Water quality purification treatment method and system for coal mining collapse area

Abstract

The invention discloses a water quality purification treatment method and system for a coal mining collapse area. The method comprises the steps that a foundation bed is constructed, and an overflow type filtering ring dam is constructed; communicating the overflow type filtering ring dam with each depression part of the coal mining subsidence area; constructing an annular blocking dam; a flow gathering area is constructed, a settling area, a water purification area and a sewage area which are communicated with one another are constructed between the overflow type filtering ring dam and the annular blocking dam, and the sewage area is communicated with the flow gathering area; a purified water discharge system is constructed in the settlement area; a silt pumping system is constructed in the conflux area; pumping water from the water purification area according to the water level monitoring data; silt pumping and chemical dosing are conducted regularly. The system comprises a foundation bed, an overflow type filtering ring dam, an annular blocking dam, a purified water discharging system and a silt pumping system. The problems that a traditional treatment method is weak in pertinence, insufficient in long-term effect and the like can be effectively solved, and the method has outstanding advantages in purification efficiency, pollution control, adaptability and practicability. The method is suitable for the technical field of water quality purification of coal mining collapse areas.

Description

Technical Field

[0001] This invention belongs to the technical field of wastewater treatment, specifically, it relates to a method and system for purifying and treating water in coal mining subsidence areas. Background Technology

[0002] Water pollution in coal mining subsidence areas is caused by complex pollution sources and the fact that the water bodies in these areas are mostly semi-enclosed with poor hydrodynamics. Its harm extends to multiple dimensions, including ecology, human health, and economic development. It disrupts the stability of aquatic ecosystems, leading to a sharp decline in biodiversity and loss of ecological functions; it threatens human health and safety by polluting drinking water sources and accumulating harm through the food chain; it hinders regional economic development, restricts agriculture and animal husbandry, and affects land and water resource utilization.

[0003] Current pollution control methods suffer from insufficient targeting, high costs, and a lack of long-term effectiveness, failing to fundamentally solve the water pollution problem. Traditional interception and isolation measures, which involve setting up isolation zones in some areas to block surface pollutants from entering subsided water bodies, are hampered by the additional slope created by land subsidence, making it easy for surface runoff to flow into the waterlogged areas. Simple isolation measures are insufficient to prevent non-point source pollution. Moreover, isolation facilities are easily damaged and rendered ineffective by long-term water flow, resulting in significant maintenance burdens and hindering the achievement of continuous pollution interception. Summary of the Invention

[0004] This invention provides a water purification treatment method and system for coal mining subsidence areas. Through structured design and multi-system collaboration, it solves the problems of weak targeting and insufficient long-term effectiveness of traditional treatment methods, and has outstanding advantages in purification efficiency, pollution control, adaptability and practicality.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for purifying water in coal mining subsidence areas includes the following steps: Step 1. Construct a foundation bed at the lowest point of the coal mining subsidence area, and construct an overflow filter ring dam at the center of the foundation bed; Step 2. Connect the overflow filter ring dam to each depression in the coal mining subsidence area, and ensure that the lowest point of each depression is higher than the water inlet of the overflow filter ring dam. Step 3. An annular barrier dam is constructed on the foundation bed, and the annular barrier dam is coaxially arranged with the overflow filter ring dam; Step 4. Construct a flow collection zone within the overflow filter ring dam. Between the overflow filter ring dam and the annular barrier dam, construct an interconnected settling zone and a clean water zone. Outside the annular barrier dam, form a wastewater zone. The wastewater zone is connected to the flow collection zone via above-ground or underground channels. Step 5. A clean water discharge system is constructed in the settling zone, and the pumping part of the clean water discharge system extends into the clean water zone; Step 6. A sludge removal system is constructed within the sedimentation zone, with the sludge removal points of the system located at the bottom of the sedimentation zone and the bottom of the sedimentation zone; Step 7. Monitor the water level in the purification area. When the water level exceeds the predetermined height, pump the water out of the purification area through the purification water discharge system and bring the water level in the purification area down to a low value. Step 8. Regularly remove the silt that has settled at the bottom of the settling and siltation zones using the silt removal system; regularly apply chemical agents to the siltation zones and each depression.

[0006] Furthermore, multiple landscape dams are constructed on the foundation bed, with the upper end of each landscape dam located above the water surface. Each landscape dam connects to an overflow filter ring dam and a corresponding depression. Above-ground channels are constructed within the landscape dams, and these channels extend downwards from the depressions along the extension direction of the landscape dams to the flow convergence zone.

[0007] Furthermore, a diversion outlet is provided on the landscape dam and located outside the ring-shaped barrier dam, and the diversion outlet is connected to the ground passage; guardrails are installed on both sides of the upper end of the landscape dam; and a multi-layer filter screen is installed at one end of the ground passage that connects to the depression.

[0008] This invention also discloses a water purification system for coal mining subsidence areas. The aforementioned water purification method treats wastewater based on this system, which includes a foundation bed, an overflow filter ring dam, an annular barrier dam, a clean water discharge system, and a sludge removal system. The overflow filter ring dam and the annular barrier dam are coaxially arranged on the foundation bed from the inside out. The upper surface of the foundation bed gradually concaves downward from the outside in. The clean water discharge system is constructed between the overflow filter ring dam and the annular barrier dam, and the sludge removal system is connected to the inside and outside of the overflow filter ring dam.

[0009] Furthermore, the overflow filter ring dam includes a ring dam body, on which multiple multi-stage filtration units are uniformly constructed in the circumference of the ring dam body. Each multi-stage filtration unit includes a protective layer, a primary filter layer, a secondary filter layer, a tertiary filter layer, and a permeable layer arranged sequentially from the inside out.

