AAO (anaerobic-anoxic-oxic) process coupled double-side-flow sludge treatment system

Abstract

The utility model relates to the technical field of sewage treatment, in particular to an AAO (anaerobic-anoxic-oxic) process coupling bilateral flow sludge treatment system which comprises an anaerobic tank, an anoxic tank, an aerobic tank and a secondary sedimentation tank which are communicated in sequence, and the secondary sedimentation tank is used for settling suspended matters in sewage treated by the aerobic tank to obtain sludge; the system further comprises a control system, the secondary sedimentation tank is communicated with the first side flow module and the second side flow module, the anaerobic tank is provided with first online monitoring equipment, and the first online monitoring equipment is used for monitoring total nitrogen, total phosphorus, COD and ammonia nitrogen data of sewage in the anaerobic tank; the control system is electrically connected with the secondary sedimentation tank, the first side flow module, the second side flow module and the first online monitoring equipment. According to the scheme, the sewage treatment effect can be effectively improved, the use of chemical agents is reduced, the method is more environment-friendly, and the method is particularly suitable for sewage plants with large inlet water quality changes in different seasons, can utilize original sewage treatment structures, is suitable for local conditions, reduces the transformation cost, and has remarkable economic and environmental benefits.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to an AAO process coupled with a two-sided flow sludge treatment system. Background Technique

[0002] The AAO process is the abbreviation of Anaerobic - Anoxic - Oxic in English. It is a commonly used secondary sewage treatment process, which has the function of synchronous nitrogen and phosphorus removal. It can be used for secondary sewage treatment or tertiary sewage treatment, and has good nitrogen and phosphorus removal effects.

[0003] However, in actual situations, the sewage to be treated has different changes. Especially, there are seasonal change trends in COD, TN, TP, etc. in the water body. Due to the relatively fixed traditional AAO process mode, for sewage with a high total phosphorus content or sewage with a high total nitrogen content in different seasons, the existing AAO process has problems with poor treatment effects, resulting in poor sewage treatment effects. Content of the Utility Model

[0004] The purpose of the utility model is to provide an AAO process coupled with a two-sided flow sludge treatment system, aiming to solve the technical problem of poor sewage treatment effect of the existing AAO process in different seasons.

[0005] To achieve the above purpose, the utility model provides an AAO process coupled with a two-sided flow sludge treatment system, which includes an anaerobic tank, an anoxic tank, an aerobic tank and a secondary sedimentation tank connected in sequence. The secondary sedimentation tank is used for settling the suspended substances in the sewage treated by the aerobic tank and obtaining sludge.

[0006] It also includes a control system. The secondary sedimentation tank is respectively connected with a first side flow module and a second side flow module. The anaerobic tank is provided with a first on-line monitoring device, which is used for monitoring the total nitrogen, total phosphorus, COD and ammonia nitrogen data of the sewage in the anaerobic tank. The control system is electrically connected with the first on-line monitoring device. The secondary sedimentation tank is respectively connected with the first side flow module and the second side flow module through a sludge pump house. The sludge pump house is used for pumping the sludge in the secondary sedimentation tank to the first side flow module when receiving a first instruction, and pumping the sludge in the secondary sedimentation tank to the second side flow module when receiving a second instruction:

[0007] When the ratio of COD to total phosphorus obtained by the first on-line monitoring device ≤ a first preset threshold, the control system issues a first instruction;

[0008] When the ratio of COD to total nitrogen obtained by the first on-line monitoring device ≤ a second preset threshold, the control system issues a second instruction.

[0009] Preferably, the first side-stream module includes an anaerobic phosphorus release tank, a sedimentation tank, and a chemical phosphorus removal tank that are connected in sequence. The secondary sedimentation tank is connected to the anaerobic phosphorus release tank. The sedimentation tank is used for sedimenting the sludge treated by the anaerobic phosphorus release tank to obtain supernatant and phosphorus release sludge.

[0010] Preferably, the sedimentation tank is connected to the aerobic tank and is used for returning the phosphorus release sludge obtained from the sedimentation tank to the aerobic tank.

[0011] The chemical phosphorus removal tank is connected to the anaerobic tank and is used for returning the supernatant treated by the chemical phosphorus removal tank to the anaerobic tank.

