Integrated sewage treatment device with unpowered internal circulation and sewage treatment method

Abstract

The application discloses a non-powered internal circulation integrated sewage treatment device and a sewage treatment method, and mainly relates to the field of sewage treatment. The device comprises a treatment pool (1), the side of the treatment pool (1) is provided with a water outlet groove (2), and the treatment pool (1) comprises a gas explosion area (3), a flow guide area (4) and a sedimentation area (5); an aerator (8) is arranged at the middle position of the gas explosion area (3), and gas stripping is formed in the gas explosion area (3); a water inlet pipe (9) is arranged at the bottom of the pool, the vertical position of the water inlet pipe (9) is located in the flow guide area (4) below the second partition plate (7), the water inlet pipe (9) horizontally inlets water at multiple points at the bottom of the pool, and the water inlet direction is towards the gas explosion area. The device has the beneficial effects that it is an automatic internal circulation integrated sewage treatment device, the biological denitrification and phosphorus removal function is added while the advantages of the aeration sedimentation tank are retained.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to an integrated wastewater treatment device and method with non-powered internal circulation. Background Technology

[0002] Aerated sedimentation tanks are commonly used structures in the completely mixed activated sludge process. They integrate the aeration tank and secondary sedimentation tank into a single tank, or separate them into aeration and sedimentation zones by a partition. Wastewater and air enter from the bottom of the aeration zone and mix with the activated sludge. This mixture then enters the sedimentation zone where it is separated into supernatant and sludge. The supernatant flows out through an effluent weir, while the settled sludge is returned to the lower aeration zone. The accompanying diagrams in the instruction manual* illustrate several types of aerated sedimentation tanks used in integrated wastewater treatment equipment and methods with non-powered internal circulation.

[0003] Aerated sedimentation tanks have the following advantages:

[0004] 1. Sludge and mixed liquor are automatically returned, eliminating the need for a separate return system and simplifying operation and management.

[0005] 2. Inside the tank, the returned sludge, influent water, and air are completely mixed, resulting in rapid adsorption and oxidative decomposition of organic matter and high treatment efficiency.

[0006] 3. Within the pool, the water quality, MLSS concentration, and DO concentration are uniform at all points, the F / M value is almost equal, the properties and quantity of the microbial community at each point are basically the same, the working conditions at each point within the pool are almost completely consistent, the mixed liquor within the pool plays a dilution role for the wastewater, weakens the peak load, and has a strong ability to withstand shock loads.

[0007] However, the shortcomings of aerated sedimentation tanks include:

[0008] 1. Continuous water intake and output may cause short circuits and easily lead to sludge bulking.

[0009] 2. The aeration zone is always in an aerobic state, making it difficult for denitrifying bacteria and phosphorus-removing bacteria to survive, and it does not have the function of biological nitrogen and phosphorus removal.

[0010] Therefore, although aerated sedimentation tanks can achieve automatic sludge and mixed liquor return and have advantages such as fewer power equipment, lower operating costs and convenient management, their poor biological nitrogen and phosphorus removal effect and the inability of the effluent quality to meet increasingly stringent discharge requirements have affected their widespread use. Summary of the Invention

[0011] The purpose of this invention is to provide an integrated wastewater treatment device and method with non-powered internal circulation. It is an integrated wastewater treatment device with automatic internal circulation, which retains the advantages of aeration sedimentation tank while adding biological nitrogen and phosphorus removal functions.

