In-situ fixing method for cutter-suction flow-state river and lake bottom mud

Abstract

The invention relates to an in-situ fixing method for cutter-suction flow-state river and lake bottom mud, which comprises the following steps: cutter-suction river and lake bottom mud into a cured mud preparation device by using a cured mud preparation system, and further treating the bottom mud through the procedures of dosing, oxygen injection, floc biological culture and dehydration to obtain cured mud; river and lake bottom mud is sucked into a centrifugal mud blank preparation device through a centrifugal mud blank preparation system, first-time centrifugal bottom mud is obtained through chemical adding, oxygen injection and first-time centrifugation procedures, then cured mud is added into the first-time centrifugal bottom mud, and centrifugal mud blank preparation is completed through centrifugation, drainage and other procedures; a plurality of pits are formed in river and lake bottom mud below a dredging base line through a second cutter suction device, prepared centrifugal mud blanks are buried in the pits through a mud discharging device, and then heavy metal can be effectively fixed. According to the method, in-situ fixing is conducted on the river and lake bottom mud, the self-repairing capacity of the centrifugal mud blank is enhanced, overlying water is effectively prevented from being polluted by the polluted bottom mud, meanwhile, the in-situ repairing difficulty of the river and lake bottom mud is reduced, and the economic cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of water environment restoration and management, and in particular to an in-situ fixation method for river and lake bottom mud in a suction flow state. Background Art

[0002] In the process of river and lake pollution control, sediment pollution control is one of the main difficulties and is also a common environmental problem. Since there is a dynamic balance of absorption and release between water and sediment, when the water is seriously polluted by external sources, some pollutants can enter the sediment through precipitation, adsorption and other effects; when the external pollution is controlled, various organic and inorganic pollutants accumulated in the sediment re-enter the overlying water through physical, chemical and biological exchanges with the overlying water, thus causing secondary pollution to the water body. In order to remove sediment pollution, sediment dredging is usually used to remove pollutants in the sediment.

[0003] However, although the use of sediment dredging to remove pollutants in sediment can effectively reduce endogenous pollution and has a good effect on improving the water quality of rivers and lakes, this method is large in engineering and the intensity of sediment removal is too large, which can easily bring a large number of benthic organisms and aquatic plants out of the water at the same time, destroying the original ecosystem of rivers and lakes. In addition, during the dredging process, if it is not handled properly, heavy metals and other harmful substances in the sludge may cause secondary pollution to the environment.

[0004] At present, the commonly used measures for dredging the bottom mud of rivers and lakes mainly include dry dredging and water dredging. Among them, dry dredging refers to the use of dredging machinery and equipment such as bulldozers or scrapers to remove the polluted bottom mud at the bottom of rivers and lakes after all the water in the rivers and lakes is drained, thereby achieving the effect of reducing pollution. However, dry dredging measures are limited to use in smaller river and lake basins, and are not applicable to large or medium-sized river and lake basins. In addition, the dehydration operation in this method is likely to have a significant negative impact on production and life around the river and lake basins. Water dredging refers to the method of using new mechanical equipment to extract sludge, nutrients and harmful substances from the bottom of rivers and lakes without draining, clearing and clearing the lake water. Although the use of water dredging can purify the underwater environment of rivers and lakes and block the source of pollution, the water dredging method has high requirements for dredgers, which in turn results in high dredging costs.

[0005] The above two dredging methods are difficult to repair the existing river and lake bottom mud in situ and have high economic costs. There is an urgent need to provide an in situ fixation method for river and lake bottom mud with low repair difficulty and low economic cost. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide an in-situ fixation method for river and lake bottom mud in a suction flow state.

