Farmland drainage interception purification and cyclic utilization system and method thereof

Abstract

The invention provides a farmland drainage intercepting, purifying and recycling system and a method thereof. The system comprises a solid-liquid separation module; the ecological treatment module is arranged in a drainage river communicated with the irrigation and drainage channel and used for removing phosphorus, nitrogen and attached microorganisms in farmland drainage; the enhanced treatment module is arranged in a drainage river communicated with the irrigation and drainage channel and is used for reducing the concentration of COD (Chemical Oxygen Demand), BOD (Biochemical Oxygen Demand) and NH3-N by releasing microorganisms; the irrigation system is used for introducing the water treated by the enhanced treatment module into the farmland; the retaining dam and the gate are arranged at the tail end of the drainage river and used for controlling the water discharge amount outside the drainage river and adjusting the water flow speed; the on-line monitoring system comprises a water quality on-line monitoring module arranged in the gate, a first water level monitoring unit arranged in the drainage river and a second water level monitoring unit arranged in the farmland; the linkage cloud platform is used for controlling the operation of the irrigation system and the gate according to the rice growth cycle and / or the weather condition; and controlling the enhanced processing module according to the water quality data.

Description

Technical Field

[0001] This application relates to the field of water treatment, and more specifically, to a farmland drainage interception, purification and recycling system and method thereof. Background Technique

[0002] During the rice planting process, fertilizers and pesticides need to be applied, and the applied chemical fertilizers and pesticides will cause agricultural non-point source pollution during the process of farmland drainage and rainwater discharge after rain; at the same time, the initial rainwater carrying a large amount of pollutants in the air and pollutants scouring the ground surface will exacerbate agricultural non-point source pollution. In addition, farmland drainage and rainwater scouring will lead to farmland soil erosion and reduced fertility. And during the rice greening stage, tillering stage, young panicle development stage and heading and flowering stage, a certain amount of water needs to be irrigated; before rice planting, basal fertilizers need to be applied, and top fertilizers need to be applied during the tillering stage, heading and flowering stage, and late heading stage. Therefore, in order to prevent and control agricultural non-point source pollution, improve farmland fertility, and save water and fertilizers, it is very necessary to develop a farmland drainage interception, purification and recycling system and method thereof.

[0003] At present, the main technologies for treating agricultural non-point source pollution are ecological restoration technologies such as ecological ditch interception, constructed wetland and ecological floating bed, which improve the self-purification ability of water bodies after degrading pollutants. Chinese Patent CN114230102A discloses a farmland drainage treatment system and method based on ecological interception and cyclic purification. The system includes a sedimentation tank, an ecological ditch, a multi-stage ecological regulation pond, an automatic detection system and a smart water-saving irrigation system; the sedimentation tank is arranged at the drainage outlet of the farmland, and all the farmland drainage discharged from the drainage outlet can enter the sedimentation tank for preliminary sedimentation; the multi-stage ecological regulation pond includes a gradually expanding section and a main reaction section connected; the main reaction section includes an aeration tank and a sedimentation tank, a first filter dam, a second filter dam and a purification tank with ecological slopes on the surrounding slopes; a number of bionic waterweeds are uniformly fixed in the purification tank and suspended vertically in the water flow direction; a water quality automatic detection system for detecting the water quality compliance is arranged at the water outlet end of the purification tank. The invention is applicable to the interception of non-point source pollutants in the drainage of farmlands in aquatic plant planting areas such as paddy fields and water chestnut fields, and can effectively reduce the amount of non-point source pollutants in farmlands entering the river. However, the invention has no sediment recovery and return system to the field, and fails to effectively improve farmland fertility; and the invention has no linkage platform for the purification equipment and irrigation equipment in the whole life cycle of rice growth, and cannot accurately control the operation of the purification equipment according to the water demand of rice, which is easy to cause waste of energy consumption. Summary of the Invention

[0004] The main purpose of this application is to provide a farmland drainage interception, purification and recycling system and method thereof, which returns sediments to the field, effectively realizes the recycling of nutrients such as nitrogen and phosphorus, thereby saving fertilizers, accurately controlling the farmland water layer and the operation of the fan, and realizing energy conservation, emission reduction and water resource conservation during the rice planting process.