[0012] To achieve the above objectives, the present invention employs the following technical solution:

[0013] An integrated wastewater treatment device with non-powered internal circulation includes a treatment tank with an effluent trough on its side. The treatment tank includes an aeration zone, a flow guiding zone, and a sedimentation zone. The aeration zone and the flow guiding zone are separated by a first partition, and the flow guiding zone and the sedimentation zone are separated by a second partition. The top of the first partition is below the liquid surface, and the top of the second partition is above the liquid surface. The design improvement is as follows:

[0014] The wastewater treatment equipment can be either a symmetrical integrated system or an asymmetrical integrated system. Based on the tank shape, it can be divided into circular and square tanks. In symmetrical integrated systems, the aeration zone is in the center of the tank, with flow guiding zones and sedimentation zones arranged sequentially on both sides or around the aeration zone. In asymmetrical integrated systems, the aeration zone is on one side of the tank, with the flow guiding zone and sedimentation zone arranged sequentially. The volume of the flow guiding zone in this equipment is larger than in traditional equipment. By increasing the volume of the flow guiding zone, the retention time of wastewater in the flow guiding zone is guaranteed to be no less than 2 hours.

[0015] An aerator is installed in the middle of the aeration zone to create an air-lift effect. The aerator uses either a single-sided swirl or double-sided swirl blower aeration. To reduce wind pressure and save energy, the aerator is installed approximately 0.8m above the water surface in the aeration zone, relying on the air-lift effect of rising air to create a liquid flow circulation between the aeration zone and the guide zone.

[0016] The pool bottom is equipped with an inlet pipe, which is vertically positioned within the flow guide zone below the second partition. The inlet pipe allows water to enter horizontally at multiple points on the pool bottom, with the water flow direction towards the aeration zone. Because the inlet pipe allows water to enter horizontally at multiple points on the pool bottom, and with the water flow direction towards the aeration zone, a jet generator is formed at the bottom of the pool. According to the jet principle, the water and sludge mixture in the flow guide zone flows downwards, but the aeration gas in the upper part of the flow guide zone does not flow downwards. Furthermore, the aerator is installed in the aeration zone at approximately 0.8m above the water surface, relying on the air lift effect when air rises. Therefore, through this lower-layer jet and upper-layer air lift effect, a liquid circulation is formed between the aeration zone and the flow guide zone.

[0017] The second baffle is equipped with several inlets. The mixed liquid flows into the sedimentation zone through these inlets for sludge-water separation. Below the sedimentation zone is a sludge backflow ramp that slopes towards the guide zone, with the lowest part of the sludge backflow ramp closest to the inlet pipe. A backflow gap is formed between the lower part of the second baffle and the sludge backflow ramp.

[0018] Aeration creates a high dissolved oxygen concentration in the areas above the aeration zone and the guide zone, forming an aerobic environment. Because the inlet pipes supply water horizontally at multiple points on the bottom of the tank, a high-resistance water distribution system is used for intermittent water intake to ensure uniformity. The flow velocity at each inlet pipe outlet is no less than 2 m / s, and the water flow direction is towards the aeration zone, thus forming a jet generator at the bottom of the tank. According to the jet principle, the water and sludge mixture in the guide zone flows downwards, but the aeration gas in the upper part of the guide zone does not flow downwards, thereby increasing the dissolved oxygen concentration in the lower part of the guide zone. The concentration is greatly reduced, creating an anoxic environment and forming an anoxic zone. During the downward flow of the water and sludge mixture in the guide zone, the mixture flows by gravity into the sedimentation zone through the inlet on the second baffle, where sludge and water are separated. After separation, the settled sludge flows back to the anoxic zone below the guide zone through the return slit between the second baffle and the sludge backflow inclined plate, while the supernatant is discharged from the effluent tank. The sludge returning through the return slit mixes again with the water and sludge mixture in the anoxic zone and the raw water flowing in through the inlet pipe. The raw water entering the tank first mixes with the returned sludge, facilitating denitrification. Because the inlet direction is towards the aeration zone, the mixture is carried back into the aeration zone, completing the return of the water and sludge mixture. The dissolved oxygen concentration in the returned mixture is almost zero; therefore, the aeration zone below the aerator is in an anaerobic environment, forming an anaerobic zone.

