JP2016023426A - Dredging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dredging system having a water feeding pump hung from a barge-type platform floating on a reservoir water surface, capable of vacuuming bottom mud with the water feeding pump for dredging and efficiently separating and recovering the vacuumed bottom mud.SOLUTION: A dredging system 100 of the present invention uses an inorganic neutral coagulant for coagulating bottom mud and transports bottom mud slurry (bottom mud and supernatant water) from a reservoir to a belt press part 80 by pumping a water feeding pump 20 and using a natural water flow. As such, condensed bottom mud may be transported to the belt press part 80 with its high concentration retained, without re-dispersing the coagulated and condensed bottom mud. The dredging system 100 of the present invention dehydrates the condensed bottom mud continuously with the belt press part 80, enabling separation and recovery of the bottom mud at an extremely high efficiency.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dredging system that sucks bottom mud collected at the bottom of a reservoir together with water and separates and collects the bottom mud.

  Conventionally, soil, sand, garbage, sludge, and other bottom mud gradually accumulate in reservoirs such as lakes, moats, artificial ponds, and agricultural ponds. The accumulation of bottom mud reduces the original function of the reservoir by reducing the depth of the reservoir, and also contributes to the deterioration of water quality. Therefore, it is preferable to periodically perform dredging to remove these bottom mud.

  In general, the dredging of the conventional reservoir is performed by heavy machinery after draining the water from the reservoir. However, this method requires water shielding to the reservoir and drainage of the reservoir, which requires some civil engineering work, a long work period, and high costs. Another problem is that the reservoir cannot be used during dredging work. Furthermore, since the water in the reservoir is extracted, there is a problem that aquatic animals and plants that inhabit the reservoir are killed, and the ecosystem of the reservoir is greatly adversely affected.

  In response to this problem, the present inventor has invented a lake water system shown in [Patent Document 1] below. In the invention described in [Patent Document 1], a water pump is suspended from a pontoon floated on the surface of a reservoir, and the bottom mud is sucked by this water pump to perform dredging. For this reason, the water shielding work and drainage work of the reservoir are unnecessary, and the work period can be shortened and the cost can be reduced. Moreover, since dredging can be performed without draining the water from the reservoir, the ecosystem of animals and plants that live in the reservoir can be maintained.

JP 2007-146425 A

  However, in the invention described in [Patent Document 1], the sucked bottom mud is mainly treated with a filter medium and an aquatic plant, and further improvement is desired in terms of processing capability.

  This invention is made | formed in view of the said situation, and it aims at providing the dredging system which can isolate | separate and collect | recover the sucked bottom mud efficiently.

The present invention
(1) A water supply pump 20 that has a stirring blade 26 for stirring the bottom mud and sucks the stirred bottom mud together with water and pumps it as a bottom mud slurry, and a trolley that floats on the water surface and suspends the water pump 20 in the water. 10, a water supply hose 12 that conveys the bottom mud slurry sucked by the water pump 20, and a separation processing device 90 that separates and collects the bottom mud from the bottom mud slurry conveyed by the water supply hose 12. There,
The separation processing device 90 removes impurities from the bottom mud slurry that has passed through the centrifugal separator 30 and the centrifugal separator 30 that removes heavy materials from the bottom mud slurry conveyed by the water supply hose 12 by centrifugation. The dust sorting unit 40, the bottom mud slurry that has passed through the dust sorting unit 40, and the flocculant are agitated, and the bottom mud is agglomerated and settled in the coagulation separation tank 50. The above-mentioned problem is solved by providing a dredging system 100 characterized by having a concentrating tank 60 for concentrating water and a belt press unit 80 for dewatering the bottom mud concentrated in the concentrating tank.
(2) The problem is solved by providing the dredging system 100 according to (1) above, wherein the flocculant is an inorganic neutral flocculant.
(3) The dredging system 100 according to (1) or (2) is provided, wherein the bottom mud slurry is conveyed from the centrifugal separator 30 to the belt press unit 80 by pressure feeding by the water pump 20 and natural flow. This solves the above problem.

