein a dredging liquid containing fine particles is used to obtain fine particles and a supernatant liquid 8).
The flow of the mixed solution in the mixing tube is 10 <Re
<10 ^5, a solid-liquid separation method for separating fine particles from the dredging liquid flow injection tube of the injection solution, characterized in that maintained in the range of 5 <Re <10 ^4. 13. The solid-liquid separation method according to claim 12, wherein the injection liquid amount is 1 to 200% of the dredging liquid amount. 14. The solid-liquid separation method according to claim 12, wherein the difference between the electrolyte concentration in the injection liquid and the electrolyte concentration in the dredging liquid is in the range of 0.1 mg / 1 to 2 × 10 ⁵ mg / 1. 15. The solid-liquid separation method according to claim 12, wherein the electrolyte concentration in the injection liquid is lower than the electrolyte concentration in the dredging liquid. 16. The solid-liquid separation method according to claim 12, wherein the electrolyte concentration in the injection liquid is higher than the electrolyte concentration in the dredging liquid.