[0019] The aeration zone and the flow guiding zone below the aerator are equipped with packing material. This increases the sludge concentration and accelerates the consumption of dissolved oxygen, which helps maintain the anoxic or anaerobic state in the anoxic and anaerobic zones, thereby improving the efficiency of organic matter degradation, nitrogen removal, and phosphorus removal.

[0020] A wastewater treatment method using an integrated wastewater treatment system with non-powered internal circulation includes the following steps:

[0021] S1, water enters from the bottom of the pool through the inlet pipe. The inlet pipe allows water to enter horizontally at multiple points on the bottom of the pool, and the direction of water entry is towards the aeration zone.

[0022] The water and sludge mixture entering from S2 and S1 surges upward from the bottom of the aeration zone, passing through the aerator in the middle of the aeration zone. The bubbles generated by the aerator can form an airlift effect in the aeration zone.

[0023] S3, the mixture of gas, sludge and water that surges up from the aerator flows to the upper area of ​​the aeration zone and then flows to the area above the guide zone. Under the action of aeration, the dissolved oxygen concentration in the area above the aeration zone and the area above the guide zone is high, which is an aerobic environment and forms an aerobic zone.

[0024] S4. Because the water inlet pipes have multiple horizontal water inlets at the bottom of the pool and the water inlet direction is towards the aeration zone, a jet generator is formed at the bottom of the pool. According to the jet principle, the water and sludge mixture in the guide zone will flow from top to bottom, but the aeration gas in the upper part of the guide zone will not flow downward, which greatly reduces the dissolved oxygen concentration in the lower part of the guide zone, creating an anoxic environment.

[0025] S5, during the flow of water and sludge mixture from top to bottom in the diversion zone, the mixture flows into the sedimentation zone through the inlet on the second baffle for sludge-water separation;

[0026] S6. After the mud and water are separated, the settled sludge flows back to the anoxic zone below the guide zone through the return gap between the second baffle and the sludge backflow inclined plate, and the supernatant is discharged from the effluent tank.

[0027] S7, the sludge returned through the return slit is mixed again with the water and sludge mixture in the anoxic zone and the raw water flowing in from the inlet pipe. Since the water inlet direction is towards the aeration zone, the mixture is carried back into the aeration zone, completing the return of the water and sludge mixture. The dissolved oxygen concentration in the returned mixture is almost zero. Therefore, the aeration zone below the aerator is in an anaerobic environment, forming an anaerobic zone.

[0028] S8, repeat steps S1 to S7 in a loop.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. By increasing the area and volume of the flow guide zone, aerobic, anoxic, and anaerobic zones can be formed within the equipment, thus enabling biological nitrogen and phosphorus removal. Specifically, the area above the aeration zone (above the aerator) and the area above the flow guide zone has a higher dissolved oxygen concentration, making it an aerobic zone where microorganisms degrade organic matter, absorb phosphates, and undergo nitrification to remove ammonia nitrogen. In the lower part of the flow guide zone, the dissolved oxygen concentration is lower, creating an anoxic zone where microorganisms undergo denitrification. Below the aerator, the dissolved oxygen concentration is even lower, sometimes zero, creating an anaerobic zone where microorganisms release phosphorus. The spontaneous formation of aerobic, anoxic, and anaerobic zones within the aeration and flow guide zones enables the integrated equipment to perform biological nitrogen and phosphorus removal, expanding its application range. The increased surface area and volume of the guide zone can completely release air bubbles in the mixed liquor, allowing the water to flow smoothly into the sedimentation zone. This ensures both the mud-water separation effect and sufficient denitrification reaction time.

[0031] 2. A multi-point horizontal inlet system is adopted in the anoxic zone at the bottom of the tank. Raw water first enters the anoxic zone and mixes with the returned sludge. Anaerobic bacteria preferentially absorb organic matter in the wastewater, and nitrate nitrogen is removed first, ensuring that the mixed liquor entering the anoxic zone is in a completely anaerobic state, which is conducive to anaerobic phosphorus release. Furthermore, the inlet also flushes the bottom of the tank during water intake, preventing sludge deposition. The inlet faces the aeration zone to prevent untreated wastewater from directly entering the sedimentation zone.

