Self-circulation integrated granular sludge denitrification equipment with partition aeration

Abstract

The utility model discloses self-circulation integrated granular sludge denitrification equipment with a partition aeration function, and belongs to the technical field of biological sewage treatment. The outer end of the perforated pipe is provided with a perforated pipe air inlet, the outer end of the perforated pipe air inlet is provided with an aeration pipe, one side of the aeration pipe is provided with a perforated pipe aeration flow meter, the other side of the aeration pipe is provided with an aeration disc aeration flow meter, the water outlet end of the backflow port is provided with a backflow pipe, and the backflow pipe is provided with a backflow pump and a backflow flow meter from near to far. The outer end of the return pipe is connected with the water inlet, and the outer end of the water inlet is provided with a water inlet flowmeter. The continuous flow granular sludge reactor is simple in structure and easy to operate, the problem that granular sludge is prone to loss or disintegration is preferentially avoided, and the problem that the stability of the sewage treatment effect is poor is avoided. In the operation process, granular sludge is prevented from being lost, and the compact structure of the granular sludge is maintained so as to ensure the sewage denitrification effect.

Description

Technical Field

[0001] This utility model relates to a self-circulating integrated granular sludge denitrification device with zoned aeration, belonging to the field of wastewater biological treatment technology. Background Technology

[0002] Excessive nitrogen is one of the main causes of eutrophication in water bodies. With the continuous improvement of environmental protection requirements, traditional nitrification-denitrification biological denitrification processes can no longer meet the requirements of low carbon, energy saving and sustainable development in the wastewater treatment industry. Especially in the treatment of high-concentration ammonia nitrogen wastewater such as landfill leachate and anaerobic digestion liquid, traditional processes have high aeration energy consumption, large carbon source requirements and generate a large amount of residual sludge that needs to be disposed of.

[0003] Anaerobic ammonia oxidation (AAO) is currently recognized as the lowest-carbon and energy-efficient biological nitrogen removal process. It can directly convert ammonia nitrogen and nitrite nitrogen into nitrogen gas and a small amount of nitrate nitrogen under anaerobic conditions. For treating high-concentration ammonia nitrogen wastewater, it needs to be used in conjunction with a partial nitrification process, where the partial nitrification process provides the nitrite nitrogen substrate for AAO. The partial nitrification-anaerobic ammonia oxidation granular sludge process is a novel wastewater denitrification technology. The partial nitrification-anaerobic ammonia oxidation granular sludge is a granular activated sludge formed by the aggregation of microorganisms through hydraulic shear force and selective pressure. Ammonia-oxidizing bacteria are coated on the surface of the granular sludge. On the one hand, they utilize dissolved oxygen to convert ammonia nitrogen into nitrite nitrogen; on the other hand, they protect the anaerobic ammonia-oxidizing bacteria from the inhibition of dissolved oxygen. The anaerobic ammonia-oxidizing bacteria, located in the anaerobic environment inside the granular sludge, utilize the ammonia nitrogen in the influent and the nitrite nitrogen produced by the ammonia-oxidizing bacteria to remove most of the nitrogen pollutants, generating nitrogen gas, and producing a small amount of nitrate nitrogen. The partial nitrification-anammox granular sludge process has advantages such as high sludge concentration, good settling performance, high nitrogen removal load, and low investment cost.

[0004] For example, the biological tank structure of a wastewater treatment plant disclosed in application number 202420810677.0 includes a treatment tank body, a biological filter plate, and a dual-inlet water pump. A tank cavity partition plate is installed in the middle of the treatment tank body, dividing the treatment tank body into a left half and a right half. An auxiliary biological filter layer is set at the bottom of the biological filter plate, and a bioceramic filter plate is set at the bottom of the auxiliary biological filter layer. A water quality analyzer is installed at the bottom of the other side of the treatment tank body. One end of the water quality analyzer extends into the interior of the right half and is equipped with a monitoring probe. The tank cavity partition plate divides the treatment tank body into a left half and a right half, and the monitoring probe and water quality analyzer are connected to the right half. Wastewater that has undergone biological filtration enters the right half and is monitored. When biological filtration fails to meet the standards, the wastewater is transported to the left half through a return conveying pipe and an external return pipe by the dual-inlet water pump for biological filtration again.