  The dredging system according to the present invention uses an inorganic neutral flocculant for agglomeration of the bottom mud, and continuously dewaters the concentrated bottom mud obtained by using a belt press unit. For this reason, the bottom mud can be separated and recovered with extremely high efficiency. Further, since the bottom mud slurry is transported under the pressure of the water pump and the natural flow, the aggregated bottom mud is not re-dispersed, and the aggregated bottom mud can be conveyed to the belt press section with a high concentration.

It is a figure which shows the dredging system which concerns on this invention. It is a figure which shows the water supply pump and trolley of the dredging system which concern on this invention. It is a figure which shows the outline | summary of the separation processing apparatus of the dredging system which concerns on this invention. It is a graph which shows the phosphorus concentration of the treated water by the dredging system which concerns on this invention. It is a figure which shows the belt press part of the scissors system based on this invention. It is a graph which shows the plant cultivation test result of the dewatered bottom mud obtained with the dredging system which concerns on this invention.

  DESCRIPTION OF EMBODIMENTS Embodiments of a bag system 100 according to the present invention will be described with reference to the drawings. A dredging system 100 according to the present invention shown in FIG. 1 includes a water pump 20 that sucks the bottom mud of a reservoir together with water and pumps it as a bottom mud slurry, and a trolley that floats on the surface of the reservoir and suspends the water pump 20 in water. 10, a water supply hose 12 for conveying the bottom mud slurry sucked by the water supply pump 20, and a separation processing device 90 for separating and recovering the bottom mud from the bottom mud slurry conveyed by the water supply hose 12. In addition, the separation processing device 90 includes a centrifugal separator 30 that removes heavy objects such as sand and pebbles from the bottom mud slurry conveyed by the water supply hose 12 by centrifugation, and the bottom mud slurry that has passed through the centrifugal separator 30. A contaminant sorting unit 40 for removing contaminants such as plant pieces and dust, a coagulation separation tank 50 for aggregating and sedimenting the bottom mud by stirring the bottom mud slurry and the flocculant that have passed through the contaminant sorting unit 40, and A concentration tank 60 for concentrating the bottom mud (aggregated bottom mud) agglomerated and settled in the aggregation separation tank 50; and a belt press unit 80 for dewatering the bottom mud (concentrated bottom mud) concentrated in the concentration tank 60. ing.

  Next, the structure of the water pump 20 and the trolley 10 of the dredging system 100 according to the present invention will be described with reference to a partial sectional view of FIG. The water pump 20 of the dredging system 100 according to the present invention is capable of pumping a slurry having an SS concentration (floating substance concentration) of about 1% to 20%, and has a built-in motor and a waterproof pump main body 21. A casing 22 installed in the lower part of the pump main body 21, an impeller 23 installed in the casing 22 and rotated by a motor, a cutter 24 installed in a water intake of the casing 22, and rotated by a motor and slanted. A stirring blade 26 having a plurality of blades facing downward and a leg portion 28 extending below the casing 22 are provided. The hose connection end 22a extends from the casing 22, and one end of the water supply hose 12 is connected to the hose connection end 22a. The power cable 15a of the water pump 20 is extended to the land along the water hose 12, and is connected to a power source such as a generator via a water pump control panel (not shown) on the separation processing device 90 side.

  Any water hose 12 may be used as long as it can be connected to the water pump 20, but it is preferable to use a water hose having an inner diameter of about 65 mm. Moreover, the float 18 is installed in the water supply hose 12 at predetermined intervals, and is supported on the water surface of the reservoir together with the power cable 15a (15b).

  Further, the trolley 10 has a sufficient float that floats on the water surface of the reservoir even when the water pump 20 and the operator are mounted, and an elevator 11 for raising and lowering the water pump 20 into the reservoir is provided at a substantially central portion of the trolley 10. Have. Further, a cage 14 for suspending the water pump 20 is installed in the upper part of the elevator 11, and an elevator 16 for elevating the water pump 20 is installed in the upper part of the cage 14. The power cable 15b of the elevator 16 is extended to the land along the water supply hose 12 together with the power cable 15a of the water pump 20, and is connected to a power source (not shown).