[0032] 3. Due to the liquid flow circulation between the aeration zone and the guide zone, and the fact that the inlet point is at the bottom of the guide zone, the wastewater concentration gradually decreases from the inlet point to the sedimentation zone. Because of this concentration gradient within the tank, the driving force for the wastewater degradation reaction is strong, resulting in high efficiency and reducing the likelihood of sludge bulking. Attached Figure Description

[0033] Appendix Figure 1 This is a schematic diagram of a symmetrical integrated sewage treatment equipment.

[0034] Appendix Figure 2 This is a schematic diagram of an asymmetric integrated wastewater treatment equipment.

[0035] Appendix Figure 3 This is a diagram of existing equipment.

[0036] The labels shown in the attached diagram:

[0037] 1. Treatment tank; 2. Effluent trough; 3. Aeration zone; 4. Flow guiding zone; 5. Sedimentation zone; 6. First baffle; 7. Second baffle; 8. Aerator; 9. Inlet pipe; 10. Inlet; 11. Sludge backflow inclined plate; 12. Return flow slot. Detailed Implementation

[0038] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0039] This invention relates to an integrated wastewater treatment device and method with non-powered internal circulation. The main structure includes a treatment tank 1, with an effluent trough 2 on its side. The treatment tank 1 includes an aeration zone 3, a flow guiding zone 4, and a sedimentation zone 5. The aeration zone 3 and the flow guiding zone 4 are separated by a first partition 6, and the flow guiding zone 4 and the sedimentation zone 5 are separated by a second partition 7. The top of the first partition 6 is below the liquid surface, and the top of the second partition 7 is above the liquid surface. The design improvements are as follows:

[0040] The wastewater treatment equipment is a symmetrical integrated device (as shown in the attached diagram of the instruction manual). Figure 1(as shown in the attached diagram) or asymmetric integrated equipment (as shown in the attached diagram). Figure 2 (As shown). Based on the tank shape, they can be divided into circular tanks and square tanks. In symmetrical integrated equipment, the aeration zone is in the center of the tank, with the guide zone 4 and sedimentation zone 5 arranged sequentially on both sides or around the aeration zone; in asymmetrical integrated equipment, the aeration zone is on one side of the tank, with the guide zone 4 and sedimentation zone 5 arranged sequentially. In this equipment, the volume of the guide zone 4 is larger than in traditional equipment. By increasing the volume of the guide zone 4, the retention time of wastewater in the guide zone 4 is ensured to be no less than 2 hours.

[0041] An aerator 8 is installed in the middle of the aeration zone 3 to create an air lift effect. The aerator 8 uses either a single-sided swirl or double-sided swirl blower aeration. To reduce wind pressure and save energy, the aerator 8 is installed in the aeration zone at a distance of about 0.8m from the water surface. It relies on the air lift effect when the air rises to create a liquid flow circulation between the aeration zone and the guide zone 4.

[0042] The bottom of the pool is equipped with an inlet pipe 9, which is vertically positioned within the guide zone 4 below the second partition 7. The inlet pipe 9 allows water to enter horizontally at multiple points on the bottom of the pool, with the water flow direction towards the aeration zone. Because the inlet pipe 9 allows water to enter horizontally at multiple points on the bottom of the pool, with the water flow direction towards the aeration zone, a jet generator is formed at the bottom of the pool. According to the jet principle, the water and sludge mixture in the guide zone 4 will flow from top to bottom, but the aeration gas in the upper part of the guide zone 4 will not flow downwards. Moreover, the aerator 8 is installed in the aeration zone at a position about 0.8m above the water surface, relying on the air lift effect when the air rises. Therefore, through this lower jet and upper air lift effect, a liquid flow circulation can be formed between the aeration zone and the guide zone 4.

