High-efficiency integrated sewage treatment equipment and process thereof

Abstract

This invention relates to the field of wastewater treatment technology and discloses a high-efficiency integrated wastewater treatment equipment and its process. The wastewater treatment equipment includes a main body containing several anaerobic tanks connected in series along the water flow direction, and a filtration and sedimentation tank located downstream of the anaerobic tanks. The main body also includes biological packing material, an aeration device, and a sludge return device. This invention, through the synergistic effect of a specific combination of biological packing material and a decreasing aeration gradient, constructs a stable aerobic-anoxic-anaerobic composite microenvironment within the equipment, achieving efficient simultaneous nitrification and denitrification, improving nitrogen and phosphorus removal efficiency, and helping to ensure stable effluent quality. Simultaneously, returning sludge from the sludge return zone to the front end maintains a high microbial concentration in the front-end reaction zone, contributing to improved system treatment efficiency and stability.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to a high-efficiency integrated wastewater treatment equipment and its process. Background Technology

[0002] With the advancement of new rural construction, the effective treatment of rural domestic sewage has become crucial for improving the living environment. Currently, integrated sewage treatment equipment is receiving widespread attention due to its small footprint and convenient installation. Existing integrated equipment typically integrates multiple treatment units such as anaerobic, anoxic, and aerobic processes, and improves treatment efficiency by filling them with biological packing materials.

[0003] However, these existing technologies still have some shortcomings: First, the combination and arrangement of their packing materials are relatively conventional, failing to be finely configured according to the water flow path and pollutant degradation gradient, resulting in unclear functional zoning of the microbial community and room for improvement in treatment efficiency; second, their aeration methods are usually relatively extensive, making it difficult to accurately construct a complex microenvironment in a compact tank that accommodates both nitrification and denitrification, resulting in unstable nitrogen and phosphorus removal effects and high energy consumption; finally, their sludge return path and control methods are relatively simple, failing to precisely match the needs of the front-end treatment unit, affecting the stability and treatment efficiency of the entire system.

[0004] Therefore, existing technologies still have considerable room for improvement in achieving efficient simultaneous nitrification and denitrification, reducing operating costs, decreasing sludge production, and enhancing the stability of effluent quality. Summary of the Invention

[0005] In view of this, the present invention proposes a high-efficiency integrated sewage treatment equipment and process, aiming to solve the problems of high cost, large amount of sludge, and unstable water quality in the existing integrated sewage treatment equipment and process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] First, the present invention provides a high-efficiency integrated sewage treatment device, including a main body of the device. The main body of the device has an inlet pipe and an outlet pipe for guiding sewage to flow through the main body of the device from front to back. Several anoxic tanks connected in series and a filtration sedimentation tank located downstream of the anoxic tanks are arranged sequentially in the main body of the device along the water flow direction. The upper front side of the anoxic tank at the front end is connected to the inlet pipe, and the upper rear side of the filtration sedimentation tank is connected to the outlet pipe. The main body of the device also includes: Biological packing material is used in all the anoxic tanks. The biological packing material in the front anoxic tank is of a different type than that in the rear anoxic tank along the water flow direction. An aeration device is provided for supplying air to the anaerobic tank, and the aeration device is configured to form an aeration gradient that decreases along the direction of water flow in several of the anaerobic tanks. The sludge return device has a sludge return zone at the bottom of the facultative tank at the rear end. The rear end of the sludge return zone is connected to the filtration sedimentation tank. The sludge return device is used to return the flocculated sludge settled in the sludge return zone to the facultative tank at the front end.

[0008] Preferably, the main body of the equipment is provided with three anoxic tank zones I, II, and III, separated by a grid plate, arranged sequentially along the water flow direction. The anoxic tank zone I is filled with spherical packing material, and the anoxic tank zones II and III are filled with curtain-type packing material.

[0009] Preferably, the spherical packing is polyurethane spherical packing, and the curtain packing is high-density curtain packing.

[0010] Preferably, the anoxic tank III zone and the filtration sedimentation tank are separated by a drop zone formed by two side grid plates, and the filtration sedimentation tank is filled with polyethylene granular columnar packing material.

[0011] Preferably, the sludge return device is an airlift internal return device, which uses part of the air source of the aeration device to return sludge from the sludge return zone to the anaerobic tank I zone.