[0012] Preferably, the anaerobic phosphorus release tank is provided with a first ORP meter for monitoring the oxidation-reduction potential, and the chemical phosphorus removal tank is provided with an orthophosphate on-line monitor for monitoring the content of orthophosphate.

[0013] The chemical phosphorus removal tank is connected to a first chemical storage tank through a first chemical dosing pump. The first chemical storage tank stores a phosphorus remover and / or a flocculant. The control system is electrically connected to the first chemical dosing pump. The control system obtains the monitoring data of orthophosphate to control the chemical dosing amount of the first chemical dosing pump to the chemical phosphorus removal tank.

[0014] Preferably, the second side-stream module includes a sludge concentrator, an acid production tank, a chemical conditioning tank, and a dehydrator that are connected in sequence. The secondary sedimentation tank is connected to the sludge concentrator.

[0015] The sludge concentrator is used for separating the sludge and water in the secondary sedimentation tank to obtain concentrated sludge and a first filtrate. The dehydrator is used for separating the sludge and water in the conditioned sludge obtained from the conditioning tank to obtain dewatered sludge and a second filtrate containing volatile fatty acids.

[0016] Preferably, the sludge concentrator is connected to the anaerobic tank and is used for returning the first filtrate obtained from the sludge concentrator to the anaerobic tank.

[0017] The dehydrator is connected to the anoxic tank and is used for returning the second filtrate obtained from the dehydrator to the anoxic tank.

[0018] Preferably, the acid production tank is provided with a pH detector, a temperature detector, a second ORP meter for monitoring the oxidation-reduction potential in the acid production tank, and a second on-line monitoring device for monitoring the data of volatile fatty acids, total nitrogen, and total phosphorus.

[0019] The chemical conditioning tank is connected to the second chemical storage tank through a second chemical dosing pump. The second chemical storage tank stores flocculant and / or coagulant. The control system is electrically connected to the second chemical dosing pump. The control system obtains the monitoring data of volatile fatty acids, total nitrogen, and total phosphorus to control the chemical dosing amount of the second chemical dosing pump to the acidogenic tank.

[0020] Preferably, a heating device and / or a heat preservation device are also provided in the acidogenic tank.

[0021] Preferably, a pretreatment module is further provided at the front end of the anaerobic tank. The pretreatment module includes a grille and a grit chamber arranged in sequence.

[0022] The AAO process coupled with the two-sided flow sludge treatment system disclosed by the present utility model has the following beneficial effects: In this solution, the first on-line monitoring equipment for monitoring total nitrogen, total phosphorus, COD, and ammonia nitrogen is installed in the anaerobic tank. When the detected influent total phosphorus data is too high, the first side flow process is started. Through this side flow process, the activated sludge completely releases phosphorus and then returns to the aerobic tank to absorb phosphorus, improving the biochemical phosphorus removal efficiency. When the detected influent total nitrogen data is too high, the second side flow process is started. The VFAs produced by the sludge are recycled as a carbon source to improve the biochemical nitrogen removal efficiency. This system can effectively improve the sewage treatment effect, reduce the use of chemical agents, be more environmentally friendly, and is especially suitable for sewage treatment plants with large changes in influent water quality in different seasons. It can also utilize the original sewage treatment structures, adapt to local conditions, and reduce the transformation cost, having significant economic and environmental benefits. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0024] Figure 1 It is a schematic structural diagram of the AAO process coupled with the two-sided flow sludge treatment system of the present utility model;

[0025] Figure 2 It is a schematic structural diagram of the first side flow module of the AAO process coupled with the two-sided flow sludge treatment system of the present utility model;

[0026] Figure 3 It is a schematic structural diagram of the second side flow module of the AAO process coupled with the two-sided flow sludge treatment system of the present utility model.

