A Contaminated Sediment Collection and Removal System Based on Terrain Modification

Abstract

This utility model relates to the field of lake dredging technology, and more particularly to a system for collecting and removing polluted bottom sediment based on terrain modification. The system includes a sediment collection trough constructed on the lakebed; a sediment well located in a low-lying area of ​​the sediment collection trough; a sludge scraper for collecting surrounding sediment into the low-lying area of ​​the sediment collection trough and the sediment well; a liftable outer sleeve that, when lowered vertically, completely covers the sediment well, with its lower end submerged in the sediment in the low-lying area and its upper end protruding above the water surface; a water pump for removing water from inside the outer sleeve; and a sediment removal device for removing the sediment collected in the outer sleeve and the sediment well. This solution has the advantages of improving sediment collection efficiency, reducing water content, and minimizing water disturbance.

Description

Technical Field

[0001] This utility model relates to the field of lake dredging technology, and in particular to a system for collecting and removing polluted bottom sediment based on terrain modification. Background Technology

[0002] Removing polluted sediment from the bottom of lakes and reservoirs is a crucial step in water environment management. Existing removal technologies generally suffer from three major problems: low removal efficiency, high moisture content in the removed sediment, and difficulties in subsequent disposal. To address these issues, a comprehensive, integrated technology for the routine and precise treatment of polluted sediment has been developed. By integrating a multi-functional dredging platform and a wheeled, low-disturbance scraper, this technology significantly improves sediment removal efficiency and reduces moisture content.

[0003] The closest existing technology employs a "lake bottom silt capture trough" structure. Based on lake flow field simulation to determine silt deposition areas, a silt capture trough supported by steel or sheet piles is deployed. It relies on the natural carrying action of water flow to collect floating and flowing silt, and periodically uses an excavator to remove the silt from the trough. This approach suffers from efficiency bottlenecks: relying solely on natural water deposition results in a low silt collection rate; the scraping, collection, and removal of silt must be performed sequentially, leading to overall low efficiency; the operation easily causes water disturbance and turbidity, damaging the ecological environment; and the removed silt has a high water content, requiring the addition of flocculants, making it unsuitable for farmland or landscaping due to the presence of chemicals, and thus only suitable for landfill disposal.

[0004] Although the aforementioned integrated technology improves collection efficiency through active sludge scraping, its series-process still has inherent defects. Sludge scraping and sludge removal cannot be carried out simultaneously, and the efficiency of the project is limited by the operation speed of a single stage. High water content sludge increases the subsequent dewatering cost and disposal difficulty.

[0005] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a system for collecting and removing contaminated sediment based on terrain modification, which has the advantages of improving sediment collection efficiency, reducing water content, and minimizing water disturbance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This application provides a system for collecting and removing contaminated sediment based on terrain modification, characterized in that it includes:

[0009] - A mud collection trough constructed on the lakebed;

[0010] - A silt well located in the low-lying area of ​​the silt collection trough;

[0011] - Sludge scraping equipment, used to collect the surrounding sludge into the low-lying area of ​​the sludge collection trough and the sludge well;

[0012] - The liftable outer sleeve completely covers the silt well when lowered vertically, with its lower end sinking into the silt in the depression and its upper end protruding above the water surface.

[0013] - A water pump used to remove water from inside the outer casing;

[0014] - A mud removal device used to remove sludge accumulated in the outer casing and sludge well.

[0015] Preferably, the diameter of the outer sleeve is larger than the diameter of the sludge well and smaller than the maximum diameter of the low-lying part of the sludge collection trough.

[0016] Preferably, the silt well is embedded with a rigid cylinder.

[0017] As a preferred option, it also includes:

[0018] - A work platform that floats on the water surface;

[0019] - Lifting device mounted on the work platform;

[0020] -The water pump is hoisted into the outer sleeve by a lifting device;

[0021] - The mud-collecting device is a grab bucket connected to the lifting device.

[0022] As a preferred option, it also includes:

[0023] A permeable sand-trapping device installed behind the sediment collection trough in the direction of river confluence.

[0024] Preferably, the silt collection trough is a linear trough, and its extension direction intersects with the direction of river inflow; the sand-blocking device is installed in the same direction as the extension direction of the silt collection trough.

[0025] Preferably, the sand-blocking device includes:

[0026] - A float that floats on the water's surface;

[0027] - A permeable net that is fixed at the top to the buoy and extends to the vicinity of the lakebed at the bottom;

[0028] - Fixed piles that anchor the buoys and permeable nets to the lakebed.

[0029] Preferably, the sand-blocking device includes:

[0030] - A permeable mesh located below the water surface;

[0031] - Fixed piles that secure the permeable netting to the lakebed.

[0032] Preferably, the bottom of the permeable net extends close to the surface of the lakebed.

