Rural domestic tail water wetland treatment and resource recycling system and use method

Abstract

The application discloses a rural domestic tail water wetland treatment and resource recycling system and a use method, and relates to the field of tail water treatment and resource recycling.The system comprises a rainwater collection control system, an ecological pond system and an artificial vegetable wetland, and can supplement water for an ecological ditch.The system uses the ecological ditch and the artificial vegetable wetland to supplement and adjust water according to the tail water volume, and the excess rainwater enters the ecological grass ditch, so that the tail water is efficiently treated through the ecological pond system and the artificial vegetable wetland, and then the tail water is effectively recycled through the water resource utilization and recycling system, the resources and nutrient elements of the rural domestic tail water are activated, the water resource purification and the nutrient element recycling are realized, the non-point source pollution in rural areas is reduced, the tail water treatment efficiency in rural areas is improved, the utilization rate of the water resource in rural areas is improved, the whole system is in the best water operation condition, and a good water environment condition is created for efficient operation of the system.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, specifically relating to a rural domestic wastewater wetland treatment and resource recycling system and its usage method. Background Technology

[0002] Rural domestic wastewater refers to sewage discharged from residential areas such as kitchens, toilets, and laundry rooms in villagers' daily lives. The most prominent characteristics of rural domestic sewage are the difficulty in collection, significant fluctuations in water quality and quantity, large volumes, and relatively dispersed discharge. These characteristics determine the difficulty of its treatment, and in some areas, the effluent quality fails to meet standards. Furthermore, due to stricter sewage discharge standards and increased requirements for wastewater resource utilization across various regions, some areas have gradually raised their sewage discharge standards from Class A to higher levels. In some economically developed areas, the standards for sewage entering rivers are gradually approaching those of Class IV surface water. Given these stringent water standards, improving the quality of wastewater entering rivers is a crucial step in enhancing the regional ecological environment.

[0003] Currently, the treatment of domestic wastewater primarily relies on ecological methods, such as constructed wetlands. These ecological treatment measures utilize the physical, chemical, and biological processes produced by plants, microorganisms, and substrates to purify the wastewater. Ecological treatment methods offer advantages such as lower investment and construction costs, lower operating costs, and better results, and are widely used in the water treatment field. While constructed wetlands and other ecological treatment methods have significant advantages, they also have the following drawbacks:

[0004] (1) Due to the unstable water volume of rural domestic sewage, the use of ecological treatment measures such as constructed wetlands to treat domestic sewage is prone to long-term high or low load operation of constructed wetlands, which reduces the performance of constructed wetland plants and fillers and weakens the treatment effect.

[0005] (2) During dry and rainy seasons, the amount of external water in the wetland varies greatly, which has a strong impact on the operation of the constructed wetland, causing the water level of the constructed wetland to be too high or too low, affecting the normal operation of the constructed wetland.

[0006] (3) The treatment effect of constructed wetlands in some areas is lower than required. As many areas have stricter requirements for the effluent from constructed wetlands, it is necessary to further control the pollutant concentration of constructed wetlands and ensure that the water quality can be maintained stably for a long time.

[0007] (4) Constructed wetlands are rich in nutrients, and effective utilization will increase the economic value of the wetlands. Moreover, after the effluent quality meets the standards, it is generally discharged into the surrounding rivers / ditches through pipes, resulting in low water resource utilization. It is necessary to revitalize the water resources and nutrients of constructed wetlands and improve the water resource utilization rate of the constructed wetland system.

[0008] Therefore, designing a rural domestic wastewater wetland treatment and resource recycling system and its application method is of great practical significance. Summary of the Invention

[0009] To address the technical problems existing in the prior art, the purpose of this invention is to provide a rural domestic wastewater wetland treatment and resource recycling system and its usage method.

[0010] To achieve the above objectives and technical effects, the technical solution adopted by this invention is as follows:

[0011] A rural domestic wastewater wetland treatment and resource recovery system includes:

[0012] A rainwater harvesting control system includes farmland drainage ditches, ecological grassed swales, ecological ditches, and a water level and volume control system. The water level and volume control system regulates the water level in the ecological ditches, and the water levels in the farmland drainage ditches and the ecological ditches are interconnected and kept at the same level.

[0013] An ecological pond system, comprising a primary sedimentation pond for wastewater mixing and an aerobic pond, wherein wastewater passes through the primary sedimentation pond for wastewater mixing and the aerobic pond in a clockwise direction, and the water level in the ecological ditch is higher than the water level in the ecological pond system;

[0014] An artificial vegetable wetland, wherein the elevation of the artificial vegetable wetland is higher than that of the ecological ditch, and the artificial vegetable wetland can be connected to the ecological ditch and can replenish the ecological ditch with water;

[0015] The water resource utilization and reuse system is connected to the artificial vegetable wetland. Water treated by the artificial vegetable wetland enters the water resource utilization and reuse system, and then enters the municipal water supply, farmland water replenishment and / or river water replenishment.

[0016] Furthermore, a mixed filler is laid in the farmland drainage ditch, and submerged plants are planted on top of the mixed filler at a planting density of 30-50 plants / m². 2 The ecological vegetated ditch slopes along the direction of water flow at an angle of 0.3%-0.5%. Low-growing wetland plants are planted on the upper part of the ditch at a density of 16-30 plants / m². 2 The lower part of the ecological grass swale is a filler layer; the artificial vegetable wetland and the ecological ditch are respectively connected to the water supply pipe. When the water level in the ecological ditch is insufficient, the water in the artificial vegetable wetland is used to replenish the ecological ditch through the water supply pipe.

[0017] Furthermore, the depth of the farmland drainage ditch is 1-1.2m. The mixed filler material includes, from top to bottom, a volcanic rock layer, a gravel layer, and a pebble layer. The volcanic rock layer is made of volcanic rock with a particle size of 1-2cm, the gravel layer is made of gravel with a particle size of 2-5cm, and the pebble layer is made of pebbles with a particle size of 5-10cm. The filler layer includes, from top to bottom, a planting soil layer, an activated carbon layer, a sand and gravel layer, and a gravel bottom layer. The activated carbon layer is made of activated carbon with a particle size of 3-5cm, and the sand and gravel layer is made of activated carbon with a particle size of 4-10cm. The ecological ditch is made of 6cm sand and gravel, with the gravel bottom layer made of gravel with a particle size of 8-10cm. The ecological ditch is 1.5-1.6m high and 0.7-1.0m wide. There are multiple horizontally arranged overflow pipes in the ecological ditch to control the water level in the ecological ditch to not exceed the preset value. The ecological pond system is connected to the sewage treatment plant through inlet pipe I. By regulating the water volume of the treated sewage treatment plant effluent and rainwater in the farmland drainage ditch, and by using water from the artificial vegetable wetland for replenishment, the water level in the ecological pond is ensured to be within a reasonable range.