  Next, the configuration of the centrifuge 30, the contaminant sorting unit 40, the agglomeration separation tank 50, and the concentration tank 60 of the separation processing apparatus 90 will be described with reference to FIG. 3. First, the centrifuge 30 of the separation processing device 90 is a well-known cyclone type centrifuge, and has an outer cylinder 32a and an inner cylinder 32b. And the water supply hose 12 is connected to the upper part of the outer cylinder 32a of the separation processing apparatus 90 toward a horizontal direction. A lower portion of the outer cylinder 32a is a hopper portion 34, and a discharge port 36 that is opened and closed by an opening / closing cock 36a is provided in the hopper portion 34. The inner cylinder 32b is connected with a pipe 5a connected to the foreign matter sorting unit 40. In addition, as piping 5a-5c which connects each part of the separation processing apparatus 90, and water piping 7a, 7b, well-known piping facilities, such as a hose and metal piping, can be used.

  Further, the contaminant sorting unit 40 of the separation processing device 90 has a contaminant sorting device 42 that removes the contaminants in the bottom mud slurry. As the foreign matter sorting device 42, any device may be used as long as it can remove foreign matters of a predetermined size or larger. However, it is particularly preferable to use a well-known belt screen having a slit of about 2 mm. . In addition, it is preferable that the foreign matter sorting unit 40 is provided with a flow rate measuring rod 44 so that the flow rate of the bottom mud slurry sucked by the water pump 20 can be confirmed.

  The flocculation / separation tank 50 of the separation processing apparatus 90 has an inner tank 50b into which the bottom mud slurry that has passed through the contaminant sorting unit 40 flows. The inner tank 50b contains the bottom mud slurry and the flocculant. A stirring device 52 for mixing and stirring is installed. The lower part of the coagulation separation tank 50 is a substantially conical hopper part 50a, and a pipe 5b connected to the concentration tank 60 is connected to the front side of the hopper part 50a. Further, a water pipe 7 a for discharging the supernatant water of the coagulation / separation tank 50 to the reservoir is connected to the upper part of the coagulation / separation tank 50.

  Further, the concentration tank 60 of the separation processing apparatus 90 has a function of allowing the aggregated bottom mud that has been aggregated and settled in the aggregation separation tank 50 to stand and further concentrate, and a pipe 5b connected to the aggregation separation tank 50 is connected to the upper part. ing. The lower part of the concentration tank 60 is a substantially conical hopper part 60a, and a pipe 5c for sending the concentrated bottom mud concentrated in the concentration tank 60 to the belt press part 80 is connected to the front side of the hopper part 60a. Has been. Further, a water pipe 7 b for discharging the supernatant water of the concentration tank 60 to the reservoir is connected to the upper part of the concentration tank 60.

  In addition, the separation treatment apparatus 90 may have a water circulation tank that temporarily stores the supernatant water of the coagulation separation tank 50 and the concentration tank 60 and discharges it to the reservoir as appropriate. According to this configuration, the supernatant water stored in the water circulation tank can be used for equipment cleaning and the like. Thereby, even when a water tap does not exist in the vicinity of the separation processing apparatus 90, operations such as cleaning of facilities can be performed smoothly. In addition, water costs for cleaning can be reduced.

  Next, the operation of the bag system 100 according to the present invention will be described. First, the separation processing device 90 is installed on the land near the reservoir for dredging. In addition, the trolley 10 is floated on a reservoir for dredging. A water pump 20 connected by a water hose 12 is installed in the trolley 10.