[0033] The above-mentioned pollution sediment collection and removal system based on terrain modification adopts the following sediment collection and dredging method, and the technical solution is as follows: Step (1), a sediment collection trough is constructed at the bottom of the lake dredging area, and a sludge well is constructed extending downward from the center of the low-lying area of ​​the sediment collection trough; Step (2), the surrounding sludge is collected into the low-lying area of ​​the sediment collection trough and the sludge well by a sludge scraping device.

[0034] Step (3): Lower the outer sleeve vertically above the low-lying area of ​​the sludge collection trough, so that the outer sleeve completely covers the sludge well and the lower end of the sleeve is submerged in the sludge in the low-lying area, while the upper end of the sleeve protrudes above the water surface.

[0035] Step (4): Remove the water from the inside of the outer casing;

[0036] Step (5): Remove the sludge collected in the outer casing and sludge well;

[0037] Step (6): The surrounding silt is collected into the sludge collection trough outside the outer sleeve by gravity collection and / or sludge scraping equipment.

[0038] Step (7): Raise the outer sleeve until its bottom opening is lower than the mud surface in the depression. The external silt flows into the silt well under the action of hydrostatic pressure to form secondary silt collection.

[0039] Step (8), repeat steps (5)-(7) to remove the secondary silt until the silt is completely removed;

[0040] The operations in steps (5) and (6) can be performed separately or simultaneously.

[0041] This technical solution constructs a graded sludge collection structure by building a sludge collection trough and a sludge well, and combines the dynamic control of the outer casing to achieve parallel operations of sludge scraping and sludge removal. The sludge collection trough and sludge well established in step (1) constitute a sedimentation zone, and the sludge is quickly collected by actively scraping in step (2); the outer casing is lowered in step (3) to form a closed space, and after pumping water in step (4), a waterless environment is formed, which promotes the efficient removal of high-concentration sludge in step (5); while sludge is continuously collected outside the outer casing in step (6), step (7) uses the hydrostatic pressure to drive the external sludge to flow into the sludge well again by precisely controlling the lifting height of the outer casing, thus achieving an uninterrupted "sludge collection-sludge removal" cycle. The repeated operation in step (8) forms a dynamic balance, which avoids the waiting time of traditional serial operations and reduces the water content of the sludge through physical sedimentation. Among them, the vertical lowering and lifting height control of the outer casing ensures closed operation and reduces water disturbance, and achieves sludge self-flow through hydrostatic pressure. The dual effect improves sludge removal efficiency and reduces dewatering costs. This solution uses a sludge collection trough, an outer casing, and a pumping method to maintain the low moisture content of the effluent sludge while enabling parallel operation of sludge scraping and sludge removal, thus improving operational efficiency. It is also compatible with the existing basket sludge collection method.

[0042] As can be seen from the above, the secondary sludge collection and dredging method and system provided in this application collects sludge in stages by constructing a sludge collection trough and a sludge well combined with an outer sleeve, and uses hydrostatic pressure to achieve secondary sludge collection. This solves the problems of low sludge collection efficiency, high water content and water disturbance in the prior art, and has the advantages of improving sludge collection efficiency, reducing water content and reducing water disturbance. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of step 3 of a secondary mud collection and dredging method provided in this application.

[0044] Figure 2 This is a schematic diagram of step 4 of a secondary sludge collection and dredging method provided in this application.

[0045] Figure 3 This is a schematic diagram of step 5 of a secondary sludge collection and dredging method provided in this application.

[0046] Figure 4 This is a schematic diagram of step 7 of a secondary sludge collection and dredging method provided in this application.

[0047] Figure 5 This is a top view of a secondary sludge collection and dredging method provided in this application.

[0048] Figure 6 A top view diagram illustrating the secondary silt collection and dredging method implemented at the river confluence.

[0049] Figure 7A side view of a secondary silt collection and dredging method implemented at the confluence of a river.

[0050] Figure 8 A frontal schematic diagram of a secondary silt collection and dredging method implemented at the confluence of a river.

[0051] Figure 9 A frontal schematic diagram of a second type of sediment trap implemented at the confluence of a river. Detailed Implementation

[0052] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0053] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation.

[0054] The fact that it is constructed and operated in a specific orientation should not be construed as a limitation of this utility model.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0056] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0057] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0058] In existing technologies, the removal of polluted sediment from the bottom of lakes and reservoirs is a crucial step in water environment management. However, current technologies generally suffer from low removal efficiency, high water content in the removed sediment, and difficulties in subsequent disposal. The closest existing technology uses steel silt capture tanks to collect silt through natural sedimentation by water flow, but this method suffers from low collection rates, inefficiencies due to the need for sequential scraping and sludge removal, and water turbidity caused by the operation. For example, in lake dredging projects, traditional methods require waiting for scraping to be completed before sludge removal, and the high water content of the removed silt necessitates the addition of chemical agents, making resource utilization impossible.