[0018] Furthermore, the water level and volume control system includes a rain gauge located in the farmland drainage ditch, a level gauge I in the ecological ditch, a solenoid valve I located at the connection between the ecological ditch and the ecological pond water system, a level gauge II in the ecological pond system, a solenoid valve II in the ecological vegetated ditch, and a solenoid valve III controlling the connection between the artificial vegetable wetland and the ecological ditch water system. The rain gauge is used to sense the amount of rainfall in the farmland drainage ditch area. The level gauges I and II are used to sense the changes in water level in the ecological ditch and the ecological pond, respectively. The solenoid valve I is used to control the water level in the ecological pond. The rain gauge, solenoid valves II and III are linked to control the water level in the ecological ditch.

[0019] Furthermore, the wastewater mixing and primary sedimentation pond is divided into a mixing zone and an ecological interception pond along the water flow direction. Wastewater enters the mixing zone for mixing before entering the ecological interception pond. The ecological interception pond is equipped with emergent plants and filler materials from top to bottom. The filler materials, from top to bottom, consist of a planting soil layer, a manganese sand layer, a zeolite layer, and a ceramsite layer. The manganese sand layer is made of manganese sand with a particle size of 1-2 cm, the zeolite layer is made of zeolite with a particle size of 2-4 cm, and the ceramsite layer is made of ceramsite with a particle size of 2-5 cm. A water collection pipe I is installed in the center of the ceramsite layer. The water collection pipe I is connected to a ventilation pipe, which supplies oxygen to the ecological interception pond. The treated effluent from the wastewater mixing and primary sedimentation pond enters the aerobic pond through the water collection pipe I and the connected pipes. Herbivorous fish and benthic animals are introduced into the aerobic pond, and root-promoting oxygen-secreting plants and oxygen-producing algae are planted. The stocking density of herbivorous fish fry is 15-20 g / m³. 2 Benthic organism release density: 1-3 g / m³ 2 Planting density: 30-50 plants / m² 2The aerobic pond is connected to the aerobic denitrification filter.

[0020] Furthermore, the aerobic pond is connected to the aerobic denitrification filter via an outlet pipe I and a distribution pipe. The aerobic denitrification filter has a semi-circular structure with a height of 1.3-1.5m and a water depth of 0.9-1m. The upper layer of the aerobic denitrification filter is a 15-20cm thick soil infiltration system, and the lower layer is a packing structure. The packing structure consists of a scraped stone layer, a crushed stone layer, and a coconut shell packing layer from top to bottom. The scraped stone layer is made of scraped stone with a particle size of 3-5cm, and the crushed stone layer is made of crushed stone with a particle size of 4-6cm. Compound bacteria are introduced into the soil infiltration system, and emergent plants are planted above the soil infiltration system. A water collection pipe II is arranged inside the packing structure. The aerobic denitrification filter is connected to the anaerobic denitrification filter via the water collection pipe II and a connected inlet pipe.

[0021] Furthermore, the anaerobic denitrification filter has a semi-circular structure with a height of 1.3-1.5m and a water depth of 0.9-1m. The bottom is filled with a 20-30cm thick layer of volcanic rock with a particle size of 5-8cm. Above the volcanic rock layer, from bottom to top, a layer of wheat straw, a layer of rice straw, and a layer of corn straw are laid sequentially. Anaerobic denitrifying bacteria are added inside the rice straw layer. Wastewater adsorbs pollutants through the volcanic rock layer, the wheat straw layer, the rice straw layer, and the corn straw layer. At the same time, the anaerobic denitrifying bacteria have strong biological and chemical activity without the action of a carbon source, and their degradation and adsorption capabilities are enhanced. The anaerobic denitrification filter achieves the purpose of water purification.

[0022] Furthermore, an installation net is installed above the corn stalk layer, and a submersible pump is installed inside the installation net. The opening and closing of the submersible pump is controlled by a float switch. The float switch controls the water level at a value of x. When the water level does not reach the value of x, the float switch is closed, and the water from the anaerobic denitrification filter cannot enter the artificial vegetable wetland. When the water level reaches the value of x, the float switch is opened, and the submersible pump diverts the water from the anaerobic denitrification filter to the artificial vegetable wetland.

[0023] Furthermore, the artificial vegetable wetland is a horizontal flow artificial wetland, which is divided into a hydroponic vegetable system and a deep purification system along the horizontal direction. The hydroponic vegetable system uses composite fiber floating wetland as planting material, on which seasonally rotated vegetable varieties are planted at a planting density of 9-12 plants / m². 2The hydroponic vegetable system and the vegetable deep purification system are separated by a mesh screen. Wastewater enters the vegetable deep purification system from the hydroponic vegetable system through the mesh screen. Aquatic vegetables are planted above the vegetable deep purification system, and wetland filler is arranged horizontally below the aquatic vegetables. The wetland filler includes an iron-aluminum sludge filler layer, sponge iron, manganese sand filter media, and gravel filler layer arranged in a certain order. The particle size of the iron-aluminum sludge filler layer is 1-2 cm, the particle size of the sponge iron is 1-2 cm, the particle size of the manganese sand filter media is 2-4 cm, and the particle size of the gravel filler layer is 8-10 cm.

[0024] This invention also discloses a method for using a rural domestic wastewater wetland treatment and resource recycling system, comprising the following steps:

[0025] The water levels in the farmland drainage ditches and the ecological ditches are interconnected and level. The water level in the ecological ditches is higher than that in the ecological ponds. The water level in the ecological ditches is regulated by a water level and volume control system.

