A non-powered prefabricated wastewater purification and reuse system for rural households

Abstract

This utility model discloses a non-powered prefabricated rural wastewater purification and reuse system, relating to the field of rural wastewater treatment technology. The device includes a prefabricated wastewater purification tank arranged fully or semi-underground, and a reuse tank connected to its outlet. A primary sedimentation tank is located at the center of the prefabricated wastewater purification tank, with multi-level layered biological filter media modules filling the space between the primary sedimentation tank and the tank wall. The system utilizes gravity flow, atmospheric pressure difference, and infiltration negative pressure to achieve non-powered operation and natural oxygen supply through an inlet pipe, a primary sedimentation water distribution device, a water collection system, and a ventilation system above ground level. The biological filter media modules employ a combination of vertical infiltration and lateral flow for anti-clogging purification. This utility model has advantages such as zero power consumption, no need for professional operation and maintenance, high land utilization, short construction period, and adaptability to the intermittent drainage characteristics of rural areas, effectively solving the problems of high energy consumption, difficult maintenance, and poor environmental compatibility in rural wastewater treatment.

Description

Technical Field

[0001] This utility model relates to the field of rural sewage treatment technology, and in particular to a non-powered prefabricated sewage purification and reuse system for rural households. Background Technology

[0002] Rural decentralized sewage treatment is characterized by "small water volume, scattered distribution, and weak operation and maintenance capabilities." Existing technologies mostly use fiberglass / PE biological combination tanks (anaerobic + anoxic + aerobic + sedimentation), but in practical applications, the following core pain points exist: Energy consumption and operation and maintenance contradiction: The existing system relies on aeration devices for oxygen supply, with an average daily power consumption of about 0.5 kWh. In rural areas, there is a lack of dedicated personnel to handle electricity costs and equipment maintenance, resulting in more than 80% of the equipment being idle after construction ("sunbathing" phenomenon). High maintenance threshold: Microbial community metabolism depends on water quality adaptation and regular adjustments, requiring professional personnel to conduct quarterly inspections and maintenance. This is out of touch with the reality that farmers "lack maintenance capabilities," and the equipment is prone to failure due to microbial imbalance. Waste of land resources: Existing equipment is mostly semi-underground or surface-mounted, with no effective design for utilizing the top. Given the scarcity of land in rural areas, farmers have strong resistance to this. Poor adaptability: Traditional equipment is designed for continuous operation. The intermittent drainage characteristics of rural areas, such as "high water volume during holidays and low water volume / no water on weekdays," result in long equipment start-up cycles (requiring 24-48 hours to restore treatment efficiency). Insufficient environmental coordination: The equipment is isolated from the surrounding environment such as farmland and courtyards, leading to low acceptance among farmers. The current national rural sewage treatment plan clearly requires a technical approach of "low cost, easy maintenance, and high adaptability." Existing equipment cannot meet these requirements, so there is an urgent need for a new treatment system that can solve the four core problems of "energy consumption, maintenance, land occupation, and adaptability." Utility Model Content

[0003] This utility model provides a non-powered, prefabricated wastewater purification and reuse device for rural households, the structure of which and its connection relationships are as follows: 1. Overall Layout Structure The device includes a prefabricated wastewater purification tank and a reuse tank. The prefabricated sewage purification tank is buried fully or semi-underground, with its top elevation within 0.5m below the ground surface; the tank structure is a modular prefabricated structure, and the material can be selected from brick-concrete structure, steel structure or reinforced PE material. Green plant modules are laid on top of the prefabricated sewage treatment tank for planting; a fence is set up around the ground surface to form an integrated layout of underground treatment and above-ground landscape.

[0004] 2. Inlet and Primary Sedimentation Unit A primary sedimentation tank is provided at the center of the prefabricated sewage purification tank. The external sewage network is connected to the inlet pipe interface and is connected to the interior of the primary sedimentation tank through the inlet pipe passing through the tank body; the inlet pipe is made of UPVC material with a diameter of DN150-300. The upper part of the primary sedimentation tank is equipped with a primary sedimentation device, which is a UPVC pipe with a diameter of DN200-300. It also has a water distribution function, which is used to evenly distribute the supernatant after primary sedimentation to the surrounding biological filter media modules.