[0010] Furthermore, multiple self-floating foam collectors are evenly installed along the circumference of the overflow filter ring dam, with each self-floating foam collector located on the upper inner side of the overflow filter ring dam.

[0011] Furthermore, the self-floating foam collector includes two foam adsorption mechanisms symmetrically installed on both sides of the assembly frame. The two foam adsorption mechanisms are connected to the adjustment mechanism installed on the assembly frame. A self-floating component is installed on the assembly frame. The assembly frame and the sliding block are connected through an angle adjustment component. The sliding block is slidably connected to the vertical guide rail, which is installed on the inner wall of the overflow filter ring dam.

[0012] Furthermore, the foam adsorption mechanism includes a plurality of foam adsorption elements spaced apart along the length of the assembly frame, each foam adsorption element being rotatably connected to the assembly frame via a transfer shaft fixedly connected to one end thereof; the adjustment mechanism includes a transmission rack movably disposed on the assembly frame and extending along the length of the assembly frame, a transmission gear being coaxially mounted on each transfer shaft, the transmission gear meshing with the transmission rack, and an adjustment screw being rotatably connected to one end of the transmission rack, the adjustment screw being threadedly connected to the assembly frame.

[0013] Furthermore, the water purification discharge system includes an annular discharge pipe coaxially disposed outside the overflow filter ring dam, a discharge main pipe connected to the annular discharge pipe, the discharge main pipe being connected to a water pump, and multiple vertical assembly pipes spaced apart along the circumference of the annular discharge pipe, with a self-floating water pump movably inserted into the upper end of each of the vertical assembly pipes.

[0014] Furthermore, the self-floating pump includes a vertical pumping pipe whose lower end is movably inserted into the vertical assembly pipe from the upper end of the vertical assembly pipe. A mounting base is coaxially constructed at the upper end of the vertical pumping pipe. A first flow guide channel communicating with the vertical pumping pipe is constructed within the mounting base. A self-floating component is coaxially and detachably connected to the mounting base. A water intake port is constructed at the lower end of the self-floating component. The water intake port is submerged below the liquid surface. A second flow guide channel communicating with the water intake port is constructed within the self-floating component. The second flow guide channel is connected to the first flow guide channel.

[0015] The technological advancements achieved by this invention compared to existing technologies, due to the aforementioned structure, are as follows: This invention constructs a tiered treatment process: wastewater zone → convergence zone → sedimentation zone → purified water zone. Wastewater flows directionally through above-ground / underground channels, preventing pollutant diffusion and achieving centralized treatment. An overflow filter ring dam intercepts suspended particulate matter and some heavy metals layer by layer from the inside out, resulting in higher filtration precision. The sludge removal system acts directly on the bottom of the sedimentation and convergence zones, periodically removing deposited sludge to prevent secondary pollution from the release of pollutants from the sludge, thus overcoming the shortcomings of traditional treatments that only treat water but not sludge. Furthermore, the sludge removal system can introduce pressurized air into the bottom of the sedimentation and convergence zones for aeration. The purified water discharge system extracts qualified water from the upper layer of the purified water zone based on water level changes, ensuring stable effluent quality, while dynamic control is achieved through water level monitoring. The design of the foundation bed, combined with the overflow filter ring dam and the connection design of various depressions, is adapted to the topographical features of coal mining subsidence areas with multiple depressions and turbulent surface runoff, ensuring that all polluted water can flow into the treatment system. The system of this invention adopts modular construction (filter ring dam, barrier dam, and various functional systems operate independently yet collaboratively), which can be flexibly adjusted according to the area of ​​the subsidence area and the number of depressions, adapting to subsidence water accumulation areas of varying depths. The structural design balances stability and ease of maintenance; the sludge removal system and chemical dosing mechanism are operated periodically, and the purified water discharge system achieves automated water level control, reducing the cost of continuous manual intervention and solving the problems of high maintenance pressure and long-term high costs associated with traditional treatment methods. In summary, this invention solves the problems of weak targeting and insufficient long-term effectiveness of traditional treatment methods, and has outstanding advantages in purification efficiency, pollution control, adaptability, and practicality. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0017] In the attached diagram: Figure 1 This is a schematic diagram of the water purification system according to an embodiment of the present invention; Figure 2 This is a top view of the water purification system according to an embodiment of the present invention; Figure 3 This is a partial structural cross-sectional view of the water purification system according to an embodiment of the present invention; Figure 4 for Figure 3 Enlarged view of the structure at part A in the middle; Figure 5 for Figure 3 Enlarged view of the structure of part B in the middle; Figure 6 for Figure 3 Enlarged view of the structure of part C in the middle; Figure 7 This is a schematic diagram of the structure of a self-floating foam collector according to an embodiment of the present invention; Figure 8 This is a top view of the structure of the self-floating foam collector according to an embodiment of the present invention; Figure 9 This is a partial structural diagram of the self-floating foam collector according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of the self-floating foam collector after angle adjustment according to an embodiment of the present invention; Figure 11 This is a partial structural diagram of the water purification discharge system according to an embodiment of the present invention; Figure 12 This is an axial structural cross-sectional view of the self-floating water pump in the water purification discharge system of this invention embodiment; Figure 13 This is a schematic diagram of the disassembled structure of the self-floating water pump in the water purification discharge system of this invention.