[0027] In the attached drawings: 1 - anaerobic tank, 11 - first on-line monitoring device, 2 - anoxic tank, 3 - aerobic tank, 4 - secondary sedimentation tank, 41 - sludge pump house, 5 - control system, 6 - first side-stream module, 61 - anaerobic phosphorus release tank, 611 - first ORP meter, 62 - sedimentation tank, 63 - chemical phosphorus removal tank, 631 - orthophosphate on-line monitor, 64 - first chemical dosing pump, 7 - second side-stream module, 71 - sludge thickener, 72 - acid-producing tank, 721 - second on-line monitoring device, 73 - chemical conditioning tank, 74 - dehydrator, 75 - second chemical dosing pump, 76 - acid-producing liquid storage tank, 8 - pretreatment module, 81 - grille, 82 - grit chamber.

[0028] The realization of the purpose, functional features and advantages of the present utility model will be further described with reference to the embodiments and the attached drawings. Specific embodiments

[0029] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the attached drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0030] It should be noted that if there are directional indications involved in the embodiments of the present utility model, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0031] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0032] As Figure 1 shown, an AAO process coupled with a double-side-stream sludge treatment system includes an anaerobic tank 1, an anoxic tank 2, an aerobic tank 3 and a secondary sedimentation tank 4 connected in sequence. The secondary sedimentation tank 4 is used to settle the suspended solids in the sewage treated by the aerobic tank 3 and obtain sludge.

[0033] It also includes a control system 5. The secondary sedimentation tank 4 is respectively connected to a first side-stream module 6 and a second side-stream module 7. The anaerobic tank 1 is provided with a first on-line monitoring device 11 for monitoring the total nitrogen, total phosphorus, COD and ammonia nitrogen data of the sewage in the anaerobic tank 1. The control system 5 is electrically connected to the secondary sedimentation tank 4, the first side-stream module 6, the second side-stream module 7 and the first on-line monitoring device 11. The secondary sedimentation tank 4 is respectively connected to the first side-stream module 6 and the second side-stream module 7 through a sludge pump house 41. The sludge pump house 41 is used to pump the sludge in the secondary sedimentation tank 4 to the first side-stream module 6 when receiving a first instruction, and pump the sludge in the secondary sedimentation tank 4 to the second side-stream module 7 when receiving a second instruction:

[0034] When the ratio of COD to total phosphorus obtained by the first on-line monitoring device 11 ≤ a first preset threshold value (i.e., COD / TP ≤ 85), the control system 5 issues a first instruction;

[0035] When the ratio of COD to total nitrogen obtained by the first on-line monitoring device 11 ≤ a second preset threshold value (i.e., COD / TN ≤ 5), the control system 5 issues a second instruction.

[0036] If both conditions are satisfied simultaneously, the second instruction is preferentially executed.

[0037] This solution provides a new AAO process coupled with a two-sided flow sludge treatment system. By adding a first side-stream module 6 and a second side-stream module 7 on the basis of the AAO process, sludge treatment and water quality adjustment are respectively carried out for the situation of high total phosphorus and total nitrogen in the influent water.

[0038] Specifically, the anaerobic tank 1 is equipped with a first on-line monitoring device 11 for total nitrogen, total phosphorus, COD and ammonia nitrogen. The sludge pump house 41 is connected to the secondary sedimentation tank 4 and the two side-stream modules, and it undertakes important sludge transportation and treatment functions. The sludge pump house 41 transports the sludge obtained from the secondary sedimentation tank 4 to the first side-stream module 6 or the second side-stream module 7 through a pumping system. When the detected total phosphorus data of the influent water is high, the first side-stream process is started, and through this side-stream process, the activated sludge completely releases phosphorus and then returns to the aerobic tank 3 to absorb phosphorus, improving the biochemical phosphorus removal efficiency; when the detected total nitrogen data of the influent water is high, the second side-stream process is started, and the VFAs (volatile fatty acids) produced by the sludge are recycled as a carbon source to improve the biochemical nitrogen removal efficiency. This system can effectively improve the sewage treatment effect, reduce the use of chemical agents, be more environmentally friendly, and is especially suitable for sewage treatment plants with large changes in influent water quality in different seasons. In addition, this system can also utilize the original sewage treatment structures, adjust measures to local conditions, reduce the transformation cost, and has significant economic and environmental benefits.