[0005] Most existing continuous flow granular sludge reactors are complex in structure, difficult to operate, and prone to granular sludge loss or disintegration, resulting in poor stability of wastewater treatment performance. Therefore, how to retain granular sludge during operation and maintain its dense structure to ensure effective wastewater denitrification is a problem that needs to be solved. Based on these issues, a self-circulating integrated granular sludge denitrification device with zoned aeration is needed to address these shortcomings. Utility Model Content

[0006] The main purpose of this invention is to provide a self-circulating integrated granular sludge denitrification device with zoned aeration.

[0007] The objective of this utility model can be achieved by adopting the following technical solution:

[0008] A self-circulating integrated granular sludge denitrification device with zoned aeration, comprising a self-circulating reaction tank;

[0009] A water outlet tank is installed above the self-circulating reaction tank;

[0010] Perforated pipes are installed diagonally across the outlet tank inside the self-circulating reaction tank;

[0011] The perforated pipe is equipped with a perforated pipe air inlet at the outer end, and an aeration pipe is installed at the outer end of the perforated pipe air inlet. A perforated pipe aeration flow meter is installed on one side of the aeration pipe, and an aeration disc aeration flow meter is installed on the other side of the aeration pipe. An aeration disc air inlet is installed at the other end of the perforated pipe air inlet, and an aeration disc is installed at the outer end of the aeration disc air inlet. The aeration disc is placed in the self-circulating reaction tank.

[0012] The effluent tank of the self-circulating reaction tank is connected to a reflux assembly.

[0013] Preferably, the recirculation assembly includes a recirculation port, a recirculation pump, an outlet tank, a recirculation flow meter, an inlet, an inlet flow meter, and a recirculation pipe;

[0014] The self-circulating reaction tank has a reflux port and an outlet on one side of the outlet tank. A reflux pipe is installed at the outlet end of the reflux port. A reflux pump and a reflux flow meter are installed on the reflux pipe from near to far. The outer end of the reflux pipe is connected to the inlet, and an inlet flow meter is installed at the outer end of the inlet.

[0015] Preferably, the self-circulating reaction tank has a closed or open structure, and the length-to-width ratio of the self-circulating reaction tank is 3:1-3:2, and the length-to-height ratio of the self-circulating reaction tank is 1:4-1:6.

[0016] Preferably, the holes on the perforated tube are 1-3mm in size, the direction of the holes on the perforated tube is 30°-60° downward from the horizontal direction, and the length of the perforated tube is 1 / 2-1 / 3 of the length of the bottom of the self-circulating reaction tank.

[0017] Preferably, the holes on the filter screen are 1-3 mm.

[0018] Preferably, an outlet is installed above the return port, and a filter screen is installed at the bottom of the outlet tank.

[0019] Preferably, the self-circulating reaction tank is driven by an aeration disc, an inlet, and a perforated pipe for circulation.

[0020] The beneficial technical effects of this utility model are as follows:

[0021] This utility model provides a self-circulating integrated granular sludge denitrification device with zoned aeration. The self-circulating reaction tank has a unique structure and operation mode. Its top design is flexible, allowing for either a closed or open configuration depending on the actual application scenario and process requirements. In terms of geometry, the length-to-width ratio is set within the range of 3:1-3:2. This ratio helps to rationally plan the water flow path and reaction zone within a limited space, ensuring efficient reaction. The length-to-height ratio is controlled within 1:4-1:6. This ratio provides sufficient space in the vertical direction of the reaction tank for effective water circulation and mixing, while also creating a suitable environment for microbial growth and metabolism. The circulation drive device plays a core role in the operation of the entire reaction tank. Currently, two aeration devices are used: perforated pipes and aeration discs, both installed on... Figure 1 The right bottom region of the reaction tank shown;