[0007] The present invention provides an in-situ fixation method for river and lake bottom mud in a cutter suction flow state, comprising a mature mud preparation system and a centrifugal mud blank preparation system, wherein the mature mud preparation system comprises a first cutter suction device and a mature mud preparation device, wherein the mature mud preparation device is installed on a shore or in a mobile container, wherein one end of the first cutter suction device is connected to the mature mud preparation device, and the other end of the first cutter suction device extends into the river and lake bottom mud; the centrifugal mud blank preparation system comprises a second cutter suction device, a centrifugal mud blank preparation device, and a mud discharge device for discharging centrifugal mud blanks, wherein the centrifugal mud blank preparation device is installed on a ship, wherein one end of the second cutter suction device is connected to the centrifugal mud blank device, and the other end of the second cutter suction device extends into the river and lake bottom mud; the mud discharge device is installed on a ship; fixing the river and lake bottom mud by using the mature mud preparation system and the centrifugal mud blank preparation system comprises the following steps:

[0008] In the mature mud preparation stage, the river and lake bottom mud is sucked into a fluid state by the first suction device and sucked into the mature mud preparation device. The river and lake bottom mud is sequentially subjected to the processes of adding medicine, injecting oxygen, cultivating flocculent organisms and dehydrating to complete the mature mud preparation;

[0009] In the centrifugal mud blank preparation stage, a dredging baseline is set at the bottom of the river and lake, and a second suction device is extended into the river and lake bottom mud above the dredging baseline for suction cleaning, and the river and lake bottom mud in a flowing state is sucked into the centrifugal mud blank preparation device through the second suction device; the river and lake bottom mud in the centrifugal mud blank preparation device is sequentially subjected to the steps of dosing, oxygen injection and centrifugation, and then mature mud is added to the first centrifugal bottom mud, and the centrifugal mud blank preparation is completed through the steps of centrifugation and drainage;

[0010] During the mud fixing stage, the second suction device is extended into the river and lake mud below the dredging baseline to perform suction, so that a plurality of pits are formed in the river and lake mud below the dredging line; the prepared centrifugal mud blanks are transferred to the mud discharge device, and the centrifugal mud blanks are buried in the pits through the mud discharge device.

[0011] Preferably, the centrifugal mud blank preparation stage also includes the following steps: the river and lake bottom mud in the centrifugal mud blank preparation device is centrifuged after the drug addition and oxygen injection processes, and the centrifugation operation is stopped after the river and lake bottom mud shows obvious stratification; then, the excess moisture of the river and lake bottom mud is removed, so that part of the moisture remains in the remaining mud, and the volume ratio of the remaining mud to part of the moisture is 1:1; then the mature mud is added to the remaining mud, and the volume ratio of the remaining mud to the mature mud is 4:3; finally, the remaining mud and the mature mud are centrifuged to remove moisture, thereby completing the preparation of the centrifugal mud blank.

[0012] Preferably, the mud discharge device includes a mud storage pipe, a mud discharge pipe, a pressure rod and a switch plate for placing the centrifugal mud blanks. The bottom of the mud discharge pipe is set to be open, and the mud storage pipe is detachably fixed in the mud discharge pipe; a pressure plate is provided at the end of the pressure rod, and the pressure plate can be movably extended into the mud storage pipe, and the pressure plate is in contact with the inner wall of the mud storage pipe; the pressure rod is connected to a hydraulic device on the ship at the end away from the pressure plate; the switch plate is movably arranged at the bottom of the mud storage pipe, and the switch plate is initially in a closed state. The pressure plate presses down the centrifugal mud blanks in the mud storage pipe, and the switch plate automatically opens. After the centrifugal mud blanks are discharged, the switch automatically closes.

[0013] Preferably, a plurality of drainage pipes are provided on the inner wall of the mud discharge pipe, and the water inlet of the drainage pipe is arranged at the bottom of the mud discharge pipe, and the drainage outlet of the drainage pipe is higher than the water surface to discharge part of the water in the pit.

[0014] Preferably, in the mature mud preparation stage, the agents added in the dosing process include iron agents, manganese agents or iron-manganese compound agents, and the addition is stopped when the river and lake bottom mud produces flocculation; when the iron content in the river and lake bottom mud is not less than 15 mg / kg and the manganese content is less than 500 mg / kg, no iron agent is added; when the iron content in the river and lake bottom mud is less than 15 mg / kg and the manganese content is not less than 500 mg / kg, no manganese agent is added; the dosing process in the centrifugal mud blank preparation stage is the same as the dosing process in the mature mud preparation stage.