[0026] When the water level in level gauge I is greater than or equal to value 'a', solenoid valve III closes, preventing water from the artificial vegetable wetland from entering the ecological ditch. If the rain gauge detects rain, solenoid valve II opens, allowing rainwater to flow into the ecological vegetated swale through the overflow pipe. If the rain gauge reading is 0, indicating no rain, solenoid valve III closes, maintaining the water level in the ecological ditch at value 'a'. When the water level in level gauge I is less than value 'a', rainwater or water from the artificial vegetable wetland needs to enter the ecological ditch. If the rain gauge indicates no rain, solenoid valve III opens, allowing water from the artificial vegetable wetland to replenish the ecological ditch through the water supply pipe. If the rain gauge detects rain, it determines whether to open solenoid valves II and III based on the amount of rainfall. If the rain gauge reading is between 0 and 5 mm, solenoid valve III opens, and the artificial vegetable wetland receives water from the water supply pipe into the ecological ditch. Once the water level in level gauge I reaches value a, solenoid valve III closes and solenoid valve II opens, allowing excess rainwater to enter the ecological vegetated ditch. If the rain gauge reading is greater than 5 mm, solenoid valves II and III close, and rainwater is supplied to the ecological ditch through the farmland drainage ditch. Once the water level in level gauge I reaches value a, solenoid valve II opens and solenoid valve III closes, allowing excess rainwater to enter the ecological vegetated ditch.

[0027] By absorbing and utilizing pollutants in rainwater through ecological grassed swales, the nutrient content in the water is reduced, thereby achieving the standard for reuse.

[0028] The water level in the ecological ditch is higher than that in the ecological pond, ensuring that water from the ecological pond does not flow back into the ecological ditch. Simultaneously, the higher elevation increases the contact area between wastewater and air, enhancing the dissolved oxygen content in the water. The ecological ditch and the ecological pond are connected by an inlet pipe II. A solenoid valve IV controls the water inflow at the connection point of inlet pipe II. Controlling the opening and closing of solenoid valve IV maintains the water level in the ecological pond at value b.

[0029] When the water level in level gauge II of the ecological pond is greater than or equal to value b, solenoid valve IV closes, preventing water from the ecological ditch from entering the ecological pond. This continues until the amount of effluent from the sewage treatment plant decreases, causing the water level in the ecological pond to fall below value b. At this point, solenoid valve IV opens, allowing water from the ecological ditch to enter the ecological pond. Once the water level in level gauge II rises to value b or above again, solenoid valve IV closes again. This process is repeated to stabilize the water level in the ecological pond at value b.

[0030] Wastewater flows clockwise through a primary sedimentation pond and an aerobic pond. The primary sedimentation pond is divided into a mixing zone and an ecological interception pond along the water flow direction. Wastewater first enters the mixing zone for mixing, and then enters the ecological interception pond through the effluent pipe and distribution pipe above the mixing zone. Emergent plants in the ecological interception pond regulate water flow rate and distribution through their root systems. At the same time, they remove particulate matter, organic matter, and nutrients from the water through root absorption and degradation by root microorganisms. Oxygen is supplied to the ecological interception pond through the aeration pipe. The treated effluent from the primary sedimentation pond enters the aerobic pond, where plants release dissolved oxygen into the water through photosynthesis. Simultaneously, the plants absorb nutrients, and benthic animals enrich the biomass of the aerobic pond, increasing biodiversity, improving the stability of the aerobic pond and the system's purification capacity, thereby improving water quality.

[0031] Water from the aerobic pond enters the aerobic denitrification filter through outlet pipe I and distribution pipe. The filter's packing material and microorganisms purify pollutants before the water enters the anaerobic denitrification filter. There, pollutants are adsorbed by layers of volcanic rock, wheat straw, rice straw, and corn straw. Simultaneously, the anaerobic denitrifying bacteria exhibit strong biological and chemical activity in the absence of a carbon source, enhancing degradation and adsorption capabilities, ultimately achieving water purification. Submersible pumps then divert the water from the anaerobic denitrification filter to an artificial vegetable wetland for further treatment. The treated water then enters the water resource utilization and reuse system, subsequently being used for municipal water supply, farmland irrigation, and / or river replenishment.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] This invention discloses a rural domestic wastewater wetland treatment and resource recycling system and its usage method. The system includes: a rainwater harvesting and control system, including farmland drainage ditches, ecological vegetated swales, ecological ditches, and a water level and volume control system. The water level and volume control system regulates the water level in the ecological ditches, ensuring that the water levels in the farmland drainage ditches and the ecological ditches are interconnected and level; an ecological pond system, including a wastewater mixing primary sedimentation pond and an aerobic pond, with wastewater passing through the wastewater mixing primary sedimentation pond and the aerobic pond in a clockwise direction, and the water level in the ecological ditches being higher than the water level in the ecological pond system; an artificial vegetable wetland, with an elevation higher than the ecological ditches, which can be connected to and replenish the ecological ditches; and a water resource utilization and recycling system, connected to the artificial vegetable wetland, where the water treated by the artificial vegetable wetland enters the water resource utilization and recycling system, and then enters municipal water supply, farmland replenishment, and / or river replenishment. The rural domestic wastewater wetland treatment and resource recycling system and method provided by this invention collects and purifies rainwater. Based on the wastewater volume, it utilizes rainwater from ecological ditches and water from artificial vegetable wetlands for replenishment and regulation. Excess rainwater enters ecological vegetated swales, achieving efficient wastewater treatment through an ecological pond system and artificial vegetable wetlands. The wastewater is then effectively reused through a water resource utilization and recycling system, allowing it to be used for municipal water supply, farmland irrigation, and / or river replenishment. The artificial vegetable wetlands utilize seasonal vegetable varieties, ensuring year-round water availability in rural areas. This system revitalizes the resources and nutrients in rural domestic wastewater, purifying water resources and reusing nutrients. It significantly reduces non-point source pollution in rural areas, improves wastewater treatment efficiency, and increases water resource utilization. The entire system operates under optimal water volume conditions, creating a favorable water environment for efficient operation. This maximizes wastewater treatment effectiveness and utilization efficiency, effectively solving the problem of rural domestic wastewater treatment, improving wastewater treatment efficiency and capacity, enhancing rural water resource allocation, and effectively ensuring the level of rural water resource reuse. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of the artificial vegetable wetland of the present invention;

[0036] Figure 3 This is a schematic diagram of the ecological pond system of the present invention;

[0037] Figure 4 This is a schematic diagram of the water distribution pipe of the present invention;

[0038] Figure 5 This is a schematic diagram of the water collection pipe of the present invention;

