Rural household domestic sewage purification system and use method thereof

Abstract

The invention relates to a rural household domestic sewage purification system and a use method thereof, the rural household domestic sewage purification system is arranged in a rural residential area with ploughing, the rural household domestic sewage purification system comprises a quality-based collection unit, a wastewater treatment unit, a resource cooperation unit, an intelligent control unit, and a decentralized sewage treatment and resource system capable of realizing a cooperative target of source quality-based, graded purification, intelligent regulation and control, and resource reuse. And the self-sufficiency of water resources is improved in a low-cost and low-energy-consumption manner.

Description

Technical Field

[0001] This invention relates to the field of rural sewage treatment and resource utilization technology, and in particular to a rural household domestic sewage purification system and its usage method. Background Technology

[0002] my country's water shortage problem is becoming increasingly severe, especially in the arid northwest, where water resources have become a key bottleneck restricting sustainable development. Domestic sewage, as a stable and reliable potential water source, is of great significance for its efficient recycling. How to achieve refined, differentiated treatment and efficient resource recovery in water-scarce rural areas is an urgent problem to be solved.

[0003] Although there are technologies based on the concept of "source separation + resource recovery", many of them are based on membrane bioreactors (MBRs), but their high investment and operating costs limit their promotion in economically underdeveloped areas. Summary of the Invention

[0004] This invention provides a rural household sewage purification system and its usage method, which is a decentralized sewage treatment and resource recovery system that can achieve the coordinated goals of "source separation, graded purification, intelligent regulation and control, and resource reuse", thereby improving water resource self-sufficiency in a low-cost and low-energy manner.

[0005] A rural household sewage purification system, installed in a rural residential area with cultivated land, includes: a separate collection unit for collecting domestic sewage separately, the separate collection unit including a grey water collection unit, a black water collection unit and a rainwater collection unit, the grey water collection unit for collecting grey water flowing from kitchen, bathing, washing machine and washing and cleaning drain pipes, the black water collection unit for collecting black water flowing from toilet drain pipes, and the rainwater collection unit for collecting rainwater; The wastewater treatment unit is used to treat the greywater, blackwater, and rainwater collected by the separate collection unit. It includes a greywater physical filtration module, a blackwater solid-liquid separation module, and a rainwater physical filtration module. The greywater physical filtration module treats greywater and includes a coarse filter layer, a medium filter layer, and a fine filter layer sequentially along the water flow direction. The blackwater solid-liquid separation module treats blackwater by separating the solids and liquids. The rainwater physical filtration module treats rainwater and includes a sedimentation tank, an overflow tank, and filter blocks sequentially along the water flow direction. The resource utilization and co-processing unit is used to utilize the products from the wastewater treatment unit. It includes a purified water utilization module and a fertilizer utilization module. The inlet of the purified water utilization module is connected to the greywater physical filtration module, and the outlet of the purified water utilization module is connected upstream to the rainwater... The physical filtration module's outlet is connected to the water inlet, and the purified water utilization module's outlet is connected to the grey water physical filtration module's inlet, the rainwater physical filtration module's filter block inlet, the toilet flushing pipe, and the irrigation pipe, respectively. The fertilizer utilization module includes a solid fertilizer composting treatment area and a liquid fertilizer anaerobic fermentation area. The solids produced by the black water solid-liquid separation module enter the solid fertilizer composting treatment area, and the liquids produced by the black water solid-liquid separation module enter the liquid fertilizer anaerobic fermentation area. The liquid fertilizer anaerobic fermentation area is connected to the irrigation pipe. The final solid fertilizer and liquid fertilizer produced by the fertilizer utilization module are applied to rural farmland. The intelligent control unit is communicatively connected to the separation collection unit, wastewater treatment unit, and resource utilization coordination unit, and is used to dynamically adjust the operating parameters of each unit based on water quality and quantity information.

