A combined wastewater treatment equipment

Abstract

This invention discloses a combined wastewater treatment device, comprising a pretreatment unit, an anaerobic treatment unit, an ecological purification unit, and a water storage and reuse unit, which are detachably connected sequentially via flange interfaces in the direction of water flow. The pretreatment unit has a black water inlet, a grey water inlet, and an internal mixing zone. The mixing zone is equipped with pluggable baffles for selectively isolating or connecting the black water and grey water flow paths. The anaerobic treatment unit is connected to the outlet of the pretreatment unit and has an internal baffle structure with multiple sets of staggered guide plates and a biological packing layer with attached microorganisms. The inlet of the ecological purification unit is connected to the outlet of the anaerobic treatment unit. The advantages of this invention are: high modularity, achieving "one machine for multiple uses," separate treatment of black and grey water, resource recycling, zero-power or low-power operation, significantly reduced operation and maintenance costs, anti-clogging and long-term operation design, and improved collection efficiency.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a combined wastewater treatment device. Background Technology

[0002] Rural living environment improvement has become an important part of agricultural and rural modernization. Rural domestic sewage mainly includes kitchen wastewater, washing wastewater, bathing wastewater, and toilet waste, characterized by dispersed discharge, high organic matter concentration, high nitrogen and phosphorus content, and large fluctuations in water quality and quantity between day and night.

[0003] Currently, rural domestic sewage treatment mainly faces the following technical challenges: 1. Insufficient adaptability of models and prominent "one-size-fits-all" phenomenon: In existing technologies, most sewage treatment equipment simply copies the centralized treatment model in urban areas, without fully considering the "largely dispersed, small-scale clustered" distribution characteristics of rural settlements. Scattered rural households in mountainous and hilly areas cannot be included in centralized treatment systems due to the high cost of pipeline laying; while some villages with small populations are forced to build standardized facilities, resulting in equipment sitting idle and causing great waste of resources.

[0004] 2. Low resource utilization rate due to mixed treatment of black water and grey water: Existing equipment typically treats toilet waste (black water, high concentration of organic matter) and kitchen wastewater (grease, containing grease and surfactants) together. This increases treatment difficulty and energy consumption, and also destroys the resource attributes of organic fertilizer produced by anaerobic fermentation of feces, resulting in the waste of valuable nitrogen and phosphorus resources in rural sewage, which is inconsistent with the concept of ecological cycle.

[0005] 3. Weak operation and maintenance management, and strong dependence on energy: Existing integrated equipment mostly adopts A / O or MBR processes, which require continuous aeration and complex control, resulting in high operating costs and the need for professional personnel to operate them. Rural areas generally lack reliable power supply and professional technicians, leading to a situation where many facilities are "affordable to build, unaffordable to use, and poorly managed."

[0006] 4. Disconnection between collection pipeline network and terminal equipment: Existing technology "emphasizes terminals and neglects pipeline network", ignoring the impact of slope and terrain on gravity collection, resulting in low sewage collection rate and terminal facilities being "underutilized".

[0007] Therefore, there is an urgent need for a modular wastewater treatment system that can be flexibly combined according to village size and terrain conditions to achieve the separation of black and gray wastewater and resource utilization, and is simple to operate and maintain, requiring no or minimal power.

[0008] Therefore, in order to address the aforementioned technical problems, it is necessary to provide a combined wastewater treatment device. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the purpose of this invention is to provide a combined wastewater treatment device to solve the problems mentioned in the background art.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a combined wastewater treatment device, comprising components detachably connected sequentially via flange interfaces in the direction of water flow: The pretreatment unit is provided with a black water inlet, a grey water inlet and a mixing zone located inside, wherein a pluggable partition is provided in the mixing zone for selectively isolating or connecting the black water and grey water flow paths. The anaerobic treatment unit is connected to the outlet of the pretreatment unit. It has a baffle structure inside, with multiple sets of staggered guide plates and a biological packing layer with attached microorganisms. The ecological purification unit has its inlet connected to the outlet of the anaerobic treatment unit. The ecological purification unit is a modular artificial wetland box, which is provided with a plant layer, a soil layer, a coarse sand layer and a gravel drainage layer from top to bottom, and is equipped with a water distribution pipe and a water collection pipe inside. The water storage and reuse unit has an inlet connected to the water collection pipe of the ecological purification unit. The water storage and reuse unit is equipped with an irrigation outlet valve at the bottom and an overflow pipe at the top.