[0012] Preferably, the aeration device includes a blower disposed outside the main body of the equipment, perforated aeration pipes disposed in each of the anaerobic tanks, and valves for adjusting the air volume of each of the perforated aeration pipes. The output end of the blower is connected to each of the perforated aeration pipes, and the aeration volume of the perforated aeration pipes in the anaerobic tank is adjusted by the valves to form an aeration gradient that decreases along the water flow direction.

[0013] Preferably, a flow switch is provided at the outlet pipe, and the flow switch is electrically connected to the aeration device to automatically start or stop the aeration device according to the outlet flow rate.

[0014] Preferably, guide plates are respectively provided on the upper and lower sides of the anoxic tank; the anoxic tank at the front end is also provided with a sludge discharge pipe that can discharge sludge to the outside of the main body of the equipment.

[0015] Preferably, the main body of the equipment is made of fiberglass.

[0016] Secondly, the present invention also provides a highly efficient integrated wastewater treatment process, which uses the above-mentioned highly efficient integrated wastewater treatment equipment and includes the following steps: a) Close the outlet pipe, input a certain amount of sewage through the inlet pipe, and let the sewage flow through several anoxic tanks in sequence, inoculating aerobic microorganisms onto the corresponding biological packing material in the anoxic tanks; b) After the surface of the biological packing material is covered with biofilm, open the outlet pipe and supply air to the anaerobic tank through the aeration device, and form an aeration gradient that decreases along the water flow direction in several anaerobic tanks, creating an aerobic-anoxic-anaerobic environment. c) Wastewater enters the filtration and sedimentation tank from the bottom of the last anoxic tank. The sludge in the tank settles into the sludge return zone at the bottom of the connection between the anoxic tank and the filtration and sedimentation tank. The sludge return device returns the flocculated sludge settled in the sludge return zone to the first anoxic tank. d) After being filtered in a sedimentation tank, the wastewater becomes clean water that meets the discharge standards and is discharged through the outlet pipe.

[0017] Compared with existing technologies, the high-efficiency integrated wastewater treatment equipment and process of the present invention have the following beneficial effects: (1) High efficiency in nitrogen and phosphorus removal and stable water quality: Several facultative tanks are filled with different types of hydrophilic fillers, which increases the enrichment and biofilm of microorganisms and can more effectively remove organic matter in wastewater. At the same time, through the synergistic effect of specific biological filler combinations and aeration gradients that decrease along the water flow direction, this invention constructs a stable, flow-distributed aerobic-anoxic-anaerobic composite microenvironment inside the equipment, which can effectively remove organic matter, achieve efficient simultaneous nitrification and denitrification reactions, reduce the addition of carbon sources, improve the removal efficiency of pollutants such as nitrogen and phosphorus, and help achieve stable compliance of effluent water quality. It also simplifies the equipment structure, reduces construction and operation costs and maintenance difficulties, and reduces odor generation.

[0018] (2) Low operating cost and energy saving: The aeration device is automatically started and stopped according to the outflow rate by the water flow switch, avoiding energy waste during ineffective operation; the sludge return is carried out by air lifting, eliminating the need to add a sludge pump, which further reduces the energy consumption and maintenance cost of the equipment.

[0019] (3) Low sludge production and easy management: By setting packing material in the filtration sedimentation tank, the removal of suspended solids in the water is enhanced; moreover, the equipment of this invention mainly adopts the biofilm method (biological contact oxidation) for pollutant degradation, which has a lower sludge production rate compared with the traditional activated sludge method, reducing the subsequent sludge disposal costs and management difficulties. The equipment has a simple and compact structure and a high degree of automation, reducing the manpower requirements for daily operation and maintenance. Attached Figure Description

[0020] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of a high-efficiency integrated sewage treatment device according to an embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of three tandem anoxic tanks in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the perforated aeration pipe structure of the aeration device in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the sludge return device in an embodiment of the present invention.