[0039] Furthermore, the first side stream module 6 includes an anaerobic phosphate release tank 61, a sedimentation tank 62 and a chemical phosphorus removal tank 63 connected in sequence, the secondary sedimentation tank 4 is connected to the anaerobic phosphate release tank 61, and the sedimentation tank 62 is used to precipitate the sludge treated by the anaerobic phosphate release tank 61 and obtain supernatant and phosphorus-released sludge.

[0040] like Figure 2 As shown, when the total phosphorus content of the influent is too high, the control system 5 starts the first side stream process: after the sludge enters the sludge pump room 41 from the secondary sedimentation tank 4, the sludge pump room 41 includes a sludge pump, which introduces a portion of the activated sludge into the anaerobic phosphorus release tank 61 for a residence time of about 3 days, and is fully stirred during this period to achieve complete phosphorus release. Afterwards, this part of the activated phosphorus-releasing sludge enters the sedimentation tank 62 for separation, and the sedimentation time is about 4 hours. After separation, the phosphorus-releasing sludge is returned to the aerobic tank 3 in the AAO process. The concentrated phosphorus-containing supernatant is reduced to below 2 mg / L by adding phosphorus removal agents and flocculants. Afterwards, the low-phosphorus supernatant is returned to the anaerobic tank 1, and the remaining sludge is discharged to the sludge dewatering workshop for dehydration and external transportation.

[0041] Furthermore, the sedimentation tank 62 is connected to the aerobic tank 3, and is used to return the phosphorus-released sludge obtained in the sedimentation tank 62 to the aerobic tank 3;

[0042] The chemical phosphorus removal tank 63 is connected to the anaerobic tank 1 and is used to return the supernatant treated in the chemical phosphorus removal tank 63 to the anaerobic tank 1 .

[0043] The phosphorus-releasing sludge is returned to the aerobic tank 3 in the AAO process, which can significantly improve the biochemical phosphorus removal efficiency of the aerobic tank 3. The low-phosphorus supernatant after treatment in the chemical phosphorus removal tank 63 is returned to the anaerobic tank 1.

[0044] Furthermore, the anaerobic phosphate release tank 61 is provided with a first ORP meter 611 for monitoring the redox potential, and the chemical phosphorus removal tank 63 is provided with an orthophosphate online monitor 631 for monitoring the orthophosphate content; the chemical phosphorus removal tank 63 is connected to the first drug storage tank through a first dosing pump 64, and the first drug storage tank stores a dephosphorus agent and / or a flocculant. The control system 5 is electrically connected to the first dosing pump 64, and the control system 5 obtains the monitoring data of orthophosphate to control the amount of drug added by the first dosing pump 64 to the chemical phosphorus removal tank 63.

[0045] In this embodiment, a first ORP meter 611 is installed in the anaerobic phosphorus release tank 61 to monitor the oxidation-reduction potential of the sludge in the anaerobic phosphorus release tank 61. An orthophosphate on-line monitor 631 is installed in the chemical phosphorus removal tank 63. The control system 5 controls the dosing pump according to the monitored data of orthophosphate to adjust the dosing amounts of the phosphorus remover and the flocculant (such as aluminum salts, polyaluminum chloride, polyferric sulfate, polyacrylamide, etc.) in the chemical phosphorus removal, which is relatively intelligent.

[0046] Further, the second side-stream module 7 includes a sludge thickener 71, an acid production tank 72, a chemical conditioning tank 73, and a dehydrator 74 that are connected in sequence. The secondary sedimentation tank 4 is connected to the sludge thickener 71.

[0047] The sludge thickener 71 is used to separate the sludge in the secondary sedimentation tank 4 into concentrated sludge and a first filtrate. The dehydrator 74 is used to separate the conditioned sludge obtained from the conditioning tank to obtain dewatered sludge and a second filtrate containing volatile fatty acids.