[0005] To achieve the above object, in a first aspect, the present application provides a farmland drainage interception, purification and recycling system, including

[0006] a solid-liquid separation module, which is arranged at the end of the irrigation and drainage canal between farmlands;

[0007] an ecological treatment module, which is arranged in the drainage river connected to the irrigation and drainage canal, and is used to remove phosphorus, nitrogen and attached microorganisms in the farmland drainage;

[0008] a strengthening treatment module, which is arranged in the drainage river connected to the irrigation and drainage canal, and reduces the concentrations of COD, BOD and NH 3 -N by releasing microorganisms;

[0009] an irrigation system, which introduces the water treated by the strengthening treatment module into the farmland;

[0010] a water retaining dam and a gate, which are arranged at the end of the drainage river to control the drainage volume outside the drainage channel and adjust the water flow velocity;

[0011] an on-line monitoring system, including a water quality on-line monitoring module arranged in the gate, a first water level monitoring unit arranged in the drainage river, and a second water level monitoring unit arranged in the farmland;

[0012] a linkage cloud platform, which controls the operation of the irrigation system and the gate according to the rice growth cycle, water level and / or weather conditions; and controls the strengthening treatment module according to the water quality data.

[0013] Optionally, the solid-liquid separation module is an inclined plate sedimentation tank.

[0014] Optionally, the ecological treatment module includes a frame placed at the bottom of the drainage river, biological filter media filled in the frame, a floating board floating on the water surface of the drainage river, aquatic plants planted on the floating board, and multiple biological ropes connected between the frame and the floating board.

[0015] Optionally, the biological filter media is a porous network active biological filter media.

[0016] Optionally, the biological rope adopts a bionic structure.

[0017] Optionally, the strengthening treatment module includes a frame arranged at the bottom of the drainage river and a blower group arranged on the water surface or on the river bank. An aeration component is arranged at the bottom inside the frame, and a tubular solidified microorganism component is filled in the upper part thereof. The aeration component includes an aerator and an aeration pipeline, and the aerators are uniformly arranged at the bottom of the frame; long strip holes are uniformly arranged along the water flow direction on the tube shell of the tubular solidified microorganism component, and slow-release microorganism strains are installed inside the tube shell.

[0018] Optionally, the tubular solidified microorganism assembly is arranged along the water flow direction.

[0019] Optionally, the slow-release microorganism strains include at least one of photosynthetic bacteria, nitrifying bacteria, nitrosifying bacteria, denitrifying bacteria, and polyphosphate-accumulating bacteria.

[0020] Optionally, the sediment separated by the solid-liquid separation module is regularly removed and transported back to the farmland.

[0021] To achieve the above object, in a second aspect, the present application provides a method for intercepting, purifying, and recycling farmland drainage, including the following steps:

[0022] S1. Within 3 to 5 days after rice planting, when the linkage cloud platform receives rainfall and the farmland water level is higher than 50 mm, the linkage cloud platform controls the farmland drainage sluice to open 50 to 150 mm, and the drainage sluice is opened for 1.5 to 3.0 h. The fan of the enhanced treatment module is turned on throughout the rainfall period, and the linkage cloud platform controls the number of fans in operation and the operation time so that the NH 3 -N concentration in the drainage river is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; at the same time, the linkage cloud platform controls the opening height of the intercepting dam gate or the number of gates opened to control the external drainage volume not to exceed the rainfall volume;

[0023] S2. During the rice green-reverting and tillering stages, when the linkage cloud platform receives rainfall and the water level in the farmland is higher than 30 mm, it controls the farmland drainage sluice to open 50 to 100 mm, and the drainage sluice is opened for 1.0 to 2.0 h. The fan of the enhanced treatment module is turned on throughout the rainfall period, and the linkage cloud platform controls the number of fans in operation and the operation time so that the COD concentration in the drainage river is lower than 150 mg / L. When the farmland water level is lower than 20 mm, the linkage cloud platform controls the irrigation system to start and irrigate the farmland with the water in the drainage river; when the water level in the intercepting dam reaches the high water level of the drainage river, increase the number of fans in operation or the operation time of the enhanced treatment module so that the NH 3 -N concentration in the drainage river is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; when the water level in the intercepting dam reaches the warning water level of the drainage river, the linkage cloud platform controls the opening height of the intercepting dam gate or the number of gates opened to control the water level of the drainage river to drop back to the preset water level;