[0022] The perforated pipe is horizontally installed at the bottom of the self-circulating reaction tank 1. It has specific design parameters: the aperture size is precisely set between 1 and 3 mm, and the opening direction is at a 30°-60° angle downwards from the horizontal. This downward-sloping opening design ensures that the bubbles generated during aeration rise towards the bottom of the tank at a certain angle, enhancing the disturbance effect on the bottom water. The length of the perforated pipe is 1 / 2 to 1 / 3 of the bottom length of the self-circulating reaction tank 1. This length ensures sufficient driving force for water circulation while avoiding energy waste and installation inconvenience due to excessive length. Because the aperture of the perforated pipe is relatively large, the generated bubbles are also large. These large bubbles, as they rise, drive the surrounding water to flow rapidly, thus providing a strong driving force for the water circulation within the reaction tank. Simultaneously, the large air-liquid contact area during the rise of the large bubbles allows for rapid transfer of oxygen from the air to the water, providing the necessary dissolved oxygen for ammonia-oxidizing bacteria, meeting their metabolic needs, and promoting the smooth progress of the ammonia oxidation reaction.

[0023] The aeration disc, installed above the perforated pipe, differs in construction from the perforated pipe. The aeration disc has smaller pores, resulting in smaller bubbles. These tiny bubbles have a larger specific surface area and rise more slowly in the water, allowing for more thorough contact with the water and thus more effectively transferring oxygen. The primary function of the aeration disc is to provide sufficient and stable dissolved oxygen for ammonia-oxidizing bacteria. Due to the small size of the bubbles, they are more evenly distributed in the water, maintaining a suitable dissolved oxygen concentration over a wider area compared to the larger bubbles produced by the perforated pipe, creating a more stable living environment for ammonia-oxidizing bacteria. Furthermore, although the bubbles produced by the aeration disc are smaller, their rising motion still disturbs the water, providing a driving force for water circulation and assisting the perforated pipe in maintaining water circulation within the reaction tank.

[0024] Under the synergistic effect of the circulation drive device composed of perforated pipes and aeration discs, the water flow in the self-circulating reaction tank can form a stable and efficient circulation. The circulating motion of the water will drive the granular sludge to flow in the reaction tank. During the flow, the granular sludge will be subjected to hydraulic shear force. Appropriate hydraulic shear force can promote the continuous renewal of microorganisms on the surface of the granular sludge, maintain their activity, and also help maintain the structural stability of the granular sludge. When the granular sludge collides and rubs against each other in the water flow, the aging microbial film can be removed in time, allowing new microorganisms to attach and grow, thereby ensuring that the granular sludge always has good metabolic function.

[0025] The effluent trough is located at the top of the reaction tank on the side opposite the drive unit. It plays a crucial role in the entire reaction system, handling both effluent and sludge retention. A filter screen with a pore size of 1-3 mm is installed at the bottom of the effluent trough. During operation, water circulates downwards on the effluent trough side, eventually passing through the filter screen at the bottom and entering the effluent trough itself. This filter screen is critical, effectively preventing granular sludge from flowing out of the reaction tank with the water flow. This ensures that granular sludge remains within the reaction tank, participating in the reaction and maintaining the quantity and activity of microorganisms in the system, guaranteeing a continuous and stable reaction. Simultaneously, the pore size of the filter screen ensures smooth water flow while preventing granular sludge loss, thus ensuring water quality and achieving efficient operation of the reaction system.

[0026] This application is for a continuous flow granular sludge reactor, which has a simple structure and is easy to operate. It prioritizes avoiding the problem of easy loss or disintegration of granular sludge, thus avoiding the problem of poor stability of wastewater treatment effect. This application retains granular sludge during operation and maintains its dense structure to ensure the denitrification effect of wastewater. Attached Figure Description

[0027] Figure 1This is a cross-sectional view of the overall structure of a preferred embodiment of a self-circulating integrated granular sludge denitrification device with zoned aeration according to the present invention.

[0028] Figure 2 This is a top view of the effluent tank and aeration system of a preferred embodiment of a self-circulating integrated granular sludge denitrification device with zoned aeration according to the present invention.