[0015] Preferably, the first centrifugal speed is 800 r / min to 1000 r / min, and the centrifugal time is 4 min to 6 min.

[0016] Preferably, the second centrifugation speed is 1×10 4 r / min~1.5×10 4 r / min, centrifugation time is 8min~12min.

[0017] Preferably, the bottom mud fixation stage also includes the following steps: after the centrifugal mud blank is placed in the pit, oxygen is supplied at a distance of 20 cm to 25 cm above the dredging baseline for 7 to 10 days to ensure that the centrifugal mud blank is completely fixed in the pit.

[0018] Preferably, in the sludge preparation stage, the following steps are specifically included: the sludge preparation device includes a first oxygen injection box. In the oxygen injection process, micro-nano bubble water is injected into the first oxygen injection box and treated at an aeration rate of 1 liter of gas / (liter of water·hour) to 2.5 liters of gas / (liter of water·hour) for 24 hours; aerobic manganese oxidizing bacteria and aerobic iron oxidizing bacteria are added to the first oxygen injection box to ensure that the bottom mud concentration is maintained at 5kg / m 3 -7kg / m3 .

[0019] Preferably, the mature mud preparation stage specifically includes the following steps: the temperature of the floc organism culture is 20°C to 25°C, the pH is 7 to 7.2, the culture time is 7 days, the oxygen injection is stopped after the floc organism culture is completed, and when the dissolved oxygen concentration in the first oxygen injection box is not higher than 3.5 mg / L, anaerobic manganese oxidizing bacteria and anaerobic iron oxidizing bacteria are added to the first oxygen injection box, and moisture is immediately removed through a dehydration process.

[0020] As described above, the present invention relates to an in-situ fixation method for river and lake bottom mud in a suction flow state, which has the following technical effects:

[0021] The present invention utilizes a mature mud preparation system to draw river and lake bottom mud into a mature mud preparation device, and then further processes the bottom mud through drug addition, oxygen injection, flocculant biological cultivation and dehydration processes to obtain mature mud; the river and lake bottom mud is drawn into a centrifugal mud blank preparation device through a centrifugal mud blank preparation system, and then obtains the first centrifugal bottom mud through drug addition, oxygen injection and the first centrifugation process, and then the mature mud is added to the first centrifugal bottom mud, and the preparation of the centrifugal mud blank is completed through the processes of centrifugation and drainage; a plurality of pits are opened in the river and lake bottom mud below the dredging baseline through a second draw-off device, and the prepared centrifugal mud blank is buried in the pits through a mud discharge device, thereby effectively fixing heavy metals.

[0022] The present invention uses suction to fluidize river and lake bottom mud and then fix and stabilize it, so as to return the sludge to the bottom of the river and lake in a short time and fix it in situ, saving time and labor and improving work efficiency. The method of the present invention is used to fix river and lake bottom mud in situ, and the fluidized river and lake bottom mud can be directly sucked to prepare semi-stable centrifugal mud blanks. Through the effect of the upper stable bottom mud, the situation of the bottom mud turning over is reduced, and the centrifugal mud blanks are slowly fixed in the pit, effectively blocking the polluted bottom mud from polluting the overlying water, while reducing the difficulty of in-situ restoration of river and lake bottom mud and saving economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a system for preparing slaked mud provided in an embodiment of the present invention.

[0024] Figure 2 A schematic diagram of a centrifugal clay preparation system provided in an embodiment of the present invention.

[0025] Figure 3 A schematic diagram of a mud storage tube during centrifugation provided in an embodiment of the present invention.