[0059] To address the aforementioned problems, the inventors discovered that existing technologies cannot simultaneously perform sludge scraping and removal, resulting in long project cycles and high costs. Analysis revealed that creating a closed environment for physical dehydration during sludge collection, coupled with a structural design that allows for continuous replenishment of external sludge, could overcome the efficiency bottleneck. Based on this, they proposed installing a vertically adjustable outer sleeve within the sludge collection tank, utilizing hydrostatic pressure to drive secondary sludge flow, thus constructing a dynamic sludge collection-dredging circulation system.

[0060] Therefore, as Figure 1-5 As shown, this embodiment proposes a system for collecting and removing contaminated sediment based on terrain modification, characterized by comprising:

[0061] - A mud collection trough 10 constructed on the lakebed;

[0062] -A sludge well is set in the low-lying area 101 of the sludge collection trough 10, and a rigid cylinder is embedded in the sludge well.

[0063] - A sludge scraping device is used to collect the surrounding sludge into the low-lying area 101 of the sludge collection trough 10 and the sludge well 3;

[0064] - A liftable outer sleeve 4, the diameter of which is larger than the diameter of the sludge well 3 and smaller than the maximum diameter of the depression 101 in the sludge collection trough 10. When the outer sleeve 4 is lowered vertically, it completely covers the sludge well 3, with its lower end sinking into the sludge in the depression 101 and its upper end protruding above the water surface;

[0065] - Pump 5 is used to pump out the water inside the outer sleeve 4;

[0066] - A mud removal device is used to remove the silt collected in the outer casing 4 and the silt well 3.

[0067] Preferably, the system also includes a floating work platform and a lifting device mounted on the work platform; the water pump 5 is lowered into the outer sleeve 4 by the lifting device; the mud removal device is a grab bucket 6 connected to the lifting device.

[0068] When the terrain-modified polluted sediment collection and removal system is installed in the river confluence area, the device also includes a permeable sediment trapping device 7 located behind the sediment collection trough 10 in the river confluence direction. In this scheme, the sediment collection trough 10 is a linear trough, and its extension direction intersects with the river confluence direction; the sediment trapping device 7 is installed in the same direction as the extension direction of the sediment collection trough 10.

[0069] like Figure 6-8 As shown, the sand-trapping device 7 includes a float 71 floating on the water surface; a permeable net 72 with its upper end fixed to the float 71 and its lower end extending to the vicinity of the lakebed; and a fixing pile 73 anchoring the float 71 and the permeable net 72 to the lakebed. The bottom of the permeable net 72 extends close to the lakebed surface. Figure 9 The second structure of the sand-blocking device 7 shown includes a permeable net (72) located below the water surface; and fixed piles (73) that fix the permeable net (72) to the lakebed.

[0070] Therefore, as Figure 1-4 As shown, this embodiment proposes a secondary sludge collection and dredging method applicable to the above-mentioned terrain-modified contaminated sediment collection and removal system, including the following steps:

[0071] Step (1): Construct a mud collection trough 10 at the bottom of the lake dredging area, and construct a mud well 3 extending downward from the center of the low-lying area 101 of the mud collection trough 10.

[0072] Step (2): The surrounding silt is collected into the low-lying area 101 of the silt collection trough 10 and the silt well 3 by the sludge scraping equipment.

[0073] Step (3): Lower the outer sleeve 4 vertically above the low point 101 of the mud collection trough 10, so that the outer sleeve 4 completely covers the sludge well 3 and the lower end of the sleeve is submerged in the sludge of the low point 101, while the upper end of the sleeve protrudes above the water surface.

[0074] Step (4): Remove the water from the inside of the outer casing 4;

[0075] Step (5): Remove the sludge collected in the outer casing 4 and sludge well 3;

[0076] Step (6): The surrounding silt is collected into the silt collection trough 10 outside the outer sleeve 4 by gravity collection and / or sludge scraping equipment; Step (7): The outer sleeve 4 is raised until its bottom opening is lower than the mud surface height of the depression 101, and the external silt flows into the silt well 3 under the action of hydrostatic pressure to form secondary silt collection.

[0077] Step (8), repeat steps (5)-(7) to remove and lift the secondary sludge until the sludge is cleaned up;

[0078] The operations in steps (5) and (6) can be performed separately or simultaneously.

[0079] In this scheme, the silt collection trough 10 refers to a trench structure built on the lake bottom to collect surrounding silt. It can be formed by excavation using excavation equipment, and its low-lying area 101 is designed to facilitate natural silt settling. The silt well 3 refers to a vertical shaft structure extending downwards from the low-lying area 101 of the silt collection trough 10. Its structural stability can be enhanced by pre-embedded rigid cylinders, and it is used to centrally store high-concentration silt. The outer casing 4 is a vertically movable cylindrical structure. When lowered, it forms a closed space to facilitate pumping operations; when raised, the hydrostatic pressure is triggered by controlling the opening height to drive the silt flow. The hydrostatic pressure effect refers to the physical phenomenon where adjusting the height of the outer casing 4 creates a water level difference between the inside and outside of the casing, using this water pressure difference to drive the surrounding silt to flow into the well.