[0011] In one or more embodiments of the present invention, the pretreatment unit further includes an oil-water separation and sedimentation zone located downstream of the grey water inlet, wherein the oil-water separation and sedimentation zone is provided with an inclined plate sedimentation assembly and an oil interception net.

[0012] In one or more embodiments of the present invention, the anaerobic treatment unit is provided with a biogas exhaust port at the top and a sludge discharge pipe at the bottom; the guide plate divides the interior of the unit into multiple series-connected baffle chambers, and the biological packing layer is fixedly installed in the baffle chambers, the packing being polyurethane sponge or porous ceramic.

[0013] In one or more embodiments of the present invention, the bottom of the ecological purification unit is provided with a backwash pipe, which is connected upstream of the irrigation outlet valve of the water storage and reuse unit via a pipeline, and a backwash valve is provided on the pipeline.

[0014] In one or more embodiments of the present invention, the device further includes a solar-powered micro-aeration system, which includes a photovoltaic panel, a battery and a micro air pump, wherein the outlet of the micro air pump is connected to the bottom of the anaerobic treatment unit or the ecological purification unit through a pipe.

[0015] In one or more embodiments of the present invention, the pluggable partition includes a vertical insert plate and a horizontal baffle; when the vertical insert plate is closed and the horizontal baffle is open, black water and grey water are mixed in the mixing zone; when the vertical insert plate is open and the horizontal baffle is closed, black water and grey water are diverted and enter subsequent units independently.

[0016] In one or more embodiments of the present invention, the bottom of the pretreatment unit is provided with casters or leveling feet to adapt to the slope requirements of different terrains.

[0017] In one or more embodiments of the present invention, the water storage and reuse unit is provided with a liquid level sensor, which is electrically connected to an alarm and is used to issue an audible and visual alarm when the liquid level exceeds the overflow pipe.

[0018] In one or more embodiments of the present invention, the single-household treatment mode of the combined wastewater treatment equipment is as follows: only a pretreatment unit and a miniaturized ecological purification unit are connected, omitting the anaerobic treatment unit, and the plant layer of the ecological purification unit is directly planted in the farmer's courtyard, and the water collection pipe is directly connected to the water storage and reuse unit for irrigating the vegetable garden.

[0019] In one or more embodiments of the present invention, the centralized treatment mode of the combined wastewater treatment equipment is as follows: 3-5 anaerobic treatment units are set in parallel, and a solar micro-power aeration system is connected in series between the anaerobic treatment units and the ecological purification units. The ecological purification units adopt a vertical subsurface flow wetland structure, and the treated effluent reaches the Class B standard before being discharged into the village landscape water body or used for farmland irrigation.

[0020] The beneficial effects of this invention are as follows: 1. Highly modular, achieving "one machine for multiple uses": This invention uses standardized interfaces to detachably connect the pretreatment unit, anaerobic treatment unit, ecological purification unit and water storage and reuse unit.

[0021] 2. Separate treatment of black and gray water to achieve resource recycling: By setting up an inlet water distribution box with pluggable partitions, the source separation and selective mixing of black water and gray water are achieved.

[0022] 3. Zero or low power operation, significantly reducing operation and maintenance costs: The core processing unit utilizes the terrain elevation difference to achieve gravity flow self-drive, eliminating the need for booster pumps.

[0023] 4. Anti-clogging and long-term operation design: Backwashing pipes are installed at the bottom of the constructed wetland and filter bed, and the stored tailwater is used for simple backwashing, which solves the problem of clogging and paralysis that is common in small rural wetlands.