[0026] Figure 4 A schematic diagram of a mud discharge device provided in an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 100, mature mud preparation system; 110, first suction device; 120, mature mud preparation device; 121, first drug adding box; 122, first oxygen injection box; 123, dehydrator; 200, centrifugal mud blank preparation system; 210, second suction device; 220, centrifugal mud blank preparation device; 221, second oxygen injection box; 222, second drug adding box; 223, centrifuge; 230, mud discharge device; 231, mud storage pipe; 232, mud discharge pipe; 233, pressure rod; 234, switch sheet; 235, drainage pipe; 236, centrifuge tube; 300, dredging baseline; 400, pit; 500, water surface. DETAILED DESCRIPTION

[0029] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0030] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0031] like Figure 1-2 As shown, the present invention provides an in-situ fixing method for river and lake bottom mud in a suction flow state, including a mature mud preparation system 100 and a centrifugal mud blank preparation system 200, the mature mud preparation system 100 includes a first suction device 110 and a mature mud preparation device 120, the mature mud preparation device 120 is installed on the shore or in a mobile container, one end of the first suction device 110 is connected to the mature mud preparation device 120, and the other end of the first suction device 110 extends into the river and lake bottom mud. Further, the mature mud preparation device 120 includes two first drug adding boxes 121, two first oxygen injection boxes 122 and a dehydrator 123, the dehydrator 123 is installed on the shore or in a mobile container, the first drug adding box 121 and the first oxygen injection box 122 are symmetrically arranged on both sides of the dehydrator 123, the first drug adding box 121 is connected to the first oxygen injection box 122 through a pipeline, and one end of the first suction device 110 is connected to the first drug adding box 121.

[0032] The centrifugal mud blank preparation system 200 includes a second suction device 210, a centrifugal mud blank preparation device 220, and a mud discharge device 230 for discharging centrifugal mud blanks. The centrifugal mud blank preparation device 230 is installed on a ship, one end of the second suction device 210 is connected to the centrifugal mud blank device 220, and the other end of the second suction device 210 extends into the river and lake bottom mud; the mud discharge device 230 is installed on a ship. Further, the centrifugal mud blank preparation device 230 includes two second drug adding boxes 222, two second oxygen injection boxes 221 and a centrifuge 223, the centrifuge 223 is fixed on the ship, the second drug adding box 222 and the second oxygen injection box 221 are symmetrically arranged on both sides of the centrifuge 223, the second drug adding box 222 is connected to the second oxygen injection box 221 through a pipeline, and one end of the second suction device 210 is connected to the second drug adding box 222.

[0033] Furthermore, if Figure 2-3 As shown, the mud discharge device 230 includes a mud storage pipe 231 for placing centrifugal mud blanks, a mud discharge pipe 232, a pressure rod 233 and a switch plate 234. The bottom of the mud discharge pipe 232 is set to be open to ensure that the centrifugal mud blanks are discharged smoothly. The mud storage pipe 231 is fixed in the mud discharge pipe 232 by a detachable connector. A pressure plate is provided at the end of the pressure rod 233, and the pressure plate can be movably extended into the mud storage pipe 231, and the pressure plate is in contact with the inner wall of the mud storage pipe 231. The pressure rod 233 is connected to the hydraulic device on the ship at one end away from the pressure plate. The switch plate 234 is connected to the bottom of the mud storage pipe 231 by an elastic reset member, and the switch plate 234 is initially in a closed state. When the pressure plate presses down the centrifugal mud blanks in the mud storage pipe 231, the switch plate 234 automatically opens. After the centrifugal mud blanks are discharged, the switch plate 234 automatically closes under the action of the elastic reset member.

[0034] Furthermore, 2 to 4 drainage pipes 235 are provided on the inner side of the mud discharge pipe 232, and the water inlet of the drainage pipe 235 is arranged at the bottom of the mud discharge pipe 232, and the drainage outlet of the drainage pipe 235 is higher than the water surface, so as to discharge part of the water in the pit 400, so that the centrifugal mud discharged from the mud storage pipe 231 can be bonded with the bottom mud in the pit 400.

[0035] like Figure 2 As shown, fixing river and lake bottom mud by using the above-mentioned mature mud preparation system 100 and centrifugal mud blank preparation system 200 specifically includes the following steps:

[0036] In the mature mud preparation stage, the river and lake bottom mud is sucked into a fluid state through the first suction device 110 and sucked into the mature mud preparation device 120. The fluid river and lake bottom mud is sequentially subjected to the processes of adding medicine, injecting oxygen, culturing flocculants and dehydrating in the mature mud preparation device 120 to complete the mature mud preparation.