[0029] In the diagram: 1. Self-circulating reaction tank; 2. Return port; 3. Outlet; 4. Return pump; 5. Outlet tank; 6. Return flow meter; 7. Aeration disc; 8. Inlet; 9. Perforated pipe air inlet; 10. Inlet flow meter; 11. Perforated pipe aeration flow meter; 12. Aeration disc aeration flow meter; 13. Aeration pipe; 14. Aeration disc air inlet; 15. Perforated pipe; 16. Return pipe; 17. Filter screen. Detailed Implementation

[0030] To enable those skilled in the art to understand the technical solution of this utility model more clearly, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of this utility model is not limited thereto.

[0031] like Figure 1 - Figure 2 As shown in the figure, this embodiment provides a self-circulating integrated granular sludge denitrification device with zoned aeration, including a self-circulating reaction tank 1;

[0032] A water outlet tank 5 is installed above the self-circulating reaction tank 1;

[0033] A perforated pipe 15 is installed diagonally across the outlet tank 5 inside the self-circulating reaction tank 1;

[0034] A perforated pipe air inlet 9 is installed at the outer end of the perforated pipe 15. An aeration pipe 13 is installed at the outer end of the perforated pipe air inlet 9. A perforated pipe aeration flow meter 11 is installed on one side of the aeration pipe 13. An aeration disc aeration flow meter 12 is installed on the other side of the aeration pipe 13. An aeration disc air inlet 14 is installed at the other end of the perforated pipe air inlet 9. An aeration disc 7 is installed at the outer end of the aeration disc air inlet 14. The aeration disc 7 is placed in the self-circulating reaction tank 1.

[0035] The effluent tank 5 on the self-circulating reaction tank 1 is connected to a reflux assembly.

[0036] The reflux assembly includes a reflux port 2, a reflux pump 4, an outlet tank 5, a reflux flow meter 6, an inlet 8, an inlet flow meter 10, and a reflux pipe 16;

[0037] A return port 2 and a water outlet 3 are installed on one side of the water outlet tank 5 on the self-circulating reaction tank 1. A return pipe 16 is installed at the water outlet end of the return port 2. A return pump 4 and a return flow meter 6 are installed on the return pipe 16 from near to far. The outer end of the return pipe 16 is connected to the water inlet 8. An inlet flow meter 10 is installed at the outer end of the water inlet 8.

[0038] The self-circulating reaction tank 1 features a unique structure and operation mode. Its top design offers flexibility, allowing for either a closed or open configuration depending on the specific application and process requirements. In terms of geometry, the length-to-width ratio is set between 3:1 and 3:2. This ratio helps to rationally plan the water flow path and reaction zone within a limited space, ensuring efficient reaction. The length-to-height ratio is controlled between 1:4 and 1:6. This ratio provides sufficient vertical space for effective water circulation and mixing, while also creating a suitable environment for microbial growth and metabolism. The circulation drive device plays a central role in the operation of the entire reaction tank. Currently, it employs two aeration devices: perforated pipe 15 and aeration disc 7, both installed on... Figure 1 The right bottom region of the reaction tank shown;

[0039] The perforated pipe 15 is horizontally installed at the bottom of the self-circulating reaction tank 1. It has specific design parameters; the aperture size of the perforated pipe 15 is precisely set between 1 and 3 mm, and the opening direction is at a downward angle of 30° to 60° to the horizontal. This downward-sloping opening design ensures that the bubbles generated during aeration rush towards the bottom of the tank at a certain angle, enhancing the disturbance effect on the bottom water. The length of the perforated pipe 15 is 1 / 2 to 1 / 3 of the bottom length of the self-circulating reaction tank 1. This length is set to ensure sufficient driving force for water circulation while avoiding energy waste and installation inconvenience due to excessive length. Because the aperture of the perforated pipe 15 is relatively large, the volume of the bubbles it generates is also large. These large bubbles, during their ascent, drive the surrounding water to flow rapidly, thus providing a strong driving force for the circulation of water within the reaction tank. Simultaneously, the large air-liquid contact area during the ascent of the large bubbles is relatively large, enabling rapid transfer of oxygen from the air to the water, providing the necessary dissolved oxygen for ammonia-oxidizing bacteria, meeting their metabolic needs, and promoting the smooth progress of the ammonia oxidation reaction.