[0043] The second partition 7 is provided with inlets 10. Several inlets 10 are provided, and the mixed liquid flows into the sedimentation zone 5 by gravity through the inlets 10. In the sedimentation zone 5, mud and water are separated. Under the action of the jet, a large portion of the mud-water mixture also flows directly from the guide zone 4. Below the sedimentation zone 5 is a sludge backflow inclined plate 11 that slopes towards the guide zone 4, with the lowest part of the sludge backflow inclined plate 11 closest to the inlet pipe 9. A return slit 12 is formed between the lower part of the second partition 7 and the sludge backflow inclined plate 11, through which the settled sludge flows back.

[0044] Under the action of aeration, the dissolved oxygen concentration in the area above the aeration zone and the area above the guide zone 4 is high, creating an aerobic environment and forming an aerobic zone. Since the inlet pipe 9 introduces water horizontally at multiple points on the bottom of the tank, a high-resistance water distribution system is used for intermittent water intake to ensure uniformity. The inlet flow velocity at the outlet of each inlet pipe 9 is not less than 2 m / s, and the inlet direction is towards the aeration zone. Therefore, a jet generator is formed at the bottom of the tank. According to the jet principle, the water and sludge mixture in the guide zone 4 will flow from top to bottom, but the aeration gas in the upper part of the guide zone 4 will not flow downwards, thus greatly reducing the dissolved oxygen concentration in the lower part of the guide zone 4. The water and sludge mixture in the guide zone 4 flows downwards, and the mixture flows into the sedimentation zone 5 through the inlet 10 on the second baffle 7 for sludge-water separation. After sludge-water separation, the settled sludge flows back to the anoxic zone below the guide zone 4 through the return slit 12 between the second baffle 7 and the sludge backflow inclined plate 11. The supernatant is discharged from the outlet trough 2. The sludge returned through the return slit 12 mixes again with the water and sludge mixture in the anoxic zone and the raw water flowing in through the inlet pipe 9. The raw water entering the tank first mixes with the returned sludge, which is beneficial for denitrification. Since the water inlet direction is towards the aeration zone, the mixture is carried back into the aeration zone, completing the return of the water and sludge mixture. The dissolved oxygen concentration in the returned mixture is almost zero. Therefore, the aeration zone below the aerator 8 is in an anaerobic environment, forming an anaerobic zone.

[0045] The aeration zone 3 and the flow guiding zone 4 below the aerator 8 are equipped with packing material. This increases the sludge concentration and accelerates the consumption of dissolved oxygen, which helps maintain the anoxic or anaerobic state in the anoxic and anaerobic zones, thereby improving the degradation of organic matter and the removal of nitrogen and phosphorus.

[0046] A wastewater treatment method using an integrated wastewater treatment system with non-powered internal circulation includes the following steps:

[0047] S1, water enters from the bottom of the pool through the water inlet pipe 9. The water inlet pipe 9 enters water horizontally at multiple points on the bottom of the pool, and the water inlet direction is towards the aeration zone.

[0048] The water and sludge mixture entering from S2 and S1 surges upward from the bottom of the aeration zone, passing through the aerator 8 in the middle of the aeration zone 3. The bubbles generated by the aerator 8 can form an air-lifting effect in the aeration zone 3.

[0049] S3, the mixture of gas, sludge and water that surges up from aerator 8 flows to the upper area of ​​the aeration zone and then flows to the area above the guide zone 4. Under the action of aeration, the dissolved oxygen concentration in the area above the aeration zone and the area above the guide zone 4 is high, and they are in an aerobic environment, forming an aerobic zone.