[0080] This method first establishes a primary sludge collection area by constructing a sludge collection trough 10. A scraping device quickly concentrates the dispersed sludge into a low-lying area 101. After the outer casing 4 is lowered, a closed space is formed, and the internal water is pumped out, allowing the sludge to dehydrate naturally. This efficiently removes high-concentration sludge. Simultaneously, the outer sludge collection trough 10 continuously collects new sludge. Two methods can be used for this: the first is gravity-based collection, which is less efficient but requires no additional operation; the second is scraping, which is more efficient. When the outer casing 4 is raised to a specific height, the external sludge automatically flows into the well under hydrostatic pressure, forming a secondary sludge collection. This process alternates between closed sludge removal and open sludge collection, achieving parallel scraping and sludge extraction operations, while simultaneously reducing the water content through physical sedimentation.

[0081] Compared to existing technologies, traditional methods rely on natural sedimentation and require sequential execution of each step. This solution, however, utilizes an adjustable outer sleeve 4 to achieve spatial separation and temporal overlap between sludge collection and dredging. Existing sludge capture tanks only passively collect sludge; this solution actively drives secondary sludge flow through hydrostatic pressure, creating a continuous replenishment mechanism. Furthermore, traditional dredging processes, due to their open operation, easily cause water turbidity. This solution, through the enclosed operation of the outer sleeve 4, reduces water disturbance and avoids secondary pollution. Through these technical solutions, this application achieves simultaneous sludge scraping and sludge removal, effectively shortening the dredging cycle. The physical sedimentation principle reduces the sludge's moisture content, decreasing subsequent dewatering costs. Since no flocculants are added, the sludge can be directly used in farmland and gardens. The enclosed dredging operation reduces water disturbance and prevents the spread of suspended solids from impacting the ecological environment. By dynamically adjusting the height of the outer sleeve 4, a continuous sludge collection-dredging cycle is formed, significantly increasing the sludge treatment capacity per unit time.

[0082] In a further design, the diameter of the outer sleeve 4 is larger than the diameter of the sludge well 3 but smaller than the maximum diameter of the depression 101 within the sludge collection trough 10. The diameter of the outer sleeve 4 refers to the maximum outer dimension of its cross-section, which can be achieved using a steel cylindrical or polygonal cylinder. This dimension must meet the operational requirements of completely covering the opening of the sludge well 3. The diameter of the sludge well 3 refers to the cross-sectional dimension of its wellhead, which can be achieved by pre-embedding a rigid cylinder or mechanically excavating to form a vertical well. This dimension must match the physical characteristics of natural sludge settling. The maximum diameter of the depression 101 within the sludge collection trough 10 refers to the maximum horizontal expansion range of the sludge collection area. This can be achieved by determining the trough outline through underwater topographic mapping and then mechanically excavating. This dimension must meet the coverage requirements of the operating radius of the sludge scraping equipment. This design, by limiting the dimensional matching relationship between the outer sleeve 4 and the surrounding structures, creates a closed working space during the pumping stage to prevent sludge inflow. During the secondary sludge collection stage, a directional sludge transport channel is established through annular gaps, achieving a synergistic improvement in sludge collection efficiency and anti-diffusion capability.

[0083] Furthermore, a rigid cylinder was pre-embedded within the silt well 3. The rigid cylinder refers to a cylindrical structure made of high-strength materials, specifically steel or concrete pipes. Its function is to resist external earth and water pressure through its rigidity, maintaining the geometric shape of the silt well 3. Pre-embedding refers to the simultaneous installation of the rigid cylinder during the construction of the silt well 3, which can be achieved through vibratory pipe laying or drilling. This operation ensures close contact between the rigid cylinder and the surrounding soil, enhancing the overall structural integrity through the synergistic effect of the structure and the soil. Specifically, during the construction of the silt well 3 at the low-lying area 101 of the silt collection trough 10, the rigid cylinder is vertically implanted into the lakebed strata. When the silt scraping equipment collects silt into the silt collection trough 10, the inner wall of the rigid cylinder forms a smooth interface, guiding the silt to settle and accumulate vertically. During the lowering of the outer sleeve 4, the outer diameter of the rigid cylinder and the inner diameter of the outer sleeve 4 are dimensionally matched. During the removal of silt from the well, the rigid cylinder isolates the grab bucket 6 from the direct mechanical force on the surrounding soil, preventing loose bottom mud particles from spreading into the water. In the secondary silt collection stage, the rigid cylinder maintains the effective volume of the silt well 3, providing a stable channel boundary for hydrostatic pressure to drive the backfilling of external silt.