[0037] Specifically, the flowing river and lake bottom mud sucked by the first suction device 110 enters the first drug-adding box 121 for drug addition and flocs are generated, and then the flowing river and lake bottom mud forming flocs is transported to the first oxygen injection box 122 for oxygen supply, and then the flocs after oxygen supply are biologically cultured, during which iron and manganese oxidizing bacteria are added to the first oxygen injection box 122, which can remove manganese ions in the water on the one hand, and generate iron and manganese oxides on the other hand to improve the fixation effect of heavy metals. After the floc biological culture is completed, the flowing river and lake bottom mud containing flocs is moved to the dehydrator 123 for dehydration to obtain mature mud.

[0038] Furthermore, the reagents added in the dosing process include iron agents, manganese agents or iron-manganese compound agents to accelerate the stabilization of the flowing river and lake sediments, and the addition is stopped when the river and lake sediments produce flocculation. Among them, Fe2O3 and Fe3O4 can be added as iron agents, and MnO, MnO2, Mn2O3 and Mn3O4 can be added as manganese agents. When the iron content in the river and lake sediments is not less than 15 mg / kg and the manganese content is less than 500 mg / kg, no iron agent is added; when the iron content in the river and lake sediments is less than 15 mg / kg and the manganese content is not less than 500 mg / kg, no manganese agent is added. In the process of adding reagents, it should be noted that iron agents, manganese agents or iron-manganese compound agents should be added at the minimum dose, and the addition should be stopped when flocculation blooms in the first dosing box 121. When the flowing river and lake sediments themselves have low iron and manganese contents, the dosage of reagents can be appropriately increased to save economic costs. Since the iron and manganese content in the mud of rivers and lakes in nature is extremely high, the above-mentioned dosing process can accelerate the stabilization of the mud.

[0039] Furthermore, the first oxygen injection box 122 is supplied with oxygen by a micro-nano bubble generator. Micro-nano bubble water is first injected into the first oxygen injection box 122, and the aeration rate is 1 liter of gas / (liter of water·hour) to 2.5 liters of gas / (liter of water·hour) for 24 hours. Aerobic manganese oxidizing bacteria and aerobic iron oxidizing bacteria are then added to the first oxygen injection box 122 to ensure that the sediment concentration is maintained at 5kg / m 3 -7kg / m 3 , thereby ensuring the smooth progress of the subsequent floc biological cultivation process.

[0040] Furthermore, during the cultivation of floc organisms, the temperature of the floc organism cultivation is maintained at 20°C to 25°C, the cultivation time is 7 days, the pH is maintained at 7 to 7.2, and the oxygen injection is stopped after the floc organism cultivation is completed. When the dissolved oxygen concentration in the first oxygen injection box 122 is not higher than 3.5 mg / L, anaerobic manganese oxidizing bacteria and anaerobic iron oxidizing bacteria are added to the first oxygen injection box 122, and the dehydrator 123 is immediately used for dehydration, thereby completing the preparation of mature mud and preparing for the complex application environment of river and lake sediments. Among them, manganese oxidizing bacteria use oxygen in the water to oxidize manganese ions into manganese oxides to remove manganese ions from the water. The biological iron manganese formed by trivalent iron has a significant fixing effect on arsenic and lead in river and lake sediments. It should be emphasized that the addition ratio of aerobic iron oxidizing bacteria and aerobic manganese oxidizing bacteria is 20% of the dry basis of the extruded river and lake sediments, and the compounding ratio of the two is converted according to the manganese-iron ratio contained in the extruded river and lake sediments. The amount of the drug added in the river and lake sediments is negligible during the conversion.

[0041] like Figure 2 As shown, in the centrifugal mud blank preparation stage, a dredging baseline 300 is set at the bottom of the river and lake, and the second suction device 210 is extended into the river and lake bottom mud above the dredging baseline 300 for suction, and all soft bottom mud above the dredging baseline 300 is cleaned, wherein the remaining hard bottom mud below the dredging baseline 300 does not need to be cleaned. The river and lake bottom mud in a fluid state is sucked into the centrifugal mud blank preparation device 220 through the second suction device 210. The fluid river and lake bottom mud in the centrifugal mud blank preparation device 220 is sequentially subjected to the steps of dosing, oxygen injection and centrifugation, and then the mature mud is added to the first centrifugal mud, and the centrifugal mud blank preparation is completed through the steps of centrifugation and drainage.