[0005] 3. Biological filter media purification unit The annular or square space between the primary sedimentation tank and the inner wall of the prefabricated wastewater purification tank is filled with biological filter media modules. The biological filter module adopts a multi-level layered structure, which includes, from top to bottom: a covering layer, a ventilation layer, an upper anti-clogging layer, a lower ventilation layer, a lower anti-clogging layer, a fine filtration layer, and a drainage layer. The biological filter media module has gravel channels connecting the water-spreading layer and the ventilation layer. After the sewage enters, part of it is vertically filtered through the anti-clogging packing under the action of gravity. The other part of the sewage that cannot be filtered in time flows laterally in the water-spreading layer packing and enters the lower anti-clogging layer through the gravel channels as a secondary water-spreading channel. This combination of vertical flow and lateral flow achieves a high degree of dispersion and multi-stage interception of pollutant load.

[0006] 4. Non-powered ventilation system The device is equipped with an exhaust pipe and a vent pipe with a diameter of DN50-150; The bottom of the exhaust pipe and the vent pipe extend into the ventilation layer of the bio-filter module, and the top is 1.5m above the ground surface; the top of the exhaust pipe is equipped with a ventilation cap made of 201 stainless steel. By utilizing the atmospheric pressure difference created by the pipes above the ground, combined with the negative pressure generated during the sewage infiltration process, natural air circulation is achieved within the filter media layer, creating an alternating "anaerobic-anoxic-aerobic" microenvironment at the microbial membrane of the fine filtration layer, eliminating the need for electric aeration.

[0007] 5. Water Discharge and Reuse Unit The drainage layer at the bottom of the biological filter module is connected to a water collection system. The water collection system collects the purified effluent and flows by gravity into the reuse tank through the water outlet pipe interface (DN150-300, UPVC material). The recycling tank is made of PE material, has a diameter of approximately 1000mm, a height of approximately 2.5m, and is buried underground. The reuse tank extends to the wellhead on the ground and is equipped with a mechanical reuse device, which is a manual water pump made of SS304 material, used to manually extract reused water for irrigation or flushing.

[0008] 6. Operating Mode This device is designed for intermittent operation (6-8 hours per cycle), which is suitable for the drainage characteristics of rural areas, such as high water volume during holidays and low water volume or no water during normal days. During periods without water, the biofilm enters a dormant state and can restore its treatment efficiency 2-4 hours after rehydration.

[0009] Compared with the prior art, the beneficial effects of this utility model are: 1) The system is powered without any power and uses natural ventilation to supply oxygen, which solves the pain point of "being able to build it but not being able to use it"; no professional personnel are required to adjust the microbial community, and only the primary sedimentation tank needs to be cleaned once every 3-6 months, which greatly reduces the maintenance threshold.

[0010] 2) Through special filter media gradation and "vertical + lateral" three-dimensional flow design, the pollutant load is effectively dispersed and the anti-clogging ability is enhanced; the system is specially designed for the intermittent drainage characteristics of rural areas, and can quickly recover after dormancy and adapt to the fluctuation of water volume during holidays.

[0011] 3) The entire underground layout combined with rooftop greening (100% land utilization) and the fence design transform the sewage treatment facility into a courtyard landscape, eliminating the NIMBY effect for farmers.

[0012] 4) Equipped with non-powered mechanical reuse equipment, the effluent meets reuse standards and can be directly used for farmland irrigation or courtyard watering, realizing the on-site recycling of water resources.

[0013] 5) The modular prefabricated assembly structure shortens the construction period by more than 50% compared with the traditional cast-in-place process, and has low construction cost, making it suitable for mass promotion in scattered farmer scenarios. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a plan view of the wastewater purification tank of this utility model; Figure 2 This is an elevation view of the prefabricated sewage purification tank of this utility model; Figure 3 Here is a detailed drawing of the biological filter media module of this utility model; Figure 4 This is a schematic cross-sectional view of the system of this utility model.

[0015] Attached reference numerals: 1 Prefabricated wastewater purification tank; 2 Primary sedimentation tank; 3 Inlet pipe interface; 4 Inlet pipe; 5 Primary sedimentation device; 6 Biological filter media module; 7 Outlet pipe interface; 8 Exhaust pipe; 9 Ventilation pipe; 10 Fence / railway; 11 Green plant module; 12 Reuse tank; 13 Mechanical reuse equipment. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] I. Overall System Structure like Figure 1 , Figure 2 and Figure 4 As shown, the present invention provides a non-powered prefabricated household sewage purification and reuse device, which mainly consists of a prefabricated sewage purification tank 1, a primary sedimentation tank 2, a biological filter media module 6, a ventilation system, a surface greening component, and a reuse system.