[0084] In a further embodiment, step (7) involves lifting the outer sleeve 4 until its bottom opening height is lower than the top surface of the sludge collection trough 10 at the edge of the depression 101. The bottom opening height refers to the vertical position of the lower end of the outer sleeve 4, which can be determined by measuring the relative height difference between the bottom of the outer sleeve 4 and the top surface of the sludge collection trough 10, for example, by using a height sensor on a lifting device for real-time monitoring. The top surface height of the sludge collection trough 10 at the edge of the depression 101 refers to the highest point of the sludge collection trough 10 outside the depression area, which can be determined by underwater three-dimensional topographic scanning, for example, by using sonar equipment to perform topographic mapping of the dredging area and establishing an elevation model. Specifically, when the outer sleeve 4 is lifted until its bottom opening is lower than the top surface of the sludge collection trough 10, the external sludge forms a flow path along the space between the top surface of the sludge collection trough 10 and the outer sleeve 4 under the drive of the hydrostatic pressure difference. At this time, the sludge well 3 and the interior of the outer sleeve 4 are connected, and the external sludge continuously flows into the well through this path to complete secondary sludge collection. During this process, the height of the bottom opening of the outer sleeve 4 is precisely controlled to be below the top surface of the sludge collection tank 10 but above the liquid level inside the sludge well 3. This prevents lake water from flowing back into the outer sleeve 4 through the opening and maintains the pressure gradient required for sludge flow. This solution creates a pressure difference-driven mechanism by actively adjusting the spatial position of the outer sleeve 4, allowing the sludge to flow directionally under hydrostatic pressure, significantly improving the stability and continuity of secondary sludge collection. Furthermore, in existing technologies, the sludge well 3 is directly connected to the external environment, which can easily lead to lake water mixing with the sludge during operation. This solution, however, effectively blocks external water intrusion through height control, preventing the problem of increased water content. Through the above technical solutions, this application solves the problem of external sludge not being able to effectively flow into the sludge well 3 during secondary sludge collection. By establishing a pressure difference-driven sludge flow path, continuous and efficient sludge collection is achieved. Simultaneously, this solution prevents the mixing of lake water and sludge through spatial height control, ensuring that the removed sludge maintains a low water content, providing a foundation for subsequent resource utilization.

[0085] Furthermore, during the process of raising the outer casing 4, if silt is found flowing into the low-lying area 101 and the silt well 3 along with lake water, the height of the outer casing 4 should be immediately lowered to prevent water ingress. The raising of the outer casing 4 refers to the stage of vertical position adjustment using a lifting device after the pumping operation is completed. Specifically, a hydraulic lifting system or a winch can be used for height adjustment, and the stability of the casing is maintained by controlling the lifting speed. This operation stage needs to be coordinated with the silt flow status.

[0086] The process of detecting silt flowing into the low-lying area 101 and silt well 3 along with lake water involves real-time monitoring of the fluid state in the area connecting silt well 3 and the outer casing 4 using monitoring devices or manual observation. Specifically, turbidity sensors or underwater cameras can be used for turbidity monitoring, triggering a response mechanism when the concentration of suspended solids in the water exceeds a threshold. This monitoring step determines whether external water has breached the isolation barrier. Immediately lowering the height of the outer casing 4 means that, upon detecting abnormal flow, the actuator lowers the casing to a predetermined position within a set time. A lifting device can be used for rapid response, with the descent distance dynamically adjusted according to the silt surface height. This action restores the physical barrier function by rebuilding the contact surface between the bottom of the casing and the silt layer. Through the above technical solutions, this application effectively blocks the reverse infiltration of external pollutants into the silt collection area during dredging operations, ensuring the stable storage of the collected silt. This technology is particularly effective in the final stage of dredging. When the outer silt layer becomes thinner, the height of the isolation device is dynamically adjusted to avoid the mixing of mud and water caused by hydrostatic pressure imbalance, thereby ensuring the low water content of the dredged silt and creating favorable conditions for subsequent resource utilization.

[0087] In the specific scheme, this method uses a floating work platform and a lifting device mounted on it to perform the following operations: the outer sleeve 4 is vertically lowered to the low-lying area 101 of the sludge collection trough 10 by the lifting device; the water pump 5 is hoisted into the outer sleeve 4 by the lifting device to pump water; the grab bucket 6 is operated by the lifting device to remove silt; and the outer sleeve 4 is lifted by the lifting device.