[0006] Preferably, the coarse filter layer of the grey water physical filtration module consists of a grid and a pebble layer along the water flow direction to intercept large particulate impurities; the medium filter layer consists of a fine sand layer and a gauze layer along the water flow direction to filter suspended solids; and the fine filter layer consists of a volcanic rock layer and an activated carbon layer along the water flow direction to adsorb soluble pollutants and odors. The coarse, medium, and fine filter layers are of standardized size and are fixed in shape by a mesh support material as an outer skeleton, which facilitates quick assembly and replacement.

[0007] Preferably, the greywater physical filtration module is assembled from several open-top cubic precast blocks made of solid waste-based concrete precast components. The greywater physical filtration module is buried underground, and the water flow direction is at least 15 degrees inclined to the horizontal plane, allowing the greywater to flow by gravity along the coarse filter layer, medium filter layer, and fine filter layer.

[0008] Preferably, the rainwater physical filtration module sedimentation tank is used to collect and settle rainwater. The supernatant in the sedimentation tank overflows into the overflow tank. The sedimentation tank and the overflow tank are separated by a partition. The partition of the appropriate height is selected according to the water level. The water in the overflow tank is pumped to the filter block. The filter block consists of a grid, pebbles, and volcanic rock layer in sequence along the water flow direction. The filter block is of a standardized size and is fixed in shape by a mesh support material as an outer skeleton, which facilitates quick assembly and replacement.

[0009] Preferably, the system comprises a sensor module, an intelligent water distribution module, and a remote monitoring platform. The sensor module is used to monitor the following data in real time: the influent and effluent flow rates of the separation collection unit, the influent and effluent flow rates, influent water quality, and effluent water quality of the wastewater treatment unit, the influent and effluent flow rates and water level of the purified water utilization module in the resource utilization collaborative unit, and the influent and effluent flow rates, temperature, and water level of the liquid fertilizer anaerobic fermentation zone. The intelligent water distribution module is used to dynamically allocate the amount of water entering the purified water utilization module from the wastewater treatment unit, dynamically allocate the water flow path and flow rate of the purified water utilization module, and dynamically allocate the influent and effluent flow rates of the fertilizer anaerobic fermentation zone based on the monitoring data from the sensor module and a preset water demand model. The remote monitoring platform is used to receive the data from the sensor module and realize remote visualization of equipment status and fault alarms.

[0010] Preferably, the intelligent control unit further includes an antifreeze protection module, which monitors the temperature of the filter blocks of the purified water utilization module, the grey water physical filtration module, and the rainwater physical filtration module in real time, and controls the liquid to circulate among the filter blocks of the purified water utilization module, the grey water physical filtration module, and the rainwater physical filtration module to prevent freezing.

[0011] A method for the separate recycling of domestic sewage, based on the aforementioned rural household domestic sewage purification system, includes the following steps: S1: Collecting domestic sewage at the source and separating it into grey water, black water, and rainwater; grey water flows from the drains of kitchens, bathrooms, washing machines, and bathroom fixtures; black water flows from the drains of toilets; and rainwater is collected from natural precipitation; S2: Guiding the grey water to the grey water physical filtration module of the wastewater treatment unit, where it undergoes step-by-step physical filtration through coarse, medium, and fine filter layers to obtain reclaimed water; using rainwater to dilute the reclaimed water, reducing its sodium content, and finally using it for toilet flushing, landscaping, or irrigation;

[0012] S3: The black water is guided to the black water solid-liquid separation module of the wastewater treatment unit to separate the black water solids and liquids. The solids of the black water enter the solid fertilizer composting treatment area, where they are mixed with crushed crop straw, sawdust, rice husks, fallen leaves and branches, waste mushroom bags and other dry materials for composting and fermentation, ultimately producing well-rotted organic fertilizer, which is evenly spread in the field and plowed into the soil. The liquid of the black water enters the liquid fertilizer anaerobic fermentation area for anaerobic fermentation and storage maturation to produce safe liquid fertilizer, which is applied to the farmland by irrigation. S4: The intelligent control unit monitors the water quality, water quantity and equipment status of each link of the system in real time, and dynamically optimizes the water flow distribution and treatment parameters based on the monitoring data to achieve adaptive operation of the system.