[0025] In the diagram: 1. Anoxic tank zone I; 2. Anoxic tank zone II; 3. Anoxic tank zone III; 4. Filtration sedimentation tank; 5. Inlet pipe; 6. Baffle plate No. 1; 7. Baffle plate No. 2; 8. Baffle plate No. 3; 9. Top cover plate No. 1; 10. Bottom support plate No. 1; 11. Polyurethane spherical packing; 12. High-density curtain packing; 13. Polyethylene granular columnar packing; 14. Reinforced steel bar No. 1; 15. Reinforced steel bar No. 2; 16. Main aeration connection pipe; 17. 18. Auxiliary aeration connecting pipe; 19. Main aeration pipe hole; 20. Sludge return pipe; 21. Flip-type check valve; 22. Pipe cap; 23. Check valve; 24. Ball valve; 25. Flow switch; 26. Water outlet pipe; 27. Air lift pipe; 28. Air lift pipe hole; 29. ​​Air lift sludge return pipe; 30. Pipe clamp; 31. No. 2 upper cover plate; 32. No. 2 lower support plate; 33. Sludge discharge pipe; 34. Main aeration pipe; 35. Auxiliary aeration pipe hole. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] Example: This invention provides a high-efficiency integrated wastewater treatment device and a process for wastewater treatment using this device, aiming to solve problems in existing integrated wastewater treatment devices such as imprecise functional zoning, inaccurate aeration control, low nitrogen and phosphorus removal efficiency, excessive sludge, high operating energy consumption, and unstable effluent quality. This device, through optimized internal structure, packing material combination, and aeration strategy, can efficiently achieve simultaneous nitrification and denitrification, reduce operating costs, and stabilize effluent quality.

[0030] For details, please refer to Figure 1 This embodiment of a high-efficiency integrated wastewater treatment device includes a main body with an inlet pipe 5 and an outlet pipe 25 for guiding wastewater to flow from front to back through the main body. Several anoxic tanks connected in series and a filtration sedimentation tank 4 located downstream of the anoxic tanks are arranged sequentially inside the main body along the water flow direction (that is, the water mixture flowing out of the last anoxic tank will enter the filtration sedimentation tank). The upper front of the anoxic tank is connected to the inlet pipe 5, and the upper rear of the filtration sedimentation tank 4 is connected to the outlet pipe 25.

[0031] The main body of the equipment also includes: biological packing material, aeration device and sludge return device.

[0032] All anoxic tanks are filled with biological packing material to provide a carrier for microorganisms to attach and grow, forming a biofilm. Furthermore, the types of biological packing material set in the front anoxic tanks and the back anoxic tanks are different along the water flow direction. This differentiated arrangement aims to build functionally specialized microbial communities. The front packing material focuses on intercepting and hydrolyzing large organic molecules, while the back packing material focuses on enriching functional microorganisms such as nitrifying and denitrifying bacteria, thereby achieving an optimized spatial configuration of treatment functions.

[0033] The aeration device supplies air to the facultative tanks and is configured to create an aeration gradient that decreases along the water flow direction within several facultative tanks. The purpose of this design is to artificially create various microenvironments, ranging from aerobic to anoxic and even anaerobic, within a compact equipment space. Precise control of this aeration gradient allows aerobic nitrification and anoxic denitrification to occur simultaneously, improving nitrogen removal efficiency and overcoming the challenge of requiring separate aerobic and anoxic tanks in traditional processes.

[0034] The bottom of the final anoxic tank is equipped with a sludge return zone, which is connected to the filtration and sedimentation tank 4 at its rear. The sludge return device is used to return the flocculent sludge settled in the sludge return zone to the front anoxic tank. The purpose of this design is to maintain a high concentration of activated sludge in the front reaction zone. The returned sludge is rich in highly efficient microbial communities that have adapted to the wastewater environment. Sending it back to the front of the system is equivalent to continuously replenishing the system with highly active microbial communities, which helps the system maintain efficient and stable treatment capacity even when the influent load fluctuates, and avoids a decline in treatment effect due to microbial loss.

[0035] In summary, the above-described scheme in this embodiment, by combining different types of biological packing materials with a decreasing aeration gradient, can construct a functionally zoned composite microenvironment with aerobic-anoxic-anaerobic properties within a compact device. This creates favorable conditions for simultaneous nitrification and denitrification, thereby contributing to the efficient removal of pollutants. Simultaneously, this embodiment returns sludge from the sludge return zone to the front end, maintaining a high microbial concentration in the front-end reaction zone, which helps improve the system's treatment efficiency and stability.

[0036] Furthermore, in a preferred embodiment, see [reference] Figure 1 The main body of the equipment is arranged in sequence along the water flow direction, with three anoxic zones: zone I, zone II, and zone III, separated by a grid plate.