[0088] The work platform refers to the floating carrier that supports the dredging equipment. Specifically, it can be a steel platform with a pontoon structure, whose floating characteristics can adapt to the operational needs of different water depths. The lifting device refers to a multi-directional lifting robotic arm, specifically a hydraulically driven rotary crane, used for precise control of the spatial positioning of the outer casing 4, water pump 5, and grab bucket 6. The water pump 5 is used to discharge water from the outer casing 4, specifically a submersible pump, which is directly deployed above the sludge well 3 for rapid dewatering. The grab bucket 6 is a mechanical device used to grab sludge, specifically a hydraulic grab bucket 6, whose opening and closing action is remotely controlled by the lifting device to remove sludge from the sludge collection trough 10. Specifically, the work platform, acting as a mobile workstation, moves along the water surface to the working area of ​​the sludge collection trough 10. The lifting device vertically lowers the outer casing 4 to a position completely covering the sludge well 3, ensuring that the lower end of the casing sinks into the sludge to form a sealed space. The water pump 5 is lowered into the outer casing 4 by a lifting device to directly extract water from the casing, accelerating the settling and dewatering of the sludge. After dewatering, the water pump 5 can be quickly removed to avoid interfering with subsequent dredging. The grab bucket 6, controlled by the lifting device, enters the sludge collection trough 10 to grab the dewatered sludge, achieving simultaneous mechanical sludge removal and hydrostatic pressure sludge collection. The lifting device adjusts the height of the outer casing 4 according to the water level changes in the sludge well 3 to maintain the hydrostatic pressure difference and promote the continuous inflow of external sludge.

[0089] In such Figure 6-8 In the preferred embodiment shown, this embodiment further proposes using the above-mentioned secondary sludge collection and dredging method in the river confluence area; specifically...

[0090] Step (1) includes the following sub-steps:

[0091] Step (1.1): Select the river confluence in the lake as the dredging area, construct a silt collection trough 10 at the bottom of the dredging area, and extend the silt collection well 3 downward from the center of the low-lying area 101 of the silt collection trough 10.

[0092] Step (1.2): Install a permeable sand-blocking device 7 on the rear side of the sediment collection trough 10 in the direction of river confluence.

[0093] The river confluence refers to a specific area in a lake that receives river flow. Because the water carries a large amount of sediment, this area is suitable for dredging. This can be achieved by determining the main river flow path through hydrological surveys, utilizing the natural flow dynamics to improve sediment collection efficiency. The sediment trap 7 refers to a permeable barrier installed behind the sediment collection trough 10. This can be implemented by suspending a permeable net 72 on a float 71 and anchoring it with fixed piles 73. This allows water flow but prevents sediment diffusion, thus preventing the collected sediment from being washed away again.

[0094] Specifically, after selecting a dredging area at the river confluence, a sediment collection trough 10 is first constructed at the bottom using mechanical or hydraulic methods. A sediment well 3 extends downwards from the low-lying area 101 within the trough, forming a directional sediment collection channel. Subsequently, a permeable sediment trap 7 is installed behind the sediment collection trough 10. This trap consists of a float 71, a permeable net 72, and fixed piles 73. The lower end of the permeable net 72 extends to near the lakebed surface, allowing water flow to maintain water exchange while intercepting upstream sediment to prevent secondary diffusion. When the sediment carried by the river flow enters the sediment collection trough 10, it naturally settles to the low-lying area 101 due to the reduced flow velocity. Some fine sediment particles, after penetrating the sediment collection trough 10 with the water flow, are blocked by the sediment trap 7 and settle in the area behind the trough, achieving a synergistic effect of efficient sediment collection and diffusion prevention. This solution proactively selects high sediment load areas to construct sediment collection structures and adds a permeable sediment trap 7. This utilizes natural water flow dynamics to enhance sediment collection while reducing sediment diffusion through physical barriers, resolving the contradiction between low efficiency and ecological disturbance in traditional technologies. Through this technical solution, this application can significantly improve the silt collection efficiency at river confluence areas, while effectively controlling secondary pollution of the water body caused by sediment diffusion during operations. The permeable enclosure structure maintains smooth water flow, avoiding water flow turbulence caused by complete interception, and creating favorable conditions for subsequent silt dewatering and resource utilization.

[0095] In the specific scheme, the sediment collection trough 10 is constructed as a linear trough, with its extension direction intersecting the direction of the river's inflow. The sediment trapping device 7 is positioned in the same direction as the extension of the sediment collection trough 10. The linear trough refers to a trough-shaped structure with a clearly defined extension direction, which can be achieved through mechanical excavation or prefabricated component assembly. Its extension direction forms an angle with the river flow, expanding the sediment interception range through spatial layout. The sediment trapping device 7 is a permeable barrier structure, which can be achieved by suspending a permeable net 72 with a float 71 and anchoring it with fixed piles 73. Its extension direction is consistent with the direction of the sediment collection trough 10, preventing the diffusion of sediment not captured by the trough 10 through continuous barriers. Specifically, the extension direction of the linear trough forms an angle with the direction of the river's inflow, such as an orthogonal or acute angle arrangement, causing the sediment carried by the water flow to settle more quickly upon entering the sediment collection trough 10 due to the change in flow direction. Simultaneously, the sediment-trapping device 7 is arranged parallel to the length of the sediment collection trough 10, forming a secondary interception zone complementary to the sediment collection trough 10, which further intercepts fine-particle sediment that bypasses the sediment collection trough 10. This spatial layout, through the synergistic effect of the sediment collection trough 10 and the sediment-trapping device 7, achieves dual interception of sediment in both the lateral and longitudinal directions. Through the above technical solution, this application can improve the sediment interception efficiency in the river's inflow, reduce the diffusion range of sediment within the lake, thereby reducing the risk of repeated pollution to surrounding waters during dredging operations, while simultaneously increasing the amount of silt collected per unit time.

