River channel water body pollution treatment method

Abstract

The invention relates to the technical field of water environment treatment, in particular to a riverway water pollution treatment method which comprises the following steps: arranging a diversion device in a suitable section of a main riverway, and introducing part of polluted river water into parallel ecological treatment branch canals; the drainage water sequentially flows through a precipitation siltation promotion area, a multi-stage compound ecological reaction area and a deep purification area in the branch canal to be subjected to stepped purification, wherein the multi-stage compound ecological reaction area is formed by connecting at least two stages of stepped units with built-in biological stuffing and aquatic plants in series; finally, the purified water flows back to the main river channel, and the diversion flow and the aeration intensity are adjusted according to water quality data feedback. According to the invention, low-disturbance, high-efficiency and ecological treatment of polluted river water is realized through technical integration of diversion burden reduction, multi-stage cooperation, ecological enhancement and intelligent regulation and control, and the system has the advantages of good treatment effect, low operation cost, strong ecological landscape compatibility and adaptability to different pollution loads.

Description

Technical Field

[0001] This invention relates to the field of water environment management technology, specifically to a method for treating river water pollution. Background Technology

[0002] With the acceleration of urbanization and industrialization, a large amount of domestic sewage, industrial wastewater and agricultural non-point source pollution flow into rivers, leading to increasingly prominent problems such as black and smelly water bodies and eutrophication. This not only disrupts the balance of aquatic ecosystems, but also threatens the safety of drinking water and the quality of the living environment.

[0003] Currently, river water pollution treatment technologies are mainly divided into three categories: physical methods, chemical methods, and biological-ecological methods. Physical methods, such as intercepting sewage, dredging, and flushing sewage, can quickly improve water quality, but they involve large-scale engineering projects, have high operating costs, and are prone to causing secondary pollution, making it difficult to achieve long-term treatment. Chemical methods, such as adding flocculants and oxidants, are effective quickly, but may introduce new chemical pollutants and disrupt the ecological balance of the water body, and are not suitable for ecologically sensitive rivers. Biological ecological methods, such as constructed wetlands, ecological floating islands, and microbial enhancement, have the advantages of being eco-friendly. However, traditional technologies have drawbacks such as low treatment load, poor spatial adaptability, and insufficient efficiency in the synergistic removal of nitrogen and phosphorus. In particular, the treatment effect is unstable in rivers with large fluctuations in pollution load.

[0004] Further analysis of existing technologies reveals that most river management methods adopt a "whole-line management" model, which significantly disturbs the hydrological and hydraulic conditions of the main river channel and fails to fully integrate the natural topographic features of the river channel to achieve differentiated treatment. At the same time, the treatment units of existing ecological management technologies are mostly designed with single functions, lacking the synergistic linkage of physical sedimentation, plant absorption, and microbial degradation, resulting in limited pollutant removal efficiency.

[0005] In addition, existing technologies generally lack precise intelligent control mechanisms, making it difficult to dynamically optimize operating parameters based on changes in water quality and ensuring the stability of treatment effects under different pollution loads.

[0006] Therefore, those skilled in the art have provided a method for treating river water pollution to solve the problems mentioned in the background art. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for treating river water pollution. This method utilizes a technical approach of diverting flow, multi-level coordination, and intelligent regulation to achieve in-situ, efficient, and low-cost ecological treatment of polluted river water, while ensuring the basic ecological flow of the main river channel and balancing the dual benefits of water quality improvement and ecological landscape enhancement.

[0008] A method for treating river water pollution includes the following steps: S1. Diversion and diversion: An adjustable diversion device is installed 50-100 meters downstream of the bend in the main river channel to divert a portion of the polluted river water into a parallel ecological treatment branch canal at a preset flow rate of 10%-40% of the average flow rate of the main river channel; the ecological treatment branch canal is 150-300 meters long, 2-5 meters wide, and 1.2-1.8 meters deep, and the bottom slope of the branch canal is 5-10‰ gentler than that of the main river channel; S2. Multi-stage ecological purification: The ecological treatment branch canal is divided into a sedimentation and siltation promotion zone, a multi-stage composite ecological reaction zone, and a deep purification zone along the water flow direction. The diverted river water flows through the above-mentioned zones in sequence to complete the step-by-step purification. The length ratio of the sedimentation and siltation promotion zone, the multi-stage composite ecological reaction zone, and the deep purification zone is 1:4-6:0.5-1.5. S3. Return and Intelligent Control: After treatment in the deep purification zone, the water is returned to the downstream area of ​​the main river through a return device set at the end of the branch canal. Online monitoring equipment is installed before the main river diversion point, at the outlet of the ecological treatment branch canal, and after the main river return point to monitor dissolved oxygen, ammonia nitrogen, chemical oxygen demand, and total phosphorus water quality parameters in real time. Based on this, the diversion flow rate of the diversion device and the aeration intensity of the multi-stage composite ecological reaction zone are adjusted.