[0048] As Figure 3 shown, when the total nitrogen in the influent is too high, the control system 5 activates the second side-stream process: After the sludge enters the sludge pump house 41 from the secondary sedimentation tank 4, the sludge pump introduces a part of the activated sludge into the sludge thickener 71 (belt filter press) for sludge-water separation. After separation, the water content of the activated sludge is reduced to about 96%, and the concentration of the activated sludge is increased. In the subsequent process, the separated filtrate is directly recycled to the anaerobic tank 1, while the concentrated activated sludge continues to enter the acid production tank 72 and stays for 10 - 15 days. After acid production is completed, the activated sludge is sent to the chemical conditioning tank 73, and PAC and PAM can be specifically added in the chemical conditioning tank 73 to remove nitrogen and phosphorus. The conditioned activated sludge enters the dehydrator 74 (dewatering workshop) for dewatering, and the dewatered sludge cake is transported out of the plant. The second filtrate generated during the dewatering process contains VFAs and re-enters the inlet pump house of the anoxic tank 2. The products obtained from acid production are stored in the acid production liquid storage tank 76. The remaining sludge in the sludge pump house 41 is directly sent to the sludge dewatering workshop for dewatering and transportation out of the plant.

[0049] Further, the sludge thickener 71 is connected to the acid production tank 72 and is used to concentrate the sludge in the secondary sedimentation tank 4, with the water content reduced to 95% - 96%, which helps to increase the sludge concentration and is conducive to increasing the total amount of volatile fatty acids produced in the subsequent acid production tank 72.

[0050] Further, the sludge thickener 71 is connected to the anaerobic tank 1 and is used to recycle the first filtrate obtained by the sludge thickener 71 into the anaerobic tank 1.

[0051] The dehydrator 74 is connected to the anoxic tank 2 and is used to recycle the second filtrate obtained by the dehydrator 74 into the anoxic tank 2.

[0052] In this solution, the purpose of the first dehydration (dehydration by the sludge concentrator 71) is to concentrate the sludge and increase the sludge concentration, thereby improving the acid production efficiency. The filtrate is a by-product, and the reflux of the filtrate is mainly to enable this part of the filtrate to meet the discharge standards after being treated by the system. The purpose of the second dehydration (dehydration by the dehydrator 74) is to obtain the second filtrate containing VFAs. The second filtrate containing VFAs (volatile fatty acids) is refluxed to the anoxic tank and can be recycled as a carbon source to improve the biochemical denitrification efficiency. This system can effectively improve the sewage treatment effect and reduce the use of chemical agents.

[0053] Furthermore, the acid production tank 72 is equipped with a pH detector, a temperature detector, a second ORP meter for monitoring the oxidation-reduction potential in the acid production tank 72, and a second on-line monitoring device 721 for monitoring data of volatile fatty acids, total nitrogen, and total phosphorus; the chemical conditioning tank 73 is connected to the second chemical storage tank through a second chemical dosing pump 75. The second chemical storage tank stores flocculants and / or coagulants. The control system 5 is electrically connected to the second chemical dosing pump 75. The control system 5 obtains the monitoring data of volatile fatty acids, total nitrogen, and total phosphorus to control the chemical dosing amount of the second chemical dosing pump 75 to the acid production tank 72.

[0054] As Figure 3 shown, the acid production tank 72 is equipped with a second ORP meter, a pH detector, and a temperature detector to monitor the oxidation-reduction potential, pH value, and temperature of the sludge in the acid production tank 72. The second ORP meter and the pH detector can be used to monitor whether the acid production tank 72 is operating normally. For example, the limiting conditions are ORP < -50 and pH < 7.5. When the detected data exceeds the above settings, it indicates that there is a problem with the operating conditions of the acid production tank. The thermometer is used to obtain the temperature of the acid production tank 72 in real time. When the temperature is relatively low, the residence time of the acid production tank can be extended, or heating equipment and / or heat preservation equipment can be added to ensure the content of volatile fatty acids in the acid production filtrate. In addition, a second on-line monitoring device 721 for VFAs, total nitrogen, and total phosphorus is also installed in the acid production tank 72 to monitor the VFAs, total nitrogen, and total phosphorus of the acid production liquid. The second chemical storage tank stores flocculants and coagulants, such as PAC, PAM, etc. The control system 5 controls the chemical dosing amounts of PAC and PAM of the second chemical dosing pump 75 to the acid production tank 72 according to the monitoring data of VFAs, total nitrogen, and total phosphorus, with a relatively high degree of automation and good purification effect.