[0040] The aeration disc 7 is installed above the perforated pipe 15, and its structure differs from that of the perforated pipe 15. The aeration disc 7 has smaller pores, resulting in smaller bubbles. These tiny bubbles have a larger specific surface area and rise more slowly in the water, allowing for more thorough contact with the water and thus more effectively transferring oxygen. The main function of the aeration disc 7 is to provide sufficient and stable dissolved oxygen for ammonia-oxidizing bacteria. Due to the small size of the bubbles it produces, they are more evenly distributed in the water, maintaining a suitable dissolved oxygen concentration over a wider area compared to the larger bubbles produced by the perforated pipe 15, creating a more stable living environment for ammonia-oxidizing bacteria. Furthermore, although the bubbles produced by the aeration disc 7 are smaller, their rising motion still disturbs the water, providing a driving force for water circulation and assisting the perforated pipe 15 in maintaining water circulation within the reaction tank.

[0041] Under the synergistic effect of the circulation drive device composed of perforated pipe 15 and aeration disc 7, the water flow in the self-circulating reaction tank 1 can form a stable and efficient circulation. The circulation of water will drive the granular sludge to flow in the reaction tank. During the flow, the granular sludge will be subjected to hydraulic shear force. Appropriate hydraulic shear force can promote the continuous renewal of microorganisms on the surface of granular sludge and maintain their activity. At the same time, it also helps to maintain the structural stability of granular sludge. When granular sludge collides and rubs against each other in the water flow, it can remove the aging microbial film in time, so that new microorganisms can attach and grow, thereby ensuring that the granular sludge always has good metabolic function.

[0042] The effluent trough 5 is located at the top of the reaction tank on the side opposite to the drive unit. It plays a crucial role in the entire reaction system, handling both effluent and sludge retention. A filter screen 17 with a pore size of 1-3 mm is installed at the bottom of the effluent trough 5. During operation, water circulates downwards along one side of the effluent trough 5, ultimately passing through the filter screen at the bottom of the effluent trough 5 and entering the effluent tank. The filter screen 17 is critical; it effectively prevents granular sludge from flowing out of the reaction tank with the water flow, ensuring that the granular sludge always participates in the reaction within the tank, maintaining the quantity and activity of microorganisms in the reaction system, and guaranteeing the continuous and stable progress of the reaction. Simultaneously, the pore size of the filter screen 17 ensures smooth water flow while preventing the loss of granular sludge, thus ensuring water quality and achieving efficient operation of the reaction system.

[0043] The self-circulating reaction tank 1 can be a closed or open structure. The length-to-width ratio of the self-circulating reaction tank 1 is 3:1-3:2, and the length-to-height ratio of the self-circulating reaction tank 1 is 1:4-1:6.

[0044] The holes on the perforated tube 15 are 1-3mm in size, and the direction of the holes on the perforated tube 15 is 30°-60° with the horizontal direction. The length of the perforated tube 15 is 1 / 2-1 / 3 of the length of the bottom of the self-circulating reaction tank 1.

[0045] The holes on the filter screen 17 are 1-3mm.

[0046] A water outlet 3 is installed above the return port 2, and a filter screen 17 is covered at the bottom of the water outlet 5.

[0047] The self-circulating reaction tank 1 is driven by the aeration disc 7, the inlet 8, and the perforated pipe 15.