[0039] The components include: 1. Equalization tank; 2. Ecological ditch; 3. Level gauge I; 4. Solenoid valve I; 5. Inlet pipe I; 6. Mixing zone; 7. Level gauge II; 8. Farmland drainage ditch; 9. Rain gauge; 10. Solenoid valve III; 11. Solenoid valve II; 12. Water supply pipe; 13. Ecological vegetated swamp; 14. Ecological interception tank; 15. Aerobic pond; 16. Aerobic denitrification filter; 17. Anaerobic denitrification filter; 18. Outlet pipe II; 19. Artificial vegetable wetland; 2 0. Water resource utilization and reuse system; 21. Outlet pipe III; 22. Inlet pipe II; 23. Overflow pipe; 24. Primary sedimentation pond for mixed wastewater; 25. Outlet pipe I; 26. Ecological pond system; 27. Submersible pump; 81. Submerged plants; 82. Volcanic rock layer; 83. Gravel layer; 84. Pebble layer; 131. Low-growing wetland plants; 132. Planting soil layer; 133. Activated carbon layer; 134. Sand and gravel layer; 141. Aeration pipe; 142. Emergent water Plants; 143. Water distribution pipe; 144. Manganese sand layer; 145. Zeolite layer; 146. Ceramsite layer; 147. Water collection pipe I; 151. Planting frame; 152. Oxygen-producing algae; 153. Herbivorous fish; 154. Oxygen-secreting plants; 155. Benthic animals; 161. Soil infiltration system; 162. Compound bacteria; 163. Scraped stone layer; 164. Crushed stone layer; 165. Coconut shell filler layer; 171. Corn stalk layer; 172. Rice straw layer ; 173. Anaerobic denitrifying bacteria; 174. Wheat straw layer; 191. Aquatic vegetables; 192. Iron-aluminum sludge packing layer; 193. Sponge iron; 194. Hydroponic vegetable system; 195. Composite fiber floating wetland; 196. Separator net; 197. Vegetable deep purification system; 1431. Main water distribution pipe; 1432. Branch water distribution pipe; 1433. Water distribution hole; 1471. Main water collection pipe; 1472. Branch water collection pipe; 1473. Water collection hole. Detailed Implementation

[0040] The present invention will now be described in detail so that its advantages and features can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0041] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0042] like Figures 1-5 As shown, a rural domestic wastewater wetland treatment and resource recycling system includes four parts: a rainwater harvesting and control system, an artificial vegetable wetland 19, a water resource utilization and recycling system 20, and an ecological pond system 26.

[0043] In this invention, the rainwater harvesting control system includes an ecological ditch 2, a farmland drainage ditch 8, a water supply pipe 12, an ecological vegetated swale 13, and a water level and volume control system. The farmland drainage ditch 8 is a type of existing field ditch in rural areas, and there are several of them. This invention involves excavating and modifying the existing drainage ditch, so that the depth of the farmland drainage ditch 8 is 1-1.2m. A 30cm thick layer of mixed filler is laid in the farmland drainage ditch 8, and one or more of the following submerged plants 81, such as *Myriophyllum spicatum*, *Vallisneria natans*, and *Potamogeton crispus*, are planted on top of the mixed filler. The planting density of the submerged plants 81 is 30-50 plants / m². 2 The mixed filler consists of: an upper layer of volcanic rock with a particle size of 1-2 cm (10 cm thick), a middle layer of gravel with a particle size of 2-5 cm (10 cm thick), and a bottom layer of pebbles with a particle size of 5-10 cm (10 cm thick).

[0044] Ecological vegetated swale 13 is a modified version of the original swale. It is created by excavating 30cm downwards from the original swale site, clearing existing vegetation, removing silt, and excavating the bottom. The total depth of the swale is 0.5-0.8m, sloping along the water flow direction at an angle of 0.3%-0.5%. The upper part of the swale is planted with one or more of the following low-growing wetland plants: umbrella sedge, canna lily, calla lily, and sweet flag, at a planting density of 16-30 plants / m². 2 The lower part is a filler layer, which consists of a 10cm thick planting soil layer 132, a 10cm thick activated carbon layer with a particle size of 3-5cm 133, a 10cm thick sand and gravel layer with a particle size of 4-6cm 134, and a 10cm thick gravel bottom layer with a particle size of 8-10cm 10cm. The ecological grass swale 13 absorbs and utilizes pollutants such as nitrogen and phosphorus in the rainwater, reduces the nutrient content in the water, and thus meets the standard for reuse.

[0045] The ecological ditch 2 has a height of 1.5-1.6m and a width of 0.7-1.0m. Multiple horizontally arranged overflow pipes 23 are located in the ecological ditch 2 at a height of 1.1m. The overflow pipes 23 are used to control the water level in the ecological ditch 2 to ensure it does not exceed a preset value (1.1m). The artificial vegetable wetland 19 and the ecological ditch 2 are connected to the water supply pipe 12. The artificial vegetable wetland 19 has a higher elevation than the ecological ditch 2. When the water level in the ecological ditch 2 is insufficient, water from the artificial vegetable wetland 19 can be used to replenish the ecological ditch 2 through the water supply pipe 12.

[0046] The ecological pond system 26 includes an ecological pond, which is circular in shape, with a height of 1.5-1.6m, a water depth of 1m, and a width of 2m. Wastewater effluent from the wastewater treatment plant is regulated in the equalization tank 1 and then enters the ecological pond through the inlet pipe I5. By regulating the flow of wastewater effluent and rainwater from the farmland drainage ditch 8, and supplementing the pond with water from the artificial vegetable wetland 19, the water level in the ecological pond is maintained within a reasonable range (1m). The regulated water is then further purified in the artificial vegetable wetland 19, thereby improving purification efficiency.

[0047] The water level and volume control system includes a rain gauge located in the farmland drainage ditch 8, a level gauge I3 in the ecological ditch, a solenoid valve I4 located at the connection between the ecological ditch 2 and the ecological pond water system, a level gauge II7 in the ecological pond system 26, a solenoid valve II11 in the ecological vegetated swale, and a solenoid valve III10 controlling the connection between the artificial vegetable wetland 19 and the ecological ditch 2. The rain gauge is used to sense the amount of rainfall in the farmland drainage ditch area. Level gauges I3 and II7 are used to sense the changes in water level in the ecological ditch 2 and the ecological pond, respectively. Solenoid valve I4 is used to control the water level in the ecological pond. The rain gauge, solenoid valve II11, and solenoid valve III10 work together to control the water level in the ecological ditch 2.