[0042] Specifically, the fluidized river and lake bottom mud sucked by the second suction device enters the second dosing box 222 for dosing to produce flocs, and the fluidized river and lake bottom mud forming flocs is transported to the second oxygen injection box 221 for oxygen supply culture, and then the floc biological culture is carried out by the same method as the floc biological culture in the above-mentioned mature mud preparation stage. After the floc biological culture is completed, the fluidized river and lake bottom mud containing flocs is moved to the mud storage pipe 231. The mud storage pipe 231 is placed in a centrifuge tube 236, and the centrifuge tube 236 is placed in a centrifuge for the first centrifugation. The first centrifugation speed is 800r / min~1000r / min, and the centrifugation time is 4min~6min. After obvious stratification appears in the mud storage pipe 231, the centrifugation operation is stopped. Then, the mud storage pipe 231 is taken out to remove the excess water in the tube to ensure that part of the water is retained in the remaining mud in the mud storage pipe 231, and the volume ratio of the remaining mud to part of the water is 1:1. Then, the matured mud is added to the remaining sludge in the mud storage tube 231, and the volume ratio of the remaining sludge to the matured mud is 4:3. Finally, the mud storage tube 231 is placed in the centrifuge tube 236, and the centrifuge tube 236 is placed in the centrifuge 223 for the second centrifugation. The second centrifugation speed is 1×10 4r / min~1.5×10 4 r / min, and the centrifugal time is 8min~12min, so that the remaining bottom mud and the mature mud are firmly bonded together to form centrifugal mud blanks, and the moisture is removed to complete the preparation of centrifugal mud blanks.

[0043] It should be noted that the reagent added to the second reagent adding box 222 in the reagent adding process is the same as the reagent added to prepare the mature mud, and the oxygen injection process for preparing the centrifugal mud is the same as the oxygen injection process for preparing the mature mud. In the floc biological cultivation process, the microorganisms added to the second oxygen injection box 221 are the same as the microorganisms in preparing the mature mud.

[0044] like Figure 2 As shown, in the stage of fixing the bottom mud, the second suction device 210 is extended into the hard river and lake bottom mud below the dredging baseline 300 for suction, so that a plurality of pits 400 are formed in the river and lake bottom mud below the dredging line 300. The prepared centrifugal mud blank is transferred to the mud discharge device 230, and the centrifugal mud blank is buried in the pit 400 by the mud discharge device 230. The diameter and depth of the pit 400 can be determined by the operating diameter of the suction cutter head in the second suction device 210.

[0045] Specifically, after the preparation of the centrifugal mud blank is completed, the mud storage pipe 231 is transferred to the mud discharge pipe 232, and the mud discharge pipe 232 is aligned with the pit 400 one by one. At this time, part of the water in the pit 400 is discharged along the drainage pipes 235 under the action of deep water pressure. The pressure rod 233 connected to the hydraulic device on the ship is pressed into the mud storage pipe 231, and the pressure rod 233 is pressed downward. When the pressure rod 233 presses the centrifugal mud blank, the switch piece 234 is automatically opened, and the centrifugal mud blank is discharged from the mud storage pipe 231 into the pit 400. After part of the water in the pit 400 is discharged, the centrifugal mud blank can be bonded with the river and lake bottom mud in the pit 400.

[0046] Furthermore, the mature mud is compacted and backfilled into the pit 400, the centrifugal mud blank is buried in the pit 400, and then micro-nano bubbles are set 20cm to 25cm above the dredging baseline for oxygen supply, which is maintained for 7 to 10 days to ensure that the centrifugal mud blank is completely fixed in the pit 400, reduce the upturning of river and lake bottom mud below the dredging baseline 300, and prevent pollutants in the river and lake bottom mud from being released into the overlying water.