[0024] S3. During the young panicle development stage and the heading and flowering stage of rice, when the linkage cloud platform receives rainfall and the water level in the farmland is higher than 30 mm, control the agricultural drainage sluice to open 50 - 100 mm, and the drainage sluice opening time lasts for 2.0 - 4.0 h. During the rainfall period, start the fans of the enhanced treatment module throughout the whole period. The linkage cloud platform controls the number and running time of the fans to make the COD concentration in the drainage river lower than 150 mg / L. When the farmland water level is lower than 10 mm, the linkage cloud platform controls the irrigation system to start and irrigate the farmland with the water in the drainage river; when the water level in the intercepting dam reaches the high water level of the drainage river, increase the number or running time of the fans of the enhanced treatment module to make the NH 3 -N concentration in the drainage river lower than 1.0 mg / L and the DO concentration in the drainage river higher than 5 mg / L; when the water level in the intercepting dam reaches the warning water level of the drainage river, the linkage cloud platform controls the opening height or the number of opened gates of the intercepting dam gate to control the water level of the drainage river to fall back to the preset water level;

[0025] S4. During the late tillering stage and the yellow ripening stage of rice, when the linkage cloud platform receives rainfall, control the agricultural drainage sluice to open 50 - 100 mm, and the drainage sluice is opened for 2.0 - 4.0 h and closed for 2.0 - 4.0 h in a cycle. During this period, start the fans of the enhanced treatment module throughout the whole period. The linkage cloud platform controls the number and running time of the fans to make the NH 3 -N concentration in the drainage river lower than 1.0 mg / L and the DO concentration in the drainage river higher than 5 mg / L; at the same time, the linkage cloud platform controls the opening height or the number of opened gates of the intercepting dam gate to control the water level of the drainage river not to be higher than the preset water level;

[0026] S5. After the rice is harvested, remove and transport the sediment of the solid-liquid separation module back to the field. During this period, supplement or replace the active biological filter material in the ecological treatment module, start some fans of the enhanced treatment module, and control the number and running time of the fans to make the DO concentration in the drainage river tend to 2 mg / L. In case of heavy rainfall, the linkage cloud platform increases the number and time of the fans of the enhanced treatment module to make the NH 3 -N concentration in the drainage river lower than 1.0 mg / L and the DO concentration in the drainage river higher than 5 mg / L; at the same time, the linkage cloud platform controls the opening height or the number of opened gates of the intercepting dam gate to control the water level of the drainage river not to be higher than the preset water level;

[0027] S6. 5 - 7 days before transplanting rice seedlings, start the fans of the enhanced treatment module. The linkage cloud platform controls the number and running time of the fans to make the COD concentration in the drainage river lower than 150 mg / L. The linkage cloud platform controls the irrigation system to start and irrigate the farmland with the water in the drainage river.

[0028] A farmland drainage interception, purification and recycling system and method provided by the present invention, compared with the prior art, has the beneficial effects that by setting a solid-liquid separation module, sediments in farmland drainage are intercepted and recycled, and the sediments are returned to the field, effectively realizing the recycling of nutrients such as nitrogen and phosphorus, thereby saving fertilizers; by setting a linkage cloud platform, combined with the water layer management requirements of the entire life cycle of rice growth and the current weather conditions, according to the different water quality requirements for recycled irrigation or external discharge after farmland drainage interception and purification, the farmland water layer and the operation of the fan are accurately controlled, realizing energy conservation, emission reduction and water resource conservation during the rice planting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings forming a part of this application are used to provide a further understanding of this application, making other features, objects, and advantages of this application more apparent. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0030] Figure 1 is the flow chart of the present invention;

[0031] Figure 2 is the plan view of the present invention;

[0032] Figure 3 is the plan view of the solid-liquid separation module;

[0033] Figure 4 is the cross-sectional view of the solid-liquid separation module;

[0034] Figure 5 is the plan view of the biological treatment module;

[0035] Figure 6 is the framework schematic diagram;

[0036] Figure 7 is the plan view of the enhanced treatment module;

[0037] Figure 8 is the cross-sectional view of the enhanced treatment module.