[0009] Preferably, in step S1, the diversion device is one of a hydraulically controlled flap gate, an electric regulating weir gate, or an adjustable water pump; when the average flow rate of the main channel is ≤0.3m³ / s, a hydraulically controlled flap gate is preferred; when the average flow rate of the main channel is >0.3m³ / s, an electric regulating weir gate is selected and equipped with a flow feedback control system.

[0010] Preferably, in step S2, a porous medium silt-promoting layer with a thickness of 20-40cm is laid at the bottom of the sedimentation and silt-promoting zone. The porous medium is crushed stone or ecological ceramsite with a particle size of 5-20cm, and the specific surface area of ​​the ecological ceramsite is ≥500m² / g. A sawtooth overflow weir is set at the end of the sedimentation and silt-promoting zone. The height of the overflow weir is adjusted to 0.8-1.2m according to the design water depth of the branch canal to ensure that the surface clarified water flows evenly into the multi-stage composite ecological reaction zone.

[0011] Preferably, in step S2, the multi-level composite ecological reaction zone is composed of 2-4 stepped units connected in series, with an elevation difference of 0.2-0.5m between adjacent units; each unit includes a support layer, a biological filler layer, and an aquatic plant planting layer from bottom to top, and a microporous aeration pipe network is embedded inside the biological filler layer. The supporting layer is gravel with a particle size of 20-30cm and a thickness of 10-15cm; The biological filler layer is composed of modified zeolite, limestone and waste biochar in a mass ratio of 3-5:2-3:1, with a thickness of 40-60 cm and a porosity of ≥45%. The aquatic plant planting layer uses at least two native aquatic plants selected from Vallisneria natans, Hydrilla verticillata, Iris tectorum, and Pickerelweed for alternating planting, with a planting density of 20-30 plants / m² and a spacing of 30-50 cm between adjacent plants.

[0012] Preferably, the aeration mode of the microporous aeration pipe network is intermittent aeration, with the aeration intensity controlled at 0.5-1.2 m³ / (m²·h); its operating cycle is dynamically adjusted according to the influent ammonia nitrogen concentration: when the influent ammonia nitrogen concentration is ≥2.0 mg / L, a cycle of "aeration for 30 minutes / aeration stop for 60 minutes" is adopted; when the influent ammonia nitrogen concentration is <2.0 mg / L, a cycle of "aeration for 15 minutes / aeration stop for 90 minutes" is adopted; the aeration pore diameter of the microporous aeration pipe network is 100-200 μm, and the pipe spacing is 0.8-1.2 m.

[0013] Preferably, in step S2, bio-rope packing material with a density of 3-5 ropes / m² is suspended in the deep purification zone, and the specific surface area of ​​the bio-rope packing material is ≥800m² / m³; at the same time, filter-feeding aquatic animals are stocked at a density of 5-10 ind / m², and the filter-feeding aquatic animals are one or more combinations of freshwater mussels, bald snails, or killifish, and the stocking ratio of different species is 1:2-3.

[0014] Preferably, in step S3, the online monitoring device monitors once every 5-10 minutes, and the data transmission delay is ≤30 seconds; the feedback adjustment logic is as follows: when the chemical oxygen demand (COD) after the main channel return point is >30 mg / L for 2 consecutive hours, the diversion flow rate is increased by 5-10 percentage points; when the dissolved oxygen in the middle section of the multi-level composite ecological reaction zone is <2.0 mg / L for 2 consecutive hours, the aeration intensity is increased by 0.2-0.3 m³ / (m²·h); when the ammonia nitrogen after the main channel return point is ≤1.0 mg / L and the COD is ≤20 mg / L, the diversion flow rate can be reduced by 5-10 percentage points to save energy.

[0015] Preferably, the inner wall of the ecological treatment branch canal is paved with ecological concrete or planted with aquatic plants for bank protection, with a bank slope of 1:2-1:3; when the ecological treatment branch canal is transformed using riverbed or abandoned ditch, the bottom of the canal needs to be compacted and a 10-15cm thick impermeable sand layer needs to be laid.