[0047] In summary, the present invention uses suction to fluidize river and lake bottom mud and then fix and stabilize it, so as to return the sludge to the bottom of the river and lake in a short time and fix it in situ, saving time and effort and improving work efficiency. The method of the present invention is used to fix the river and lake bottom mud in situ, and the fluidized river and lake bottom mud can be directly sucked to prepare semi-stable centrifugal mud blanks. Through the effect of the upper stable bottom mud, the situation of the bottom mud turning over is reduced, and the centrifugal mud blanks are slowly fixed in the pits, effectively blocking the polluted bottom mud from polluting the overlying water, while reducing the difficulty of in-situ restoration of river and lake bottom mud and saving economic costs.

[0048] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An in-situ fixation method for river and lake sediments in a suction flow state, characterized in that: The invention comprises a mature mud preparation system (100) and a centrifugal mud blank preparation system (200), wherein the mature mud preparation system (100) comprises a first dragging and suction device (110) and a mature mud preparation device (120), wherein the mature mud preparation device (120) is installed on a shore or in a mobile container, wherein one end of the first dragging and suction device (110) is connected to the mature mud preparation device (120), and the other end of the first dragging and suction device (110) extends into the river and lake bottom mud; and the centrifugal mud blank preparation system (200) comprises a second dragging and suction device The invention relates to a centrifugal mud blank preparation system (210), a centrifugal mud blank preparation system (220), and a mud discharge device (230) for discharging the centrifugal mud blank, wherein the centrifugal mud blank preparation system (230) is installed on a ship, one end of the second suction device (210) is connected to the centrifugal mud blank preparation system (220), and the other end of the second suction device (210) extends into the river and lake bottom mud; the mud discharge device (230) is installed on a ship; fixing the river and lake bottom mud by using the matured mud preparation system (100) and the centrifugal mud blank preparation system (200) comprises the following steps: In the mature mud preparation stage, the river and lake bottom mud is twisted and sucked into a fluid state by the first twisting and sucking device (110) and sucked into the mature mud preparation device (120). The river and lake bottom mud is sequentially subjected to the processes of adding medicine, injecting oxygen, cultivating flocculent organisms and dehydrating in the mature mud preparation device (120) to complete the mature mud preparation; In the centrifugal mud blank preparation stage, a dredging baseline (300) is set at the bottom of a river or lake, and a second suction device (210) is extended into the river or lake bottom mud above the dredging baseline (300) for suction cleaning, and the suctioned river or lake bottom mud in a flowing state enters the centrifugal mud blank preparation device (220) through the second suction device (210); the river or lake bottom mud in the centrifugal mud blank preparation device (220) is sequentially subjected to the steps of dosing, oxygen injection, and first centrifugation, and then mature mud is added to the first centrifuged bottom mud, and the second centrifugation and drainage steps are performed to complete the preparation of the centrifugal mud blank; During the sediment fixing stage, the second suction device (210) is extended into the river and lake sediment below the dredging baseline (300) to perform suction, so that a plurality of pits (400) are formed in the river and lake sediment below the dredging line (300); the prepared centrifugal mud blank is transferred to the mud discharge device (230), and the centrifugal mud blank is buried in the pits (400) through the mud discharge device (230).

2. The in-situ fixation method of river and lake sediment in a suction state according to claim 1 is characterized in that: In the centrifugal mud blank preparation stage, the following steps are also included: The river and lake bottom mud in the centrifugal mud blank preparation device (220) is centrifuged after the steps of adding medicine and injecting oxygen. After the river and lake bottom mud shows obvious stratification, the centrifugation operation is stopped; then, excess water in the river and lake bottom mud is removed, so that part of the water remains in the remaining mud, and the volume ratio of the remaining mud to part of the water is 1:1; then, the mature mud is added to the remaining mud, and the volume ratio of the remaining mud to the mature mud is 4:3; finally, the remaining mud and the mature mud are centrifuged to remove the water, thereby completing the preparation of the centrifugal mud blank.