[0038] Wherein: 1 - farmland, 2 - solid-liquid separation module, 21 - inclined plate assembly, 22 - sediment recovery bin, 3 - ecological treatment module, 31 - cage-shaped framework, 32 - active biological filter material, 33 - biological rope, 34 - floating board, 35 - aquatic plants, 4 - enhanced treatment module, 41 - fan group, 42 - framework, 43 - solidified microorganism assembly, 44 - aeration assembly, 441 - aerator, 442 - aeration pipe, 5 - interception dam and gate, 6 - on-line monitoring system, 7 - irrigation system, 8 - linkage cloud platform. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0040] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of this application described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products, or devices.

[0041] In this application, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated devices, elements, or components must have a specific orientation or be constructed and operated in a specific orientation.

[0042] Moreover, in addition to being able to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0043] In addition, the meaning of the term "plurality" should be two or more.

[0044] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will detail this application with reference to the drawings and in conjunction with the embodiments.

[0045] As Figures 1 - 8 shown, a farmland drainage interception, purification and recycling system includes a solid-liquid separation module, an ecological treatment module, a strengthening treatment module, a water retaining dam and a gate, an irrigation system, a water quality on-line monitoring system, and a linkage cloud platform.

[0046] The solid-liquid separation module is arranged at the end of the irrigation and drainage channel between farmlands, preferably an inclined plate sedimentation tank. The farmland drainage is discharged from the irrigation and drainage channel into the solid-liquid separation module for sediment-water separation and then flows into the drainage river. The sediment accumulated by the solid-liquid separation module contains a large amount of nutrients such as nitrogen and phosphorus required by rice. It is regularly removed and transported back to the farmland to improve the soil erosion and fertility loss caused by the backwater or rainwater scouring of the farmland.

[0047] The ecological treatment module is arranged in the drainage river. Its lower part is a cage-shaped framework filled with porous mesh active biological filter media; the upper part is a floating plate on which a variety of aquatic plants are planted; the cage-shaped framework and the floating plate are connected by biological ropes, and the biological ropes adopt a bionic structure. The porous mesh active biological filter media is used to remove phosphorus in the farmland drainage; a variety of aquatic plants planted on the floating plate remove nutrients such as nitrogen and phosphorus in the farmland drainage through the absorption of the roots; the biological ropes adopt a bionic structure, with a large specific surface area and good biological affinity, and can attach a large number of microorganisms to quickly form a biological film, thereby purifying the water body, and are arranged along the water flow direction without hindering the water body flow;

[0048] Since the filter media is filled in the framework in this module, the framework can be placed at any position in the water, and the set density can also be selected according to actual needs, which is flexible and convenient to use, and makes the water body purification more uniform. The aquatic plants are planted on the floating plate, so that the planting in the water is not limited to the slope, improving the absorption efficiency of the aquatic plants. In addition, the bionic rope body not only plays a role in limiting the floating plate 4 in the water, but also can attach a large number of microorganisms.

[0049] The enhanced treatment module is arranged in the drainage river, including a framework and a fan group. The framework sinks to the bottom of the river. An aeration component is arranged at the bottom inside the framework, and tubular solidified microbial components are filled in the middle and upper parts. The aeration component includes an aerator and an aeration pipeline, and the aerators are evenly arranged at the bottom of the framework; the tubular solidified microbial components are arranged along the water flow direction, and long strip holes are evenly arranged on the pipe shell along the water flow direction. A slow-release microbial strain is installed in the pipe shell, and the strain is preferably photosynthetic bacteria, nitrifying bacteria, nitrosifying bacteria, denitrifying bacteria, polyphosphate-accumulating bacteria, etc.; the fan group is arranged on the water surface or on the river bank. The farmland drainage evenly flows through the tubular solidified microbial components from the pipe orifices and long strip holes. The solidified microbial components release nutrients and microorganisms, and the fan is turned on to provide an aerobic environment for the microorganisms. COD, BOD and NH 3 -N are decomposed and transformed by microorganisms under aerobic conditions, and the concentration is greatly reduced.

[0050] The ecological treatment module and the enhanced treatment module are arranged alternately in the drainage river. While degrading pollutants, an ecological system in the drainage river is constructed to improve the self-purification ability of the drainage river.

[0051] The water retaining dam and the gate are arranged at the end of the drainage river, controlling the external drainage volume of the drainage channel, regulating the water flow velocity, and forming a water flow drop. When the water body passes through the dam body, the flow velocity increases sharply, making full contact with the air, realizing water body oxygenation, and being beneficial to the decomposition of organic pollutants by microorganisms.

