An AAO wastewater treatment device based on anaerobic ammonium oxidation

Abstract

This invention provides an AAO wastewater treatment device based on anaerobic ammonia oxidation, comprising a treatment tank. The tank is internally divided into an anaerobic reaction chamber, an anoxic reaction chamber, an aerobic reaction chamber, and a sedimentation chamber. Two pneumatic agitators are installed at the center of the bottom wall of each of the anaerobic, anoxic, and aerobic reaction chambers. Adjustable-spacing biofilm hangers are installed in the center of each of the anaerobic and anoxic reaction chambers. Each adjustable-spacing biofilm hanger includes a drive device that allows the two ends of the fork-shaped telescopic frame to retract towards the center. In this invention, the pneumatic agitators are all located at the bottom of the reaction chamber, which does not affect the installation of the biofilm. When the pneumatic agitators are running, the biofilm on the adjustable-spacing biofilm hangers will move towards the center, allowing the turbid wastewater to fully contact the anaerobic bacteria on the biofilm during agitation, effectively improving the wastewater treatment effect. When the pneumatic agitators are not running, the biofilm can move away from each other under the action of the drive unit, ensuring the wastewater treatment effect.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to an AAO wastewater treatment device based on anaerobic ammonia oxidation. Background Technology

[0002] Anaerobic ammonia oxidation (AAO) is a novel biological nitrogen removal technology. Under anaerobic conditions, anaerobic ammonia-oxidizing bacteria utilize nitrite as an electron acceptor to oxidize ammonia nitrogen into nitrogen gas. Currently, AAO technology has been effectively applied in wastewater treatment. Combining AAO with AAO wastewater treatment technology not only achieves effective wastewater treatment but also significantly reduces operating costs compared to traditional AAO wastewater treatment technologies.

[0003] Patent application number 2020108884561 discloses a method for modifying the AAO process in urban wastewater treatment plants based on anaerobic ammonia oxidation. While the disclosed reaction device exhibits good nitrogen removal performance, it still has some design flaws. The device includes a stirrer in each of the anaerobic, anoxic, and aerobic reactors. This not only increases operating costs but, more importantly, prevents the formation of biofilms in the anaerobic and anoxic reactors, thus reducing wastewater treatment efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide an AAO wastewater treatment device based on anaerobic ammonia oxidation, which solves the problem that the stirrer and biofilm cannot be designed simultaneously in existing AAO process coupled with anaerobic ammonia oxidation reaction devices.

[0005] According to one objective of the present invention, the present invention provides an AAO wastewater treatment device based on anaerobic ammonia oxidation, comprising a treatment tank and a control cabinet. The interior of the treatment tank is divided into an anaerobic reaction chamber, an anoxic reaction chamber, an aerobic reaction chamber, and a sedimentation chamber by several partitions from left to right. A first overflow port, a second overflow port, and an overflow pipe are respectively provided on the partitions from left to right. An inlet pipe is provided on the outer wall of the anaerobic reaction chamber, and a clear water discharge pipe is provided on the outer wall of the sedimentation chamber. Two pneumatic stirrers are provided at the center of the bottom wall of each of the anaerobic reaction chamber, the anoxic reaction chamber, and the aerobic reaction chamber. The pneumatic stirrers are connected in series by air pipes. An air compressor is provided on the outer side of the treatment tank. The air compressor is connected to the first pneumatic stirrer in the anaerobic reaction chamber. An aeration head is provided on the air pipe located in the aerobic reaction chamber.

[0006] Both the anaerobic reaction chamber and the anoxic reaction chamber are equipped with adjustable-spacing biofilm hangers. Each adjustable-spacing biofilm hanger includes horizontal grooves on the side walls of the anaerobic or anoxic reaction chamber. Two aligned fork-shaped telescopic frames are arranged between the two horizontal grooves. A crossbar is provided at the center intersection of each of the two fork-shaped telescopic frames. Both ends of the crossbar are provided with sliders that extend into the horizontal grooves. Multiple biofilms are spaced apart on each crossbar. The adjustable-spacing biofilm hanger also includes a drive device for retracting the two ends of the fork-shaped telescopic frames towards the center.