[0024] 5. Improved collection efficiency: The equipment integrates an optional end-of-line lifting function, which solves the problem of sewage backflow caused by undulating terrain and ensures the integrity of the pipe network collection. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure and water flow connection of a combined wastewater treatment device according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the adaptive selection of a governance mode based on village type for a combined wastewater treatment device according to an embodiment of the present invention. Figure 3 This is a process flow diagram of a single-household wastewater treatment and courtyard resource utilization process of a combined wastewater treatment device according to an embodiment of the present invention. Figure 4 This is a flowchart illustrating the combined wastewater treatment equipment of the present invention, specifically a centralized wastewater collection and parallel anaerobic treatment process for individual households. Figure 5 This is a flowchart of a combined wastewater treatment device for a central village high-standard model of sewage treatment and solar micro-power system, according to one embodiment of the present invention. Figure 6 This is a schematic diagram illustrating the switching of the working state of a pluggable partition in a combined wastewater treatment device according to an embodiment of the present invention. Figure 7 This is a schematic diagram of the backwashing operation process of the ecological purification unit of a combined wastewater treatment device according to an embodiment of the present invention. Figure 8 This is a schematic diagram illustrating the working principle of a liquid level monitoring and overflow alarm system for a combined wastewater treatment device according to an embodiment of the present invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1: like Figures 1 to 8As shown, one embodiment of the present invention presents a combined wastewater treatment device suitable for scattered farmhouses in mountainous and hilly areas. This embodiment targets typical mountainous rural areas in central and western my country, where farmhouses are scattered, with individual households more than 200 meters apart, and the terrain is undulating, lacking the conditions for laying pipelines. Farmhouse households typically have 3-5 members, generating an average of 0.3-0.5 cubic meters of wastewater daily, mainly consisting of toilet waste (black water) and kitchen washing wastewater (grey water). The surrounding area has vegetable gardens or orchards, providing land suitable for wastewater resource utilization.

[0029] The equipment combination used in this embodiment is: pretreatment unit + micro ecological purification unit + water storage and reuse unit, omitting the anaerobic treatment unit.

[0030] The pretreatment unit is placed on higher ground outside the farmer's house, while the micro-ecological purification unit and the water storage and reuse unit are placed on lower ground next to the courtyard and vegetable garden. The three units are connected in series by gravity flow through a DN110 PVC pipe. The outlet of the pretreatment unit is directly connected to the water distribution pipe of the micro-ecological purification unit, and the water collection pipe of the micro-ecological purification unit is connected to the inlet of the water storage and reuse unit.

[0031] The pretreatment unit uses a 1.5 cubic meter PE plastic tank. The black water inlet connects to the outlet of the farmer's three-compartment septic tank; the grey water inlet connects to the kitchen drainage ditch. In the internal mixing zone, the vertical baffle in the pluggable partition is pulled out (opened), and the horizontal baffle is inserted (closed), allowing the black water and grey water to mix in the mixing zone to dilute the high concentration of organic matter in the black water and prevent subsequent blockages. The grease trap downstream of the grey water inlet uses inclined tube packing to intercept vegetable leaves, food scraps, and grease, and is cleaned weekly.

[0032] The micro-ecological purification unit measures 1.2 meters long × 0.6 meters wide × 0.8 meters high and is made of fiberglass. From bottom to top, it consists of: a 0.2-meter-thick layer of gravel drainage (20-30mm particle size), a 0.2-meter-thick layer of coarse sand (2-5mm particle size), and a 0.3-meter-thick layer of soil. A PVC water distribution pipe with a 3% porosity is buried at the interface between the coarse sand and soil layers. Native plants with well-developed root systems, such as canna lilies or irises, are planted on top of the soil layer. A backwash pipe is pre-installed at the bottom, connecting to a water storage and reuse unit.

[0033] The water storage and reuse unit is a 0.5 cubic meter plastic tank, buried underground. A quick-connect fitting is installed at the bottom irrigation outlet valve, connecting to a hose for watering vegetables.

[0034] Workflow and technical parameters: During the morning period (7:00-9:00): Grey water generated from farmers' washing and kitchen use is filtered to remove grease and suspended solids before entering the mixing zone. Simultaneously, black water from toilet flushing, after preliminary fermentation in the septic tank, also enters the mixing zone. The combined COD is approximately 300-400 mg / L.

[0035] Gravity flow transport: Mixed wastewater flows into the micro-ecological purification unit by relying on the natural slope (not less than 0.5%).

[0036] Ecological treatment: Wastewater is evenly infiltrated into the soil and coarse sand layers through distribution pipes. Through soil capillary action and oxygen secretion from plant roots, organic matter in the wastewater is decomposed by microorganisms, and ammonia nitrogen is absorbed by plants. The hydraulic load is controlled at 0.2m. 3 / (m 2 ·d).

[0037] Effluent and Reuse: The treated effluent is collected in the gravel drainage layer and flows into the water storage and reuse unit. The effluent COD ≤ 100 mg / L and suspended solids ≤ 30 mg / L, meeting the "Standards for Irrigation Water Quality" (GB5084-2021).