  Next, an operator gets on the carriage 10 and moves the carriage 10 to a dredging place. Then, using a surveying instrument such as a dredge, the rough water depth and the thickness of the bottom mud are grasped. Next, the operator operates the elevator 16 to put the water pump 20 into the reservoir. Next, the worker requests the worker on the separation processing device 90 side to operate the water pump 20. In response to this request, the operator on the separation processing device 90 side operates the water pump control panel to operate the water pump 20. As a result, the motor in the pump body 21 rotates, and the impeller 23 and the stirring blade 26 rotate. The water in the reservoir is sucked from the water intake port of the casing 22 and is pumped to the separation processing device 90 via the water supply hose 12.

  Next, an operator on the side of the carriage 10 operates the elevator 16 to hold the water pump 20 at an appropriate position in the reservoir. This appropriate position is a position where the concentration of the bottom mud slurry sucked by the water pump 20 is 5% to 10%. The concentration of the bottom mud slurry is confirmed by visual inspection or the like by an operator on the separation processing apparatus 90 side, and adjusted appropriately by contacting the operator on the base boat 10 side.

  When the water pump 20 is held at an appropriate position near the surface layer of the bottom mud, the stirring blade 26 stirs the bottom mud, and the downward water flow generated by the rotation operation of the stirring blade 26 soars the bottom mud. The raised bottom mud is sucked from the intake port of the casing 22 together with the water in the reservoir by the rotation of the impeller 23, and is pumped to the separation processing device 90 through the water supply hose 12 as a bottom mud slurry. At this time, fallen leaves, dead branches, leaf stem roots of aquatic plants, vinyl, and other debris mixed in the bottom mud are separated from the cutter 24 installed at the intake port of the casing 22, the rotating impeller 23 and the stirring blade 26. It is crushed to an appropriate size. Thereby, the entanglement of these garbage in the water supply pump 20 and clogging in the casing 22 and the water supply hose 12 can be prevented. Further, the stirring blade 26 jumps away relatively large and hard foreign matters such as empty cans and prevents these foreign matters from being sucked by the water supply pump 20. In addition, when the bottom mud is thick, after dripping the bottom mud near the surface layer, it is preferable that the water pump 20 is gradually lowered to dredge the bottom mud.

  The bottom mud slurry sucked and pumped by the water pump 20 is discharged through the water hose 12 to the outer cylinder 32a of the centrifugal separator 30 in the lateral direction. Then, the discharged bottom mud slurry flows down in the outer cylinder 32a in a vortex. At this time, relatively heavy heavy objects such as sand and pebbles fall downward along the outer cylinder 32 a of the centrifugal separator 30 and accumulate on the hopper portion 34 of the centrifugal separator 30. Further, the other bottom mud slurry is conveyed from the lower end of the inner cylinder 32b through the inner cylinder 32b to the contaminant sorting unit 40 side. In addition, the heavy load deposited on the hopper 34 is discharged from the discharge port 36 by appropriately opening and closing the open / close cock 36a, and appropriate processing such as disposal and sorting is performed.

  Also, the bottom mud slurry that has passed through the centrifugal separator 30 is discharged to the flow rate measuring rod 44 of the contaminant sorting unit 40 via the pipe 5a, and the operator on the separation processing device 90 side uses the flow rate measuring rod 44 to remove the bottom mud slurry. Know the flow rate of Then, the rotational speed of the water pump 20 is adjusted so that the bottom mud slurry has an appropriate flow rate by operating the water pump control panel. Moreover, the density | concentration of bottom mud slurry is confirmed visually etc., and when a density | concentration is not appropriate, it will instruct | indicate the operator of the trolley 10 side, and will perform the position adjustment of the water pump 20.

  The bottom mud slurry that has passed through the flow rate measuring basin 44 is discharged to the trash screening device 42 of the trash screening unit 40. Then, in this foreign matter sorting device 42, the foreign matter mixed in the bottom mud slurry, that is, the trash crushed by the cutter 24 is sorted out. In this example, an example in which a belt screen is used as the foreign matter sorting device 42 is shown, and the sorted foreign matter is automatically discharged by the movement of the belt screen. The discharged contaminants slide down on the slider 46, for example, fall into a contaminant collection bag, etc., and are subjected to appropriate processing such as disposal. In addition, it is preferable that the contaminant sorting unit 40 is installed above the agglomeration separation tank 50 and a flocculant is added to the contaminant sorting unit 40. The flocculant is added as appropriate by the operator's visual judgment according to the flow rate and concentration of the bottom mud slurry. Further, the flocculant may be added by an automatic machine. The amount of the flocculant added is approximately 1 wt% with respect to the bottom mud (dry weight).