[0007] Furthermore, the drive device includes lead screw nuts connected to the frontmost and rearmost crossbars, with a bidirectional lead screw threaded onto the two lead screw nuts, and a lead screw motor connected to one end of the bidirectional lead screw.

[0008] Furthermore, the pneumatic stirrer includes a support and a disc shell. The disc shell is connected to the upper end of the support. A rotating shaft extending into the support is concentrically rotatably connected in the disc shell. A pneumatic impeller is provided on the rotating shaft located inside the disc shell. A stirring blade located in the support is connected to the lower end of the rotating shaft. Two tangential tubes connected to the air pipe are connected to the circumferential surface of the disc shell.

[0009] Furthermore, a sealed bearing that mates with the rotating shaft is provided at the connection between the disc outer shell and the bracket.

[0010] Furthermore, the air compressor is connected to a three-way valve at its outlet, and the air compressor is connected to the air pipes in the anaerobic reaction chamber and the aerobic reaction chamber respectively through the three-way valve.

[0011] Furthermore, a biological sludge interception mechanism is provided on the partition located at the second overflow port. The biological sludge interception mechanism includes a filter cover connected to the partition. The second overflow port is connected to the filter cover. Filter holes are provided at the lower end of the filter cover.

[0012] Furthermore, the filter cover is provided with belt rollers at both the upper and lower ends. One end of the belt roller at the upper end is connected to a drive motor. A sludge scraping belt is provided between the two belt rollers. Multiple sludge scraping blades are connected at equal intervals on the outer side of the sludge scraping belt.

[0013] Furthermore, a sludge return port is provided on the partition plate located above the second overflow port. A sludge return plate is inclinedly inserted into the sludge return port. A pressing protrusion is provided at the end of the sludge return plate. A spring is provided between the pressing protrusion and the partition plate. A cam that interacts with the pressing protrusion is provided on the roller shaft of the belt roller located at the upper end.

[0014] Furthermore, the sedimentation chamber is equipped with a sedimentation hopper, the overflow pipe extends into the upper opening of the sedimentation hopper, and the lower end of the sedimentation hopper is connected to a sludge auger conveyor extending out of the treatment box.

[0015] Furthermore, the anaerobic reaction chamber, the anoxic reaction chamber, and the aerobic reaction chamber are all equipped with online pH monitors and temperature detection and control devices.

[0016] In this invention, the pneumatic agitators are all located at the bottom of the reaction chamber, which does not affect the installation of biofilms in the anaerobic and anoxic reaction chambers. When the pneumatic agitator is running, the adjustable-spacing biofilm hangers allow the biofilms to move closer to the center, ensuring sufficient contact between the turbid wastewater and the anaerobic bacteria on the biofilm during agitation, effectively improving wastewater treatment. When the pneumatic agitator is not running, the multiple biofilms can move away from each other under the action of the drive unit, filling the entire anaerobic or anoxic reaction chamber and ensuring effective wastewater treatment at every location within the treatment chamber. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a frontal perspective view of the present invention;

[0019] Figure 2 This is a three-dimensional structural diagram of the back of the present invention;

[0020] Figure 3 This is a schematic diagram of the first state structure inside the processing box in this invention;

[0021] Figure 4 This is a schematic diagram of the second state structure inside the processing box in this invention;

[0022] Figure 5 For the present invention Figure 4 Mid-top view of the internal planar structure;

[0023] Figure 6 This is a three-dimensional structural diagram of the adjustable-spacing biofilm hanger of the present invention;

[0024] Figure 7 This is a three-dimensional structural diagram of the pneumatic stirrer in this invention;

[0025] Figure 8 This is a three-dimensional cross-sectional structural diagram of the pneumatic stirrer in this invention;

[0026] Figure 9 This is a three-dimensional structural diagram of the bio-sludge interception mechanism in this invention.

