Intelligent diversion and reinforced purification system for agricultural drainage canal and operation method thereof

Abstract

The application provides an agricultural drainage ditch intelligent diversion and reinforced purification system and a running method thereof, and relates to the field of agricultural drainage ditch purification. The agricultural drainage ditch intelligent diversion and reinforced purification system comprises an agricultural drainage ditch, an aeration sedimentation zone, a water-permeable concrete wall and a reinforced purification zone. The agricultural drainage ditch is communicated with the aeration sedimentation zone through an inlet channel. The reinforced purification zone comprises an ecological purification zone at the upper part and an iron-carbon filler zone at the lower part. The height of the water-permeable concrete wall matches that of the ecological purification zone. A vegetable floating bed is arranged in the ecological purification zone. The bottom of the vegetable floating bed is provided with a three-dimensional elastic filler. The bottom of the iron-carbon filler zone is communicated with the agricultural drainage ditch through an outlet pipe. The application can efficiently remove different water quality types without affecting the irrigation of the upstream and downstream of the agricultural drainage ditch and the original flood discharge capacity of the ditch.

Description

Technical Field

[0001] This invention relates to the field of ecological ditch purification technology, specifically to an intelligent diversion and enhanced purification system for agricultural irrigation and drainage ditches and its operation method. Background Technology

[0002] Currently, most farmland irrigation and drainage ditches cannot be separated, serving the dual functions of irrigation and drainage. In the event of flooding or rainfall, the irrigation and drainage ditches carry large amounts of organic matter, nitrogen, and phosphorus into sensitive water bodies such as lakes and reservoirs, causing eutrophication or other water quality deterioration problems.

[0003] Existing patents primarily address pollution load reduction through ecological ditches, small-scale constructed wetlands, and ecological slope protection. Ecological ditches mainly involve planting aquatic plants within the ditch, utilizing their absorption, adsorption, and root microbial degradation to purify the water. However, this can easily lead to secondary pollution from plant decay and reduce the flood discharge capacity of the ditch section. Small-scale constructed wetlands at the ditch's end or key nodes can utilize the synergistic effects of wetland plants, microorganisms, and substrates to remove pollutants such as nitrogen, phosphorus, organic matter, and heavy metals. However, constructed wetlands are difficult to manage, especially in agricultural irrigation ditches where seasonal water shortages and significant wet-dry cycles mean that many aquatic plants cannot survive prolonged periods without water. Ecological slope protection uses technologies such as ecological concrete and vegetated slope protection to reduce soil erosion and enhance the ditch's self-purification capacity. However, this requires widening the land on both sides of the ditch and is not suitable for small irrigation and drainage ditches.

[0004] A Chinese patent with publication number CN222477363U discloses an interception and purification device suitable for irrigation ditches flowing into rivers and farmland. The device includes an interception structure and a purification structure. The interception structure comprises a sedimentation tank and a steel grating. A denitrification device containing denitrifying phosphorus-accumulating bacteria and adsorbent mineral materials is placed in the sedimentation tank. A sedimentation inlet and outlet are located on opposite sides of the sedimentation tank. The steel grating is positioned at the sedimentation outlet, and the sedimentation inlet is used to connect with the ecological ditch. The purification structure includes an ecological purification pool and a gabion bed. The ecological purification pool has a purification inlet and a purification outlet, both of which are equipped with gabions. The ecological purification pool is located adjacent to the sedimentation tank, with the purification inlet directly opposite and connected to the sedimentation inlet. The gabion bed is placed within the ecological purification pool. This patent describes a single infiltration process, resulting in extremely limited treatment capacity.

[0005] Therefore, it is necessary to propose an eco-friendly, simple to manage and maintain, and highly efficient technical method for purifying nitrogen, phosphorus and organic matter in farmland tailwater and surface runoff without affecting the irrigation upstream and downstream of agricultural irrigation canals or the original flood discharge capacity of the canals, and to adapt well to different weather conditions and changes in the water volume of agricultural irrigation canals. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals, and its operation method.