[0018] Components labeled: 100-Foundation substrate, 101-Collection zone, 102-Settling zone, 103-Clean water zone, 104-Waste water zone, 200-Overflow filter ring dam, 201-Protective layer, 202-Primary filter layer, 203-Secondary filter layer, 204-Tertiary filter layer, 205-Permeable layer, 300-Annular barrier dam, 400-Landscape dam, 401-Above-ground passage, 402-Confluence port, 403-Drainage port, 500-Self-floating foam collector, 501-Assembly frame, 502-Adapter shaft, 503-Foam adsorption component, 504-Transmission gear, 505-Transmission rack, 506-Adjusting screw, 507-Operating handwheel, 508-First self-floating body, 509-Second self-floating body 510-Adapter, 511-Connecting post, 512-First positioning hole, 513-Vertical guide rail, 514-Sliding block, 515-Connecting sleeve, 516-Second positioning hole, 600-Clean water discharge system, 601-Annular discharge pipe, 602-Discharge main pipe, 603-Vertical assembly pipe, 604-Self-floating pump, 6041-Vertical pumping pipe, 6042-Mounting base, 6043-First flow guide channel, 6044-First fixing hole, 6045-Self-floating component, 6046-Suction port, 6047-Second flow guide channel, 6048-Second fixing hole, 700-Sludge pumping system, 701-Sludge pumping channel, 702-Sludge collection chamber, 703-Sludge pumping plate, 704-Sludge pumping main pipe. Detailed Implementation

[0019] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0020] This invention discloses a method for water purification in coal mining subsidence areas, such as... Figure 1-13 As shown, it includes the following steps: Step 1. Construct a foundation bed 100 at the lowest point of the coal mining subsidence area, and construct an overflow filter ring dam 200 at the center of the foundation bed 100; the size of the foundation bed 100 is adjusted according to the size of the lowest point of the coal mining subsidence area, and it is constructed by assembling precast concrete blocks.

[0021] Step 2. Connect the overflow filter ring dam 200 to each depression in the coal mining subsidence area, and make sure that the lowest point of the depression is higher than the water inlet of the overflow filter ring dam 200. Step 3. An annular barrier dam 300 is constructed on the foundation bed 100, and the annular barrier dam 300 is coaxially arranged with the overflow filter ring dam 200; Step 4. Construct a flow collection zone 101 within the overflow filter ring dam 200. Between the overflow filter ring dam 200 and the annular barrier dam 300, construct an interconnected settling zone 102 and a clean water zone 103. Outside the annular barrier dam 300, form a wastewater zone 104. The wastewater zone 104 is connected to the flow collection zone 101 via an above-ground passage 401 or an underground passage. Step 5. A water purification system 600 is constructed in the settling zone 102, and the water pumping part of the water purification system 600 extends into the water purification zone 103; Step 6. A sludge removal system 700 is constructed within the flow accumulation zone 101, and the sludge removal section of the sludge removal system 700 is located at the bottom of the settling zone 102 and the bottom of the flow accumulation zone 101. Step 7. Monitor the water level in the water purification zone 103. When the water level exceeds the predetermined height, the water in the water purification zone 103 is pumped out through the water purification discharge system 600, and the water level in the water purification zone 103 is brought down to a low value. Step 8. Periodically remove the silt settled at the bottom of the settling zone 102 and the flow accumulation zone 101 using the sludge removal system 700; periodically apply chemical agents to the flow accumulation zone 101 and each depression.

[0022] This invention utilizes the natural law of "water flowing downhill" to direct all polluted water bodies (such as stagnant water containing heavy metals and acidic substances) scattered in different depressions into the system, avoiding the problems of incomplete treatment and cross-regional spread of pollutants caused by the dispersion of water bodies in traditional treatment methods, and achieving centralized control of polluted water bodies. This invention divides the space into a layered structure: wastewater zone 104 → convergence zone 101 → sedimentation zone 102 → purification zone 103. Wastewater first enters the convergence zone 101 for initial collection, then enters the sedimentation zone 102 through an overflow filter ring dam 200, where gravity causes suspended particulate matter, silt, and other pollutants to settle. Finally, the water entering the purification zone 103 has undergone both filtration and sedimentation treatment, resulting in a significant reduction in pollutant concentration. This layered design avoids the problem of wastewater mixing with purified water, and significantly improves purification efficiency compared to traditional single-body water treatment. This invention monitors the water level in the purification zone 103, only pumping out the upper layer of compliant water when the water level exceeds the limit, and controlling the water level to a low value. On the one hand, it prevents the water level in the purification zone 103 from being too high, causing insufficiently purified water to overflow; on the other hand, it ensures that a certain amount of water is always retained in the purification zone 103 to maintain a stable environment for sedimentation and filtration, preventing the filter layer from being exposed and the purification function from failing due to shallow water, and ensuring that the water discharged each time meets the quality requirements. Step 6 applies the sludge pumping system 700 to the bottom of the sedimentation zone 102 and the flow collection zone 101, and step 8 regularly removes the sludge, which can prevent the release of pollutants such as heavy metals and organic matter in the deposited sludge due to water disturbance, thereby reducing the risk of secondary pollution from the source and making up for the shortcomings of traditional treatment that only treats water and not sludge; at the same time, the flow collection zone 101 and various depressions are regularly treated with chemicals (such as targeted heavy metal chelating agents and acid-base regulators), which can accurately treat stubborn pollutants that are difficult to remove by filtration and sedimentation, further improving the comprehensiveness of water purification. Since coal mining subsidence areas generally have multiple scattered depressions and turbulent surface runoff, traditional isolation measures are difficult to cover all polluted areas. This invention connects the overflow filter ring dam 200 with each depression, forming a structure of a central ring dam plus multi-channel confluence. This allows for flexible adaptation to different numbers and locations of depressions, ensuring that regardless of the distribution of polluted water, it can be incorporated into the treatment system, solving the problems of incomplete coverage and low adaptability of traditional treatment methods. This invention constructs a ring-shaped barrier dam 300 coaxial with the overflow filter ring dam 200, creating a concentric circle layout for the flow collection zone 101 (inner), the settling zone 102 + clean water zone 103 (middle), and the wastewater zone 104 (outer). This design not only fully utilizes the core space of the lowest point in the depression, but also ensures that the wastewater flow path closely matches the purification process (from coarse filtration to fine filtration), reducing water flow resistance, improving purification efficiency, and avoiding stagnant water zones (areas where pollutants remain for extended periods) caused by chaotic spatial layout.The foundation bed 100 of this invention provides stable support for all dam bodies and functional systems. The dam structure of the overflow filter ring dam 200 and the annular barrier dam 300 can resist water erosion (avoiding the problem of easy damage to traditional isolation zones). At the same time, the siltation system 700 acts directly on the source of pollutant deposition, reducing the corrosion of the dam body and pipelines by pollutants, extending the service life of the entire treatment system, and ensuring the long-term stability of pollution control effects. The water quality of the clean water zone 103 treated by this method meets the standards and can be directly used for farmland irrigation, landscape water replenishment, etc.