[0027] In the diagram: 1. Treatment tank; 101. Anaerobic reaction chamber; 102. Anoxic reaction chamber; 103. Aerobic reaction chamber; 104. Sedimentation chamber; 105. Inlet pipe; 106. Clear water outlet pipe;

[0028] 2. Control cabinet; 3. Air compressor; 4. First partition; 401. First overflow port;

[0029] 5. Second baffle; 501. Second overflow outlet; 502. Sludge return outlet;

[0030] 6. Third partition; 601. Overflow pipe;

[0031] 7. Pneumatic agitator; 701. Support frame; 702. Disc housing; 703. Tangent tube; 704. Shaft; 705. Sealed bearing; 706. Pneumatic impeller; 707. Agitator blade;

[0032] 8. First air pipe; 9. Second air pipe; 10. Third air pipe; 11. Three-way valve; 12. First air inlet pipe; 13. Second air inlet pipe; 14. Aeration head; 15. Adjustable spacing biofilm hanger; 151. Horizontal chute; 152. Fork-type telescopic frame; 153. Crossbar; 154. Slider; 155. Lead screw nut; 156. Bidirectional lead screw; 157. Lead screw motor; 158. Biofilm attachment;

[0033] 16. Sedimentation hopper; 17. Biological sludge interception mechanism; 171. Filter cover; 172. Belt roller; 173. Sludge scraper belt; 174. Sludge scraper; 175. Sludge return plate; 176. Pressing protrusion; 177. Spring; 178. Drive motor; 179. Cam;

[0034] 18. Sludge auger conveyor. Detailed Implementation

[0035] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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 limiting this invention.

[0037] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Example 1

[0039] like Figures 1-4 As shown, an AAO wastewater treatment device based on anaerobic ammonia oxidation includes a treatment tank 1, a control cabinet 2, and an air compressor 3. Inside the treatment tank 1, from left to right, are arranged a first partition 4, a second partition 5, and a third partition 6, which divide the interior of the treatment tank 1 into an anaerobic reaction chamber 101, an anoxic reaction chamber 102, an aerobic reaction chamber 103, and a sedimentation chamber 104. Each of the anaerobic reaction chamber 101, anoxic reaction chamber 102, and aerobic reaction chamber 103 is equipped with an online pH monitor and a temperature detection and control device, all of which are prior art and are not illustrated in this embodiment.

[0040] An inlet pipe 105 is installed on the outer sidewall of the anaerobic reaction chamber 101. A first overflow port 401 is opened on the first partition 4, a second overflow port 501 is opened on the second partition 5, and a row of overflow pipes 601 is installed on the third partition 6. The horizontal heights of the inlet pipe 105, the first overflow port 401, the second overflow port 501, and the overflow pipes 601 gradually decrease. In the wastewater treatment process, wastewater enters the anaerobic reaction chamber 101 through the inlet pipe 105, and then enters the anoxic reaction chamber 102 through the first overflow port 401. In the anaerobic reaction chamber 101 and the anoxic reaction chamber 102, the wastewater is denitrified by anaerobic ammonia-oxidizing bacteria and denitrifying bacteria. The denitrified wastewater then enters the aerobic reaction chamber 103, where aerobic bacteria remove phosphorus under aeration. Finally, the treated wastewater enters the sedimentation chamber 104 through the overflow pipe 601 for sedimentation. The clear water after sedimentation is discharged directly.