[0007] According to the present invention, an intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals includes: an agricultural irrigation and drainage canal, an aeration and sedimentation zone, a permeable concrete wall, and an enhanced purification zone, wherein the enhanced purification zone, the permeable concrete wall, and the aeration and sedimentation zone are arranged sequentially from the inside to the outside. The aeration and sedimentation zone is equipped with a push-flow aerator, and a sludge settling zone is set at the bottom of the aeration and sedimentation zone. The agricultural irrigation and drainage canal is connected to the aeration and sedimentation zone through an inlet canal. The inlet canal is equipped with an automatic control gate for switching on and off. Rainfall sensors and liquid level sensors are installed in the agricultural irrigation and drainage canal. The enhanced purification zone includes an upper ecological purification zone and a lower iron-carbon filler zone. The permeable concrete wall is matched with the height of the ecological purification zone. Vegetable floating beds are installed in the ecological purification zone, and three-dimensional elastic filler is installed at the bottom of the vegetable floating beds. The bottom of the iron-carbon filler zone is connected to the agricultural irrigation and drainage canal through a water outlet pipe.

[0008] Preferably, both the aeration sedimentation zone and the permeable concrete wall are annular, the bottom of the aeration sedimentation zone is provided with a V-shaped sludge settling zone, and the permeability coefficient of the permeable concrete wall is in the range of 0.02-0.03 cm / s.

[0009] Preferably, the height of the ecological purification zone is 0.5-1m, and an upper reserved space for the iron-carbon filler is provided between the ecological purification zone and the iron-carbon filler zone, and the bottom of the three-dimensional elastic filler can extend into the upper reserved space of the iron-carbon filler.

[0010] Preferably, the iron-carbon packing zone is filled with iron-carbon micro-electrolysis packing, the packing height of the iron-carbon packing zone is between 0.8 and 1.5 m, and the Fe / C ratio of the packing components is between 3:1 and 5:1.

[0011] Preferably, the bottom height of the connection section between the outlet pipe and the agricultural irrigation and drainage canal is consistent with the bottom of the permeable concrete wall.

[0012] According to the present invention, an operation method for an intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals includes: a primary rainfall measurement operation method, a secondary rainfall measurement operation method, a tertiary rainfall measurement operation method, and a quaternary rainfall measurement operation method. The primary rainfall measurement operation method involves rainfall of <0.5 mm / h during the irrigation period; the secondary rainfall measurement operation method involves rainfall of <0.5 mm / h during the farmland tailwater discharge period; the tertiary rainfall measurement operation method involves rainfall between 0.5 mm / h and 2 mm / h; and the quaternary rainfall measurement operation method involves rainfall of >2 mm / h.

[0013] Preferably, the first-level rainfall operation method includes the following steps: opening the automatic control gate, closing the inlet of the water inlet channel, and purifying the stored water in the enhanced purification zone.

[0014] Preferably, the secondary rainfall operation method includes the following steps: the automatic control gate is closed, the inlet of the water inlet is opened, the water in the agricultural irrigation and drainage canal enters the aeration sedimentation zone, the water passes through the permeable concrete wall and enters the enhanced purification zone, the enhanced purification zone purifies the water, and the treated water is discharged into the agricultural irrigation and drainage canal through the outlet pipe.

[0015] Preferably, the three-level rainfall operation method includes the following steps: the automatic control gate is closed, the inlet of the water inlet is opened, the water in the agricultural irrigation and drainage canal enters the aeration and sedimentation zone, the push-flow aerator is turned on, the water passes through the permeable concrete wall and enters the enhanced purification zone, the enhanced purification zone purifies the water, and the treated water is discharged into the agricultural irrigation and drainage canal through the outlet pipe.