[0052] The on-line monitoring system includes a water quality on-line monitoring module arranged in the gate, a first water level monitoring unit arranged in the drainage river, and a second water level monitoring unit arranged in the farmland. The water quality on-line monitoring module is used to monitor the water quality after interception and purification, specifically monitoring COD, ammonia nitrogen, total phosphorus, pH, dissolved oxygen, and uploading the water quality data to the linkage cloud platform; the first water level monitoring unit is used to monitor the water level of the drainage river; the second water level monitoring unit is used to monitor the water level of the farmland.

[0053] The linkage cloud platform receives the data of the local weather station, monitors the growth of rice, and controls the operation of the irrigation system and the gate according to the rice growth cycle, water level and / or weather conditions; according to the water quality data, controls the operation quantity and time of the fans to avoid unnecessary waste of water resources and energy consumption.

[0054] The method for intercepting, purifying and recycling farmland drainage is as follows:

[0055] Within 3 to 5 days after rice planting, when the linkage cloud platform receives rainfall and the farmland water level is higher than 50 mm, the platform controls the farmland drainage gate to open 50 to 150 mm, and the drainage gate is opened for 1.5 to 3.0 h, and it is appropriate to maintain the farmland water level at 30 to 50 mm to promote the greening of rice. During the rainfall period, the fans of the enhanced treatment module are turned on all the time, and the operation quantity and operation time of the fans are controlled by the platform in real time according to the water quality data to ensure that the NH 3 -N concentration in the drainage river is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; at the same time, the platform controls the opening height of the intercepting dam gate or the number of opened gates to control the external drainage volume not to be greater than the rainfall.

[0056] During the greening and tillering period of rice, when the linkage cloud platform receives rainfall and the water level in the farmland is higher than 30 mm, it controls the farmland drainage gate to open 50 to 100 mm, and the drainage gate is opened for 1.0 to 2.0 h, and it is appropriate to maintain the farmland water level at 20 to 30 mm to promote the greening and tillering of rice. During the rainfall period, the fans of the enhanced treatment module are turned on all the time, and the operation quantity and operation time of the fans are controlled by the platform in real time according to the water quality data to ensure that the COD concentration in the drainage river is lower than 150 mg / L. When the farmland water level is lower than 20 mm, the platform controls the irrigation system to start and irrigate the farmland with the water in the drainage river; when the water level in the intercepting dam reaches the high water level of the drainage river, increase the operation quantity or operation time of the fans of the enhanced treatment module to ensure that the NH 3The concentration of -N is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; when the water level in the intercepting dam reaches the warning water level of the drainage river, the platform controls the opening height or the number of opening of the intercepting dam gate to control the water level of the drainage river to fall back to the normal water level.

[0057] During the young panicle development stage and the heading and flowering stage of rice, when the linkage cloud platform receives rainfall and the water level in the farmland is higher than 30 mm, it controls the agricultural drainage sluice to open 50 - 100 mm, and the drainage sluice is opened for 2.0 - 4.0 h, and it is appropriate to maintain the water level in the farmland at 10 - 30 mm to promote the heading and flowering of rice. During the rainfall period, the fans of the enhanced treatment module are turned on all the time, and the number and running time of the fans are controlled by the platform in real time according to the water quality data to ensure that the COD concentration in the drainage river is lower than 150 mg / L. When the water level in the farmland is lower than 10 mm, the platform controls the irrigation system to start and irrigate the farmland with the water in the drainage river; when the water level in the intercepting dam reaches the high water level of the drainage river, increase the number or running time of the fans of the enhanced treatment module to ensure that the concentration of NH 3 The concentration of -N is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; when the water level in the intercepting dam reaches the warning water level of the drainage river, the platform controls the opening height or the number of opening of the intercepting dam gate to control the water level of the drainage river to fall back to the normal water level.

[0058] In the late tillering stage and the yellow ripening stage of rice, when the linkage cloud platform receives rainfall, it controls the agricultural drainage sluice to open 50 - 100 mm, and the drainage sluice is opened for 2.0 - 4.0 h and closed for 2.0 - 4.0 h in a cycle. During this period, the fans of the enhanced treatment module are turned on all the time to cope with the pollution caused by heavy rainfall at any time. The number and running time of the fans are controlled by the platform in real time according to the water quality data to ensure that the concentration of NH 3 The concentration of -N is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; at the same time, the platform controls the opening height or the number of opening of the intercepting dam gate to control the water level of the drainage river not to be higher than the high water level.