[0023] In a preferred embodiment of the present invention, multiple landscape dams 400 are constructed on the foundation bed 100. The upper end of each landscape dam 400 is above the water surface, and each landscape dam 400 connects an overflow filter ring dam 200 and a corresponding depression. A surface channel 401 is constructed within the landscape dam 400, and the surface channel 401 extends downwards from the depression along the extension direction of the landscape dam 400 to the flow collection area 101. Specifically, multiple confluence outlets 402 are provided on the overflow filter ring dam, and the surface channel 401 connects to the flow collection area 101 through the corresponding confluence outlets 402. This embodiment utilizes gravity to allow the polluted water (such as water containing coal slag and suspended particles) dispersed in each depression to flow naturally towards the flow collection area 101 along the surface channel 401 without additional power. Furthermore, the surface channel 401 can be cleaned and dredged periodically to prevent blockage. Compared to traditional treatment methods that rely on pumping or uncontrolled runoff, this approach reduces energy consumption and prevents leakage and diffusion caused by chaotic flow paths during wastewater collection. It ensures that all dispersed wastewater is precisely incorporated into the core purification system (collection zone 101 → settling zone 102 → clean water zone 103), achieving complete collection without omission. The above-ground passageway 401 within the landscape dam 400 simultaneously performs pretreatment: as wastewater flows along the passageway 401 towards the collection zone 101, coarse impurities such as coal slag, dead branches, and large suspended particles gradually settle. This prevents coarse impurities from directly entering the collection zone 101 and the overflow filter ring dam 200, preventing clogging of the filter layer (extending filter layer lifespan and reducing the cost of frequent filter replacements). It also reduces the accumulation of coarse impurities in the settling zone 102 (lowering the sludge removal frequency and load of the sludge pumping system 700), optimizing the operating efficiency of the core purification system from the source. This embodiment is adapted to the complex topography of the subsidence area and solves the problem of confluence in areas with multiple depressions and high elevation differences. The landscape dam 400 integrates the confluence channel with the dam structure (the above-ground channel 401 is constructed within the landscape dam 400), eliminating the need to excavate a large number of scattered ditches in the subsidence area. This reduces additional disturbance to the surface of the subsidence area, avoids damage to the soil structure caused by ditches, and prevents new soil erosion or pollution spread. Furthermore, the overflow filter ring dam 200 and the landscape dam 400 themselves provide support, stabilizing the local topography of the subsidence area and preventing the above-ground channel 401 from breaking due to surface subsidence during the confluence process.

[0024] In a preferred embodiment of the present invention, a flow guide 403 is provided on the landscape dam 400 and located outside the annular barrier dam 300, and the flow guide 403 is connected to the ground passage 401; guardrails are installed on both sides of the upper end of the landscape dam 400; and a multi-layer filter screen is installed at one end of the ground passage 401 that connects to the depression. In this embodiment, the flow guide 403 is located on the landscape dam 400 outside the annular barrier dam 300 and is connected to the ground passage 401, forming a dual-path structure with the main flow convergence of the ground passage 401 and the secondary flow diversion of the flow guide 403. When a sudden increase in sewage volume occurs in a depression due to rainfall or groundwater recharge, sewage exceeding the carrying capacity of the above-ground channel 401 can be directly diverted through the diversion port 403 to the sewage zone 104 outside the annular retaining dam 300 (instead of all flowing into the collection zone 101). This avoids the core purification system (collection zone 101 - settling zone 102) from insufficient filtration and reduced settling effect due to excessive water intake in a short period. Conversely, when the sewage volume is small, the sewage can flow into the collection zone 101 through the above-ground channel 401, ensuring that the treatment efficiency of the core system is not wasted. This dynamic regulation capability solves the shortcomings of traditional single-path flow and the susceptibility to system overload or idleness caused by water volume fluctuations. If the sewage zone 104 outside the annular retaining dam 300 accumulates too much water for a long period, the water level may be too high and break through the annular retaining dam 300, causing untreated sewage to backflow into the settling zone 102 and the purification zone 103, polluting the purified water. The diversion port 403 can control the amount of water diverted to the sewage zone 104, balancing the water level in the sewage zone 104 (avoiding excessively high water levels). Simultaneously, it allows the water in the sewage zone 104 to slowly flow into the collection zone 101 via the subsequent above-ground channel 401 / underground channel, creating a slow-paced treatment process. This prevents the risk of backflow and ensures that the water in the sewage zone 104 does not stagnate for extended periods or breed new pollution (such as excessive algae growth). This embodiment employs a multi-layer filter to achieve pre-interception of coarse pollutants, protecting the core purification system from the source. One end of the above-ground channel 401, connecting to the depression, is the first inlet for sewage into the treatment system. The multi-layer filter (usually a combination of filter screens with different pore sizes, such as a coarse filter combined with a fine filter) can intercept coarse particulate impurities such as coal slag, gravel, dead branches, and large pieces of silt carried in the sewage at this point. If these impurities directly enter the ground channel 401 or the collection zone 101, they may clog the ground channel 401, leading to poor flow, wear and tear on the sludge pumping system 700 pipes, or accumulate at the bottom of the settling zone 102, increasing the difficulty of sludge removal. However, the pre-filter interception can remove coarse impurities from the sewage entering the core system, significantly reducing the risk of filter layer clogging in the subsequent overflow filter ring dam 200, extending the filter layer replacement cycle, reducing consumable costs, and at the same time reducing the amount of sludge accumulation in the settling zone 102, reducing the operating frequency and energy consumption of the sludge pumping system 700, thus optimizing the efficiency and economy of the entire purification process from the source.The upper part of the landscape dam 400 is located above the water surface and serves as the core platform for maintenance personnel to carry out routine operations, such as checking for filter blockages, cleaning impurities, and maintaining the diversion inlet 403. Installing guardrails on both sides of the upper part of the landscape dam 400 creates a physical protective barrier, preventing maintenance personnel from falling into the water bodies (sewage area 104 or clean water area 103) due to slippery ground or operational errors. The safety of the guardrails is particularly crucial during severe weather conditions such as rain or freezing.