[0013] Preferably, in step S2, the grey water generated in real time passes through the grey water physical filtration module to the purified water utilization module, and the rainwater is stored in the sedimentation tank and overflow tank. When it is necessary to flush the toilet, all the reclaimed water flows out from the purified water utilization module for flushing the toilet. When it is necessary to irrigate, the reclaimed water and the filtered rainwater are taken at the same time, and water is drawn according to the set ratio and sent to the irrigation pipe.

[0014] Preferably, in step S3, when the liquid fertilizer is to be used for irrigation, the liquid fertilizer flows into the irrigation pipe while simultaneously taking reclaimed water and filtered rainwater, and then taking water according to a set ratio for irrigation.

[0015] Preferably, in step S2, the greywater physical filtration module is assembled from several open-top cubic precast blocks made of solid waste-based concrete precast components. The greywater physical filtration module is buried underground, and the water flow direction is at least 15 degrees inclined to the horizontal plane, allowing greywater to flow and filter by gravity along the direction of the coarse filter layer, the medium filter layer, and the fine filter layer. Each precast block contains a material, and several precast blocks form the coarse filter layer, the medium filter layer, and the fine filter layer.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. High-efficiency separation and resource recycling: Through source separation and targeted treatment, the system achieves high-efficiency recycling of three resources: greywater reuse (toilet flushing, greening), blackwater fertilizer production (agricultural liquid fertilizer), and rainwater utilization. Calculations show that the system's water resource recovery rate can reach over 68%, and nutrient recovery rate can reach over 89%.

[0018] 2. Significantly low cost and low energy consumption: The system uses low-cost materials such as "self-mixed filter media" to construct the core processing unit, mainly relying on gravity flow for purification, eliminating the energy consumption of long-distance pipeline transportation. The solid waste-based precast concrete components are inexpensive and sufficient for the intended purpose.

[0019] 3. Intelligent and Modular Design: Integrating intelligent sensing and control technologies enables unattended operation, adaptive operation, and remote monitoring. Each functional unit adopts a modular design, facilitating large-scale production, rapid deployment, and flexible operation and maintenance, significantly improving the replicability and scalability of the technology.

[0020] 4. Precise regional adaptability: Designed to address the pain points of rural areas in water-scarce regions such as Northwest China, it solves the problems of difficult pipeline coverage, high operating costs, and low resource recovery rate, providing a practical and feasible technical solution for decentralized wastewater resource utilization, with significant social, economic, and environmental benefits. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the process of the rural household domestic sewage purification system of the present invention. Figure 2 This is a schematic diagram of one embodiment of the solid waste-based concrete precast component of the grey water physical filtration module of the present invention, with filter material filling the middle. Figure 3 This is a schematic diagram of one embodiment of the mesh-like support material that forms the outer skeleton for the coarse filter layer, medium filter layer, fine filter layer, and filter block of the present invention, with filter material filling the middle.

[0022] In the diagram: Grey water collection unit 1, Black water collection unit 2, Grey water physical filtration module 3, Black water solid-liquid separation module 4, Rainwater physical filtration module 5, Purified water utilization module 6. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] As attached Figure 1 As shown, a rural household sewage purification system is installed in a rural residential area with cultivated land, including a separate collection unit, a wastewater treatment unit, a resource recovery and co-processing unit, and an intelligent control unit. Details are as follows:

[0025] The separate collection unit is used to collect domestic sewage separately. It includes a grey water collection unit 1, a black water collection unit 2, and a rainwater collection unit. Grey water collection unit 1 collects grey water from kitchen, bathroom, washing machine, and bathroom cleaning drains. Black water collection unit 2 collects black water from toilet drains. The rainwater collection unit collects rainwater.