[0048] The water level control method in ecological ditch 2 is as follows:

[0049] The water levels in farmland drainage ditch 8 and ecological ditch 2 are interconnected and equal. When the water level in level gauge I3 is greater than or equal to 1.1m, solenoid valve III10 closes, preventing water from the artificial vegetable wetland 19 from entering the ecological ditch 2. If the rain gauge detects rain, solenoid valve II11 opens, allowing rainwater to enter the ecological vegetated swale 13 through overflow pipe 23. If the rain gauge reading is 0, indicating no rain, solenoid valve III10 closes, maintaining the water level in ecological ditch 2 at 1.1m. When the water level in level gauge I3 is less than 1.1m, rainwater or water from the artificial vegetable wetland 19 needs to enter the ecological ditch 2. If the rain gauge indicates no rain, solenoid valve III10 opens, allowing water from the artificial vegetable wetland 19 to replenish through water supply pipe 12. If the rain gauge detects rain in the ecological ditch 2, it determines whether to open solenoid valves II11 and III10 based on the amount of rainfall. If the rain gauge reading is between 0-5mm, solenoid valve III10 opens, and the artificial vegetable wetland 19 replenishes water into the ecological ditch 2 through the water supply pipe 12. Once the water level in level gauge I3 reaches 1.1m, solenoid valve III10 closes and solenoid valve II11 opens, allowing excess rainwater to enter the ecological vegetated swale 13. If the rain gauge reading is greater than 5mm, solenoid valves II11 and III10 close, and rainwater replenishes the ecological ditch 2 through the farmland drainage ditch 8. When the water level in level gauge I3 reaches 1.1m, solenoid valve II11 opens and solenoid valve III10 closes, allowing excess rainwater to enter the ecological vegetated swale 13 through the overflow pipe 23.

[0050] The water level control method for ecological ponds is as follows:

[0051] Ecological ditch 2 and ecological pond are connected by inlet pipe II 22. A solenoid valve IV controls the water inflow at the connection point of inlet pipe II 22. Inlet pipe II 22 is positioned at the 1.05-1.1m water level line. The water level in the ecological pond is controlled at 1m. The water level in ecological ditch 2 is higher than that in the ecological pond to prevent backflow of water from the ecological pond into ecological ditch 2. This elevation difference also increases the contact area between wastewater and air, enhancing the dissolved oxygen content in the water. When the water level in level gauge II 7 of the ecological pond is greater than or equal to 1m, solenoid valve IV closes, preventing water from ecological ditch 2 from entering the ecological pond. This continues until the wastewater treatment plant's effluent flow decreases, causing the water level in the ecological pond to fall below 1m. At this point, solenoid valve IV opens, allowing water from ecological ditch 2 to enter the ecological pond. Once the water level in level gauge II 7 rises back to 1m or above, solenoid valve IV closes again, and so on. This process maintains the water level in the ecological pond at 1m.

[0052] Through the above measures, this invention can scientifically determine the amount of rainwater replenishment based on the relationship between rainwater and effluent volume and the water level difference between the ecological ditch 2 and the ecological pond, ensuring that the ecological treatment operates at the optimal water volume. Furthermore, when rainfall is insufficient, water can be added to the ecological ditch 2 through the artificial vegetable wetland 19, thereby maximizing the wastewater treatment effect. Preliminary regulation of rainwater through the ecological ditch 2 and preliminary purification of rainwater through ecological vegetated swales can reduce non-point source pollution in rural areas, improve rural water resource security, effectively reduce pollutant concentrations in rural watersheds, and ensure rural water safety.

[0053] The ecological pond system 26 includes a primary sedimentation pond 24 for wastewater mixing and an aerobic pond 15. The length (or area) ratio of the primary sedimentation pond 24 to the aerobic pond 15 is 1:3. Wastewater passes through the primary sedimentation pond 24 and the aerobic pond 15 in a clockwise direction. The primary sedimentation pond 24 is a primary purification area for the mixing and settling of wastewater effluent and rainwater. The primary sedimentation pond 24 is divided into a mixing zone 6 and an ecological interception pond 14 along the water flow direction. The length (or area) ratio of the mixing zone 6 to the ecological interception pond 14 is 1:3. Wastewater enters the mixing zone 6 for mixing and then flows through the outlet pipe and distribution pipe above the mixing zone 6 into the mains. Entering the ecological interception pond 14, the water distribution pipe 143 is located above the uppermost planting soil layer. The water distribution pipe 143 includes a main water distribution pipe 1431 and branch water distribution pipes 1432. The branch water distribution pipes 1432 are located on the side of the main water distribution pipe 1431, that is, the branch water distribution pipes 1432 are distributed on both sides of the main water distribution pipe 1431. The branch water distribution pipes 1432 and the main water distribution pipe 1431 are arranged in a cross shape. The length of each branch water distribution pipe 1432 is 0.7m. The branch water distribution pipe 1432 has a row of water distribution holes 1433 along the direction of water flow. By setting up the main water distribution pipe 1431 and the branch water distribution pipes 1432, the water flows evenly into the interior of the ecological interception pond 14. The ecological interception pond 14 is arranged from top to bottom with emergent plants 142 and filler. The emergent plants 142 regulate water flow and distribution through the interception effect of their root systems. At the same time, they remove particulate matter, organic matter, and nutrients from the water through root absorption and degradation by root microorganisms. The emergent plants 142 include irises, cannas, calamus, and thaliana, with a planting density of 9 plants / m². 2The filler material, from top to bottom, consists of a 20cm thick planting soil layer, a 10cm thick layer of 1-2cm diameter manganese sand 144, a 10cm thick layer of 2-4cm diameter zeolite 145, and a 10cm thick layer of 2-5cm diameter expanded clay 146. A water collection pipe I 147 is installed in the center of the bottom expanded clay layer 146 (5cm from the bottom of the pond). A ventilation pipe 141 extends upwards from the joint of water collection pipe I, supplying oxygen to the pond. The treated effluent from the primary sedimentation pond 24 flows through water collection pipe I 147 and connecting pipes into the aerobic pond 15. Herbivorous fish 153 (grass carp, blunt snout bream) and benthic organisms 155 (snails, shellfish) are stocked in the aerobic pond 15. The stocking density of the herbivorous fish fry is 15-20g / m³. 2 The release density of benthic organisms 155 is 1-3 g / m³. 2 In addition, 154 plants with strong root oxygen-secreting properties, such as Vallisneria natans, Elodea nuttallii, and Hydrilla verticillata, were planted at a density of 30-50 plants / m². 2 Oxygen-secreting plants 154 occupy 30% of the water surface, and oxygen-producing algae 152, such as oxygen-producing unicellular algae, green algae, and diatoms, are planted in planting frames 151. The planting frames 151 occupy 20% of the water surface area. The planting frames 151 are used to prevent excessive algae growth from affecting the growth of other plants. The plants release dissolved oxygen into the water through photosynthesis, while the plants absorb nutrients. Benthic animals enrich the biomass of the aerobic pond, increase biodiversity, improve the stability of the aerobic pond and the purification capacity of the system, thereby improving water quality.