[0025] This invention also discloses a water purification system for coal mining subsidence areas. The aforementioned water purification method is based on this system to treat wastewater, such as... Figure 1-13 As shown, it includes a foundation bed 100, an overflow filter ring dam 200, an annular barrier dam 300, a purified water discharge system 600, and a sludge removal system 700. The overflow filter ring dam 200 and the annular barrier dam 300 are coaxially arranged on the foundation bed 100 from the inside out. The upper surface of the foundation bed 100 gradually concaves downward from the outside in. The purified water discharge system 600 is constructed between the overflow filter ring dam 200 and the annular barrier dam 300. The sludge removal system 700 is connected to the inside and outside of the overflow filter ring dam 200.

[0026] As a preferred embodiment of the present invention, such as Figure 3 , Figure 5 As shown, the overflow filter ring dam 200 includes a ring dam body, on which multiple multi-stage filtration units are uniformly constructed circumferentially. Each multi-stage filtration unit includes, from the inside out, a protective layer 201, a primary filter layer 202, a secondary filter layer 203, a tertiary filter layer 204, and a permeable layer 205. This embodiment significantly improves the accuracy and comprehensiveness of pollutant removal through multi-stage gradient filtration. During normal filtration, the water level in the overflow filter ring dam 200 is higher than that in the settling zone 102 and the clean water zone 103. That is, when the water level in the clean water zone 103 is high (1-2m lower than the water level in the flow collection zone 101), the clean water discharge system 600 extracts the clean water from the clean water zone 103 to create a certain height difference between the flow collection zone 101 and the clean water zone 103, thereby ensuring that the sewage can smoothly pass through the multi-stage filtration units and enter the clean water zone 103.