3. The in-situ fixation method of river and lake sediment in a suction state according to claim 1 or 2, characterized in that: The mud discharge device (230) comprises a mud storage pipe (231) for placing the centrifugal mud blanks, a mud discharge pipe (232), a pressure rod (233) and a switch plate (234); the bottom of the mud discharge pipe (232) is arranged to be open, and the mud storage pipe (231) is detachably fixed in the mud discharge pipe (232); a pressure plate is arranged at the end of the pressure rod (233), and the pressure plate can be movably extended into the mud storage pipe (231), and the pressure plate is in contact with the inner wall of the mud storage pipe (231); the pressure rod (233) is connected to a hydraulic device on the ship at one end away from the pressure plate; the switch plate (234) is movably arranged at the bottom of the mud storage pipe (231), and the switch plate (234) is initially in a closed state; when the pressure plate presses down the centrifugal mud blanks in the mud storage pipe (231), the switch plate (234) automatically opens, and after the centrifugal mud blanks are discharged, the switch plate (234) automatically closes.

4. The in-situ fixation method for river and lake sediments in a cutter suction flow state according to claim 3 is characterized in that: The inner wall of the mud discharge pipe (232) is provided with a plurality of drainage pipes (235), and the water inlet of the drainage pipe (235) is arranged at the bottom of the mud discharge pipe (232). The drainage outlet of the drainage pipe (235) is higher than the water surface, so as to discharge part of the water in the pit (400).

5. The in-situ fixation method of river and lake sediment in a suction state according to claim 1 is characterized in that: In the mature mud preparation stage, the agents added in the dosing process include iron agents, manganese agents or iron-manganese compound agents, and the addition is stopped when the river and lake bottom mud produces flocculation; when the iron content in the river and lake bottom mud is not less than 15 mg / kg and the manganese content is less than 500 mg / kg, no iron agent is added; when the iron content in the river and lake bottom mud is less than 15 mg / kg and the manganese content is not less than 500 mg / kg, no manganese agent is added; the dosing process in the centrifugal mud blank preparation stage is the same as the dosing process in the mature mud preparation stage.

6. The in-situ fixation method of river and lake sediment in a suction state according to claim 2 is characterized in that: The first centrifugal speed is 800 r / min to 1000 r / min, and the centrifugal time is 4 min to 6 min.

7. The in-situ fixation method of river and lake sediment in a suction state according to claim 2 is characterized in that: The second centrifugation speed is 1×10 4 r / min~1.5×10 4 r / min, centrifugation time is 8min~12min.

8. The in-situ fixation method for river and lake sediments in a suction state according to claim 1 is characterized in that: The sediment fixation stage further comprises the following steps: After the centrifugal mud is placed in the pit (400), oxygen is supplied at a position 20 cm to 25 cm above the dredging baseline for 7 to 10 days to ensure that the centrifugal mud is completely fixed in the pit (400).

9. The in-situ fixation method of river and lake sediment in a suction state according to claim 1 is characterized in that: In the slaked mud preparation stage, the following steps are specifically included: The matured mud preparation device (220) comprises a first oxygen injection box (122). In the oxygen injection process, micro-nano bubble water is injected into the first oxygen injection box (122) and treated at an aeration rate of 1 liter of gas / (liter of water·hour) to 2.5 liters of gas / (liter of water·hour) for 24 hours; aerobic manganese oxidizing bacteria and aerobic iron oxidizing bacteria are then added into the first oxygen injection box (122) to ensure that the sludge concentration in the first oxygen injection box (122) is maintained at 5kg / m 3 -7kg / m 3 .

10. The in-situ fixation method for river and lake bottom mud in a suction state according to claim 1 or 9, characterized in that: The slaked mud preparation stage specifically includes the following steps: The temperature of the floc biological culture is 20°C to 25°C, the pH is 7 to 7.2, and the culture time is 7 days. After the floc biological culture is completed, the oxygen injection is stopped. When the dissolved oxygen concentration in the first oxygen injection box (122) is not higher than 3.5 mg / L, anaerobic manganese oxidizing bacteria and anaerobic iron oxidizing bacteria are added to the first oxygen injection box (122), and water is immediately removed through a dehydration process.

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