[0050] S4. Because the water inlet pipe 9 has multiple horizontal water inlets at the bottom of the pool and the water inlet direction is towards the aeration zone, a jet generator is formed at the bottom of the pool. According to the jet principle, the water and sludge mixture in the guide zone 4 will flow from top to bottom, but the aeration gas in the upper part of the guide zone 4 will not flow downward, which will greatly reduce the dissolved oxygen concentration in the lower part of the guide zone 4, creating an oxygen-deficient environment and forming an oxygen-deficient zone.

[0051] S5, during the flow of water and sludge mixture from top to bottom in the diversion zone 4, the mixture flows into the sedimentation zone 5 through the inlet 10 on the second baffle 7 for sludge-water separation.

[0052] S6. After the mud and water are separated, the settled sludge flows back to the anoxic zone below the guide zone 4 through the return gap 12 between the second baffle 7 and the sludge backflow inclined plate 11. The supernatant is discharged from the effluent tank 2.

[0053] S7, the sludge returned through the return slit 12 is mixed again with the water and sludge mixture in the anoxic zone and the raw water flowing in through the inlet pipe 9. Since the water inlet direction is towards the aeration zone, the mixture is carried back into the aeration zone, completing the return of the water and sludge mixture. The dissolved oxygen concentration in the returned mixture is almost zero. Therefore, the aeration zone area below the aerator 8 is in an anaerobic environment, forming an anaerobic zone.

[0054] S8, repeat steps S1 to S7 in a loop.

[0055] In summary:

[0056] By increasing the area and volume of the guide zone 4, aerobic, anoxic, and anaerobic zones can be formed within the equipment, thus enabling biological nitrogen and phosphorus removal. Specifically, the area above aerator 8 and above guide zone 4, with higher dissolved oxygen concentrations, is an aerobic zone where microorganisms degrade organic matter, absorb phosphates, and undergo nitrification to remove ammonia nitrogen. In the lower part of guide zone 4, with lower dissolved oxygen concentrations, this is an anoxic zone where microorganisms undergo denitrification. Below aerator 8, the dissolved oxygen concentration is even lower, sometimes zero, making this an anaerobic zone where microorganisms release phosphorus. The spontaneous formation of aerobic, anoxic, and anaerobic zones within the aeration zone and guide zone 4 enables the integrated equipment to perform biological nitrogen and phosphorus removal, expanding its application range. The increased surface area and volume of the guide zone 4 allow for the complete release of air bubbles in the mixed liquid, enabling the water to flow smoothly into the sedimentation zone 5. This ensures both effective mud-water separation and sufficient denitrification reaction time.

[0057] The system employs a multi-point horizontal inlet method within the anoxic zone at the bottom of the tank. Raw water first enters the anoxic zone and mixes with the returned sludge. Anaerobic bacteria preferentially absorb organic matter from the wastewater, removing nitrate nitrogen first, ensuring the mixed liquor entering the anoxic zone is in a completely anaerobic state, which is beneficial for anaerobic phosphorus release. Furthermore, the inlet also flushes the bottom of the tank during water intake, preventing sludge deposition. The inlet 10 faces the aeration zone, preventing untreated wastewater from directly entering the sedimentation zone 5.

[0058] Because there is liquid circulation between the aeration zone and the guide zone 4, and the inlet point is at the bottom of the guide zone 4, the wastewater concentration gradually decreases from the inlet point to the sedimentation zone 5. Due to this concentration gradient within the tank, the driving force for the wastewater degradation reaction is greater, the efficiency is higher, and sludge bulking is less likely to occur.