[0054] Water from aerobic pond 15 enters aerobic denitrification filter 16 through outlet pipe I25 and distribution pipe. Aerobic denitrification filter 16 is semi-circular, 1.3-1.5m high, with a water depth of 0.9-1m. Distribution pipes are installed at the top. The upper layer of aerobic denitrification filter 16 is a 15-20cm soil infiltration system 161. The lower layer of aerobic denitrification filter 16 is a packing structure, consisting of a 30-35cm thick layer of 3-5cm diameter scraped stone 163, a 20-25cm thick layer of 4-6cm diameter crushed stone 164, and a 20-30cm thick layer of coconut shell packing 165. A compound bacteria 162 composed of Bacillus, Pseudomonas, and Phosphorus-removing Paracoccus is introduced into the soil. 10g of Bacillus:Pseudomonas:Denitrifying and Phosphorus-Degrading Paracoccus (mass / weight ratio) of 1:1:3 was used to plant emergent plants 142 above the soil infiltration system 161. Emergent plants 142 included irises, cannas, calamus, and Thalia dealbata, with a planting density of 9 plants / m². 2Wastewater is evenly dripped into the aerobic denitrification filter 16 through the water distribution pipe. Through the action of the packing material and microorganisms in the aerobic denitrification filter 16, the effect of purifying pollutants in the water is enhanced. The lower packing material of the aerobic denitrification filter 16 is arranged with a water collection pipe II. The water collection pipe II is located inside the coconut shell packing layer 165. Water enters the anaerobic denitrification filter 17 from the bottom of the aerobic denitrification filter 16 through the water collection pipe II and the connected inlet pipe.

[0055] The anaerobic denitrification filter 17 is semi-circular, with a height of 1.3-1.5m and a water depth of 0.9-1m. The bottom is filled with a 20-30cm thick layer of volcanic rock with a particle size of 5-8cm. Above the volcanic rock layer, from bottom to top, a 10cm thick layer of wheat straw 174, a 10cm thick layer of rice straw 172, and a 10-15cm thick layer of corn straw 171 are laid in sequence. 5g of anaerobic denitrifying bacteria (such as Paracoccus tropenopsis) is added inside the rice straw layer 172. Wastewater adsorbs pollutants through the volcanic rock layer and the three straw layers (wheat straw layer 174, rice straw layer 172, and corn straw layer 171). At the same time, the anaerobic denitrifying bacteria 173 have strong biological and chemical activity under the action of carbon sources, enhancing their degradation and adsorption capacity, ultimately achieving the purpose of water purification.

[0056] The effluent pipe II 18 installed on the anaerobic denitrification filter 17 has a height of 0.7-0.8m. An installation net is installed above the corn stalk layer 171 of the anaerobic denitrification filter 17. A submersible pump 27 is installed inside the installation net. The submersible pump 27 is controlled by a float switch. The float switch controls the water level at 0.8m. When the water level is below 0.8m, the float switch is closed, and sewage cannot enter the artificial vegetable wetland 19. When the water level reaches 0.8m, the float switch is opened, and the submersible pump 27 diverts the water from the anaerobic denitrification filter 17 to the artificial vegetable wetland 19.

[0057] Artificial vegetable wetland 19 has a depth of 1.2m and a length-to-width ratio of 3:2. It is a horizontal flow artificial wetland, divided horizontally into a hydroponic vegetable system and a deep purification system. The hydroponic vegetable system uses composite fiber floating wetland 195 as the planting material, cultivating a seasonal rotation of vegetable varieties: in spring, leafy heat-absorbing plants such as bok choy, chives, amaranth, and water spinach are planted; in summer, aquatic vegetables such as lettuce, cabbage, romaine lettuce, and cauliflower are planted; in autumn, aquatic vegetables such as cabbage, spinach, coriander, and garland chrysanthemum are planted; and in winter, aquatic vegetables such as celery, spinach, mustard greens, and shepherd's purse are selected. The planting density is 9-12 plants / m². 2The hydroponic vegetable system and the deep purification system are separated by a mesh 196. Wastewater flows from the hydroponic vegetable system into the deep purification system through the mesh 196. Aquatic vegetables are planted above the deep purification system, and below them is a horizontally arranged wetland packing material. The selected aquatic vegetables include tall-stemmed varieties such as celery, tomatoes, peppers, and eggplants, with a planting density of 9 plants / m². 2 The wetland filler material, from left to right, consists of a 20cm thick layer of 1-2cm diameter iron-aluminum sludge filler (192), a 40cm thick layer of 1-2cm diameter sponge iron filler (193), a 30cm thick layer of 2-4cm diameter manganese sand filter media, and a 20cm thick layer of 8-10cm diameter gravel filler. By cultivating vegetables in the artificial vegetable wetland (19), the vegetables can absorb pollutants. Furthermore, as an economic crop, large-scale vegetable cultivation can effectively improve the resource utilization level of rural wastewater, while also creating economic value for rural areas and promoting local economic development.

[0058] Water treated by the artificial vegetable wetland 19 enters the water resource utilization and reuse system 20 through the outlet pipe III 21. The water resource utilization and reuse system 20 controls the reclaimed water to enter municipal water use, farmland irrigation, river irrigation, and other water resource reuse systems. The water resource utilization and reuse system 20 and the above four water resource reuse directions are connected by manual valves. When a certain system needs water replenishment, the corresponding valve is opened to realize water resource management, effectively solve the problem of rural domestic wastewater treatment, improve the efficiency and capacity of rural domestic wastewater treatment, improve the allocation capacity of rural water resources, and effectively ensure the level of rural water resource reuse.

[0059] This invention can regulate water volume in the ecological pond by utilizing the water level difference between the ecological ditch 2 and the ecological pond according to the amount of rural domestic sewage, thereby ensuring the best ecological treatment effect. Excess rainwater is intercepted and purified through the ecological grass ditch 13, and further purified through the artificial vegetable wetland 19. The treated effluent then enters the water resource utilization and reuse system 20. The water resource utilization and reuse system 20 controls the reclaimed water to enter municipal water use, farmland irrigation, and river replenishment, realizing the regulation of effluent volume and effective resource utilization of effluent, which is conducive to maximizing the function of the rural effluent water resource system.