[0016] The technical effects and advantages of this invention are as follows: 1. Diversion design, low disturbance and high efficiency and energy saving: Adopting the "partial diversion and quality treatment" mode, it only treats 10%-40% of the water in the main river channel, which greatly reduces the construction scale and operating energy consumption of the treatment unit; at the same time, it ensures that the basic ecological flow of the main river channel is not interrupted, and has little disturbance to the original hydrological and hydraulic conditions, which is suitable for the treatment needs of ecologically sensitive rivers.

[0017] 2. Multi-stage synergistic purification with high pollutant removal efficiency: The structure achieves three-dimensional removal of suspended solids, nitrogen, phosphorus, and organic matter through a four-fold synergistic effect of physical sedimentation-siltation layer, plant absorption-aquatic plants, microbial degradation-biological packing and aeration, and animal filter feeding-filter feeders. Actual measurements show that the removal rate of suspended solids in water is >85%, and the average removal rates of chemical oxygen demand, ammonia nitrogen, and total phosphorus are ≥70%, 65%, and 60%, respectively. The treatment effect is superior to traditional single ecological technologies.

[0018] 3. Eco-friendly and with significant landscape benefits: All aquatic plants and animals are native species, avoiding the invasion of alien species, while rapidly restoring the biodiversity of the riparian zone; the ecological treatment branch canals and bank protection designs are integrated into the natural landscape, realizing the integration of water management and landscaping, and improving the quality of the living environment.

[0019] 4. Intelligent control and strong long-term stability: Through online monitoring and dynamic feedback adjustment, the system can adapt to fluctuations in river pollution load, ensuring stable compliance under different operating conditions; the system relies on natural ecological processes and low-energy aeration, with a simple structure, convenient maintenance, and operating costs that are only 30%-50% of traditional chemical methods, making it feasible for long-term promotion and application.

[0020] 5. Wide spatial adaptability: Ecological treatment branch canals can be built or renovated from river beaches and abandoned ditches, with low requirements for site space. They are suitable for the restoration of different types of river water bodies with different pollution loads, such as urban landscape rivers and rural sewage rivers. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall floor plan provided in an embodiment of this application; Figure 2 This is a schematic diagram of the sedimentation and siltation promotion zone in a river water pollution treatment method provided in this application embodiment; Figure 3 This is a schematic diagram of the structure of a multi-level composite ecological reaction zone in a river water pollution treatment method provided in this application embodiment; Figure 4 This is a schematic diagram of the recirculation device in a river water pollution treatment method provided in this application embodiment; In the picture: 1. Main channel; 2. Diversion device; 3. Ecological treatment branch canal; 31. Sedimentation and siltation zone; 311. Siltation layer; 312. Overflow weir; 32. Multi-level composite ecological reaction zone; 321. Support layer; 322. Biological filler layer; 323. Aquatic plant planting layer; 324. Microporous aeration pipe network; 33. Deep purification zone; 331. Biological rope filler; 332. Filter-feeding aquatic animals; 4. Return device; 5. Online monitoring equipment. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0023] Example 1

[0024] Please see Figures 1-4 This embodiment provides a method for treating river water pollution, including... Example 1: Restoration of urban landscape waterways with light to moderate pollution This embodiment focuses on a lightly to moderately polluted urban landscape river. Its basic parameters are: average flow rate of the main river channel is 0.5 m³ / s, and the current water quality is: chemical oxygen demand 65-80 mg / L, ammonia nitrogen 3-5 mg / L, total phosphorus 0.5-1.0 mg / L, and suspended solids in water 50-80 mg / L.

[0025] The specific steps for treating the problem using the method of this invention are as follows: S1. Diversion and diversion: A hydraulically controlled flap gate is installed 60 meters downstream of the bend in the main river channel as a diversion device. The height of the flap gate is adjusted to stabilize the diversion flow at 20% of the average flow of the main river channel, i.e., 0.1 m³ / s. The ecological treatment branch canal is newly built, with a length of 200 meters, a width of 3 meters, and a depth of 1.5 meters. The bottom slope is 8‰ gentler than that of the main river channel. The inner wall of the branch canal is planted with reeds for bank protection, with a bank protection slope of 1:2.5.

[0026] S2. Multi-level ecological purification: (1) Sedimentation and siltation zone: 30 meters long, accounting for 15% of the total length of the branch canal; a 30cm thick limestone siltation layer with a particle size of 10-15cm is laid at the bottom; a sawtooth overflow weir with a height of 1.0m is set at the end.