[0026] The wastewater treatment unit is used to treat the grey water, black water and rainwater collected by the separate collection unit separately, including grey water physical filtration module 3, black water solid-liquid separation module 4 and rainwater physical filtration module 5.

[0027] The greywater physical filtration module 3 is used to treat greywater. The underground greywater physical filtration module 3 is assembled from several top-opening cubic precast blocks made of solid waste-based concrete precast components. The water flow direction is at least 15 degrees to the horizontal plane, allowing the greywater to flow by gravity along the coarse, medium, and fine filter layers. Solid waste-based concrete precast components are inexpensive.

[0028] One embodiment of the solid waste-based precast concrete structure is shown in the attached figure. Figure 2 As shown, the filter includes a coarse filter layer, a medium filter layer, and a fine filter layer in sequence along the water flow direction. The two ends of the solid waste-based concrete precast component in the water flow direction are sealed by pipes, making the gray water physical filtration module 3 a sealed structure as a whole.

[0029] The coarse filter layer, along the water flow direction, consists of a screen and a pebble layer to intercept large particles of impurities. The medium filter layer, along the water flow direction, consists of a fine sand layer and a gauze layer to filter suspended solids. The fine filter layer, along the water flow direction, consists of a volcanic rock layer and an activated carbon layer to adsorb soluble pollutants and odors. In practice, along the water flow direction, the precast concrete components for solid waste can be filled with pebbles, fine sand, gauze, volcanic rock, and activated carbon in sequence; at least one of any one of these filter materials can be placed.

[0030] The coarse, medium, and fine filter layers achieve directional, step-by-step interception of particles from large to small, effectively reducing the risk of filter clogging and extending service life. Figure 3 As shown, the coarse, medium, and fine filter layers are of standardized size and are held in place by a mesh support material forming the outer frame. The material can also be wrapped in old clothing and placed inside the frame for easy assembly and replacement. The greywater treated by the greywater physical filtration module 3 is reclaimed water that meets the minimum water quality requirements for irrigation and toilet use.

[0031] The black water solid-liquid separation module 4 is used to treat black water. It uses a solid-liquid separation device to separate the black water into solid and liquid components. The rural dry toilet itself can store black water for a period of time. The black water is regularly separated into solid and liquid components to obtain organic fertilizer.

[0032] The rainwater physical filtration module 5 is used to treat rainwater and includes a sedimentation tank, an overflow tank, and filter blocks in sequence along the water flow direction. The sedimentation tank is located on an open area to collect and settle rainwater. Drainage pipes under the eaves of residents' houses are also connected to the sedimentation tank. During periods of heavy rainfall, the overflow tank also serves as a water storage area. The supernatant from the sedimentation tank overflows into the overflow tank. The sedimentation tank and overflow tank are separated by a partition, the height of which is selected according to the water level. Water in the overflow tank is pumped to the filter blocks. The filter blocks, in sequence along the water flow direction, consist of a grid, pebbles, and a layer of volcanic rock. The filter blocks are standardized in size and have a mesh support material as an outer frame to maintain their shape, facilitating material filling and quick assembly and replacement. Rainwater is mainly used to dilute reclaimed water and black water to obtain liquid fertilizer.

[0033] The resource utilization collaborative unit is used to utilize the products treated by the wastewater treatment unit. It includes a purified water utilization module 6 and a fertilizer utilization module. The inlet end of the purified water utilization module 6 is connected to the gray water physical filtration module 3, and the upstream of the outlet end of the purified water utilization module 6 is connected to the outlet of the rainwater physical filtration module 5. The outlet end of the purified water utilization module 6 is connected to the inlet of the gray water physical filtration module 3, the inlet of the filter block of the rainwater physical filtration module 5, the toilet flushing pipe, and the irrigation pipe. The fertilizer utilization module includes a solid fertilizer composting treatment area and a liquid fertilizer anaerobic fermentation area. The solids produced by the black water solid-liquid separation module 4 enter the solid fertilizer composting treatment area, and the liquids produced by the black water solid-liquid separation module 4 enter the liquid fertilizer anaerobic fermentation area. The liquid fertilizer anaerobic fermentation area is connected to the irrigation pipe. The solid fertilizer and liquid fertilizer finally produced by the fertilizer utilization module are applied to rural farmland.