[0018] Prefabricated wastewater treatment tank: The prefabricated sewage purification tank 1 serves as the main structure and is buried underground or semi-underground. The top elevation of the tank is 0.5m below the ground surface. The tank structure can be made of brick-concrete structure, steel structure, or modular prefabricated components reinforced with PE material, which are assembled on site, effectively shortening the construction period by more than 50%.

[0019] Primary sedimentation and water distribution system: The primary sedimentation tank 2 is located in the center of the prefabricated sewage purification tank 1. External sewage (household kitchen sewage, toilet sewage and septic tank effluent) is collected through the existing sewage pipe and introduced into the primary sedimentation tank 2 through the inlet pipe interface 3 and the inlet pipe 4 (DN150-300, UPVC material).

[0020] The primary sedimentation tank 2 is equipped with a primary sedimentation device 5 (DN200-300, UPVC material) at the top, which serves as a water distribution device to evenly distribute the supernatant after sedimentation to the top of the surrounding biological filter media module 6, so as to avoid local overload leading to blockage.

[0021] Biological filter media module: like Figure 3 and Figure 4 As shown, the biological filter media module 6 fills the space between the inner walls of the primary sedimentation tank 2 and the purification tank 1; the module adopts a multi-level layered design, which includes, from top to bottom: a covering layer, an upper ventilation layer, an upper anti-clogging layer, a lower ventilation layer, a lower anti-clogging layer, a fine filtration layer, and a drainage layer.

[0022] Anti-clogging mechanism: The module is equipped with gravel channels (equivalent to secondary drainage channels) connecting the drainage layer and the ventilation layer. When sewage enters the biological infiltration unit, a portion of it is vertically filtered through the anti-clogging packing under gravity; the sewage that cannot be filtered in time flows laterally in the drainage layer packing and enters the lower anti-clogging layer through the gravel channels. This design highly disperses the pollutant load (especially suspended particulate matter), and combined with the interception of different particle size packing and the decomposition of microbial films, it greatly improves the system's anti-clogging capability.

[0023] Ventilation system (non-powered oxygen supply): The system is equipped with an exhaust pipe 8 and a ventilation pipe 9 (DN50-150), with the top of the pipe 1.5m above the ground. The exhaust pipe 8 is fitted with a 201 stainless steel ventilation cap. The bottom of the pipe extends to the ventilation layer of the biological filter module 6. The system utilizes atmospheric pressure difference and the negative pressure generated by sewage infiltration to achieve natural air circulation, providing oxygen to the microbial membrane of the fine filter layer and forming an alternating "anaerobic-anoxic-aerobic" microenvironment inside the filter media, without the need for electric aeration.

[0024] Surface greening and reuse system: The top of the prefabricated sewage treatment tank 1 is covered with green plant modules 11 (general specifications 500*400*300mm), and a PVC fence 10 with a height of 0.3-0.5m is set around it to form a layout of "underground treatment + above-ground greening".

[0025] The purified water is collected through the bottom water collection system and flows to the reuse tank 12 through the water outlet interface 7. The reuse tank 12 is a PE material tank with a diameter of 1000mm and a height of 2.5m; the top of the tank is equipped with a mechanical reuse device 13 (SS304 material manual water pump) for farmers to manually pump out the purified water for farmland irrigation or yard watering, realizing on-site resource utilization.

[0026] II. Operating Parameters and Implementation Results This device is designed for intermittent operation, with a single cycle of 6-8 hours. During holidays when there is a high water volume, it can continuously receive water. During normal days when there is a low water volume or no water, the biofilm is in a dormant state and can recover its efficiency in 2-4 hours after rehydration.

[0027] 1. Influent and effluent water quality indicators In this embodiment, the influent water quality is designed with reference to the typical water quality of rural black water and grey water after collection. After treatment by this system, the effluent water quality indicators are as follows: Influent water quality: CODcr≤350mg / L; BOD5≤180mg / L; SS≤200mg / L; Ammonia nitrogen≤35mg / L; Total nitrogen≤45mg / L; Total phosphorus≤5mg / L; pH: 6-9.

[0028] Effluent water quality: CODcr≤80mg / L; SS≤20mg / L; Ammonia nitrogen≤15mg / L; Total nitrogen≤20mg / L; Total phosphorus≤2mg / L; pH: 6-9.

[0029] The quality of the above-mentioned effluent meets the requirements for farmland irrigation or discharge standards.