  Further, as the flocculant added here, a neutral inorganic flocculant mainly composed of calcium is used. This inorganic neutral flocculant mainly composed of calcium does not contain chemical substances that do not exist in nature such as organic polymers. Moreover, it does not contain components that change pH or adversely affect animals and plants. Therefore, the dredging system 100 according to the present invention can use the dehydrated bottom mud separated and recovered by using this inorganic neutral flocculant as it is as the cultivation soil for plant cultivation. Moreover, the separated supernatant water can be discharged into the reservoir as it is.

  Further, the inorganic neutral flocculant mainly composed of calcium fixes the phosphorus component in the bottom mud slurry on the bottom mud side. Here, FIG. 4 shows the phosphoric acid phosphorus concentration of the water in the reservoir before treatment, the phosphoric acid phosphorus concentration of the supernatant water of the coagulation separation tank, and the phosphoric phosphorus concentration of the supernatant water of the concentration tank, respectively. . From FIG. 4, the phosphoric acid phosphorus concentration of the water in the reservoir before treatment is 0.059 mg / L, whereas the phosphoric acid phosphorus concentration of the supernatant water of the coagulation separation tank is 0.024 mg / L, which is concentrated. The phosphate phosphorus concentration of the supernatant water of the tank was 0.017 mg / L. From this, it can be seen that the phosphorus concentration of the water in the reservoir is reduced to about 1/3 by the treatment of the separation treatment device 90. This means that the phosphorus component in water was fixed to the bottom mud side by an inorganic neutral flocculant mainly composed of calcium and removed together with the bottom mud. Therefore, the dehydrated bottom mud obtained by the present invention contains phosphorus components useful for plant cultivation, the phosphorus component of the supernatant water decreases, and the rich water of the reservoir is returned to the reservoir by returning the supernatant water having a low phosphorus component to the reservoir. Nutrition can be suppressed.

  The bottom mud slurry that has passed through the contaminant sorting unit 40 is discharged to the inner tank 50b of the agglomeration separation tank 50. The discharged bottom mud slurry and the flocculant are further mixed and stirred by the stirring device 52 installed in the inner tank 50b. Due to the effect of the flocculant, the mud in the bottom mud slurry and the bottom mud such as sludge are aggregated and settled on the lower hopper 50a. Then, the precipitated aggregated bottom mud is pushed out to the pipe 5b connected to the hopper 50a by the inflow of new bottom mud slurry into the aggregated separation tank 50, and discharged to the upper part of the concentration tank 60 through this pipe 5b. Moreover, the supernatant water of the coagulation separation tank 50 is discharged to the reservoir through the water pipe 7a.

  The agglomerated bottom mud discharged to the concentration tank 60 is allowed to stand in the concentration tank 60 and settles down to the hopper portion 60a below the concentration tank 60 to be further concentrated. Then, the concentrated bottom mud is pushed out to the pipe 5c connected to the hopper 60a by the inflow of new agglomerated bottom mud into the concentration tank 60, and is conveyed to the belt press unit 80 through the pipe 5c. The supernatant water of the concentration tank 60 is discharged to the reservoir through the water pipe 7b.

  Next, the structure of the belt press part 80 suitable for the scissors system 100 according to the present invention will be described with reference to FIG. A belt press unit 80 suitable for the present invention includes a cloth-like belt-like filter cloth 82, a slurry dam part 81 for depositing slurry (concentrated bottom mud) on the filter cloth 82, and excess slurry on the filter cloth 82. A suction part 83 that sucks moisture and a dehydration part 86 that dehydrates the slurry on the filter cloth 82 are provided. Then, the conveyance roller 84 that feeds the filter cloth 82 rotates, so that the filter cloth 82 continuously moves through the slurry dam part 81, the suction part 83, and the dehydration part 86.