[0034] The intelligent control unit is communicatively connected to the wastewater collection unit, wastewater treatment unit, and resource utilization coordination unit, and is used to dynamically adjust the operating parameters of each unit based on water quality and quantity information. The intelligent control unit includes: a sensor module, an intelligent water distribution module, an anti-freeze protection module, and a remote monitoring platform. The sensor module is used to monitor the following data in real time: the influent and effluent flow rates of the wastewater collection unit, the influent and effluent flow rates, influent water quality, and effluent water quality of the wastewater treatment unit; the influent and effluent flow rates, water level, and influent and effluent flow rates, temperature, and water level of the purified water utilization module 6 in the resource utilization coordination unit; the intelligent water distribution module is used to dynamically allocate the amount of water entering the purified water utilization module 6 from the wastewater treatment unit, dynamically allocate the water flow path and flow rate of the purified water utilization module 6, and dynamically allocate the inflow and outflow of the anaerobic fermentation zone of the fertilizer, based on the monitoring data from the sensor module and a preset water demand model. The remote monitoring platform is used to receive data from the sensor module and realize remote visualization of equipment status and fault alarms. The antifreeze protection module monitors the temperature of the filter blocks in the purified water utilization module 6, the grey water physical filtration module 3, and the rainwater physical filtration module 5 in real time, and controls the circulation of liquid among these filter blocks to prevent freezing.

[0035] This invention also provides a method for the differentiated recycling of rural domestic sewage, based on the rural household domestic sewage purification system described above, including the following steps: S1: Collecting domestic sewage at the source and separating it into grey water, black water, and rainwater; grey water flows from the drains of kitchens, bathrooms, washing machines, and bathroom cleaning facilities, black water flows from the toilet drains, and rainwater is collected from natural precipitation; S2: Guiding the grey water to the grey water physical filtration module 3 of the wastewater treatment unit, where it undergoes step-by-step physical filtration through coarse, medium, and fine filter layers to obtain reclaimed water; using rainwater to dilute the reclaimed water, reducing the sodium content, and finally using it for toilet flushing, landscaping, or irrigation; the grey water generated in real time reaches the purified water utilization module 6 after passing through the grey water physical filtration module 3, and the rainwater is stored in a sedimentation tank and an overflow tank. When toilet flushing is needed, all the reclaimed water flows out from the purified water utilization module 6 for toilet flushing. When irrigation is needed, reclaimed water and filtered rainwater are taken at the same time, and water is drawn according to a set ratio and directed to the irrigation pipeline.

[0036] The greywater physical filtration module is assembled from several top-opening cubic precast blocks made of solid waste-based precast concrete. The module is buried underground, with the water flow direction at least 15 degrees to the horizontal plane. Greywater is allowed to flow by gravity through coarse, medium, and fine filter layers. Each precast block contains one type of filter material, and several blocks form the coarse, medium, and fine filter layers. The underground burial design makes the entire system more resistant to cold weather and also facilitates the removal and placement of filter materials.

[0037] S3: The black water is guided to the black water solid-liquid separation module 4 of the wastewater treatment unit to separate the black water into solid and liquid components. The solid portion of the black water enters the solid fertilizer composting treatment area, where it is mixed with crushed crop straw, sawdust, rice husks, fallen leaves and branches, discarded mushroom spawn bags, and other dry materials for composting and fermentation, ultimately producing well-rotted organic fertilizer. This fertilizer is then evenly spread in the field and plowed into the soil. The liquid portion of the black water enters the liquid fertilizer anaerobic fermentation area for anaerobic fermentation and post-fermentation storage, producing safe liquid fertilizer. When the liquid fertilizer is needed for irrigation, it flows into the irrigation pipe while simultaneously drawing reclaimed water and filtered rainwater according to a set ratio for irrigation. S4: The intelligent control unit monitors the water quality, quantity, and equipment status of each stage of the system in real time and dynamically optimizes water flow distribution and treatment parameters based on the monitoring data, achieving adaptive system operation.