[0059] After the rice is harvested, the sediment of the solid-liquid separation module is cleared and returned to the field to improve the soil and water loss and fertility of the farmland. During this period, the active biological filter material in the ecological treatment module is supplemented or replaced, and some fans of the enhanced treatment module are turned on. The number and running time of the fans are controlled by the platform in real time according to the water quality data to maintain the DO concentration in the drainage river at about 2 mg / L. In case of heavy rainfall, the linkage platform increases the number and time of the fans of the enhanced treatment module to ensure that the concentration of NH 3 The concentration of -N is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; at the same time, the platform controls the opening height or the number of opening of the intercepting dam gate to control the water level of the drainage river not to be higher than the high water level.

[0060] 5 to 7 days before transplanting, turn on the blower of the strengthening treatment module. The number and running time of the blowers are controlled in real time by the platform according to the water quality data to ensure that the COD concentration in the drainage river is lower than 150 mg / L. Then the platform controls the irrigation system to start and irrigate the farmland with the water in the drainage river.

[0061] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A farmland drainage interception, purification and recycling system, characterized in that: include A solid-liquid separation module is installed at the end of the irrigation and drainage channel between farm fields; An ecological treatment module, which is arranged in a drainage river connected to the irrigation and drainage channel, and is used to remove phosphorus, nitrogen and attached microorganisms in farmland drainage; An enhanced treatment module is arranged in a drainage river connected to the irrigation and drainage channel, and reduces the concentrations of COD, BOD and NH3-N by releasing microorganisms; Irrigation system, which introduces water treated by the enhanced treatment module into the farmland; A water retaining dam and a gate are arranged at the end of the drainage river to control the amount of water discharged outside the drainage river and to adjust the water flow speed; The online monitoring system comprises a water quality online monitoring module arranged in the gate, a first water level monitoring unit arranged in the drainage river, and a second water level monitoring unit arranged in the farmland; The cloud platform is linked to control the operation of the irrigation system and gates according to the rice growth cycle, water level and / or weather conditions; and the enhanced processing module is controlled according to water quality data.

2. A farmland drainage interception, purification and recycling system as claimed in claim 1, characterized in that: The solid-liquid separation module is an inclined plate sedimentation tank.

3. A farmland drainage interception, purification and recycling system and method as claimed in claim 1, characterized in that: The ecological treatment module includes a frame placed at the bottom of the drainage river, biological filter materials filled in the frame, a floating board floating on the surface of the drainage river, aquatic plants planted on the floating board, and a plurality of biological ropes connected between the frame and the floating board.

4. A farmland drainage interception, purification and recycling system as claimed in claim 3, characterized in that: The biological filter material is a porous mesh active biological filter material.

5. The farmland drainage interception, purification and recycling system according to claim 3, characterized in that: The biological rope adopts a bionic structure.

6. The farmland drainage interception, purification and recycling system according to claim 1, characterized in that: The enhanced treatment module includes a frame arranged at the bottom of the drainage river and a fan unit arranged on the water surface or on the river bank. An aeration component is arranged at the bottom of the frame, and a tubular solidified microorganism component is filled at the upper part. The aeration component includes an aerator and an aeration pipe, and the aerators are evenly arranged at the bottom of the frame; the tube shell of the tubular solidified microorganism component is evenly provided with long holes along the water flow direction, and the tube shell is filled with slow-release microbial strains.

7. A farmland drainage interception, purification and recycling system as claimed in claim 6, characterized in that: The tubular solidified microorganism assembly is arranged along the water flow direction.

8. The farmland drainage interception, purification and recycling system according to claim 6, characterized in that: The slow-release microbial strains include at least one of photosynthetic bacteria, nitrifying bacteria, nitrite bacteria, denitrifying bacteria, and polyphosphate bacteria.

9. The farmland drainage interception, purification and recycling system according to claim 1, characterized in that: The sediment separated by the solid-liquid separation module is regularly transported back to the farmland.