[0030] 2. Implementation Scale and Selection This utility model supports both single-household and multi-household modes. The specific implementation specifications of the system are shown in the table below, depending on the number of households: Table 1: Estimated Water Consumption for Joint Households Table 2: Process Design Specifications (Note: Design load 0.2-0.4 m³ / m²·d, wet-dry ratio 1:7) III. Maintenance Instructions Cleaning and maintenance: The sediment (sludge) in the primary sedimentation tank 2 only needs to be cleaned once every 3-6 months through the reserved cleaning port, which is the same frequency as traditional septic tanks.

[0031] Routine maintenance: The system has no powered components and no daily electricity costs. The mechanical recycling equipment 13 has a simple structure and can be operated by farmers themselves.

[0032] Seasonal adaptability: The system is entirely underground and covered with a green layer, providing good thermal insulation and enabling it to operate in winter.

[0033] The above-described embodiments are merely examples of several implementations of this utility model, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this utility model patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. A non-powered, prefabricated household wastewater purification and reuse system, characterized in that, It includes a prefabricated wastewater purification tank (1) and a reuse tank (12) connected thereto; The prefabricated sewage purification tank (1) is arranged in a fully underground or semi-underground manner, and a primary sedimentation tank (2) is set in the center of its interior. The space between the primary sedimentation tank (2) and the inner wall of the prefabricated sewage purification tank (1) is filled with biological filter media modules (6). The system also includes: The water inlet system includes an inlet pipe (4) that passes through the prefabricated sewage purification tank (1) and connects to the interior of the primary sedimentation tank (2); Water distribution device: The primary sedimentation tank (2) is equipped with a primary sedimentation device (5) at the top, which is used to evenly distribute the sewage that has undergone primary sedimentation to the top of the biological filter media module (6). The water collection and drainage system, located at the bottom of the biological filter module (6), is used to collect the filtered water and discharge it through the outlet pipe interface (7); The ventilation system includes an exhaust pipe (8) and a vent pipe (9) that connect to the atmosphere, for creating natural air circulation within the pool; The outlet pipe interface (7) is connected to the reuse tank (12) through a pipeline. The reuse tank (12) is equipped with a mechanical reuse device (13) for extracting reused water.

2. The non-powered prefabricated household wastewater purification and reuse system according to claim 1, characterized in that, The biological filter module (6) adopts a layered structure, which includes, from top to bottom, a covering layer, an upper ventilation layer, an upper anti-clogging layer, a lower ventilation layer, a lower anti-clogging layer, a fine filtration layer, and a drainage layer; The effluent from the primary sedimentation device (5) enters the upper anti-clogging layer and / or the diffuser layer. The sewage is vertically filtered under gravity and undergoes a combination of lateral and vertical flow through fillers of different particle sizes.

3. The non-powered prefabricated household wastewater purification and reuse system according to claim 2, characterized in that, The biological filter module (6) is provided with a gravel channel connecting the water distribution layer and the ventilation layer, forming a secondary water distribution channel, so that sewage that has not been vertically filtered in time can flow laterally and enter the lower anti-clogging layer through the gravel channel.

4. The non-powered prefabricated household wastewater purification and reuse system according to claim 1, characterized in that, The ventilation system utilizes atmospheric pressure difference and negative pressure generated by sewage infiltration to achieve oxygen supply without power. The top of the exhaust pipe (8) and the ventilation pipe (9) are higher than the ground level, and the bottom extends to the ventilation layer of the biological filter module (6), forming a microenvironment with alternating anaerobic, hypoxic and aerobic conditions inside the biological filter module (6).

5. A non-powered prefabricated household wastewater purification and reuse system according to claim 1, characterized in that, The top of the prefabricated sewage purification tank (1) is covered with green plant modules (11), which are planted with plants, and the top elevation of the prefabricated sewage purification tank (1) is within 0.5m below the ground surface. The prefabricated sewage purification tank (1) is surrounded by a fence (10) on the ground surface.

6. The non-powered prefabricated household wastewater purification and reuse system according to claim 1, characterized in that, The reuse tank (12) is a PE material tank and is buried underground; the mechanical reuse device (13) is a stainless steel manual water pump and is installed at the wellhead of the reuse tank (12) extending out of the ground.

7. The non-powered prefabricated household wastewater purification and reuse system according to claim 1, characterized in that, The main structure of the prefabricated sewage purification tank (1) is assembled on-site using modular prefabricated components. The material of the modular prefabricated components includes one of brick-concrete structure, steel structure or reinforced PE material.

8. A non-powered prefabricated household wastewater purification and reuse system according to claim 4, characterized in that, The top of the exhaust pipe (8) and the ventilation pipe (9) is 1.5m above the ground surface, and the top of the exhaust pipe (8) is equipped with a ventilation cap.

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