[0048] like Figure 1 - Figure 2 As shown in the figure, the working process of the self-circulating integrated granular sludge denitrification equipment with zoned aeration provided in this embodiment is as follows:

[0049] Step 1: The self-circulating reaction tank 1 features a unique structure and operation mode. Its top design is flexible, allowing for either a closed or open configuration depending on the application scenario and process requirements. In terms of geometry, the length-to-width ratio is set between 3:1 and 3:2. This ratio helps to rationally plan the water flow path and reaction area within a limited space, ensuring efficient reaction. The length-to-height ratio is controlled between 1:4 and 1:6. This ratio provides sufficient space in the vertical direction for effective water circulation and mixing, while also creating a suitable environment for microbial growth and metabolism. The circulation drive device plays a core role in the operation of the entire reaction tank. Currently, two aeration devices are used: perforated pipe 15 and aeration disc 7, both installed on... Figure 1 The right bottom region of the reaction tank shown;

[0050] Step 2: The perforated pipe 15 is horizontally installed at the bottom of the self-circulating reaction tank 1. It has specific design parameters; the aperture of the perforated pipe 15 is precisely set between 1 and 3 mm, and the opening direction is at a 30°-60° angle downwards from the horizontal. This downward-sloping opening design ensures that the bubbles generated during aeration rush towards the bottom of the tank at a certain angle, enhancing the disturbance effect on the bottom water. The length of the perforated pipe 15 is 1 / 2 to 1 / 3 of the bottom length of the self-circulating reaction tank 1. This length is set to ensure sufficient driving force for water circulation while avoiding energy waste and installation inconvenience due to excessive length. Because the aperture of the perforated pipe 15 is relatively large, the volume of the bubbles it generates is also large. These large bubbles, during their ascent, drive the surrounding water to flow rapidly, thus providing a strong driving force for the circulation of water within the reaction tank. Simultaneously, the large air-liquid contact area during the ascent of the large bubbles is relatively large, enabling rapid transfer of oxygen from the air to the water, providing the necessary dissolved oxygen for ammonia-oxidizing bacteria, meeting their metabolic needs, and promoting the smooth progress of the ammonia oxidation reaction.

[0051] Step 3: The aeration disc 7 is installed above the perforated pipe 15, and its structure differs from that of the perforated pipe 15. The aeration disc 7 has smaller pores, resulting in smaller bubbles. These tiny bubbles have a larger specific surface area and rise more slowly in the water, allowing for more thorough contact with the water and thus more effectively transferring oxygen to the water. The main function of the aeration disc 7 is to provide sufficient and stable dissolved oxygen for ammonia-oxidizing bacteria. Due to the small size of the bubbles it produces, they are more evenly distributed in the water, maintaining a suitable dissolved oxygen concentration over a wider area compared to the larger bubbles produced by the perforated pipe 15, creating a more stable living environment for ammonia-oxidizing bacteria. In addition, although the bubbles produced by the aeration disc 7 are smaller, they still cause some disturbance to the water during their ascent, thus providing driving force for water circulation and assisting the perforated pipe 15 in maintaining water circulation within the reaction tank.

[0052] Step 4: Under the synergistic effect of the circulation drive device composed of perforated pipe 15 and aeration disc 7, the water flow in the self-circulating reaction tank 1 can form a stable and efficient circulation. The circulation of water will drive the granular sludge to flow in the reaction tank. During the flow, the granular sludge will be subjected to hydraulic shear force. Appropriate hydraulic shear force can promote the continuous renewal of microorganisms on the surface of granular sludge and maintain their activity. At the same time, it also helps to maintain the structural stability of granular sludge. When granular sludge collides and rubs against each other in the water flow, it can remove the aging microbial film in time, so that new microorganisms can attach and grow, thereby ensuring that the granular sludge always has good metabolic function.

[0053] Step 5: The effluent trough 5 is located at the top of the reaction tank on the side opposite to the drive unit. It plays a crucial role in the entire reaction system, handling both effluent and sludge retention. A filter screen 17 with a pore size of 1-3 mm is installed at the bottom of the effluent trough 5. During the operation of the reaction tank, water circulates downwards on one side of the effluent trough 5, eventually passing through the filter screen at the bottom of the effluent trough 5 and entering the effluent tank itself. The filter screen 17 is of critical importance; it effectively prevents granular sludge from flowing out of the reaction tank with the water flow, ensuring that the granular sludge always participates in the reaction within the tank, maintaining the quantity and activity of microorganisms in the reaction system, and ensuring the continuous and stable progress of the reaction. Simultaneously, the pore size of the filter screen 17 ensures smooth water flow while preventing the loss of granular sludge, thus guaranteeing water quality and achieving efficient operation of the reaction system.