[0027] As a preferred embodiment of the present invention, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 , Figure 10As shown, multiple self-floating foam collectors 500 are evenly installed circumferentially on the overflow filter ring dam 200, with each self-floating foam collector 500 located on the upper inner side of the overflow filter ring dam 200. Each self-floating foam collector 500 includes two foam adsorption mechanisms symmetrically installed on both sides of the assembly frame 501. The two foam adsorption mechanisms are drively connected to an adjustment mechanism installed on the assembly frame 501. A self-floating assembly is installed on the assembly frame 501, comprising a first self-floating body 508 and a second self-floating body 509, both of which are installed within the assembly frame 501. The assembly frame 501 is connected to a sliding block 514 via an angle adjustment component. The sliding block 514 is slidably connected to a vertical guide rail 513, which is installed on the inner wall of the overflow filter ring dam 200. The foam adsorption mechanism includes multiple foam adsorption components 503 spaced apart along the length of the assembly frame 501. Each foam adsorption component 503 is rotatably connected to the assembly frame 501 via a transition shaft 502 fixedly connected to one end. The angle adjustment component includes a transition seat 510, which is detachably connected to the assembly frame 501. A connecting post 511 is installed on the transition seat 510. Multiple first positioning holes 512 are evenly formed along the circumference of the outer circumference of the connecting post 511. A connecting sleeve 515 is constructed on the sliding block 514. Multiple second positioning holes 516 are evenly formed along the circumference of the connecting sleeve 515. By rotating the angle of the connecting post 511, the assembly frame 501 is rotated synchronously, thereby adjusting the angle between the foam adsorption component 503 and the liquid surface (generally the adjusted angle is 0-90°). After adjustment, the angle is locked by inserting a positioning pin into the aligned first positioning hole 512 and second positioning hole 516. In this embodiment, the adjustment mechanism includes a transmission rack 505, which is movably mounted on the assembly frame 501 and extends along the length of the assembly frame 501. A transmission gear 504 is coaxially mounted on each adapter shaft 502, meshing with the transmission rack 505. An adjusting screw 506 is rotatably connected to one end of the transmission rack 505, and the adjusting screw 506 is threadedly connected to the assembly frame 501. An operating handwheel 507 is installed at the other end of the adjusting screw 506. In this embodiment, the self-floating foam collector 500 is evenly installed circumferentially along the overflow filter ring dam 200, and is located on the upper inner side of the ring dam. This position corresponds precisely to the surface area of ​​the water in the flow collection zone 101 (foam, due to its low density, always floats on the water surface). As the sewage in the flow collection zone 101 is filtered outwards, the foam on the liquid surface diffuses outwards with the water flow, which is then captured by the circumferentially distributed self-floating foam collector 500, avoiding the foam accumulation problem caused by traditional single-point collection.In this embodiment, two foam adsorption mechanisms are symmetrically installed on both sides of the assembly frame 501. Each mechanism includes multiple foam adsorption components 503 (such as highly absorbent sponges or hydrophobic fiber components) spaced apart along the length direction. This dual-sided, multi-adsorption component design significantly increases the foam adsorption area of ​​a single self-floating foam collector 500 compared to the traditional single-sided structure. When a large area of ​​foam appears on the water surface of the flow collection zone 101, the foam adsorption components 503 on both sides can simultaneously contact the liquid surface and quickly adsorb the foam. Even if the foam distribution is uneven, a single-sided mechanism can work independently, avoiding the problem of collection interruption due to single-sided failure, and greatly increasing the amount of foam removed per unit time. When the operating handwheel 507 is turned, the adjusting screw 506 pushes the transmission rack 505 to move along the length direction of the assembly frame 501. The transmission rack 505 drives the meshing transmission gear 504 to rotate, thereby causing all foam adsorption components 503 to adjust their angle synchronously through the adapter shaft 502. This synchronous adjustment function allows for flexible adjustment of the contact area between the foam adsorption component 503 and the liquid surface according to the thickness of the foam. When the foam is thick, the foam adsorption component 503 is tilted at a large angle to increase the adsorption depth; when the foam is thin, it is adjusted to a small angle to spread out, expanding the contact range. Compared with the inefficient mode of manual adjustment of a single adsorption component in the traditional method, this method is more convenient to operate and has higher capture accuracy. The first self-floating body 508 and the second self-floating body 509 (such as high-density foam or hollow buoyancy components) on the assembly frame 501 provide stable buoyancy for the self-floating foam collector 500, so that the entire self-floating foam collector 500 can rise and fall synchronously with the water level changes in the flow collection zone 101. Regardless of whether the water level rises due to sewage inflow or decreases due to filtration and infiltration, the foam adsorption component 503 can always maintain contact with the liquid surface, avoiding the problems of traditional fixed-height collectors that detach from the liquid surface and cannot capture when the water level drops, or are submerged and fail when the water level rises. Therefore, the self-floating foam collector 500 can adjust its height in real time, ensuring that the foam adsorption component 503 is always in the surface area where foam floats, and the collection effect is not affected by water level changes. In this embodiment, the sliding block 514 is slidably connected to the vertical guide rail 513 on the inner wall of the overflow filter ring dam 200, so that the self-floating foam collector 500 can only move up and down in the vertical direction and cannot be shifted laterally with the water flow. The water body in the coal mining subsidence area 101 may experience local water flow disturbance due to confluence (such as the rapid influx of sewage after heavy rain). The lateral limiting design can prevent the self-floating foam collector 500 from being washed away from the preset position by the water flow, ensuring that it is always in the foam concentration area inside the overflow filter ring dam 200; at the same time, the cooperation between the vertical guide rail 513 and the sliding block 514 also provides stable guidance for the raising and lowering of the self-floating foam collector 500, preventing tilting and jamming caused by uneven buoyancy, and extending the service life of the equipment.In this embodiment, the angle-adjustable component, combined with a detachable design, reduces maintenance difficulty and enhances functional flexibility. When handling light, loose foam (such as algal foam), the angle of the foam adsorption component 503 can be adjusted to 10-30° for flat contact, expanding the adsorption range. When handling viscous, heavy foam (such as oil and coal slime mixed foam), it can be adjusted to 45-60° for tilted scraping to enhance adsorption. During maintenance and cleaning, it can be adjusted to 90° (foam adsorption component 503 vertically upward) to facilitate disassembly and cleaning, preventing foam residue from generating odors. This multi-angle adaptability allows the self-floating foam collector 500 to handle foam from different pollution sources in coal mining subsidence areas, such as residual chemical foam in mine water, algal growth foam, and oily foam brought in by surface runoff, overcoming the limitation of traditional collectors that cannot adapt to multiple types of foam with a single angle.