[0016] Preferably, the four-level rainfall operation method includes the following steps: the automatic control gate is opened, the inlet of the water channel is closed, the rainwater enters the aeration sedimentation zone and the enhanced purification zone and mixes with the stored water, and the enhanced purification zone purifies the water body.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention utilizes an intelligent diversion and enhanced purification system for agricultural irrigation and drainage ditches, comprising an agricultural irrigation and drainage canal, an aeration sedimentation zone, a permeable concrete wall, and an enhanced purification zone. It adjusts its operation according to the varying water quality and quantity changes in irrigation and drainage ditches during different rainfall and irrigation periods. This system ensures that it does not affect upstream and downstream irrigation or the original flood discharge capacity of the irrigation ditches, while simultaneously providing targeted and efficient removal of different water quality types. This includes efficient interception of silt, soil particles, and adsorbed organic matter; enhanced phosphate removal through iron-carbon micro-electrolysis; and enhanced denitrification through a hypoxic environment at the bottom layer. The system is simple to manage and maintain, highly intelligent, and well-adapted to different weather conditions and variations in irrigation canal water volume, demonstrating broad application prospects.

[0018] 2. This invention, through innovative optimization and integration of ecological floating beds, biofilm contact oxidation, and iron-carbon micro-electrolysis processes, can achieve a removal rate of 30%-50% for particulate matter, chemical oxygen demand, total nitrogen, and total phosphorus in agricultural wastewater. The vegetable floating bed, combined with three-dimensional elastic filler, can adapt to different water volume conditions in agricultural irrigation and drainage canals, maintain biofilm activity throughout the year, is eco-friendly, and generates certain economic benefits from vegetables. The core unit for removing dissolved pollutants combines high-efficiency iron-carbon micro-electrolysis filler, three-dimensional elastic filler, and plant absorption processes, which can treat high-load agricultural wastewater and achieve aerobic degradation of organic matter, denitrification, and phosphorus removal without the need for adding bacterial agents. Attached Figure Description

[0019] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram illustrating the structure of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals, which is the main feature of this invention. Figure 2 This is a schematic diagram illustrating the three-stage rainfall operation method of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals, which is the main feature of this invention. Figure 3 This is a schematic diagram illustrating the secondary rainfall operation method of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals, which is the main feature of this invention. Figure 4 This is a schematic diagram illustrating the primary and secondary rainfall operation methods of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals, which are the main features of this invention.

[0020] The diagram shows: 1. Agricultural irrigation and drainage canal; 2. Rainfall sensor; 3. Liquid level sensor; 4. Automatic control gate; 5. Inlet canal; 6. Aeration and sedimentation zone; 7. Flow aerator; 8. Permeable concrete wall; 9. Enhanced purification zone; 10. Iron-carbon micro-electrolysis packing; 11. Vegetable floating bed; 12. Outlet pipe; 13. Three-dimensional elastic packing; 14. Sedimentation zone; 15. Reserved space above the iron-carbon packing. Detailed Implementation

[0021] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0022] like Figures 1 to 4 As shown, an intelligent diversion and enhanced purification system for agricultural irrigation and drainage ditches according to the present invention includes: an agricultural irrigation and drainage ditches 1, an aeration and sedimentation zone 6, a permeable concrete wall 8, and an enhanced purification zone 9, which are arranged sequentially from the inside to the outside; a propulsion aerator 7 is installed in the aeration and sedimentation zone 6, and a sedimentation zone 14 is provided at the bottom of the aeration and sedimentation zone 6; the agricultural irrigation and drainage ditches 1 are connected to the aeration and sedimentation zone 6 through an inlet channel 5; the inlet channel 5 is equipped with an automatic control gate 4 for switching on and off; a rainfall sensor 2 and a liquid level sensor 3 are installed in the agricultural irrigation and drainage ditches 1; the enhanced purification zone 9 includes an upper ecological purification zone and a lower iron-carbon filler zone; the permeable concrete wall 8 is matched with the height of the ecological purification zone; a vegetable floating bed 11 is provided in the ecological purification zone; a three-dimensional elastic filler 13 is provided at the bottom of the vegetable floating bed 11; and the bottom of the iron-carbon filler zone is connected to the agricultural irrigation and drainage ditches 1 through an outlet pipe 12.