[0054] Example

[0055] like Figure 1 - Figure 2As shown, the self-circulating reaction tank 1 features a unique structure and operation mode. Its top design is flexible, allowing for either a closed or open configuration depending on the application scenario and process requirements. In terms of geometry, the length-to-width ratio is set between 3:1 and 3:2. This ratio helps to rationally plan the water flow path and reaction zone within a limited space, ensuring efficient reaction. The length-to-height ratio is controlled between 1:4 and 1:6. This ratio provides sufficient space in the vertical direction for effective water circulation and mixing, while also creating a suitable environment for microbial growth and metabolism. The circulation drive device plays a core role in the operation of the entire reaction tank. Currently, two aeration devices are used: perforated pipe 15 and aeration disc 7, both installed on... Figure 1 The right bottom region of the reaction tank shown;

[0056] The perforated pipe 15 is horizontally installed at the bottom of the self-circulating reaction tank 1. It has specific design parameters; the aperture size of the perforated pipe 15 is precisely set between 1 and 3 mm, and the opening direction is at a downward angle of 30° to 60° to the horizontal. This downward-sloping opening design ensures that the bubbles generated during aeration rush towards the bottom of the tank at a certain angle, enhancing the disturbance effect on the bottom water. The length of the perforated pipe 15 is 1 / 2 to 1 / 3 of the bottom length of the self-circulating reaction tank 1. This length is set to ensure sufficient driving force for water circulation while avoiding energy waste and installation inconvenience due to excessive length. Because the aperture of the perforated pipe 15 is relatively large, the volume of the bubbles it generates is also large. These large bubbles, during their ascent, drive the surrounding water to flow rapidly, thus providing a strong driving force for the circulation of water within the reaction tank. Simultaneously, the large air-liquid contact area during the ascent of the large bubbles is relatively large, enabling rapid transfer of oxygen from the air to the water, providing the necessary dissolved oxygen for ammonia-oxidizing bacteria, meeting their metabolic needs, and promoting the smooth progress of the ammonia oxidation reaction.

[0057] The aeration disc 7 is installed above the perforated pipe 15, and its structure differs from that of the perforated pipe 15. The aeration disc 7 has smaller pores, resulting in smaller bubbles. These tiny bubbles have a larger specific surface area and rise more slowly in the water, allowing for more thorough contact with the water and thus more effectively transferring oxygen. The main function of the aeration disc 7 is to provide sufficient and stable dissolved oxygen for ammonia-oxidizing bacteria. Due to the small size of the bubbles it produces, they are more evenly distributed in the water, maintaining a suitable dissolved oxygen concentration over a wider area compared to the larger bubbles produced by the perforated pipe 15, creating a more stable living environment for ammonia-oxidizing bacteria. Furthermore, although the bubbles produced by the aeration disc 7 are smaller, their rising motion still disturbs the water, providing a driving force for water circulation and assisting the perforated pipe 15 in maintaining water circulation within the reaction tank.

[0058] Under the synergistic effect of the circulation drive device composed of perforated pipe 15 and aeration disc 7, the water flow in the self-circulating reaction tank 1 can form a stable and efficient circulation. The circulation of water will drive the granular sludge to flow in the reaction tank. During the flow, the granular sludge will be subjected to hydraulic shear force. Appropriate hydraulic shear force can promote the continuous renewal of microorganisms on the surface of granular sludge and maintain their activity. At the same time, it also helps to maintain the structural stability of granular sludge. When granular sludge collides and rubs against each other in the water flow, it can remove the aging microbial film in time, so that new microorganisms can attach and grow, thereby ensuring that the granular sludge always has good metabolic function.