[0038] Maintenance: Every 3 months, open the backwash valve and use the wastewater from the water storage and reuse unit to backwash the micro-ecological purification unit for 5 minutes to prevent soil compaction. Harvest the above-ground parts of the plants before each winter.

[0039] This embodiment achieves on-site full collection, treatment, and reuse of sewage from a single household. The construction cost is approximately 1800 yuan per household, requiring no electricity consumption, and the annual operation and maintenance cost is only 50 yuan (mainly for replanting). Compared to the traditional model of constructing a three-chamber septic tank with regular cleaning, this embodiment solves the problem of direct discharge of greywater into alleyways, and farmers can obtain liquid fertilizer free of charge, saving approximately 200 yuan in fertilizer expenses annually, resulting in high villager satisfaction.

[0040] Example 2: This example focuses on a typical hilly village in Southwest China, with 15 households distributed along a mountainside, totaling approximately 60 people. The daily wastewater volume is about 6-8 cubic meters. There is a collective vegetable garden within the village. Due to elevation differences, connection to urban water supply networks is not feasible, but a small-scale centralized treatment facility can be constructed. The environment is not within a strictly protected water source area, allowing for compliant discharge or reuse.

[0041] The equipment combination used in this embodiment is: pretreatment unit + anaerobic treatment unit + ecological purification unit + water storage and reuse unit.

[0042] Connection Relationship: A hybrid "series + parallel" connection is adopted. Due to the scattered nature of the villages, three pretreatment units are set up in the upper, middle, and lower sections of the villages, respectively, and the water is collected through a branch network to the central treatment station at the lowest point of the terrain. In the central treatment station, the effluent from the three pretreatment units is first combined into a main influent regulating tank (an extension of the pretreatment units), and then sequentially connected in series into a set of parallel anaerobic treatment units (two individual anaerobic units are connected in parallel due to the large water volume), followed by a series connection into the ecological purification unit, and finally into the water storage and reuse unit.

[0043] Internal structural additions: Anaerobic treatment unit: Made of corrosion-resistant carbon steel, each unit has a volume of 6 cubic meters and is equipped with 5 sets of staggered upper and lower baffles to form 6 baffle chambers. Each chamber is filled with suspended polyurethane biological packing material (biological packing layer), with a filling rate of 30%. A biogas exhaust port is set at the top, connected to an exhaust pipe 2 meters above the ground.

[0044] Ecological purification unit: A horizontal subsurface flow constructed wetland, measuring 8 meters long × 3 meters wide × 1 meter deep. A geomembrane is laid at the bottom. Internal filling: a 0.4-meter-thick layer of crushed stone (bottom), a 0.3-meter-thick layer of coarse sand (middle), and a 0.2-meter-thick layer of expanded clay (top). Water distribution pipes are located at the upper front of the wetland, and water collection pipes are located at the bottom of the wetland's end, forming a horizontal plug flow.

[0045] Workflow and technical parameters: Collection and Pretreatment: Wastewater from each household flows by gravity into the pretreatment unit of their respective area. At this stage, the oil-water separator and grit chamber intercepts most of the suspended solids, and the removable baffles are set to a black and gray mixing mode.

[0046] Anaerobic biological treatment: Mixed wastewater enters parallel anaerobic treatment units. The wastewater is deflected vertically by baffles, ensuring full contact with the biological packing layer. The deflection chambers are clearly zoned: the front chamber primarily performs hydrolysis and acidification, while the rear chamber performs methanogenesis. The hydraulic retention time (HRT) is 36 hours. During this stage, COD removal rates can reach 70%–80%, and BOD removal rates can reach 85%.

[0047] Ecological deep treatment: Anaerobic effluent enters the ecological purification unit. Wastewater flows horizontally within the packing layer, where plant roots and the biofilm on the packing surface further degrade organic matter and ammonia nitrogen. The hydraulic retention time is 24 hours. During this stage, ammonia nitrogen removal rate can reach 60%, and total phosphorus removal rate can reach 50%.

[0048] Wastewater discharge: The final effluent enters the water storage and reuse unit. Since this embodiment is located near the vegetable field, the water storage and reuse unit is designed with a volume of 20 cubic meters. The water quality meets the Class I standard of the "Water Pollutant Discharge Standard for Rural Domestic Sewage Treatment Facilities" (DB51 / 2626-2019). It is used for irrigation of the vegetable field in summer and discharged into the downstream ditch via an overflow pipe in winter.