[0096] exist Figure 8In the specific scheme shown, the sediment-trapping device 7 includes multiple floats 71 floating on the surface of the river inlet, a permeable net 72 with its upper end fixed to the floats 71 and its lower end below the water surface, and fixed piles 73 securing the floats 71 and the permeable net 72 to the lakebed. The floats 71 are buoyant floating units, which can be made of hollow polyethylene buoys. They support the permeable net 72 through buoyancy and automatically adjust their vertical position according to water level changes. The permeable net 72 is a flexible filter material with a porous structure, which can be made of nylon woven mesh. Its pore size is set according to the target sediment particle size, forming a physical barrier that water can penetrate. The fixed piles 73 are anchoring components vertically inserted into the lakebed, which can be made of steel piles. The friction between the piles and the lakebed maintains the spatial stability of the floats 71 and the permeable net 72. Specifically, the floats 71 form a continuous floating band on the water surface, keeping the permeable net 72 vertically suspended. When the river level fluctuates, the float 71 moves the permeable net 72 synchronously up and down, ensuring that the lower end of the permeable net 72 remains within the effective interception area below the water surface. The permeable net 72 extends from the water surface to near the lakebed surface, forming a filter layer covering the entire water depth, allowing water flow while trapping suspended sediment. The anchoring piles 73 secure the float 71 and the permeable net 72 as a whole, preventing structural displacement due to water flow impact. The bottom of the permeable net 72 is close to the lakebed surface, eliminating sediment escape paths caused by gaps between the bottom of traditional enclosures and the lakebed, and intercepting high-concentration sediment-laden water flow near the bottom. In some specific embodiments, the spacing of the floats 71 can be set to 3-5 meters, the distance between the bottom of the permeable net 72 and the lakebed surface can be controlled within 10 centimeters, and the anchoring piles 73 can be driven into the ground to a depth of more than 2 meters. The porosity of the permeable net 72 can be set to 60%-70%, ensuring water flow while trapping sediment particles larger than 0.1 mm. Through the above technical solution, this application solves the problem of interception failure caused by water level fluctuations in traditional sediment interception devices 7, eliminates the escape path of sediment at the bottom, and improves sediment interception efficiency. The synergistic effect of the permeable net 72, the float 71, and the fixed pile 73 maintains the water exchange capacity while achieving directional sediment enrichment, creating stable preconditions for efficient sediment collection in the subsequent sediment collection tank 10 and reducing the risk of secondary pollution.

[0097] exist Figure 9 In the specific embodiment shown, the sediment-trapping device 7 includes: a permeable net 72 located below the water surface; and fixed piles 73 that secure the permeable net 72 to the lakebed. The permeable net 72 in this embodiment is used to intercept sediment particles, forming a physical barrier that water flow can penetrate, which is similar to the embodiment described above and will not be repeated here. Compared to... Figure 8 The implementation shown eliminates the float 71, thereby reducing the impact of the estuary flow on the sediment trap 7 and making it more stable.

[0098] Furthermore, the bottom of the permeable net 72 extends close to the lakebed surface. "Close to the lakebed surface" means that the bottom of the permeable net 72 maintains a non-rigid contact with the lakebed surface. This can be achieved by suspending counterweights or embedding flexible ballast strips at the lower end of the permeable net 72, allowing the net to naturally droop to a position less than 10 cm from the lakebed surface. This design minimizes the escape space of bottom sediment while avoiding damage to the lakebed surface ecosystem. Specifically, the permeable net 72 extends downwards from the surface float 71 to near the lakebed surface, forming a continuous interception zone from the water surface to near the lakebed surface. When river water carrying sediment enters the lake, the permeable net 72 filters the water flow through its porous structure, trapping the suspended sediment on the water-facing side of the net. Because the bottom of the permeable net 72 is close to the lakebed surface, bottom-moving sediment that might escape from the gaps at the bottom of traditional enclosures is physically blocked, while water can still slowly permeate through the mesh, preventing the formation of localized eddies behind the enclosure. Meanwhile, the flexible contact between the permeable net 72 and the lakebed surface avoids the destruction of benthic habitats caused by the insertion of rigid structures into the lakebed, thus maintaining the natural state of the bottom sediments.

[0099] In summary, the secondary sludge collection and dredging method proposed in this scheme has the following significant advantages, summarized in order of importance:

[0100] 1. Simultaneous operation of sludge scraping and sludge removal: The adjustable outer sleeve 4 enables spatial separation and temporal overlap of sludge collection and dredging, breaking through the limitations of traditional methods that require sequential execution of sludge scraping and sludge removal, significantly shortening the project cycle and reducing time costs.