[0059] The effluent trough 5 is located at the top of the reaction tank on the side opposite to the drive unit. It plays a crucial role in the entire reaction system, handling both effluent and sludge retention. A filter screen 17 with a pore size of 1-3 mm is installed at the bottom of the effluent trough 5. During operation, water circulates downwards along one side of the effluent trough 5, ultimately passing through the filter screen at the bottom of the effluent trough 5 and entering the effluent tank. The filter screen 17 is critical; it effectively prevents granular sludge from flowing out of the reaction tank with the water flow, ensuring that the granular sludge always participates in the reaction within the tank, maintaining the quantity and activity of microorganisms in the reaction system, and guaranteeing the continuous and stable progress of the reaction. Simultaneously, the pore size of the filter screen 17 ensures smooth water flow while preventing the loss of granular sludge, thus ensuring water quality and achieving efficient operation of the reaction system.

[0060] The above description is only a further embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the scope disclosed by the present utility model, based on the technical solution and concept of the present utility model, shall fall within the protection scope of the present utility model.

Claims

1. A self-circulating integrated granular sludge denitrification device with zoned aeration, comprising a self-circulating reaction tank (1); Its features are: A water outlet tank (5) is installed above the self-circulating reaction tank (1); A perforated pipe (15) is installed diagonally opposite the outlet tank (5) inside the self-circulating reaction tank (1); A perforated pipe air inlet (9) is installed at the outer end of the perforated pipe (15), an aeration pipe (13) is installed at the outer end of the perforated pipe air inlet (9), a perforated pipe aeration flow meter (11) is installed on one side of the aeration pipe (13), an aeration disc aeration flow meter (12) is installed on the other side of the aeration pipe (13), an aeration disc air inlet (14) is installed at the other end of the perforated pipe air inlet (9), an aeration disc (7) is installed at the outer end of the aeration disc air inlet (14), and the aeration disc (7) is placed in the self-circulating reaction tank (1). The effluent tank (5) on the self-circulating reaction tank (1) is connected to a reflux assembly.

2. The self-circulating integrated granular sludge denitrification device with zoned aeration according to claim 1, characterized in that: The reflux assembly includes a reflux port (2), a reflux pump (4), an outlet tank (5), a reflux flow meter (6), an inlet (8), an inlet flow meter (10), and a reflux pipe (16); A return port (2) and an outlet (3) are installed on one side of the outlet tank (5) on the self-circulating reaction tank (1). A return pipe (16) is installed at the outlet end of the return port (2). A return pump (4) and a return flow meter (6) are installed on the return pipe (16) from near to far. The outer end of the return pipe (16) is connected to the inlet (8). An inlet flow meter (10) is installed at the outer end of the inlet (8).

3. The self-circulating integrated granular sludge denitrification equipment with zoned aeration according to claim 2, characterized in that: The self-circulating reaction tank (1) is a closed or open structure. The length-to-width ratio of the self-circulating reaction tank (1) is 3:1-3:2, and the length-to-height ratio of the self-circulating reaction tank (1) is 1:4-1:

6.

4. The self-circulating integrated granular sludge denitrification equipment with zoned aeration according to claim 3, characterized in that: The holes on the perforated tube (15) are 1-3mm in diameter, and the direction of the holes on the perforated tube (15) is 30°-60° to the horizontal direction. The length of the perforated tube (15) is 1 / 2-1 / 3 of the length of the bottom of the self-circulating reaction tank (1).

5. The self-circulating integrated granular sludge denitrification equipment with zoned aeration according to claim 4, characterized in that: The holes on the filter screen (17) are 1-3 mm.

6. The self-circulating integrated granular sludge denitrification device with zoned aeration according to claim 5, characterized in that: An outlet (3) is installed above the return port (2), and a filter screen (17) covers the bottom of the outlet tank (5).

7. The self-circulating integrated granular sludge denitrification device with zoned aeration according to claim 6, characterized in that: The self-circulating reaction tank (1) is driven by the aeration disc (7), the inlet (8) and the perforated pipe (15).

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