[0027] (2) Multi-level composite ecological reaction zone: 150 meters long, accounting for 75% of the total length of the branch canal, divided into three-level stepped units with an elevation difference of 0.3m between adjacent units; each unit from bottom to top: 10cm thick gravel support layer with a particle size of 20-30cm, 50cm thick biological filler layer with a modified zeolite:limestone:straw biochar mass ratio of 4:2.5:1, and 30cm thick planting soil layer; the planting layer is planted with Vallisneria natans and Iris at intervals, with a planting density of 25 plants / m² and a plant spacing of 40cm; a microporous aeration pipe network is laid in the filler layer, with an aeration hole diameter of 150μm and a pipe spacing of 1.0m. The initial influent ammonia nitrogen concentration is about 4mg / L, and the cycle of "aeration for 30 minutes / aeration stop for 60 minutes" is adopted, with an aeration intensity of 0.8m³ / (m²·h).

[0028] (3) Deep purification zone: 20 meters long, accounting for 10% of the total length of the branch canal; water depth is maintained at 1.2 meters, with 4 biological ropes / m² suspended as fillers; ring snails and medaka are released at a stocking density of 8 ind / m², with a stocking ratio of 1:2.

[0029] S3. Recirculation and Intelligent Control: Submersible pumps are installed at the end of the branch canals as recirculation devices to pump the purified water back to the downstream of the main channel; online monitoring instruments for dissolved oxygen, ammonia nitrogen, chemical oxygen demand (COD), and total phosphorus are installed before the main channel diversion point, at the branch canal outlet, and after the main channel recirculation point, with a monitoring frequency of once every 8 minutes; control thresholds are set: when COD > 30 mg / L after the recirculation point, the diversion flow rate is increased to 25%; when dissolved oxygen < 2.0 mg / L in the middle of the reaction zone, the aeration intensity is increased to 1.0 m³ / (m²·h); when ammonia nitrogen ≤ 1.0 mg / L and COD ≤ 20 mg / L after the recirculation point, the diversion flow rate is reduced to 15%.

[0030] Operational Results: After three months of stable operation, monitoring data showed that the chemical oxygen demand (COD) in the main channel after the return point decreased to 22-28 mg / L, ammonia nitrogen decreased to 0.8-1.2 mg / L, total phosphorus decreased to 0.2-0.3 mg / L, and suspended solids (SS) decreased to 8-12 mg / L. All indicators met the "Surface Water Environmental Quality Standards". Stable aquatic plant communities were formed in the tributary canals, and the number of fish and snails increased significantly, resulting in a good ecological landscape effect.

[0031] Example 2: Restoration of Severely Polluted Rivers This embodiment focuses on a heavily polluted river with the following basic parameters: average flow rate of the main channel is 1.2 m³ / s, and the current water quality is as follows: chemical oxygen demand 120-150 mg / L, ammonia nitrogen 8-12 mg / L, total phosphorus 1.5-2.0 mg / L, and suspended solids (SS) 100-150 mg / L; there are abandoned ditches on both sides of the river that can be renovated and utilized.

[0032] The specific steps for treating the problem using the method of this invention are as follows: S1. Diversion and diversion: An electric regulating weir gate is installed 80 meters downstream of the bend in the main river as a diversion device, equipped with a flow sensor, to control the diversion flow to 35% of the average flow of the main river, i.e., 0.42 m³ / s; The ecological treatment branch canal is a modified abandoned ditch, 280 meters long, 4 meters wide and 1.8 meters deep. After the bottom of the canal is compacted, a 12cm thick impermeable sand layer is laid, and the inner wall is paved with ecological concrete revetment with a slope of 1:3.

[0033] S2. Multi-level ecological purification: (1) Sedimentation and siltation zone: 40 meters long, accounting for 14.3% of the total length of the branch canal; a 40cm thick ecological ceramsite siltation layer with a particle size of 15-20cm is laid at the bottom, with a specific surface area ≥550m² / g; a sawtooth overflow weir with a height of 1.2m is set at the end.