  Then, the concentrated bottom mud discharged from the pipe 5c accumulates in the slurry dam portion 81, and in this state, the filter cloth 82 moves at a constant speed and accumulates on the filter cloth 82 with a substantially constant thickness. The concentrated bottom mud deposited on the filter cloth 82 is conveyed to the suction unit 83, and excess water is sucked and removed from the back surface side of the filter cloth 82 by the suction unit 83. The sucked water is discharged to the reservoir through the drainage part 89. Next, the filter cloth 82 is conveyed to the dehydrating unit 86. The dewatering unit 86 includes a dewatering roller including a large roller 86a and a plurality of small rollers 86b. The large roller 86a is located on the concentrated bottom mud side, and the small roller 86b is located on the back side of the filter cloth 82. The concentrated bottom mud is passed along the filter cloth 82 between the dewatering rollers 86a and 86b, and dewatered by the pressure contact of the dewatering rollers 86a and 86b. The dehydrated water is discharged to the reservoir through the drainage part 89. And the dewatering of this belt press part 80 turns the concentrated bottom mud into a dewatered bottom mud having a water content of about 50% to 55%. The dewatered bottom mud is peeled off by the scraper 87 and sent to the dewatered bottom mud collection bag 1 and collected.

  Here, the plant cultivation test result of dehydrated bottom mud is shown in FIG. The plant cultivation test here conforms to “Method of cultivation test on damage to plants (No. 1943, No. 1943, dated April 18, 1984)”, and there is no hole in the bottom. In a test container (inner diameter 11.3 cm, height 6.5 cm), add dehydrated bottom mud obtained from reservoir A, dehydrated bottom mud obtained from reservoir B, and commercially available black soil, and sprinkle 20 pine rapeseed seeds each. The number of germination and the length (plant height) and wet weight of the seedling above 25 days after sowing were measured. The measurement sample was cultivated in a constant temperature bath at 25 ° C. by alternately irradiating fluorescent lamp illumination (3500 lux) in 12 hours of light and dark. Three measurement samples were prepared for each soil, and the average was taken. Further, the plant height and wet weight were measured by extracting 7 plants from the higher plant height of the germinated seedlings and measuring the average plant height and total weight.

  FIG. 6A shows the relationship between the number of days elapsed after sowing and the number of germination. From FIG. 6 (a), it can be seen that there is no significant difference in the germination rate of the plant between the dehydrated bottom mud and the commercially available black soil, and there is no significant difference between the two. FIG. 6 (b) shows the average length and total weight of seedlings 25 days after sowing. From FIG. 6 (b), both the average length and the total weight of the seedlings were cultivated with dehydrated bottom mud, which was higher than that cultivated with commercially available black soil, and the dehydrated bottom mud grew better than the commercially available black soil. I understand that. From these facts, it can be understood that the dewatered bottom mud obtained by the dredging system 100 of the present invention has no obstruction factor in plant cultivation and is suitable for plant cultivation. This is because the dewatered bottom mud obtained by the dredging system 100 of the present invention contains abundant organic matter accumulated at the bottom of the reservoir, and also contains the phosphorus component useful for plant cultivation and the calcium component of the flocculant as described above. This is probably because of this. Moreover, the dewatered bottom mud obtained by the dredging system 100 of the present invention is moderately aggregated and excellent in water retention, which is also considered to be a factor suitable for plant cultivation.

  As described above, the dredging system 100 according to the present invention suspends the water pump 20 from the trolley 10 floated on the water surface of the reservoir, and sucks the bottom mud with the water pump 20 to dredge. For this reason, the water shielding work and drainage work of the reservoir are unnecessary, and the work period can be shortened. Also, dredging can be performed at low cost. Moreover, since the water in the reservoir is not drained, dredging work can be performed while maintaining the function of the reservoir. In particular, the deterioration of the landscape due to dredging work can be minimized in parks and ponds of sightseeing spots. Furthermore, since dredging can be performed without draining water from the reservoir, the ecosystem of animals and plants that live in the reservoir can be maintained.