[0041] like Figure 3 and Figure 5 As shown, two pneumatic stirrers 7 are installed at the center of the bottom wall of each of the anaerobic reaction chamber 101, the anoxic reaction chamber 102, and the aerobic reaction chamber 103. A first air pipe 8 is connected between the two pneumatic stirrers 7 in each of the three chambers. A second air pipe 9 is connected between the two pneumatic stirrers 7 in the anaerobic reaction chamber 101 and the anoxic reaction chamber 102. A third air pipe 10 is connected between the two pneumatic stirrers 7 in the anoxic reaction chamber 102 and the aerobic reaction chamber 103. A three-way valve 11 is connected to the outlet of the air compressor 3. The three-way valve 11 is connected to a first air inlet pipe 12 and a second air inlet pipe 13. The end of the first air inlet pipe 12 is connected to the first pneumatic agitator 7 in the anaerobic reaction chamber 101, while the second air inlet pipe 13 is connected to the third air pipe 10 in the aerobic reaction chamber 103. Multiple aeration heads 14 are also installed on the first air pipe 8 of the aerobic reaction chamber 103. Through this structural design, when it is necessary to agitate the anaerobic reaction chamber 101 and the anoxic reaction chamber 102 to improve wastewater treatment efficiency, the three-way valve 11 is controlled to open the first air inlet pipe 12. Then, the air compressor 3 is started, allowing compressed gas to sequentially enter the pneumatic agitators 7 in the anaerobic reaction chamber 101, the anoxic reaction chamber 102, and the aerobic reaction chamber 103. The pneumatic agitators 7 agitate the wastewater during the treatment process. Finally, the compressed air is discharged from the aeration heads 14 in the aerobic reaction chamber 103, achieving aeration.

[0042] like Figure 7 and Figure 8As shown, the pneumatic agitator 7 includes a support 701 and a disc housing 702. The disc housing 702 is fixedly mounted on the upper end of the support 701. Two tangential pipes 703 are connected to the circumferential surface of the disc housing 702, allowing compressed air supplied from the pipes to enter or exit the disc housing 702 along a tangential direction. A rotating shaft 704 is concentrically rotatably connected within the disc housing 702, and a sealed bearing 705 suitable for the rotating shaft 704 is provided at the connection between the support 701 and the disc housing 702. A pneumatic impeller 706 is provided on the rotating shaft 704 located inside the disc housing 702, and multiple agitator blades 707 are provided at the lower end of the rotating shaft 704 extending out of the disc housing 702. The above-mentioned pneumatic agitator 7 is designed to use high-pressure gas as a power source to act on the impeller blades 706, causing the shaft 704 to rotate. During the rotation of the shaft 704, the wastewater in the treatment process is stirred by the agitator blades 707 at the lower end, thereby improving the wastewater treatment efficiency.

[0043] like Figure 3 and Figure 6 As shown,

[0044] Adjustable-spacing biofilm hangers 15 are installed in both the anaerobic reaction chamber 101 and the anoxic reaction chamber 102. Each adjustable-spacing biofilm hanger 15 includes horizontal grooves 151 located at the upper ends of both sides of the anaerobic reaction chamber 101 or the anoxic reaction chamber 102. Two left-right aligned fork-type telescopic frames 152 are positioned between the two horizontal grooves 151, and a crossbar 153 is installed at each central intersection of the two fork-type telescopic frames 152. Each crossbar 153 has a slider 154 at both ends that matches the horizontal groove 151. Lead screw nuts 155 are fixedly connected to the two crossbars 153 at the front and rear ends, and the two lead screw nuts 155 are aligned on the same straight line. A bidirectional lead screw 156 is threaded between the two lead screw nuts 155, with the helical directions at both ends of the bidirectional lead screw 156 being opposite. A lead screw motor 157 connected to the bidirectional lead screw 156 is installed on the outer side of the treatment box 1. Finally, multiple biofilms 158 are spaced apart on each crossbar 153 along its left-right direction. The adjustable-spacing biofilm hanger 15 in this embodiment is designed so that before the pneumatic agitator 7 operates, the screw motor 157 is started, and the transmission between the bidirectional screw 156 and the screw nut 155 causes all the crossbars 153 to move towards the center under the action of the fork-type telescopic frame 152. When all the crossbars 153 are close to each other, the biofilms 158 on the crossbars 153 are all clustered together and located directly above the pneumatic agitator 7. At this time, combined with the agitation of the wastewater at the center by the pneumatic agitator 7, the contact effect between the wastewater and the anaerobic ammonia-oxidizing bacteria and nitrifying bacteria on the biofilm is greatly improved, resulting in optimal wastewater treatment efficiency for anaerobic bacteria in the anaerobic reaction chamber 101 and the anoxic reaction chamber 102. When the anaerobic reaction chamber 101 and the anoxic reaction chamber 102 are performing normal wastewater treatment, the screw motor 157 is started in reverse, so that all the crossbars 153 move away from each other, thereby causing the biofilm 158 on the crossbars 153 to cover the entire anaerobic reaction chamber 101 or the anoxic reaction chamber 102.