[0023] Rainfall sensors 2 and level sensors 3 are installed in the agricultural irrigation and drainage canal 1 to acquire real-time rainfall and canal water volume data, identify potential pollution sources (whether it is mainly farmland drainage or rainfall-induced surface load) and water volume, thereby guiding the opening or closing of the automatic control gate 4. When the automatic control gate 4 is opened, the canal water is introduced into the aeration and sedimentation zone 6 through the inlet channel 5, where a large amount of silt and soil particles contained in the raw water settle.

[0024] Both the aeration sedimentation zone 6 and the permeable concrete wall 8 are annular. The water volume in farmland ditches varies greatly, with intermittent flow and unstable water flow, making it unsuitable for intensive treatment within a specific unit. The annular structure creates a reciprocating annular flow from a smaller volume of water, increasing particle settling and oxygenation. A V-shaped sedimentation zone 14 is located at the bottom of the aeration sedimentation zone 6, facilitating manual removal in later stages. A flow-pushing aerator 7 is installed within the aeration sedimentation zone 6. When the organic matter content is high, it is activated to create an annular flow of water, increasing the water's self-purification capacity and providing aeration. The permeability coefficient of the permeable concrete wall 8 ranges from 0.02 to 0.03 cm / s, allowing the water, after particle removal, to slowly enter the internal intensive purification zone 9.

[0025] The enhanced purification zone 9 is divided into two main parts. The upper part is an ecological purification zone composed of a vegetable floating bed 11 and a three-dimensional elastic packing material 13. The height of the ecological purification zone ranges from 0.5 to 1 m. Lettuce, water spinach, or amaranth are selected as vegetables. The vegetable roots continuously absorb nutrients such as nitrogen and phosphorus, and they are harvested every 3 months. The lower part of the enhanced purification zone 9 is an iron-carbon packing zone, which is filled with iron-carbon micro-electrolysis packing material 10. Considering that a large amount of organic matter has already been removed in the aeration sedimentation zone 6, this unit only needs to enhance denitrification and phosphorus removal. In order to achieve better denitrification, the height of the packing material in the iron-carbon packing zone is between 0.8 and 1.5 m. In order to enhance the co-sedimentation of phosphates, the Fe / C ratio of the packing material is between 3:1 and 5:1. A reserved space 15 for the upper part of the iron-carbon filler is provided between the ecological purification zone and the iron-carbon filler zone. The bottom of the three-dimensional elastic filler 13 can extend into the reserved space 15. The reserved space 15 allows the vegetable floating bed 11 and the three-dimensional elastic filler 13 to fall into it to maintain moisture and activity when there is no water intake. The reserved space 15 and the sides and bottom of the iron-carbon filler zone need to be lined with concrete, and any leaks in the expansion joints need to be repaired.

[0026] The treated effluent is discharged again into the downstream agricultural irrigation and drainage canal 1 through the effluent pipe 12 at the bottom of the iron-carbon filler area. The bottom height of the connection section between the effluent pipe 12 and the agricultural irrigation and drainage canal 1 is consistent with the bottom of the permeable concrete wall 8. In practical applications, the effluent pipe 12 is generally more than 50cm lower than the inlet pipe, utilizing the slope of the agricultural irrigation and drainage canal 1, the downstream ditch, and the height difference with the upstream to achieve gravity-flow effluent.

[0027] According to the present invention, an operation method for an intelligent diversion and enhanced purification system for agricultural irrigation and drainage ditches is provided, taking into account the changes in water quality and quantity in agricultural irrigation ditches during different rainfall and irrigation periods. The method includes: a first-level rainfall operation method, a second-level rainfall operation method, a third-level rainfall operation method, and a fourth-level rainfall operation method. The rainfall in the first-level rainfall operation method is <0.5 mm / h and is during the irrigation period; the rainfall in the second-level rainfall operation method is <0.5 mm / h and is during the farmland tailwater discharge period; the rainfall in the third-level rainfall operation method is between 0.5 mm / h and 2 mm / h; and the rainfall in the fourth-level rainfall operation method is >2 mm / h.