[0028] As a preferred embodiment of the present invention, such as Figure 1 , Figure 11 , Figure 12 , Figure 13As shown, the water purification discharge system 600 includes an annular discharge pipe 601, which is coaxially arranged outside the overflow filter ring dam 200. A discharge main pipe 602 is connected to the annular discharge pipe 601 and is connected to a water pump. Multiple vertical assembly pipes 603 are arranged at intervals along the circumference of the annular discharge pipe 601. A self-floating water pump 604 is movably inserted into the upper end of each vertical assembly pipe 603. The self-floating pump 604 of this embodiment includes a vertical pumping pipe 6041, a mounting base 6042, and a self-floating component 6045. The lower end of the vertical pumping pipe 6041 is movably inserted into the vertical assembly pipe 603 via the upper end of the vertical assembly pipe 603. The mounting base 6042 is coaxially constructed at the upper end of the vertical pumping pipe 6041. A first flow channel 6043 communicating with the vertical pumping pipe 6041 is constructed within the mounting base 6042. Multiple first fixing holes 6044 are provided at the upper end of the mounting base 6042. The self-floating component 6045 is coaxially mounted on the mounting base 6042. Multiple second fixing holes 6048 are provided on the self-floating component 6045, with each second fixing hole 6048 corresponding to one of the first fixing holes 6044, and are secured by connecting bolts. A water intake port 6046 is constructed at the lower end of the self-floating component 6045, which is submerged below the liquid surface. A second flow guide channel 6047 communicating with the water intake port 6046 is constructed inside the self-floating component 6045, and the second flow guide channel 6047 is connected to the first flow guide channel 6043. In this embodiment, the annular discharge pipe 601 is coaxially arranged with the overflow filter ring dam 200, and multiple vertical mounting pipes 603 are distributed at intervals along the circumference. This layout allows the purified water discharge point to evenly cover the purified water area 103 (or sedimentation area 102) outside the overflow filter ring dam 200. Regardless of the local water level difference in the water body of the purification zone 103 caused by filtration and infiltration, the self-floating pumps 604 distributed around the perimeter can pump water synchronously, avoiding the problems of local water accumulation and partial emptying in the purification zone 103 caused by traditional single-point / single-side drainage. This ensures that the overall water level of the purification zone 103 drops steadily, preventing the formation of stagnant water zones (where long-term water retention leads to secondary pollution). It also provides a stable water level environment for the continuous infiltration filtration of the overflow filter ring dam 200, preventing the filter layer from being exposed and the purification function from being interrupted due to excessively low local water levels. The core of the self-floating pump 604 in this embodiment is the self-floating component 6045, which is fixed to the mounting base 6042 by connecting bolts. It can rise and fall synchronously with the water level changes in the purification zone 103, thereby driving the vertical pumping pipe 6041 to slide up and down along the vertical assembly pipe 603.Because the water intake 6046 at the lower end of the self-floating component 6045 is always submerged below the liquid surface and located in the upper layer of the water (the water in the upper layer of the water purification zone 103 has the best water quality due to sufficient filtration and sedimentation), the water intake 6046 can always draw up the upper layer of purified water that meets the water quality standards, regardless of whether the water level in the water purification zone 103 rises due to increased filtered water intake or falls due to water discharge. This avoids the problem of traditional fixed-height water intakes failing to draw water when the water level drops or drawing up the lower layer of insufficiently purified water when the water level rises, ensuring that the water discharged each time meets the purification standards. The self-floating component 6045 is fixed to the mounting base 6042 by connecting bolts. When the self-floating component 6045 ages (e.g., buoyancy decreases), the suction port 6046 becomes clogged, or a different type of self-floating component 6045 needs to be replaced according to water quality requirements (e.g., replacing it with a self-floating component 6045 with a pre-filtration function for high-turbidity water), only the connecting bolts need to be removed to separate the self-floating component 6045 from the mounting base 6042, without having to remove the entire vertical assembly pipe 603 or the annular discharge pipe 601. This reduces the need for specialized tools and shortens maintenance time.

[0029] As a preferred embodiment of the present invention, such as Figure 1 , Figure 2 , Figure 3 , Figure 6As shown, the dredging system 700 includes multiple dredging channels 701, which are evenly arranged circumferentially along the settling zone 102. Each dredging channel 701 connects the bottom of the settling zone 102 to the center of the bottom of the flow collection zone 101. A flow collection cavity 702 is formed at the center of the foundation bed 100, and each dredging channel 701 is connected to the flow collection cavity 702. A dredging plate 703 is installed at the bottom of the flow collection zone 101, and multiple dredging holes are formed on the dredging plate 703. These dredging holes are connected to the flow collection cavity 702. A dredging main pipe 704 is installed at the center of the dredging plate 703. The lower end of the dredging main pipe 704 is connected to the flow collection cavity 702 through the dredging plate 703, and the upper end of the dredging main pipe 704 is connected to the dredging pump. The silt at the bottom of the subsidence zone 102 and the flow convergence zone 101 in the coal mining subsidence area is rich in a large amount of pollutants such as heavy metals (e.g., Pb, Cd) and organic matter (e.g., residual chemicals from the mine). If these pollutants are deposited at the bottom of the water body for a long time, they are easily released back into the water body due to water flow disturbance and microbial activity, leading to water quality rebound. The silt pumping system 700 acts directly on the source of silt deposition. It pumps silt from the bottom of the subsidence zone 102 through the silt pumping channel 701 and from the bottom of the flow convergence zone 101 through the silt pumping plate 703. This allows these high-pollution-risk silts to be transferred out of the purification system in a timely manner, cutting off the pollutant release path from silt to water at the source, avoiding secondary pollution, and solving the problem of water quality recurrence caused by traditional treatment methods that only treat the water and not the silt. Because the foundation bed 100 gradually slopes downwards from the outside in, this terrain design allows the sludge in the clean water zone 103 to naturally flow towards the settling zone 102 under gravity and settle there, without the need for additional power. All sludge is ultimately pumped out through the central sludge pumping manifold 704. Maintenance personnel only need to operate at the connection point between the sludge pumping manifold 704 and the sludge pump (such as starting the pump and cleaning the manifold inlet), without having to wade into the water in the settling zone 102 or the flow collection zone 101. This significantly reduces the safety risks and labor costs of maintenance, making it particularly suitable for complex environments with large areas and deep water in coal mining subsidence areas. After the sludge is pumped out by the sludge pumping system 700, it can be directly transported through the sludge pumping manifold 704 to designated sludge treatment sites (such as dewatering and drying plants or harmless treatment stations), avoiding the cumbersome process of traditional decentralized sludge removal and manual transportation, and reducing secondary pollution of the surrounding environment during sludge transportation. Meanwhile, the collected sludge, after being treated to render it harmless, can also be utilized as a resource, such as being made into building filler or used to improve soil, thereby enhancing the overall effectiveness of pollution control in coal mining subsidence areas.