10. A method for intercepting, purifying and recycling farmland drainage, characterized in that: The following steps are involved: S1. Within 3 to 5 days after rice planting, when the Linkage Cloud Platform receives rainfall and the farmland water level is higher than 50 mm, the Linkage Cloud Platform controls the farmland drainage gate to open 50 to 150 mm, and the drainage gate is open for 1.5 to 3.0 hours. The fans of the enhanced treatment module are turned on all the time during the rainfall period. The Linkage Cloud Platform controls the number and operation time of the fans to make the NH3-N concentration in the drainage river lower than 1.0 mg / L and the DO concentration in the drainage river higher than 5 mg / L; at the same time, the Linkage Cloud Platform controls the opening height of the interception dam gate or controls the number of gates opened to control the external drainage volume not to be greater than the rainfall; S2. During the rice greening and tillering period, when the linkage cloud platform receives rainfall and the water level in the farmland is higher than 30mm, the farmland drainage gate is controlled to open 50-100mm, and the drainage gate is opened for 1.0-2.0h. The fan of the enhanced treatment module is turned on during the rainy period. The linkage cloud platform controls the number and operation time of the fans to make the COD concentration in the drainage river lower than 150mg / L. When the farmland water level is lower than 20mm, the linkage cloud platform controls the irrigation system to start and irrigate the farmland with water from the drainage river; when the water level in the interception dam reaches the high water level of the drainage river, the number or operation time of the fans in the enhanced treatment module is increased to make the NH3-N concentration in the drainage river lower than 1.0mg / L and the DO concentration in the drainage river higher than 5mg / L; when the water level in the interception dam reaches the warning water level of the drainage river, the linkage cloud platform controls the opening height of the interception dam gate or controls the number of gates opened to control the water level of the drainage river to fall back to the preset water level; S3. During the rice panicle development period and heading and flowering period, when the linkage cloud platform receives rainfall and the water level in the farmland is higher than 30mm, the agricultural drainage gate is controlled to open 50-100mm, and the drainage gate is opened for 2.0-4.0h. The fan of the enhanced treatment module is turned on during the whole rainfall period. The linkage cloud platform controls the number and operation time of the fans to make the COD concentration in the drainage river lower than 150mg / L. When the farmland water level is lower than 10mm, the linkage cloud platform controls the irrigation system to start and irrigate the farmland with water from the drainage river; when the water level in the interception dam reaches the high water level of the drainage river, the number or operation time of the fans in the enhanced treatment module is increased to make the NH3-N concentration in the drainage river lower than 1.0mg / L and the DO concentration in the drainage river higher than 5mg / L; when the water level in the interception dam reaches the warning water level of the drainage river, the linkage cloud platform controls the opening height of the interception dam gate or controls the number of gates opened to control the water level of the drainage river to fall back to the preset water level; S4. In the late tillering and yellowing stages of rice, when the linkage cloud platform receives rainfall, it controls the agricultural drainage gate to open 50-100 mm, the drainage gate to open for 2.0-4.0 hours, and close for 2.0-4.0 hours. During this period, the fan of the enhanced treatment module is turned on all the time. The linkage cloud platform controls the number and operation time of the fans to make the NH3-N concentration in the drainage river lower than 1.0 mg / L and the DO concentration in the drainage river higher than 5 mg / L; at the same time, the linkage cloud platform controls the opening height of the interception dam gate or controls the number of gates to be opened to control the water level of the drainage river not higher than the preset water level; S5. After rice harvest, the sediment in the solid-liquid separation module is transported back to the field. During this period, the active biological filter material in the ecological treatment module is supplemented or replaced, and the fans of some enhanced treatment modules are turned on. The number and time of fans are controlled so that the DO concentration in the drainage river tends to 2 mg / L. In case of heavy rainfall, the linkage cloud platform increases the number and time of fans in the enhanced treatment module so that the NH3-N concentration in the drainage river is lower than 1.0 mg / L and the DO concentration in the drainage river is higher than 5 mg / L; at the same time, the linkage cloud platform controls the opening height of the interception dam gate or controls the number of gates to be opened, so that the water level in the drainage river is not higher than the preset water level; S6. 5 to 7 days before transplanting, turn on the fans of the enhanced treatment module, and link the cloud platform to control the number and operation time of the fans to make the COD concentration in the drainage river lower than 150 mg / L. Link the cloud platform to control the start of the irrigation system and use the water in the drainage river to irrigate the farmland.

Images