[0037] This embodiment physically separates the three anoxic tanks by installing a grid plate. This allows water flow while effectively preventing the mixing of biological packing materials, ensuring that the three anoxic tanks operate as independent reaction units. This method physically guarantees the plug flow characteristics of the water, prevents short-circuiting, and allows wastewater to sequentially and fully contact the specific packing materials and microorganisms in each area, thereby achieving a more stable and controllable staged treatment effect.

[0038] Meanwhile, spherical packing material is used in zone I of the anoxic tank, while curtain-type packing material is used in zones II and III of the anoxic tank. This combination of packing materials with differentiated morphologies is designed to fully utilize the physical and biological characteristics of different packing materials. The spherical packing material at the front end has a large porosity and good hydraulic performance, effectively intercepting suspended solids in the influent and preventing system blockage. Its surface is also suitable for the attachment of hydrolytic acidifying bacteria. The curtain-type packing material at the rear end has a large specific surface area, which can enrich a large number of nitrifying and denitrifying bacteria and other functional microorganisms, enhancing nitrogen and phosphorus removal. Through this functional gradient layout, an optimized transition from coarse to fine treatment of pollutants is achieved, improving overall treatment efficiency.

[0039] Furthermore, the spherical packing is polyurethane spherical packing 11, and the curtain packing is high-density curtain packing 12.

[0040] The polyurethane spherical packing 11 has good hydrophilicity and biocompatibility, which can accelerate the biofilm attachment process; while the high-density curtain packing 12 can provide a larger biofilm attachment surface area, further increasing the biomass in the system, thereby improving the overall treatment load and shock resistance of the equipment.

[0041] Furthermore, in a preferred embodiment, the anoxic tank III zone 3 and the filtration sedimentation tank 4 are separated by a drop zone formed by two side grid plates, and the filtration sedimentation tank 4 is filled with polyethylene granular columnar packing material 13.

[0042] For more details, please refer to Figure 1 , Figure 2 Wastewater enters the equipment through the inlet pipe 5 and first reaches the anoxic tank I zone 1. The anoxic tank I zone 1 is filled with polyurethane spherical packing material 11. These polyurethane spherical packing materials 11 are fixed by the No. 1 upper cover plate 9 and the No. 1 lower support plate 10 and leave a certain proportion of space, which can prevent them from drifting away with the water flow and ensure sufficient water passage space.

[0043] The water then flows through the grid plate (not separately labeled, but serving as a separator between the two zones) between anoxic tank I zone 1 and anoxic tank II zone 2, enters anoxic tank II zone 2, and then enters anoxic tank III zone 3 in a similar manner. Both anoxic tank II zone 2 and anoxic tank III zone 3 are filled with suspended high-density curtain packing material 12. These high-density curtain packing materials 12 are fixed and tensioned by reinforcing steel bars 14 (No. 1) and 15 (No. 2), respectively, allowing them to maintain a natural vertical descent in the water.

[0044] Wastewater is purified by being aerated and propelled through the aforementioned facultative anaerobic tank zone, where it undergoes simultaneous nitrification and denitrification at different depths of the packing material.

[0045] The water mixture flowing out of zone 3 of the anoxic tank enters the filtration sedimentation tank 4. This tank is filled with polyethylene granular columnar packing material 13, which is fixed by a top cover plate 30 and a bottom support plate 31. Water flows upwards in the filtration sedimentation tank 4, where suspended solids and sludge settle. Simultaneously, as the water flows through the polyethylene granular columnar packing material 13, fine suspended solids are further filtered and trapped. The further purified water is finally discharged from the outlet pipe 25 at the top of the equipment.

[0046] Furthermore, in a preferred embodiment, the sludge return device is an airlift internal return device, which utilizes part of the air source of the aeration device to return the sludge from the sludge return zone to the facultative tank I zone 1.

[0047] The principle here is to utilize the abundant denitrifying bacteria and residual organic carbon source in Zone III (low dissolved oxygen zone) of the facultative anaerobic tank, and rapidly return them to Zone I (high dissolved oxygen zone), creating favorable conditions for simultaneous nitrification and denitrification. This design eliminates the need for additional sludge pumps or other power equipment, utilizing part of the air source from the aeration device to achieve internal sludge circulation. This not only maintains a high microbial concentration in the upstream facultative anaerobic tank Zone I, enhancing the system's treatment capacity, but also reduces equipment operating energy consumption and maintenance costs.