[0028] The operation method for Level 1 rainfall includes the following steps: the automatic control gate 4 is opened, the inlet of the water inlet channel 5 is closed, and the enhanced purification zone 9 purifies the stored water. More specifically, in scenarios where the rainfall is <0.5mm / h and it is during the irrigation period of the area, there is no significant rainfall, and the water level does not change significantly within 1 hour. At this time, the upstream and downstream irrigation water is the main source, the automatic control gate 4 is automatically opened, and the water in the agricultural irrigation and drainage canal 1 is not introduced into this system to ensure normal irrigation downstream; there is no water in the upper part of the aeration sedimentation zone 6 and the enhanced purification zone 9, and the water level drops to the bottom height of the permeable concrete wall 8; only the iron-carbon filler zone has stored water, and the vegetable floating bed 11 and the three-dimensional elastic filler 13 fall into the reserved space 15 above the iron-carbon filler zone to keep them moist and active; the biofilm on the three-dimensional elastic filler 13, the absorption by vegetable roots, and the iron-carbon micro-electrolysis process continuously purify the stored water, which is then naturally discharged from the outlet pipe 12 during the next rainfall cycle.

[0029] The secondary rainfall monitoring operation method includes the following steps: The automatic control gate 4 is closed, the inlet of the inlet channel 5 is opened, and the water in the agricultural irrigation and drainage canal 1 enters the aeration and sedimentation zone 6. The water then passes through the permeable concrete wall 8 into the enhanced purification zone 9, where it is purified. The treated water is then discharged into the agricultural irrigation and drainage canal 1 through the outlet pipe 12. More specifically, in scenarios where rainfall is <0.5mm / h and the area is in the peak period for farmland tailwater discharge, with no significant rainfall and a noticeable rise in water level within 1 hour, the automatic control gate 4 is closed, and all water in the agricultural irrigation and drainage canal 1 is introduced into this system. At this time, the water is mainly farmland tailwater with low organic matter content, so the aerator 7 does not need to be turned on, saving energy. Intermittently flowing ditch water is introduced into the aeration and sedimentation zone 6 through the inlet channel 5, where a large amount of silt and soil particles in the raw water settle. Subsequently, the water slowly passes through the permeable concrete wall 8 into the internal enhanced purification zone 9, where it is further purified. In the purification zone, the vegetable floating bed 11 absorbs nitrogen and phosphorus nutrients, and the three-dimensional elastic packing 13 serves as the attachment medium for the microbial film, further removing organic matter and nitrogen and phosphorus under the action of microorganisms. Due to the small amount of water, as the water level drops, part of the vegetable floating bed 11 with the suspended three-dimensional elastic packing 13 falls into the reserved space 15 above the iron-carbon packing zone. The iron-carbon packing zone is filled with iron-carbon micro-electrolysis packing 10, which removes nitrates at the bottom layer. The iron-carbon micro-electrolysis packing particularly enhances the co-sedimentation removal of phosphates. The treated effluent is discharged again into the downstream irrigation and drainage canal 1 through the curved effluent pipe 12 at the bottom of the packing zone.

[0030] The three-level rainfall operation method includes the following steps: the automatic control gate 4 is closed, the inlet of the inlet channel 5 is opened, the water in the agricultural irrigation and drainage canal 1 enters the aeration and sedimentation zone 6, the push-flow aerator 7 is turned on, and the water passes through the permeable concrete wall 8 into the enhanced purification zone 9. The enhanced purification zone 9 purifies the water, and the treated water is discharged into the agricultural irrigation and drainage canal 1 through the outlet pipe 12. More specifically, in the scenario where the rainfall is between 0.5 mm / h and 2 mm / h, the liquid level rises significantly within 1 hour (the liquid level rises rapidly within 1 hour, approaching full flow), the automatic control gate 4 is automatically closed, and all the water in the agricultural irrigation and drainage canal 1 is introduced into this system. At this time, the farmland tailwater mixed with the surface impact load is high and rich in organic matter, so the push-flow aerator 7 needs to be turned on to introduce the ditch water into the aeration and sedimentation zone 6 through the inlet channel 5. A large amount of silt and soil particles contained in the raw water are precipitated in the aeration and sedimentation zone 6, and most of the organic matter is adsorbed and settled; under the oxygenation and propulsion action of the push-flow aerator 7, dissolved organic matter is further precipitated. During the circular flow of the water, rapid degradation occurs; subsequently, the water slowly permeates through the permeable concrete wall 8 and enters the internal enhanced purification zone 9. In the enhanced purification zone 9, the vegetable floating bed 11 absorbs nitrogen and phosphorus nutrients, and the three-dimensional elastic packing 13 serves as the attachment medium for the microbial film, further removing organic matter and nitrogen and phosphorus under the action of microorganisms; the lower part is the iron-carbon packing zone, filled with iron-carbon micro-electrolysis packing 10, where nitrates are removed at the bottom layer, and the iron-carbon micro-electrolysis packing 10 particularly enhances the co-sedimentation removal of phosphates; the treated effluent is discharged again into the downstream agricultural irrigation and drainage canal 1 through the curved effluent pipe 12 at the bottom of the iron-carbon packing zone.