Claims

1. A wastewater treatment method using an integrated wastewater treatment device with non-powered internal circulation, characterized in that: The integrated wastewater treatment equipment with non-powered internal circulation includes a treatment tank (1), an effluent trough (2) on the side of the treatment tank (1), and the treatment tank (1) includes an aeration zone (3), a flow guiding zone (4), and a sedimentation zone (5); the aeration zone (3) and the flow guiding zone (4) are separated by a first partition (6), and the flow guiding zone (4) and the sedimentation zone (5) are separated by a second partition (7), the top of the first partition (6) is below the liquid surface, and the top of the second partition (7) is above the liquid surface; an aerator (8) is installed in the middle of the aeration zone (3), and an aerator (8) is installed in the aeration zone. (3) Forming an air lift effect; The bottom of the pool is provided with an inlet pipe (9), the vertical position of which is located in the guide zone (4) below the second partition (7), the inlet pipe (9) is horizontally inlet at multiple points on the bottom of the pool, and the inlet direction is towards the aeration zone; The second partition (7) is provided with an inlet (10); The sedimentation zone (5) is provided with a sludge backflow inclined plate (11) that is inclined towards the guide zone (4), and the bottom of the sludge backflow inclined plate (11) is close to the inlet pipe (9); The aeration zone (3) area below the aerator (8) and the guide zone (4) area below the aerator (8) are provided with packing material; The wastewater treatment method includes the following steps: S1, water enters from the bottom of the pool through the water inlet pipe (9). The water inlet pipe (9) enters the pool horizontally at multiple points on the bottom of the pool, and the water inlet direction is towards the aeration zone. The water and sludge mixture entering from S2 and S1 surges from bottom to top in the aeration zone, passing through the aerator (8) in the middle of the aeration zone (3). The bubbles generated by the aerator (8) can form an airlift effect in the aeration zone (3). S3, the mixture of gas, sludge and water that surges up from the aerator (8) flows to the upper area of ​​the aeration zone and then flows to the area above the guide zone (4). Under the action of aeration, the dissolved oxygen concentration in the area above the aeration zone and the area above the guide zone (4) is high, and they are in an aerobic environment, forming an aerobic zone. S4, because the water inlet pipe (9) enters water horizontally at multiple points at the bottom of the pool and the water inlet direction is towards the aeration zone; therefore, a jet is formed at the bottom of the pool. According to the jet principle, the water and sludge mixture in the guide zone (4) will flow from top to bottom, but the aeration gas in the upper part of the guide zone (4) will not flow downward, thereby greatly reducing the dissolved oxygen concentration in the lower part of the guide zone (4), creating an oxygen-deficient environment and forming an oxygen-deficient zone; S5, During the flow of water and sludge mixture in the diversion zone (4) from top to bottom, the mixture flows into the sedimentation zone (5) through the inlet (10) on the second partition (7) for sludge-water separation; S6, After the mud and water are separated, the settled sludge flows back to the anoxic zone below the guide zone (4) through the return gap (12) between the second partition (7) and the sludge backflow inclined plate (11), and the supernatant is discharged from the outlet tank (2). S7, the sludge returned through the return slit (12) is mixed again with the water and sludge mixture in the anoxic zone and the raw water flowing in through the inlet pipe (9). Since the water inlet direction is towards the aeration zone, the mixture is carried into the aeration zone again, completing the return of the water and sludge mixture. The dissolved oxygen concentration in the returned mixture is almost zero. Therefore, the aeration zone area below the aerator (8) is in an anaerobic environment, forming an anaerobic zone. S8, repeat steps S1 to S7 in a loop.

2. The wastewater treatment method of the integrated wastewater treatment equipment with non-powered internal circulation according to claim 1, characterized in that: The water inlet pipe (9) is powered to allow water to enter intermittently through a high-resistance water distribution system.

3. The wastewater treatment method of the integrated wastewater treatment equipment with non-powered internal circulation according to claim 2, characterized in that: The aerator (8) uses either a single-sided swirl or double-sided swirl blower aeration.

4. The wastewater treatment method of the integrated wastewater treatment equipment with non-powered internal circulation according to claim 3, characterized in that: The inlet flow velocity at the outlet of each inlet pipe (9) shall not be less than 2 m / s.

5. The wastewater treatment method of the integrated wastewater treatment equipment with non-powered internal circulation according to claim 4, characterized in that: The wastewater treatment equipment is either a symmetrical integrated device or an asymmetrical integrated device.

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