[0060] Any parts or structures not specifically described in this invention can be made using existing technologies or products, and will not be elaborated upon here.

[0061] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A rural domestic wastewater wetland treatment and resource recycling system, characterized in that, include: A rainwater harvesting control system includes farmland drainage ditches, ecological grassed swales, ecological ditches, and a water level and volume control system. The water level and volume control system regulates the water level in the ecological ditches, and the water levels in the farmland drainage ditches and the ecological ditches are interconnected and kept at the same level. An ecological pond system, comprising a primary sedimentation pond for sewage mixing and an aerobic pond, wherein rural domestic wastewater flows sequentially through the primary sedimentation pond for sewage mixing and the aerobic pond in a clockwise direction, and the water level in the ecological ditch is higher than the water level in the ecological pond system, and the ecological ditch is connected to the ecological pond system via an inlet pipe II. An artificial vegetable wetland, wherein the elevation of the artificial vegetable wetland is higher than that of the ecological ditch, and the artificial vegetable wetland can be connected to the ecological ditch and can replenish the ecological ditch with water; The water resource utilization and reuse system is connected to the artificial vegetable wetland. The water treated by the artificial vegetable wetland enters the water resource utilization and reuse system, and then enters the municipal water supply, farmland water replenishment and / or river water replenishment. The wastewater mixing and primary sedimentation pond is divided into a mixing zone and an ecological interception pond along the water flow direction. Rural domestic wastewater enters the mixing zone for mixing before entering the ecological interception pond. The ecological interception pond is equipped with emergent plants and filler materials from top to bottom. The filler materials, from top to bottom, consist of a planting soil layer, a manganese sand layer, a zeolite layer, and a ceramsite layer. The manganese sand layer is made of manganese sand with a particle size of 1-2 cm, the zeolite layer is made of zeolite with a particle size of 2-4 cm, and the ceramsite layer is made of ceramsite with a particle size of 2-5 cm. A water collection pipe I is installed in the center of the ceramsite layer. The water collection pipe I is connected to a ventilation pipe, which supplies oxygen to the ecological interception pond. The treated effluent from the wastewater mixing and primary sedimentation pond enters the aerobic pond through the water collection pipe I and the connecting pipes. Herbivorous fish and benthic animals are introduced into the aerobic pond, and root-promoting oxygen-secreting plants and oxygen-producing algae are planted. The stocking density of herbivorous fish fry is 15-20 g / m³. 2 Benthic animal release density: 1-3 g / m³ 2 Planting density: 30-50 plants / m² 2 The aerobic pond is connected to the aerobic denitrification filter, the aerobic denitrification filter is connected to the anaerobic denitrification filter, and the anaerobic denitrification filter is connected to the artificial vegetable wetland.

2. The rural domestic wastewater wetland treatment and resource recycling system according to claim 1, characterized in that, The farmland drainage ditch is lined with a mixed filler material, and submerged plants are planted on top of the mixed filler material at a density of 30-50 plants / m². 2 The slope angle of the ecological vegetated swale is 0.3%-0.5%, and the upper part of the swale is planted with low-growing wetland plants at a density of 16-30 plants / m². 2 The lower part of the ecological grass swale is a filler layer; the artificial vegetable wetland and the ecological ditch are respectively connected to the water supply pipe. When the water level in the ecological ditch is insufficient, the water in the artificial vegetable wetland is used to replenish the ecological ditch through the water supply pipe.

3. A rural domestic wastewater wetland treatment and resource recycling system according to claim 2, characterized in that, The depth of the farmland drainage ditch is 1-1.2m. The mixed filler includes, from top to bottom, a volcanic rock layer, a gravel layer, and a pebble layer. The volcanic rock layer is made of volcanic rock with a particle size of 1-2cm. The gravel layer is made of gravel with a particle size of 2-5cm. The pebble layer is made of pebble with a particle size of 5-10cm. The filler layer includes, from top to bottom, a planting soil layer, an activated carbon layer, a sand and gravel layer, and a gravel bottom layer. The activated carbon layer is made of activated carbon with a particle size of 3-5cm. The sand and gravel layer is made of sand and gravel with a particle size of 4-6cm. The gravel bottom layer is made of gravel with a particle size of 8-10cm. The height of the ecological ditch is 1.5-1.6m and the width is 0.7-1.0m. The ecological ditch has multiple horizontally arranged overflow pipes that connect to the ecological vegetated swales to control the water level in the ecological ditch to not exceed a preset value. The ecological pond system is connected to the rural domestic sewage treatment plant through inlet pipe I.

4. A rural domestic wastewater wetland treatment and resource recycling system according to claim 3, characterized in that, The water level and volume control system includes a rain gauge located in the farmland drainage ditch, a level gauge I in the ecological ditch, a solenoid valve I located at the connection between the ecological ditch and the ecological pond system, a level gauge II in the ecological pond system, a solenoid valve II located at the connection between the ecological ditch and the ecological vegetated ditch system, and a solenoid valve III located at the connection between the artificial vegetable wetland and the ecological ditch system. The rain gauge is used to sense the amount of rainfall in the farmland drainage ditch area. The level gauges I and II are used to sense the changes in water level in the ecological ditch and the ecological pond system, respectively. The solenoid valve I is used to control the water level in the ecological pond system. The rain gauge, solenoid valves II and III are linked to control the water level in the ecological ditch.

5. A rural domestic wastewater wetland treatment and resource recycling system according to claim 1, characterized in that, The aerobic pond is connected to the aerobic denitrification filter via an outlet pipe I and a distribution pipe. The aerobic denitrification filter has a semi-circular structure with a height of 1.3-1.5m and a water depth of 0.9-1m. The upper layer of the aerobic denitrification filter is a 15-20cm thick soil infiltration system, and the lower layer is a packing structure. The packing structure consists of a scraped stone layer, a crushed stone layer, and a coconut shell packing layer from top to bottom. The scraped stone layer is made of scraped stone with a particle size of 3-5cm, and the crushed stone layer is made of crushed stone with a particle size of 4-6cm. Compound bacteria are introduced into the soil infiltration system, and emergent plants are planted above the soil infiltration system. A water collection pipe II is arranged inside the packing structure. The aerobic denitrification filter is connected to the anaerobic denitrification filter via the water collection pipe II and a connected inlet pipe.