[0031] The operation method for Level IV rainfall includes the following steps: the automatic control gate 4 is opened, the inlet of the inlet channel 5 is closed, and rainwater enters the aeration sedimentation zone 6 and the enhanced purification zone 9 to mix with the stored water. The enhanced purification zone 9 purifies the water. More specifically, if the rainfall is >2mm / h for more than 3 hours and the water level remains high, this is considered heavy to torrential rain. The automatic control gate 4 is opened, and water from the agricultural irrigation and drainage canal 1 is not introduced into this system to ensure the flood discharge channel. Although there is no inflow, a small amount of rainfall enters the aeration sedimentation zone 6 and the enhanced purification zone 9, mixes with the existing stored water in the iron-carbon filler zone, and is continuously purified under the action of the biofilm on the three-dimensional elastic filler 13, absorption by vegetable roots, and iron-carbon micro-electrolysis. The water is then naturally discharged from the outlet pipe 12 during the next rainfall cycle.

[0032] This application is an innovative and optimized integration of ecological floating beds, biofilm contact oxidation, and iron-carbon micro-electrolysis processes. It can achieve a removal rate of 30%-50% for particulate matter, chemical oxygen demand, total nitrogen, and total phosphorus in farmland tailwater, which is eco-friendly and generates certain economic benefits for vegetables.

[0033] The vegetable floating bed 11 of this application, combined with the three-dimensional elastic packing material 13, can adapt to different water volume conditions in agricultural irrigation and drainage canals 1, maintain biofilm activity throughout the year, and generate economic benefits from the vegetables. The core unit for removing dissolved pollutants in this application combines multiple processes of enhanced absorption, including iron-carbon micro-electrolysis high-efficiency packing material 10, three-dimensional elastic packing material 13, and plant absorption. This combination can treat high-load farmland tailwater, achieving aerobic degradation of organic matter, denitrification, and phosphorus removal without the need for added microbial agents.

[0034] The particulate matter removal rate of this application is significantly higher than that of ordinary sedimentation processes, and it also avoids the clogging problem in the subsequent functional filler areas. This application does not affect upstream and downstream irrigation in agricultural irrigation canals, nor does it affect the original flood discharge capacity of the canals. This application provides targeted and efficient removal for different water quality types: including efficient interception of silt and soil particles and adsorbed organic matter, iron-carbon micro-electrolysis-enhanced phosphate removal, and enhanced denitrification in the anoxic environment of the bottom layer. This application is simple to manage and maintain, highly intelligent, and well-adapted to different weather conditions and changes in irrigation canal water volume, showing broad application prospects.