[0048] Furthermore, in a preferred embodiment, the aeration device includes a blower installed outside the main body of the equipment, perforated aeration pipes installed in each facultative anoxic tank, and valves for adjusting the air volume of each perforated aeration pipe. The output end of the blower is connected to each perforated aeration pipe, and the aeration volume of the corresponding perforated aeration pipe in the facultative anoxic tank is adjusted by the valves to form an aeration gradient that decreases along the water flow direction.

[0049] For more details, please refer to Figure 1 , Figure 3 Main aeration pipes 33 are installed in anoxic tank I zone 1 and anoxic tank II zone 2, and auxiliary aeration pipes 34 are installed in anoxic tank III zone 3. The main aeration pipe 33 has a main aeration pipe hole 18, and the auxiliary aeration pipe 34 has an auxiliary aeration pipe hole 35. The main aeration pipe 33 is connected to the main aeration connecting pipe 16 and the ball valve 23, and the auxiliary aeration pipe 34 is connected to the auxiliary aeration connecting pipe 17. The gas from the two branches is collected through a three-way valve and connected to the flap check valve 20. Finally, it is connected to the aeration main pipe of the blower to realize the supply and regulation of air volume of the two aeration paths.

[0050] Air is pumped in by a blower and released into the water as tiny bubbles through the corresponding main aeration pipe holes 18 and secondary aeration pipe holes 35 on the main aeration pipe 33 and secondary aeration pipe 34. The design principle is that perforated aeration provides a more uniform air distribution. By installing independent valves on the pipes connecting aeration pipes in different zones, operators can easily adjust the air volume entering zones I, II, and III of the anaerobic tank independently. This simple mechanical structure achieves an aeration gradient with progressively decreasing aeration volume along the water flow direction, and also offers advantages such as low cost, ease of implementation, and maintenance. Furthermore, to ensure the stability and sealing of the piping system, the ends of the aeration pipes can be sealed with pipe caps 21, and the pipe body can be reliably fixed to the bottom of the tank using pipe clamps 29.

[0051] For more details, please refer to Figure 4 The power for the airlift internal reflux device comes from a small stream of airflow branching off from the secondary aeration connecting pipe 17. This airflow is introduced into the airlift pipe 26 located at the bottom of the anoxic tank III zone 3 and released through the airlift pipe hole 27. The air bubbles rise rapidly within the airlift pipe 26, generating negative pressure that draws in the sludge mixture from the sludge return zone at the bottom of the anoxic tank III zone and lifts it along the airlift sludge return pipe 28. The lifted sludge then flows back to the anoxic tank I zone 1 through the sludge return pipe 19 and a check valve 22. The airlift sludge return pipe 28 and the sludge return pipe 19 with the check valve 22 are connected by a T-junction. The entire process involves no mechanical rotating parts, achieving low-energy consumption and simplified maintenance of the internal sludge circulation.

[0052] Furthermore, in a preferred embodiment, a flow switch 24 is provided at the outlet pipe 25. The flow switch 24 is electrically connected to the aeration device and is used to automatically start or stop the aeration device according to the outlet flow rate. The aeration time can be automatically adjusted by the opening and closing degree of the flow switch.

[0053] The working principle of this design is that the flow switch 24 monitors in real time whether there is water flow through the outlet pipe. When sewage flows into the equipment and is discharged from the outlet pipe 25 after treatment, the flow switch 24 detects the outflow rate and triggers a switch signal to the PLC. The system recognizes the signal and starts the blower to begin aeration after 3 seconds. When the water inflow stops and there is no water flow in the outlet pipe, the flow switch 24 disconnects, automatically stopping the blower in the aeration device. This embodiment, by introducing this control logic that automatically starts and stops based on the outflow rate, addresses the problem of large time-varying sewage flow rates in rural areas, and low or even zero flow rates at night or during non-peak water usage periods. It avoids energy waste caused by the aeration device running idly during ineffective periods, thus achieving energy-saving effects.

[0054] Meanwhile, in this embodiment, the change in the opening and closing degree of the water flow switch at the outlet pipe also delays the hydraulic residence time, creating a denitrification environment. By enhancing the denitrification effect, it can achieve a more effective removal of organic matter and suspended solids.