6. A rural domestic wastewater wetland treatment and resource recycling system according to claim 5, characterized in that, The anaerobic denitrification filter has a semi-circular structure with a height of 1.3-1.5m and a water depth of 0.9-1m. The bottom is filled with a 20-30cm thick layer of volcanic rock with a particle size of 5-8cm. Above the volcanic rock layer, from bottom to top, a layer of wheat straw, a layer of rice straw, and a layer of corn straw are laid in sequence. Anaerobic denitrifying bacteria are added inside the rice straw layer. Rural domestic wastewater adsorbs pollutants through the volcanic rock layer, the wheat straw layer, the rice straw layer, and the corn straw layer.

7. A rural domestic wastewater wetland treatment and resource recycling system according to claim 6, characterized in that, An installation net is installed above the corn stalk layer, and a submersible pump is installed inside the installation net. The opening and closing of the submersible pump is controlled by a float switch. The float switch controls the water level at a value of x. When the water level does not reach the value of x, the float switch is closed, and the water from the anaerobic denitrification filter cannot enter the artificial vegetable wetland. When the water level reaches the value of x, the float switch is opened, and the submersible pump diverts the water from the anaerobic denitrification filter to the artificial vegetable wetland.

8. A rural domestic wastewater wetland treatment and resource recycling system according to claim 1, characterized in that, The artificial vegetable wetland is a horizontal flow artificial wetland, which is divided into a hydroponic vegetable system and a deep purification system along the horizontal direction. The hydroponic vegetable system uses composite fiber floating wetland as planting material, on which seasonal vegetable varieties are planted, with a planting density of 9-12 plants / m². 2 The hydroponic vegetable system and the vegetable deep purification system are separated by a mesh screen. Wastewater enters the vegetable deep purification system from the hydroponic vegetable system through the mesh screen. Aquatic vegetables are planted above the vegetable deep purification system, and wetland filler is arranged horizontally below the aquatic vegetables. The wetland filler consists of an iron-aluminum sludge filler layer, a sponge iron layer, a manganese sand filter media layer, and a gravel filler layer from left to right. The particle size of the iron-aluminum sludge filler layer is 1-2 cm, the particle size of the sponge iron layer is 1-2 cm, the particle size of the manganese sand filter media is 2-4 cm, and the particle size of the gravel filler layer is 8-10 cm.

9. The method of using a rural domestic wastewater wetland treatment and resource recycling system according to claim 4, characterized in that, Includes the following steps: The water levels in the farmland drainage ditches and the ecological ditches are interconnected and level. The water level in the ecological ditches is higher than that in the ecological pond system. The water level in the ecological ditches is regulated by a water level and volume control system. When the water level in level gauge I is greater than or equal to value a, solenoid valve III closes, preventing water from the artificial vegetable wetland from entering the ecological ditch. If the rain gauge detects rain, solenoid valve II opens, allowing rainwater to enter the ecological vegetated swale through the overflow pipe. If the rain gauge reading is 0, indicating no rain, solenoid valve III closes, maintaining the water level in the ecological ditch at value a. When the water level in level gauge I is less than value a, rainwater or water from the artificial vegetable wetland needs to enter the ecological ditch. If the rain gauge indicates no rain, solenoid valve III opens, allowing water from the artificial vegetable wetland to replenish the ecological ditch through the water supply pipe. Inside, if the rain gauge detects rain, it determines whether to open solenoid valves II and III based on the amount of rainfall. If the rain gauge reading is between 0 and 5 mm, solenoid valve III opens, and the artificial vegetable wetland receives water from the water supply pipe into the ecological ditch. Once the water level in level gauge I reaches value a, solenoid valve III closes and solenoid valve II opens, allowing excess rainwater to enter the ecological vegetated ditch. If the rain gauge reading is greater than 5 mm, solenoid valves II and III close, and rainwater is supplied to the ecological ditch through the farmland drainage ditch. Once the water level in level gauge I reaches value a, solenoid valve II opens and solenoid valve III closes, allowing excess rainwater to enter the ecological vegetated ditch. By absorbing and utilizing pollutants in rainwater through ecological grassed swales, the nutrient content in the water is reduced, thereby achieving the standard for reuse. The water level in the ecological ditch is higher than that in the ecological pond system, ensuring that water from the ecological pond system does not flow back into the ecological ditch. Simultaneously, the higher elevation increases the contact area between wastewater and air, enhancing the dissolved oxygen content in the water. The ecological ditch and the ecological pond system are connected by an inlet pipe II. At the connection point of inlet pipe II, there is a solenoid valve I that controls the inflow of water. By controlling the opening and closing of solenoid valve I, the water level in the ecological pond system is controlled at value b. When the water level of level gauge II in the ecological pond system is greater than or equal to value b, solenoid valve I is closed, preventing water from the ecological ditch from entering the ecological pond system. This continues until the amount of effluent from the rural domestic sewage treatment plant decreases, causing the water level in the ecological pond system to fall below value b. At this point, solenoid valve I opens, allowing water from the ecological ditch to enter the ecological pond system. Once the water level of level gauge II rises again to value b or above, solenoid valve I closes again. This process is repeated to stabilize the water level in the ecological pond system at value b. Rural domestic wastewater flows clockwise through a primary sedimentation pond and an aerobic pond. The primary sedimentation pond is divided into a mixing zone and an ecological interception pond along the water flow direction. The wastewater first enters the mixing zone for mixing, and then flows into the ecological interception pond through the outlet pipe and distribution pipe above the mixing zone. Emergent plants in the ecological interception pond regulate the water flow rate through their root systems. At the same time, they remove particulate matter, organic matter, and nutrients from the water through root absorption and degradation by root microorganisms. Oxygen is supplied to the ecological interception pond through the aeration pipe. The treated effluent from the primary sedimentation pond enters the aerobic pond, where the plants release dissolved oxygen through photosynthesis. The plants also absorb nutrients, and benthic animals enrich the biomass of the aerobic pond, increasing biodiversity, improving the stability of the aerobic pond and the system's purification capacity, thereby improving water quality. Water from the aerobic pond enters the aerobic denitrification filter through outlet pipe I and distribution pipe. The filter media and microorganisms in the aerobic denitrification filter purify pollutants in the water before it enters the anaerobic denitrification filter. The anaerobic denitrification filter absorbs pollutants in the water through volcanic rock layers, wheat straw layers, rice straw layers, and corn straw layers. The water from the anaerobic denitrification filter is then pumped to an artificial vegetable wetland for further treatment. After treatment in the artificial vegetable wetland, the water enters the water resource utilization and reuse system, and then enters the municipal water supply, farmland irrigation, and / or river irrigation systems.

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