[0038] Example effect:

[0039] A pilot application was conducted in a rural residential area with farmland in Ningxia. The farmer uses approximately 100 liters of water daily. Through this system, approximately 18.6 m³ of greywater is recycled annually, and approximately 20 m³ of rainwater is collected, achieving a water resource recovery rate of 68.3%. All blackwater is converted into liquid fertilizer, with a nitrogen and phosphorus nutrient recovery rate of approximately 89.8%. The system does not require long-distance external sewage pipe networks, relying primarily on gravity filtration. Electricity is only used for a small number of booster pumps and controllers, resulting in extremely low annual operating electricity costs. Compared to traditional systems that require connection to urban pipe networks or the construction of small-scale integrated MBR equipment, this system reduces initial investment by approximately 50% and operating costs by over 60%, achieving significant economic and environmental benefits.

[0040] The core concept of this project is to achieve inclusive benefits through systematic innovation based on "quality separation, resource utilization, and intelligence." It utilizes source separation and graded treatment as a foundation, employing low-cost materials (such as self-mixed filter media like bar screens, fine sand, and activated carbon) to construct a layered filtration system. This system achieves the step-by-step directional separation of impurities in wastewater from large to small particles, significantly reducing the risk of clogging and maintenance frequency. Simultaneously, it integrates modules for intelligent water distribution, liquid fertilizer preparation, and rainwater utilization. Under the premise of meeting farmland reuse standards, the reclaimed water purified by the rural household wastewater purification system can be directly used for farmland irrigation, greening, and toilet flushing, significantly reducing tap water consumption. Organically rich toilet wastewater is efficiently converted into agricultural organic fertilizer, achieving nutrient recycling. Furthermore, the integrated first-rainwater collection and purification function further supplements the water source, forming a low-threshold solution suitable for farmers, easy to maintain, and reusable. This effectively reduces users' water bills and daily maintenance burden, promotes the inclusive recycling of water resources in water-scarce areas, and effectively enhances the system's adaptability and sustainability in water-scarce regions.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rural household domestic sewage purification system, characterized in that, The application discloses a grey water physical filtration module, which is made of a plurality of solid waste-based concrete prefabricated pieces and is assembled into an upper opening cubic prefabricated block.

2. The rural household domestic wastewater purification system according to claim 1, characterized in that, The grey water physical filtration module is buried underground, and the water flow direction is at least 15 degrees with the horizontal plane, so that the grey water flows along the coarse filter layer, the middle filter layer and the fine filter layer directions by itself.

3. The rural household domestic wastewater purification system according to claim 2, characterized in that, ​ 4. The rural household domestic wastewater purification system according to claim 1, characterized in that, The rainwater physical filtration module sedimentation tank is used for collecting and settling rainwater, supernatant in the sedimentation tank overflows to the overflow tank, the sedimentation tank and the overflow tank are separated by a partition, the partition with a corresponding height is selected according to the water level, and the water in the overflow tank is pumped to the filter block, the filter block sequentially comprises a grid, goose eggs and a volcanic rock layer along the water flow direction, the filter block has a standardized size, an outer skeleton made of a net-shaped supporting material is used to keep the shape fixed, and the filter block is convenient for quick assembly and replacement.