[0055] Furthermore, in a preferred embodiment, guide plates are respectively provided on the upper and lower sides of each anoxic tank to guide the water flow to form a specific "S" shape or zigzag flow path in the tank, thereby extending the hydraulic residence time.

[0056] Specifically, such as Figure 1 , Figure 2 As shown, guide plates 6 (No. 1) are installed on the upper and lower sides of zone I of the anoxic tank, guide plates 7 (No. 2) are installed on the upper and lower sides of zone II of the anoxic tank, and guide plates 8 (No. 3) are installed on the upper and lower sides of zone III of the anoxic tank. The overall process is as follows: wastewater passes through zone I of the anoxic tank, zone II of the anoxic tank, zone III of the anoxic tank, and the filtration and sedimentation tank 4 in sequence through the inlet pipe 5. In the above-mentioned anoxic tanks, the wastewater is pushed by the main aeration pipe hole 18 and the secondary aeration pipe hole 35 and flows down along guide plates 6 (No. 1), 7 (No. 2), and 8 (No. 3) to form a cascading oxygen state (i.e., from top to bottom, it goes through the aerobic-anoxic-anaerobic process), removing organic matter from the wastewater. Suspended solids are intercepted by the polyethylene granular columnar packing material 13 in the filtration and sedimentation tank 4 and flow out through the outlet pipe 25.

[0057] Furthermore, in a preferred embodiment, the anoxic tank at the foremost end is also equipped with a sludge discharge pipe 32 that can discharge sludge to the outside of the main body of the equipment. The main purpose is to prevent excessive debris at the inlet end and the accumulation of backflow sludge from causing water quality deterioration, and to be used for backup sludge suction treatment.

[0058] Furthermore, in a preferred embodiment, the main body of the equipment is made of fiberglass, which gives it the characteristics of long service life and strong corrosion resistance.

[0059] Furthermore, in a preferred embodiment, the inlet pipe 5 is connected to the booster pump, and a check valve and a flow meter are also installed on the inlet pipe 5.

[0060] This embodiment further provides a highly efficient integrated wastewater treatment process, employing the aforementioned highly efficient integrated wastewater treatment equipment, including the following steps: a) Biofilm cultivation: Close the outlet pipe 25 and input a certain amount of sewage into the anoxic tank I, anoxic tank II and anoxic tank III through the inlet pipe 5. Inoculate aerobic microorganisms into the anoxic tank and let it stand and aerate to allow the microorganisms to be inoculated onto the biological packing. b) After the surface of the biological packing material is covered with biofilm, open the outlet pipe 25 so that the sewage continuously enters the anoxic tank I zone 1 through the inlet pipe 5, then flows into the anoxic tank II zone 2 through the corresponding bar screen, and then flows into the anoxic tank III zone 3 through the corresponding bar screen. After passing through the drop zone, it enters the filtration sedimentation tank 4. Turn on the blower to aerate the anoxic tank and form an aeration gradient that decreases along the water flow direction in several anoxic tanks to ensure the DO value in the anoxic tank and simultaneously achieve an aerobic-anoxic-anaerobic environment so that pollutants can be removed. c) After the wastewater enters the filtration sedimentation tank 4 from the lower end of the anoxic tank III zone 3, the sludge settles to the bottom and is then airlifted back to the anoxic tank I zone 1 through the sludge return device at the connection between the anoxic tank III zone 3 and the filtration sedimentation tank 4, so that the amount of sludge in the anoxic tank I zone 1 reaches the usage requirements for the reproduction of anoxic microorganisms. The other part of the sludge is discharged through the sludge discharge pipe 32 in the anoxic tank I zone 1. d) After being filtered by the polyethylene granular columnar packing material 13 at the upper end of the filtration sedimentation tank 4, the wastewater becomes clean water that meets the discharge standards and is discharged through the outlet pipe 25.

[0061] This method can fully leverage the structural advantages of the aforementioned equipment, and achieve efficient and stable treatment of rural domestic sewage through coordinated control of water flow path, aeration gradient, and sludge return.