[0045] like Figure 3 and Figure 4 As shown, a sedimentation hopper 16 is installed inside the sedimentation chamber 104. A row of overflow pipes 601 on the third partition 6 extends into the upper opening of the sedimentation hopper 16. A sludge auger conveyor 18 is connected to the lower end of the sedimentation hopper 16, and the discharge end of the sludge auger conveyor 18 extends out of the rear side of the sedimentation chamber 104. A clean water discharge pipe 106 is installed at the lower end of the sedimentation chamber 104. The treated liquid is sent to the sedimentation hopper 16 for sedimentation through the overflow pipe 601. The settled clean water flows down from the upper end of the sedimentation hopper 16 and is discharged from the entire treatment tank 1 through the clean water discharge pipe 106. At the same time, whenever the sludge in the sedimentation hopper 16 reaches a certain amount, the sludge auger conveyor 18 is activated to promptly discharge the settled sludge.

[0046] The existing wastewater treatment equipment does not have a sludge retention mechanism between the anoxic reactor and the aerobic reactor. This results in the need to frequently start the return pump during operation to return the mixed liquor from the aerobic reactor to the anoxic reactor in order to maintain a stable bacterial count inside the anoxic reactor. However, the mixed liquor has a high oxygen concentration, and the frequent return of the mixed liquor will increase the oxygen content of the reaction liquid inside the anoxic reactor. As a result, the anaerobic bacteria in the anoxic reactor cannot maintain a high treatment efficiency after each return.

[0047] like Figure 3 , Figure 4 and Figure 9 As shown, a biological sludge interception mechanism 17 is provided at the second overflow port 501 on the second partition 5. The biological sludge interception mechanism 17 includes a filter cover 171 provided on the right side of the second overflow port 501. A large number of filter holes are provided at the lower end of the filter cover 171, so that the sewage flowing into the aerobic reaction chamber 103 from the second overflow port 501 is filtered through the filter holes first, and the biological sludge is intercepted at the lower end of the filter cover 171 after filtration.

[0048] A belt roller 172 is provided at both the upper and lower ends of the filter cover 171. A scraper belt 173 is provided between the two belt rollers 172. Multiple scraper plates 174 are connected at equal intervals on the outer side of the scraper belt 173. Filter holes are also provided on the scraper plates 174 to filter water during the scraping process.

[0049] A sludge return port 502 is located above the second overflow port 501, and the sludge return port 502 is aligned with the upper end of the filter cover 171. A sludge return plate 175 is obliquely inserted into the sludge return port 502, and a pressing protrusion 176 is provided at the end of the sludge return plate 175. A spring 177 is connected between the pressing protrusion 176 and the second partition 5. The biological sludge interception mechanism 17 also includes a drive motor 178 provided on the outer side of the treatment tank 1. The motor shaft of the drive motor 178 is connected to the upper belt roller 172, and a cam 179 is provided on the roller shaft of the belt roller 172 to interact with the pressing protrusion 176.