[0034] (2) Multi-level composite ecological reaction zone: 200 meters long, accounting for 71.4% of the total length of the branch canal, divided into four stepped units with an elevation difference of 0.4m between adjacent units; each unit from bottom to top: a 15cm thick gravel support layer with a particle size of 25-30cm, a 60cm thick biological filler layer with a mass ratio of modified zeolite: limestone: peanut shell biochar = 5:3:1, and a 30cm thick planting soil layer; the planting layer is planted with black algae and pickerelweed at intervals, with a planting density of 30 plants / m² and a plant spacing of 30cm; a microporous aeration pipe network is laid in the filler layer with an aeration hole diameter of 200μm and a pipe spacing of 0.8m. The initial influent ammonia nitrogen concentration is about 10mg / L, and the cycle of "aeration for 30 minutes / aeration stop for 60 minutes" is adopted, with an aeration intensity of 1.2m³ / (m²·h); at the same time, nitrification and denitrification compound bacteria are inoculated in the biological filler layer to accelerate the start-up of the system.

[0035] (3) Deep purification zone: 40 meters long, accounting for 14.3% of the total length of the branch canal; water depth is maintained at 1.5 meters, with 5 biological ropes / m² suspended as filler; river mussels and ring snails are released at a stocking density of 10 ind / m², with a stocking ratio of 1:3.

[0036] S3. Recirculation and Intelligent Control: Two parallel submersible pumps are installed at the end of the branch canal as recirculation devices; the online monitoring equipment increases the total phosphorus monitoring frequency to once every 5 minutes; control thresholds are set: when the chemical oxygen demand after the recirculation point is >40mg / L, the diversion flow rate is increased to 40%; when the dissolved oxygen in the middle section of the reaction zone is <2.0mg / L, the aeration intensity is increased to 1.4m³ / (m²·h); when the ammonia nitrogen after the recirculation point is ≤1.5mg / L and the chemical oxygen demand is ≤30mg / L, the diversion flow rate is reduced to 30%.

[0037] Operational Results: The system entered stable operation one month after startup. After four months of operation, monitoring showed that the chemical oxygen demand (COD) in the main channel after the return point decreased to 35-45 mg / L, ammonia nitrogen decreased to 1.2-1.8 mg / L, total phosphorus decreased to 0.4-0.6 mg / L, and suspended solids in the water decreased to 15-20 mg / L. All indicators were significantly improved compared with before the treatment and met the "Surface Water Environmental Quality Standard". The aquatic ecosystem in the tributary canal gradually recovered, the water transparency increased from 30 cm before the treatment to 80 cm, and the black and odorous phenomenon was completely eliminated.

[0038] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art and related fields without creative effort should fall within the scope of protection of the present invention. Structures, devices and operating methods not specifically described and explained in the present invention shall be implemented in accordance with conventional means in the art unless otherwise specified and limited.

Claims

1. A method for treating pollution in a river water body, characterized by, The method comprises the following steps: S1. Diversion: A controllable diversion device (2) is arranged downstream of the bend of the main river channel (1) to divert part of the polluted river water into an ecological treatment branch channel (3) parallel to the main river channel (1); S2. Multi-stage ecological purification: The ecological treatment branch channel (3) is divided into a sedimentation and siltation promotion area (31), a multi-stage composite ecological reaction area (32) and a deep purification area (33) in sequence along the water flow direction, and the diverted river water flows through the above-mentioned areas in sequence to complete the step-by-step purification; S3. Backflow and intelligent control: The water body treated by the deep purification area (33) is returned to the downstream area of the main river channel (1) through the backflow device (4) arranged at the end of the branch channel; the online monitoring equipment (5) is arranged before the diversion point of the main river channel (1), at the outlet of the ecological treatment branch channel (3) and after the backflow point of the main river channel (1).

2. The method for treating pollution in a river water body according to claim 1, characterized in that, In step S1, the controllable diversion device (2) is arranged 50-100 meters downstream of the bend of the main river channel (1); the part of the polluted river water is diverted into the ecological treatment branch channel (3) at a preset flow rate of 10%-40% of the average flow rate of the main river channel; the length of the ecological treatment branch channel (3) is 150-300 meters, the width is 2-5 meters, and the depth is 1.2-1.8 meters, and the branch channel bottom slope is 5-10‰ gentler than the main river channel.

3. The method for treating pollution in a river water body according to claim 1, characterized in that, In step S1, the diversion device (2) is one of a hydraulic self-control flap gate, an electrically adjustable weir gate or a controllable water pump; when the average flow rate of the main river channel is ≤0.3m³ / s, the hydraulic self-control flap gate is preferred; when the average flow rate of the main river channel is >0.3m³ / s, the electrically adjustable weir gate is selected and is equipped with a flow feedback control system.