  Moreover, since the dredging system 100 according to the present invention performs the treatment of bottom mud by installing the separation processing device 90, dredging work can be performed in a space-saving manner as compared with dredging using conventional heavy machinery. Moreover, since the separation processing apparatus 90 can be disassembled and assembled on site, it is possible to perform dredging work on a reservoir into which a large transport vehicle cannot enter.

  Moreover, the dredging system 100 according to the present invention uses an inorganic neutral flocculant for agglomeration of bottom mud, and a water pump for conveying bottom mud slurry (bottom mud and supernatant water) from the reservoir to the belt press unit 80. 20 pumping and natural flow. For this reason, the condensed bottom mud and the concentrated bottom mud are not redispersed, and the concentrated bottom mud can be conveyed to the belt press unit 80 with a high concentration. And since the dredging system 100 which concerns on this invention performs dehydration of concentrated bottom mud continuously using the belt press part 80, it can separate and collect | recover bottom mud with very high efficiency.

  Furthermore, the dredging system 100 according to the present invention uses an inorganic neutral flocculant mainly composed of calcium as the flocculant, so that there are no harmful components to animals and plants in the dewatered bottom mud, but the organic matter accumulated at the bottom of the reservoir It contains abundantly the phosphorus component in water and calcium which is the main component of the flocculant. Therefore, the dewatered bottom mud separated and recovered by the dredging system 100 according to the present invention can be used as it is for plant cultivation as an excellent culture soil rich in nutrient components. Moreover, the flocculant component does not elute into the supernatant water separated by the dredging system 100 according to the present invention, and the pH of the water is not changed. Therefore, even if the supernatant water is discharged to the reservoir as it is, it does not adversely affect the animals and plants that live. In addition, since the inorganic neutral flocculant fixes the phosphorus component in the water and separates it as bottom mud, discharging the supernatant water to the reservoir reduces the phosphorus concentration in the reservoir and suppresses eutrophication of the reservoir. Can do.

  It should be noted that the shape, configuration, operation mechanism, piping path, and the like of each part of the dredging system 100 shown in this example are examples, and the present invention can be modified and implemented without departing from the scope of the present invention. .

10 boats
12 Water hose
20 Water pump
26 Stirrer blade
30 Centrifuge section
40 Foreign matter sorting section
50 Coagulation separation tank
60 Concentration tank
80 Belt press
90 Separation processing equipment
100 kite system

Claims (3)

A water supply pump that has a stirring blade for stirring the bottom mud, sucks the stirred bottom mud together with water, and pumps it as a bottom mud slurry,
A trolley that floats on the water surface and suspends the water pump underwater;
A water supply hose for conveying the bottom mud slurry sucked by the water supply pump;
A separation processing device for separating and collecting bottom mud from the bottom mud slurry conveyed by the water supply hose,
The separation processing apparatus includes:
A centrifuge for removing heavy objects by centrifugation from the bottom mud slurry conveyed by the water supply hose;
A contaminant sorting unit for removing contaminants from the bottom mud slurry that has passed through the centrifugal separator;
Agglomeration separation tank for aggregating the bottom mud slurry and the flocculant that have passed through the contaminant sorting unit, and aggregating and sedimenting the bottom mud;
A concentration tank for concentrating the bottom mud coagulated and settled in the aggregation separation tank;
And a belt press section for dewatering the bottom mud concentrated in the concentration tank. The dredging system according to claim 1, wherein the flocculant is an inorganic neutral flocculant. The dredging system according to claim 1 or 2, wherein conveyance of the bottom mud slurry from the centrifugal separation unit to the belt press unit is performed by pressure feeding by a water pump and natural flow.

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