[0035] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals, characterized in that, include: Agricultural irrigation and drainage canal (1), aeration sedimentation zone (6), permeable concrete wall (8) and enhanced purification zone (9), wherein the enhanced purification zone (9), permeable concrete wall (8) and aeration sedimentation zone (6) are arranged sequentially from the inside to the outside; The aeration sedimentation zone (6) is equipped with a push-flow aerator (7), and a sedimentation zone (14) is set at the bottom of the aeration sedimentation zone (6). The agricultural irrigation and drainage canal (1) is connected to the aeration sedimentation zone (6) through the inlet channel (5). The inlet channel (5) is equipped with an automatic control gate (4) for switching on and off. The agricultural irrigation and drainage canal (1) is equipped with a rain sensor (2) and a liquid level sensor (3). The enhanced purification zone (9) includes an upper ecological purification zone and a lower iron-carbon filler zone. The permeable concrete wall (8) is matched with the height of the ecological purification zone. A vegetable floating bed (11) is provided in the ecological purification zone. A three-dimensional elastic filler (13) is provided at the bottom of the vegetable floating bed (11). The bottom of the iron-carbon filler zone is connected to the agricultural irrigation and drainage canal (1) through a water outlet pipe (12).

2. The intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 1, characterized in that, The aeration sedimentation zone (6) and the permeable concrete wall (8) are both annular. The bottom of the aeration sedimentation zone (6) is provided with a V-shaped sedimentation zone (14). The permeability coefficient of the permeable concrete wall (8) ranges from 0.02 to 0.03 cm / s.

3. The intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 1, characterized in that, The height range of the ecological purification zone is 0.5-1m. An upper reserved space (15) for iron and carbon filler is provided between the ecological purification zone and the iron and carbon filler zone. The bottom of the three-dimensional elastic filler (13) can extend into the upper reserved space (15) for iron and carbon filler.

4. The intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 1, characterized in that, The iron-carbon packing zone is filled with iron-carbon micro-electrolysis packing (10), the packing height of the iron-carbon packing zone is between 0.8-1.5m, and the Fe / C ratio of the packing composition is between 3:1 and 5:

1.

5. The intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 1, characterized in that, The bottom height of the connection section between the outlet pipe (12) and the agricultural irrigation and drainage canal (1) is consistent with the bottom of the permeable concrete wall (8).

6. A method for operating the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in any one of claims 1-5, characterized in that, include: The four rainfall operation methods are: Level 1 rainfall operation method, Level 2 rainfall operation method, Level 3 rainfall operation method, and Level 4 rainfall operation method. In Level 1 rainfall operation method, the rainfall is <0.5 mm / h and it is during the irrigation period. In Level 2 rainfall operation method, the rainfall is <0.5 mm / h and it is during the farmland tailwater discharge period. In Level 3 rainfall operation method, the rainfall is between 0.5 mm / h and 2 mm / h. In Level 4 rainfall operation method, the rainfall is >2 mm / h.

7. The operation method of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 6, characterized in that, The first-level rainfall operation method includes the following steps: the automatic control gate (4) is opened, the inlet of the water inlet channel (5) is closed, and the enhanced purification zone (9) purifies the stored water.

8. The operation method of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 6, characterized in that, The secondary rainfall operation method includes the following steps: the automatic control gate (4) is closed, the inlet of the water inlet channel (5) is opened, the water in the agricultural irrigation and drainage canal (1) enters the aeration sedimentation zone (6), the water passes through the permeable concrete wall (8) and enters the enhanced purification zone (9), the enhanced purification zone (9) purifies the water, and the treated water is discharged into the agricultural irrigation and drainage canal (1) through the outlet pipe (12).

9. The operation method of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 6, characterized in that, The three-level rainfall operation method includes the following steps: the automatic control gate (4) is closed, the inlet of the water inlet channel (5) is opened, the water in the agricultural irrigation and drainage canal (1) enters the aeration sedimentation zone (6), the push flow aerator (7) is turned on, the water passes through the permeable concrete wall (8) and enters the enhanced purification zone (9), the enhanced purification zone (9) purifies the water, and the treated water is discharged into the agricultural irrigation and drainage canal (1) through the outlet pipe (12).

10. The operation method of the intelligent diversion and enhanced purification system for agricultural irrigation and drainage canals as described in claim 6, characterized in that, The four-level rainfall operation method includes the following steps: the automatic control gate (4) is opened, the inlet of the water inlet channel (5) is closed, the rainwater enters the aeration sedimentation zone (6) and the enhanced purification zone (9) and mixes with the stored water, and the enhanced purification zone (9) purifies the water body.

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