[0050] This invention utilizes a biological sludge interception mechanism 17 to allow wastewater flowing from the second overflow port 501 to enter the lower end of the filter cover 171. The biological sludge in the wastewater is intercepted through the filter holes at the lower end of the filter cover 171. When the amount of biological sludge intercepted at the lower end of the filter cover 171 reaches a certain level, it will clog the filter holes. At this point, the drive motor 178 is activated, causing the scraper belt 173 to begin driving. Under the action of the scraper belt 173, the scraper plate 174 moves, thereby scraping up the biological sludge intercepted at the lower end of the filter cover 171. When the scraper plate 174, carrying biological sludge, moves past the top of the scraper belt 173, the non-protruding part of the cam 179 interacts with the pressing protrusion 176. Under the action of the spring 177, the upper end of the return plate 175 extends into the upper end of the filter cover 171, thereby receiving the overturned biological sludge. The biological sludge then falls into the anoxic reaction chamber 102 through the sludge return port 502. Next, as the drive motor 178 continues to rotate, the protrusion of the cam 179 will press against the protrusion 176, causing the upper end of the mud return plate 175 to move to the lower left, thus not obstructing the movement of the mud scraper belt 173 and ensuring the normal operation of the mud scraper belt 173.

[0051] This invention employs specially designed pneumatic agitators in the anaerobic, anoxic, and aerobic reaction chambers to agitate wastewater. Since the pneumatic agitators are all located at the bottom of the reaction chambers, they do not interfere with the installation of biofilm in the anaerobic and anoxic reaction chambers. Furthermore, the pneumatic agitators in each reaction chamber are connected in series by air pipes, and all pneumatic agitators can be operated simultaneously using only compressed gas generated by an air compressor. This effectively reduces the high energy consumption problem of multiple vertical agitators in existing technologies. Moreover, the compressed gas can be discharged from the aeration head to achieve aeration in the aerobic reaction chamber, resulting in lower operating costs for the entire AAO wastewater treatment device.

[0052] This invention also incorporates a specially designed adjustable-spacing biofilm hanger based on the pneumatic agitator. When the pneumatic agitator is running, the biofilms move towards the center until all biofilms are positioned directly above the agitator. During agitation, the turbid wastewater can fully contact the anaerobic bacteria on the biofilms, effectively improving wastewater treatment. Furthermore, when the pneumatic agitator is not running, the multiple biofilms can move away from each other under the action of the drive unit, allowing multiple biofilms to fill the entire anaerobic or anoxic reaction chamber, ensuring effective wastewater treatment at every location within the treatment chamber.