[0030] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for purifying water in coal mining subsidence areas, characterized in that, Includes the following steps: Step 1. Construct a foundation bed at the lowest point of the coal mining subsidence area, and construct an overflow filter ring dam at the center of the foundation bed; Step 2. Connect the overflow filter ring dam to each depression in the coal mining subsidence area, and ensure that the lowest point of each depression is higher than the water inlet of the overflow filter ring dam. Step 3. An annular barrier dam is constructed on the foundation bed, and the annular barrier dam is coaxially arranged with the overflow filter ring dam; Step 4. Construct a flow collection zone within the overflow filter ring dam. Between the overflow filter ring dam and the annular barrier dam, construct an interconnected settling zone and a clean water zone. Outside the annular barrier dam, form a wastewater zone. The wastewater zone is connected to the flow collection zone via above-ground or underground channels. Step 5. A clean water discharge system is constructed in the settling zone, and the pumping part of the clean water discharge system extends into the clean water zone; Step 6. A sludge removal system is constructed within the sedimentation zone, with the sludge removal points of the system located at the bottom of the sedimentation zone and the bottom of the sedimentation zone; Step 7. Monitor the water level in the purification area. When the water level exceeds the predetermined height, pump the water out of the purification area through the purification water discharge system and bring the water level in the purification area down to a low value. Step 8. Regularly remove the silt that has settled at the bottom of the settling and siltation zones using the silt removal system; regularly apply chemical agents to the siltation zones and each depression.

2. The water purification treatment method for coal mining subsidence areas according to claim 1, characterized in that: Multiple landscape dams are constructed on the foundation bed, with the upper end of each landscape dam located above the water surface. Each landscape dam connects to an overflow filter ring dam and a corresponding depression. Above-ground channels are constructed within the landscape dams, and these channels extend downwards from the depressions along the extension direction of the landscape dams to the flow convergence zone.

3. The water purification treatment method for coal mining subsidence areas according to claim 2, characterized in that: A diversion outlet is provided on the landscape dam and located outside the circular barrier dam, and the diversion outlet is connected to the ground passage; guardrails are installed on both sides of the upper end of the landscape dam; and a multi-layer filter screen is installed at one end of the ground passage that connects to the depression.

4. A water purification and treatment system for coal mining subsidence areas, characterized in that, The water purification treatment method according to any one of claims 1-3 treats wastewater based on the water purification treatment system, which includes a foundation bed, an overflow filter ring dam, an annular barrier dam, a purified water discharge system, and a sludge removal system. The overflow filter ring dam and the annular barrier dam are coaxially arranged on the foundation bed from the inside to the outside. The upper surface of the foundation bed gradually concaves downward from the outside to the inside. The purified water discharge system is constructed between the overflow filter ring dam and the annular barrier dam. The sludge removal system is connected to the inside and outside of the overflow filter ring dam.

5. A water purification and treatment system for coal mining subsidence areas according to claim 4, characterized in that: The overflow filter ring dam includes a ring dam body, and multiple multi-stage filtration units are uniformly constructed around the ring dam body. Each multi-stage filtration unit includes a protective layer, a primary filter layer, a secondary filter layer, a tertiary filter layer, and a permeable layer arranged sequentially from the inside out.

6. A water purification system for coal mining subsidence areas according to claim 4, characterized in that: Multiple self-floating foam collectors are evenly installed along the circumference of the overflow filter ring dam, and each self-floating foam collector is located on the upper inner side of the overflow filter ring dam.

7. A water purification and treatment system for coal mining subsidence areas according to claim 6, characterized in that: The self-floating foam collector includes two foam adsorption mechanisms symmetrically installed on both sides of the assembly frame. The two foam adsorption mechanisms are connected to the adjustment mechanism installed on the assembly frame. A self-floating component is installed on the assembly frame. The assembly frame and the sliding block are connected through an angle adjustment component. The sliding block is slidably connected to the vertical guide rail, which is installed on the inner wall of the overflow filter ring dam.

8. A water purification and treatment system for coal mining subsidence areas according to claim 7, characterized in that: The foam adsorption mechanism includes multiple foam adsorption components spaced apart along the length of the assembly frame. Each foam adsorption component is rotatably connected to the assembly frame via a transition shaft fixedly connected to one end of the component. The adjustment mechanism includes a transmission rack movably mounted on the assembly frame and extending along the length of the assembly frame. A transmission gear is coaxially mounted on each transition shaft. The transmission gear meshes with the transmission rack. An adjustment screw is rotatably connected to one end of the transmission rack. The adjustment screw is threadedly connected to the assembly frame.

9. A water purification and treatment system for coal mining subsidence areas according to claim 4, characterized in that: The purified water discharge system includes an annular discharge pipe coaxially disposed outside the overflow filter ring dam, a main discharge pipe connected to the annular discharge pipe, the main discharge pipe being connected to a water pump, and multiple vertical assembly pipes spaced apart along the circumference of the annular discharge pipe, with a self-floating water pump movably inserted into the upper end of each of the vertical assembly pipes.

10. A water purification and treatment system for coal mining subsidence areas according to claim 9, characterized in that: The self-floating pump includes a vertical pumping pipe whose lower end is movably inserted into the vertical assembly pipe from the upper end. A mounting base is coaxially constructed at the upper end of the vertical pumping pipe. A first flow guide channel communicating with the vertical pumping pipe is constructed within the mounting base. A self-floating component is coaxially and detachably connected to the mounting base. A water intake port is constructed at the lower end of the self-floating component. The water intake port is submerged below the liquid surface. A second flow guide channel communicating with the water intake port is constructed within the self-floating component. The second flow guide channel is connected to the first flow guide channel.

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