[0101] 2. Actively drive secondary flow of sludge: Utilize hydrostatic pressure difference to construct a dynamic sludge collection-dredging circulation system, so that the peripheral sludge continuously flows into sludge well 3, forming an active replenishment mechanism and solving the problem of low collection rate in traditional technology.

[0102] 3. Physical dehydration reduces moisture content: Pumping operations within the enclosed space of the outer casing 4 promote natural dehydration of the sludge, reducing the need for subsequent chemical treatment. The removed sludge can be directly used in farmland and gardens, achieving resource utilization.

[0103] 4. Enclosed operation reduces secondary pollution: The enclosed operation of the outer casing avoids water disturbance and the spread of suspended solids during dredging, protects the aquatic ecological environment, and solves the problem of water turbidity that is easily caused by traditional open operations.

[0104] 5. Dynamic cycle improves treatment efficiency: By alternating between closed dredging and open sludge collection, combined with dynamic adjustment of the outer sleeve 4, a continuous sludge collection-dredging cycle is formed, which significantly increases the amount of sludge treated per unit time.

[0105] 6. Directional optimization of river inlet: A linear sediment collection trough 10 is constructed in the river inlet area and a permeable sand-blocking device 7 is installed. The sediment collection efficiency is improved by utilizing the natural water flow dynamics, while the diffusion of sediment is reduced by physical barriers, thus solving the problem of dredging in areas with high sediment load.

[0106] 7. Eco-friendly permeable enclosure design: The permeable net 72 works in conjunction with the floats 71 and the fixed piles 73 to intercept sediment and maintain water exchange, avoiding the ecological damage caused by traditional rigid enclosures. The bottom design close to the lakebed eliminates the escape path of sediment.

[0107] This solution, through systematic innovation, comprehensively optimizes everything from operational modes and structural design to ecological protection, significantly improving dredging efficiency and resource utilization, while combining technological advancement with environmental friendliness.

[0108] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0109] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A system for collecting and removing contaminated sediment based on terrain modification, characterized in that, include: - A mud collection trough (10) constructed on the lakebed; - A silt well (3) is set in the low-lying area (101) of the silt collection trough (10); - Sludge scraping equipment is used to collect the surrounding sludge into the low-lying area (101) of the sludge collection trough (10) and into the sludge well; - The liftable outer sleeve (4) completely covers the silt well (3) when it is lowered vertically. Its lower end of the sleeve is sunken into the silt in the depression (101), and its upper end of the sleeve is exposed above the water surface. - A water pump (5) is used to pump out the water inside the outer sleeve (4); - A mud removal device is used to remove the silt collected in the outer casing (4) and the silt well (3).

2. The contaminated sediment collection and removal system based on terrain modification according to claim 1, characterized in that: The diameter of the outer sleeve (4) is greater than the diameter of the silt well (3) and smaller than the maximum diameter of the depression (101) of the silt collection trough (10).

3. The contaminated sediment collection and removal system based on terrain modification according to claim 1, characterized in that: The silt well (3) is embedded with a rigid cylinder.

4. The system for collecting and removing contaminated sediment based on terrain modification according to claim 1, characterized in that, Also includes: - A floating work platform (1); - Lifting device (2) mounted on the work platform (1); - The water pump (5) is hoisted into the outer sleeve (4) by the lifting device (2); - The mud-removing device is a grab bucket (6) connected to the lifting device (2).

5. A system for collecting and removing contaminated sediment based on terrain modification according to claim 1, characterized in that, Also includes: A permeable sand-trapping device (7) is installed on the back side of the sediment collection trough (10) in the direction of river confluence.

6. A system for collecting and removing contaminated sediment based on terrain modification according to claim 5, characterized in that: The silt collection trough (10) is a linear trough, and its extension direction intersects with the direction of river confluence; The sand-blocking device (7) is set in the same direction as the extension direction of the mud collection trough (10).

7. A system for collecting and removing contaminated sediment based on terrain modification according to claim 5, characterized in that: The sand-blocking device (7) includes: -Floating buoys (71) on the water surface; - The upper end is fixed to the buoy (71), and the lower end extends to the permeable net (72) near the lakebed; - Fixed piles (73) that anchor the buoy (71) and the permeable net (72) to the lakebed.

8. A system for collecting and removing contaminated sediment based on terrain modification according to claim 5, characterized in that: The sand-blocking device (7) includes: - A permeable net (72) located below the water surface; - Fixing piles (73) to secure the permeable net (72) to the lakebed.

9. A system for collecting and removing contaminated sediment based on terrain modification according to claim 7 or 8, characterized in that: The bottom of the permeable net (72) extends to a position close to the lakebed surface.

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