[0053] The design of the biological sludge interception mechanism of this invention can filter the wastewater flowing from the anoxic reaction chamber into the aerobic reaction chamber. Only the filtered wastewater is discharged into the aerobic reaction chamber, while the intercepted biological sludge is conveyed upward by the scraper belt and scraper plate. After the scraper plate moves past the top of the scraper belt, the scraped sludge is discharged into the return sludge plate, and then put back into the anoxic reaction chamber through the return sludge plate. The design of the entire biological sludge interception mechanism not only effectively avoids the loss of biological sludge in the anoxic reaction chamber, ensuring that the amount of biological sludge in the anoxic reaction chamber is always maintained within the optimal value, but also the circulating movement of the scraper plate can clean the intercepted sludge, preventing the filter holes at the lower end of the filter cover from becoming blocked, thus ensuring the filtration and interception effect of wastewater.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An AAO wastewater treatment device based on anaerobic ammonia oxidation, characterized in that, The system includes a treatment box and a control cabinet. The interior of the treatment box is divided into an anaerobic reaction chamber, an anoxic reaction chamber, an aerobic reaction chamber, and a sedimentation chamber from left to right by several partitions. A first overflow port, a second overflow port, and an overflow pipe are respectively provided on the partitions from left to right. A water inlet pipe is provided on the outer wall of the anaerobic reaction chamber, and a clear water outlet pipe is provided on the outer wall of the sedimentation chamber. Two pneumatic stirrers are provided at the center of the bottom wall of each of the anaerobic reaction chamber, the anoxic reaction chamber, and the aerobic reaction chamber. The pneumatic stirrers are connected in series through air pipes. An air compressor is provided on the outer side of the treatment box. The air compressor is connected to the first pneumatic stirrer in the anaerobic reaction chamber. An aeration head is provided on the air pipe located in the aerobic reaction chamber. Both the anaerobic reaction chamber and the anoxic reaction chamber are equipped with adjustable-spacing biofilm hangers. Each adjustable-spacing biofilm hanger includes horizontal grooves on the side walls of the anaerobic reaction chamber or the anoxic reaction chamber. Two aligned fork-type telescopic frames are arranged between the two horizontal grooves. A crossbar is provided at the center intersection of each of the two fork-type telescopic frames. Both ends of the crossbar are provided with sliders that extend into the horizontal grooves. Multiple biofilms are spaced apart on each crossbar. The adjustable-spacing biofilm hanger also includes a drive device for retracting the two ends of the fork-type telescopic frames towards the center. The pneumatic agitator includes a support frame and a disc-shaped outer shell. The disc-shaped outer shell is connected to the upper end of the support frame. A rotating shaft extending into the support frame is concentrically rotatably connected within the disc-shaped outer shell. A pneumatic impeller is mounted on the rotating shaft inside the disc-shaped outer shell. A stirring blade located within the support frame is connected to the lower end of the rotating shaft. Two tangential tubes connected to the air pipe are connected to the circumferential surface of the disc-shaped outer shell. A bio-sludge retention mechanism is provided on the baffle plate located at the second overflow port. The bio-sludge retention mechanism includes a filter cover connected to the baffle plate. The second overflow port is connected to the filter cover. The filter cover is connected in a series of configurations. A filter hole is provided at the lower end of the filter cover. A belt roller is provided at both the upper and lower ends of the filter cover. A drive motor is connected to one end of the upper belt roller. A sludge scraping belt is provided between the two belt rollers. Multiple sludge scraping plates are evenly spaced on the outer side of the sludge scraping belt. A sludge return port is provided on the partition plate above the second overflow port. A sludge return plate is inserted obliquely into the sludge return port. A pressing protrusion is provided at the end of the sludge return plate. A spring is provided between the pressing protrusion and the partition plate. A cam is provided on the roller shaft of the upper belt roller.

2. The AAO wastewater treatment device based on anaerobic ammonia oxidation according to claim 1, characterized in that, The drive device includes lead screw nuts connected to the frontmost and rearmost crossbars, and a bidirectional lead screw is threaded onto the two lead screw nuts. One end of the bidirectional lead screw is connected to a lead screw motor.

3. The AAO wastewater treatment device based on anaerobic ammonia oxidation according to claim 1, characterized in that, A sealed bearing that mates with the rotating shaft is provided at the connection between the outer shell of the disc and the support.

4. The AAO wastewater treatment device based on anaerobic ammonia oxidation according to claim 1, characterized in that, The air compressor is connected to a three-way valve at its outlet, and the air compressor is connected to the air pipes in the anaerobic reaction chamber and the aerobic reaction chamber respectively through the three-way valve.

5. The AAO wastewater treatment device based on anaerobic ammonia oxidation according to claim 1, characterized in that, The sedimentation chamber is equipped with a sedimentation hopper, and the overflow pipe extends into the upper opening of the sedimentation hopper. The lower end of the sedimentation hopper is connected to a sludge auger conveyor that extends out of the treatment box.

6. The AAO wastewater treatment device based on anaerobic ammonia oxidation according to claim 1, characterized in that, The anaerobic reaction chamber, the anoxic reaction chamber, and the aerobic reaction chamber are all equipped with online pH monitors and temperature detection and control devices.

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