[0049] This embodiment solved the sewage treatment problem for 15 connected households. The construction cost was approximately 45,000 yuan (3,000 yuan per household), with the main energy consumption being a very small amount of electricity used for nighttime lighting. Although the biogas produced by the anaerobic unit is small in quantity, it is safely released through the exhaust pipe, posing no safety risk. Operation and maintenance are handled part-time by a village sanitation worker, who cleans the screens weekly and removes sludge every six months. This achieved low-cost improvement of the area's water environment.

[0050] Example 3: This example focuses on a village upstream of a water source in East China with a dense network of waterways, which is also a key village for rural tourism. The village is concentrated, with 120 households and approximately 450 people, plus 5 guesthouses. The daily wastewater volume is approximately 50-60 tons, with significant fluctuations in water quality and a high proportion of restaurant wastewater. Environmental protection requirements are stringent; effluent must meet the Class A standard of the "Discharge Standard of Pollutants for Urban Wastewater Treatment Plants" (GB18918-2002), and some indicators must exceed this standard.

[0051] This embodiment adopts a complete combination of elements: pretreatment unit (enhanced type) + multiple anaerobic treatment units + solar micro-power aeration system + ecological purification unit (vertical subsurface flow wetland) + water storage and reuse unit.

[0052] Connections: The pretreatment unit is expanded to 20 cubic meters, integrating a mechanical bar screen and an oil separator. Four anaerobic treatment units are connected in parallel (total volume 40 cubic meters). The innovation lies in inserting a solar-powered micro-aeration system between the anaerobic treatment unit and the ecological purification unit, which elevates the anaerobic effluent to an aerobic contact oxidation tank (integrated into the downstream section of the anaerobic unit or a separate module) before it enters the ecological purification unit.

[0053] Structural improvements: Solar-powered micro-powered aeration system: Installed on top of the ecological purification unit, it includes a 200W photovoltaic panel, a 12V / 100Ah battery, and a DC micro air pump. The air pump supplies air to the aerobic tank through the aeration discs, maintaining dissolved oxygen at 2-3 mg / L.

[0054] Ecological purification unit: Employs a vertical subsurface flow wetland with an area of ​​80 square meters. Controlled by valves, it achieves alternating "downward flow - upward flow" operation to enhance nitrogen and phosphorus removal efficiency. It is filled with a special phosphorus removal packing material (steel slag + zeolite).

[0055] Automatic control: An electrical control cabinet is installed in the water storage and reuse unit. When the water level reaches the high level, the ultraviolet disinfection device is automatically activated (optional). After meeting the standards, the water is discharged into the landscape river.

[0056] Workflow and technical parameters: Enhanced pretreatment: Restaurant wastewater is pretreated in an grease trap before being mixed with domestic sewage. Mechanical bar screens remove large debris.

[0057] Hydrolysis acidification: Wastewater undergoes hydrolysis acidification in the anaerobic treatment unit, converting large organic molecules into small volatile fatty acids and improving biodegradability. HRT = 24 hours.

[0058] Aerobic Deep Degradation (Core Improvement): Anaerobic effluent enters the aerobic contact oxidation tank. The solar-powered micro-powered aeration system is powered by photovoltaics during the day and charges the storage battery, while at night it is powered by the storage battery, ensuring 24-hour intermittent aeration (2 hours of aeration followed by 1 hour of rest). During this stage, nitrifying bacteria oxidize ammonia nitrogen to nitrate nitrogen, reducing the organic pollutant COD to below 50 mg / L.

[0059] Ecological fine filtration: Aerobic effluent enters a vertical subsurface flow wetland. Since most organic matter has been removed upstream, the wetland primarily performs denitrification and phosphorus removal. By adjusting the wetland water level to create an oxygen-deficient environment, denitrifying bacteria utilize residual organic matter to reduce nitrate nitrogen to nitrogen gas. Effluent total nitrogen <15 mg / L, total phosphorus <0.5 mg / L.

[0060] Disinfection and discharge: The water storage and reuse unit collects the wastewater, which is then disinfected with ultraviolet light. Part of the wastewater is used for village greening and street washing, while the remainder is discharged into the landscape river, effectively supplementing the ecological base flow.