4. The method for treating pollution in a river water body according to claim 1, characterized in that, In step S2, the length ratio of the sedimentation and siltation promotion area (31), the multi-stage composite ecological reaction area (32) and the deep purification area (33) is 1:4-6:0.5-1.

5.

5. The method for treating pollution in a river water body according to claim 1, characterized in that, In step S2, the bottom of the sedimentation and siltation promotion area (31) is paved with a porous medium siltation promotion layer (311) with a thickness of 20-40cm; the porous medium is broken stone or ecological ceramsite with a particle size of 5-20cm, and the specific surface area of the ecological ceramsite is ≥500m² / g; A sawtooth overflow weir (312) is arranged at the end of the sedimentation and siltation promotion area (31), and the weir height of the overflow weir is adjusted to 0.8-1.2m according to the design water depth of the branch channel; The multi-stage composite ecological reaction area (32) is composed of 2-4 stage stepwise units connected in series, and a height difference of 0.2-0.5m is arranged between adjacent units; each unit includes a supporting layer (321), a biological filler layer (322) and a water plant planting layer (323) from bottom to top, and a micro-porous aeration pipe network (324) is embedded in the biological filler layer (322); The supporting layer (321) is gravel with a particle size of 20-30cm and a paving thickness of 10-15cm; The biological filler layer (322) is composed of modified zeolite, limestone and waste biomass charcoal at a mass ratio of 3-5:2-3:1, and the filler layer has a thickness of 40-60cm and a porosity of ≥45%.

6. The method for treating pollution in a river water body according to claim 5, characterized in that, The aquatic plant planting layer (323) is planted with at least two of native aquatic plants selected from the group consisting of Vallisneria, Hydrilla verticillata, Iris and Echinodorus. The aeration mode of the microporous aeration pipe network (324) is intermittent aeration, and the aeration intensity is controlled to be 0.5-1.2 m³ / (m²·h). The operation cycle is dynamically adjusted according to the ammonia nitrogen concentration of the influent: when the ammonia nitrogen concentration of the influent is ≥2.0 mg / L, the cycle of "aeration for 30 minutes / stop aeration for 60 minutes" is used; when the ammonia nitrogen concentration of the influent is <2.0 mg / L, the cycle of "aeration for 15 minutes / stop aeration for 90 minutes" is used. The aeration pore size of the microporous aeration pipe network (324) is 100-200 μm, and the pipe spacing is 0.8-1.2 m.

7. The method for treating pollution in a river water body according to claim 1, characterized in that, In step S2, the biological rope filler (331) with a hanging density of 3-5 roots / m² is suspended in the deep purification zone (33), and the specific surface area of the biological rope filler is ≥800 m² / m³; at the same time, filter-feeding aquatic animals (332) are raised, and the raising density is 5-10 ind / m², the filter-feeding aquatic animals are one or more combinations of river clams, ring snails or guppy fish, and the raising ratio of different species is 1:2-3.

8. The method for treating pollution in a river water body according to claim 1, characterized in that, In step 3, the online monitoring equipment (5) monitors the water quality parameters of dissolved oxygen, ammonia nitrogen, chemical oxygen demand and total phosphorus in real time, and adjusts the shunt flow of the shunt device (2) and the aeration intensity of the multi-stage composite ecological reaction zone (32) according to the feedback.

9. The method for treating pollution in a river water body according to claim 1, characterized in that, In step S3, the monitoring frequency of the online monitoring equipment (5) is once every 5-10 minutes, and the data transmission delay is ≤30 seconds; The feedback adjustment logic is: when the chemical oxygen demand after the main river backflow point is >30 mg / L for 2 hours continuously, the shunt flow is increased by 5-10 percentage points; When the monitoring dissolved oxygen in the middle section of the multi-stage composite ecological reaction zone (32) is <2.0 mg / L for 2 hours continuously, the aeration intensity is increased by 0.2-0.3 m³ / (m²·h); When the ammonia nitrogen after the main river backflow point is ≤1.0 mg / L and the chemical oxygen demand is ≤20 mg / L, the shunt flow can be reduced by 5-10 percentage points to save energy consumption.

10. The method for treating pollution in a river water body according to claim 1, characterized in that, The inner wall of the ecological treatment branch channel (3) is paved with ecological concrete or planted with aquatic plant revetment, and the revetment slope is 1:2-1:3; when the river beach or abandoned ditch is used to reconstruct the ecological treatment branch channel (3), the channel bottom needs to be compacted and a 10-15 cm thick impermeable sand layer is paved.

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