5. The rural household domestic sewage purification system according to claim 1, characterized in that, The intelligent control unit comprises a sensor module, an intelligent water distribution module and a remote monitoring platform; the sensor module is used for monitoring the following data in real time: the water inflow and outflow of the quality-based collection unit, the water inflow and outflow, water quality of the wastewater treatment unit, the water inflow and outflow, water level of the purified water utilization module in the resourceization and cooperation unit, the water inflow and outflow, temperature and water level of the liquid fertilizer anaerobic fermentation area; the intelligent water distribution module is used for dynamically distributing the water inflow of the wastewater treatment unit into the purified water utilization module, dynamically distributing the water flow path and flow of the purified water utilization module and dynamically distributing the inflow and outflow of the fertilizer anaerobic fermentation area according to the monitoring data of the sensor module and a preset water demand model; and the remote monitoring platform is used for receiving the data of the sensor module and realizing remote visualization and fault alarm of the equipment state.

6. The rural household domestic sewage purification system according to claim 4, characterized in that, The intelligent control unit further comprises an anti-freezing protection module, which monitors the temperature of the purified water utilization module, the greywater physical filtration module and the rainwater physical filtration module filter block in real time, and controls the circulation of liquid between the purified water utilization module, the greywater physical filtration module and the rainwater physical filtration module filter block, thereby playing an anti-freezing role.

7. A method for using a rural household domestic sewage purification system, based on the rural household domestic sewage purification system according to any one of claims 1-7, characterized in that, The method comprises the following steps: S1: collecting domestic sewage at the source and separating it into greywater, blackwater and rainwater; the greywater is discharged from the kitchen, bath, washing machine and cleaning sink pipeline, the blackwater is discharged from the toilet pipeline, and the rainwater is collected by natural precipitation; S2: guiding the greywater to the greywater physical filtration module of the wastewater treatment unit, performing step-by-step physical filtration through a coarse filter layer, a medium filter layer and a fine filter layer to obtain regenerated water; diluting the regenerated water with rainwater to reduce the content of sodium elements in the regenerated water, and finally using the regenerated water for toilet flushing, greening or irrigation; S3: guiding the blackwater to the blackwater solid-liquid separation module of the wastewater treatment unit, performing solid-liquid separation on the blackwater, and mixing the solids of the blackwater with dry materials such as crushed crop straws, sawdust, rice husks, dry branches and leaves and waste mushroom bags to perform pile fermentation, thereby producing decomposed organic fertilizer which is uniformly applied to farmland and ploughed into the soil; the liquid of the blackwater enters the liquid fertilizer anaerobic fermentation area, performs anaerobic fermentation and storage after-ripening, and produces safe liquid fertilizer which is applied to farmland in the form of irrigation; S4: monitoring the water quality, water quantity and equipment state of each link of the real-time monitoring system by the intelligent control unit, dynamically optimizing the water flow distribution and treatment parameters based on the monitoring data, and realizing adaptive operation of the system.

8. The method for using the rural household domestic sewage purification system according to claim 7, characterized in that, In step S2, the real-time generated grey water passes through the grey water physical filtration module to reach the purified water utilization module, the rainwater is stored in the sedimentation tank and overflow tank, when the toilet needs to be flushed, the regenerated water is taken out from the purified water utilization module to flush the toilet, when irrigation is needed, the regenerated water and the filtered rainwater are taken out at the same time, the water is taken according to the set proportion and is led to the irrigation pipeline.

9. The method for using the rural household domestic sewage purification system according to claim 7, characterized in that, In step S3, when the liquid fertilizer needs to be irrigated, the liquid fertilizer flows into the irrigation pipeline at the same time, the regenerated water and the filtered rainwater are taken out, the water is taken according to the set proportion and is irrigated.

10. The method for using the rural household domestic sewage purification system according to claim 7, characterized in that, In step S2, the grey water physical filtration module is composed of a plurality of solid waste-based concrete prefabricated blocks with open top and is assembled into a cubic prefabricated block, the grey water physical filtration module is buried underground, the water flow direction is inclined to the horizontal plane by at least 15 degrees, the grey water is filtered along the coarse filter layer, the medium filter layer and the fine filter layer, one kind of material is placed in each prefabricated block, and a plurality of prefabricated blocks form the coarse filter layer, the medium filter layer and the fine filter layer.

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