[0061] Although this embodiment incorporates a micro-power system, it utilizes solar power, resulting in near-zero annual electricity consumption, with only the battery requiring replacement every three years. Compared to integrated equipment employing the AAO process (annual electricity cost of approximately 20,000 yuan), this embodiment incurs almost no electricity expenses. The effluent quality consistently meets Class A standards, and the wetland landscape becomes a scenic feature of the village, promoting rural tourism development. This model demonstrates the feasibility of the "ecological treatment as the primary method, supplemented by micro-power" approach under stringent environmental requirements, achieving a balance between economic efficiency and environmental standards.

[0062] Obviously, the above-described embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A combined wastewater treatment device, characterized in that, Including those that can be detachably connected via flange interfaces in sequence according to the direction of water flow: The pretreatment unit is provided with a black water inlet, a grey water inlet and a mixing zone located inside, wherein a pluggable partition is provided in the mixing zone for selectively isolating or connecting the black water and grey water flow paths. The anaerobic treatment unit is connected to the outlet of the pretreatment unit. It has a baffle structure inside, with multiple sets of staggered guide plates and a biological packing layer with attached microorganisms. The ecological purification unit has its inlet connected to the outlet of the anaerobic treatment unit. The ecological purification unit is a modular artificial wetland box, which is provided with a plant layer, a soil layer, a coarse sand layer and a gravel drainage layer from top to bottom, and is equipped with a water distribution pipe and a water collection pipe inside. The water storage and reuse unit has an inlet connected to the water collection pipe of the ecological purification unit. The water storage and reuse unit is equipped with an irrigation outlet valve at the bottom and an overflow pipe at the top.

2. The combined wastewater treatment equipment as described in claim 1, characterized in that, The pretreatment unit also includes an oil-water separation and sedimentation zone located downstream of the grey water inlet, which is equipped with an inclined plate sedimentation assembly and an oil interception net.

3. The combined wastewater treatment equipment as described in claim 1, characterized in that, The anaerobic treatment unit is equipped with a biogas exhaust port at the top and a sludge discharge pipe at the bottom; the guide plate divides the interior of the unit into multiple series-connected baffle chambers, and the biological packing layer is fixedly installed in the baffle chambers. The packing material is polyurethane sponge or porous ceramic.

4. The combined wastewater treatment equipment as described in claim 1, characterized in that, The bottom of the ecological purification unit is equipped with a backwash pipe, which is connected upstream of the irrigation outlet valve of the water storage and reuse unit via a pipeline, and a backwash valve is installed on the pipeline.

5. The combined wastewater treatment equipment as described in claim 1, characterized in that, The equipment also includes a solar-powered micro-aeration system, which comprises a photovoltaic panel, a battery, and a micro air pump. The outlet of the micro air pump is connected to the bottom of the anaerobic treatment unit or the ecological purification unit via a pipe.

6. The combined wastewater treatment equipment as described in claim 1, characterized in that, The pluggable partition includes a vertical insert and a horizontal baffle; when the vertical insert is closed and the horizontal baffle is open, black water and grey water are mixed in the mixing zone; when the vertical insert is open and the horizontal baffle is closed, black water and grey water are diverted and enter the subsequent units independently.

7. The combined wastewater treatment equipment as described in claim 1, characterized in that, The pretreatment unit is equipped with casters or leveling feet at the bottom to adapt to the slope requirements of different terrains.

8. The combined wastewater treatment equipment as described in claim 1, characterized in that, The water storage and reuse unit is equipped with a liquid level sensor, which is electrically connected to an alarm to issue an audible and visual alarm when the liquid level exceeds the overflow pipe.

9. A single-household treatment mode based on the combined wastewater treatment equipment according to any one of claims 1 to 8, characterized in that: It connects only a pretreatment unit and a miniaturized ecological purification unit, omitting the anaerobic treatment unit. The plant layer of the ecological purification unit is directly planted in the farmer's courtyard, and the water collection pipe is directly connected to the water storage and reuse unit for irrigating the vegetable garden.

10. A centralized treatment mode based on the combined wastewater treatment equipment according to any one of claims 1 to 8, characterized in that: Three to five anaerobic treatment units are set up in parallel, and a solar-powered micro-aeration system is connected in series between the anaerobic treatment units and the ecological purification units. The ecological purification units adopt a vertical subsurface flow wetland structure, and the treated effluent meets the Class B standard before being discharged into the village landscape water body or used for farmland irrigation.

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