[0062] In summary, the high-efficiency integrated wastewater treatment equipment and process provided by this invention solves the relevant problems existing in the prior art through innovative design and organic combination of reaction zone zoning, packing material combination, aeration method, sludge return path and automatic control. It has the advantages of high treatment efficiency, good nitrogen and phosphorus removal effect, low operating cost, low sludge production, high degree of automation and stable effluent quality. It is particularly suitable for treating rural domestic sewage that is scattered and has large fluctuations in water volume.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-efficiency integrated wastewater treatment device, comprising a main body, the main body having an inlet pipe and an outlet pipe for guiding wastewater to flow through the main body from front to back, characterized in that, The main body of the equipment is provided with several anoxic tanks connected in series along the water flow direction and a filtration and sedimentation tank located downstream of the anoxic tanks; the front upper side of the anoxic tank is connected to the water inlet pipe, and the rear upper side of the filtration and sedimentation tank is connected to the water outlet pipe. The main body of the device also includes: Biological packing material is used in all the anoxic tanks. The biological packing material in the front anoxic tank is of a different type than that in the rear anoxic tank along the water flow direction. An aeration device is provided for supplying air to the anaerobic tank, and the aeration device is configured to form an aeration gradient that decreases along the direction of water flow in several of the anaerobic tanks. The sludge return device has a sludge return zone at the bottom of the facultative tank at the rear end. The rear end of the sludge return zone is connected to the filtration sedimentation tank. The sludge return device is used to return the flocculated sludge settled in the sludge return zone to the facultative tank at the front end.

2. The high-efficiency integrated sewage treatment equipment according to claim 1, characterized in that, The main body of the equipment is provided with three anoxic tank zones I, II, and III, separated by a grid plate, arranged sequentially along the water flow direction. Anoxic tank zone I is filled with spherical packing material, while anoxic tank zones II and III are filled with curtain-type packing material.

3. The high-efficiency integrated sewage treatment equipment according to claim 2, characterized in that, The spherical packing is polyurethane spherical packing, and the curtain packing is high-density curtain packing.

4. The high-efficiency integrated sewage treatment equipment according to claim 2, characterized in that, The anoxic tank III and the filtration sedimentation tank are separated by a drop zone formed by two side grid plates, and the filtration sedimentation tank is filled with polyethylene granular columnar packing material.

5. The high-efficiency integrated sewage treatment equipment according to claim 2, characterized in that, The sludge return device is an airlift internal return device, which uses part of the air source of the aeration device to return sludge from the sludge return zone to the anaerobic tank I zone.

6. The high-efficiency integrated sewage treatment equipment according to claim 1, characterized in that, The aeration device includes a blower installed outside the main body of the equipment, perforated aeration pipes installed in each of the anaerobic tanks, and valves for adjusting the air volume of each of the perforated aeration pipes. The output end of the blower is connected to each of the perforated aeration pipes. The aeration volume of the perforated aeration pipes in the anaerobic tank is adjusted by the valves to form an aeration gradient that decreases along the water flow direction.

7. A high-efficiency integrated sewage treatment device according to claim 1 or 6, characterized in that, A flow switch is installed at the outlet pipe. The flow switch is electrically connected to the aeration device and is used to automatically start or stop the aeration device according to the outlet flow rate.

8. The high-efficiency integrated sewage treatment equipment according to claim 1, characterized in that, Each of the anoxic tanks is equipped with guide plates on its upper and lower sides respectively; the anoxic tank at the front end is also equipped with a sludge discharge pipe that can discharge sludge to the outside of the main body of the equipment.

9. The high-efficiency integrated sewage treatment equipment according to claim 1, characterized in that, The main body of the equipment is made of fiberglass.

10. A highly efficient integrated wastewater treatment process, employing the highly efficient integrated wastewater treatment equipment as described in any one of claims 1-9, characterized in that, Includes the following steps: a) Close the outlet pipe, input a certain amount of sewage through the inlet pipe, and let the sewage flow through several anoxic tanks in sequence, inoculating aerobic microorganisms onto the corresponding biological packing material in the anoxic tanks; b) After the surface of the biological packing material is covered with biofilm, open the outlet pipe and supply air to the anaerobic tank through the aeration device, and form an aeration gradient that decreases along the water flow direction in several anaerobic tanks, creating an aerobic-anoxic-anaerobic environment. c) Wastewater enters the filtration and sedimentation tank from the bottom of the last anoxic tank. The sludge in the tank settles into the sludge return zone at the bottom of the connection between the anoxic tank and the filtration and sedimentation tank. The sludge return device returns the flocculated sludge settled in the sludge return zone to the first anoxic tank. d) After being filtered in a sedimentation tank, the wastewater becomes clean water that meets the discharge standards and is discharged through the outlet pipe.

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