[0055] Furthermore, a heating device and / or a heat preservation device are also provided in the acid-producing tank 72. According to the climate conditions and the shortage of carbon sources in the location of the sewage treatment plant, the user can decide whether to install a heating device and a heat preservation device in the acid-producing tank 72. For areas where the average winter temperature is lower than 10 °C and the carbon sources are relatively scarce, it can be considered to install a heating device and a heat preservation device in the acid-producing tank 72 to improve the acid production efficiency. Pilot studies have shown that when the reaction temperature in the acid-producing tank 72 reaches above 55 °C, under the same residence time, the VFAs generated per milligram of sludge are 1.5 times that under the condition of 20 °C.

[0056] Furthermore, a pretreatment module 8 is also provided at the front end of the anaerobic tank 1. The pretreatment module 8 includes a grille 81 and a grit chamber 82 arranged in sequence. The pretreatment module 8 can remove impurities in the sewage at the front end. The sewage first passes through the grille 81, and the grille 81 filters out large-size impurities in the sewage. Then the sewage enters the grit chamber 82. After the sewage stays in the grit chamber 82 for a period of time, relatively smaller sand grains or other impurities can be removed.

[0057] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An AAO process coupled with a bilateral flow sludge treatment system, characterized in that, It includes an anaerobic tank (1), an anoxic tank (2), an aerobic tank (3), and a secondary sedimentation tank (4) that are connected in sequence. The secondary sedimentation tank (4) is used to settle the suspended solids in the sewage treated by the aerobic tank (3) and obtain sludge. It further includes a control system (5). The secondary sedimentation tank (4) is respectively connected to a first side-stream module (6) and a second side-stream module (7). The anaerobic tank (1) is provided with a first on-line monitoring device (11) that is used to monitor the total nitrogen, total phosphorus, COD, and ammonia nitrogen data of the sewage in the anaerobic tank (1). The control system (5) is electrically connected to the first on-line monitoring device (11). The secondary sedimentation tank (4) is connected to the first side-stream module (6) and the second side-stream module (7) respectively through a sludge pump house (41). The sludge pump house (41) is used to pump the sludge in the secondary sedimentation tank (4) to the first side-stream module (6) when receiving a first instruction, and pump the sludge in the secondary sedimentation tank (4) to the second side-stream module (7) when receiving a second instruction. When the ratio of COD to total phosphorus obtained by the first on-line monitoring device (11) ≤ a first preset threshold, the control system (5) issues a first instruction. When the ratio of COD to total nitrogen obtained by the first on-line monitoring device (11) ≤ a second preset threshold, the control system (5) issues a second instruction.

2. The AAO process-coupled bilateral flow sludge treatment system according to claim 1, characterized in that, The first side-stream module (6) includes an anaerobic phosphorus release tank (61), a sedimentation tank (62), and a chemical phosphorus removal tank (63) that are connected in sequence. The secondary sedimentation tank (4) is connected to the anaerobic phosphorus release tank (61). The sedimentation tank (62) is used to sediment the sludge treated by the anaerobic phosphorus release tank (61) and obtain supernatant and phosphorus release sludge.

3. An AAO process-coupled bilateral flow sludge treatment system according to claim 2, characterized in that, The sedimentation tank (62) is connected to the aerobic tank (3) and is used to return the phosphorus release sludge obtained by the sedimentation tank (62) to the aerobic tank (3). The chemical phosphorus removal tank (63) is connected to the anaerobic tank (1) and is used to return the supernatant treated by the chemical phosphorus removal tank (63) to the anaerobic tank (1).

4. An AAO process-coupled bilateral flow sludge treatment system according to claim 2, wherein The anaerobic phosphorus release tank (61) is provided with a first ORP meter (611) for monitoring the oxidation-reduction potential, and the chemical phosphorus removal tank (63) is provided with an orthophosphate on-line monitor (631) for monitoring the content of orthophosphate. The chemical phosphorus removal tank (63) is connected to a first chemical storage tank through a first chemical dosing pump (64). The first chemical storage tank stores phosphorus remover and / or flocculant. The control system (5) is electrically connected to the first chemical dosing pump (64). The control system (5) obtains the monitoring data of orthophosphate to control the chemical dosing amount of the first chemical dosing pump (64) to the chemical phosphorus removal tank (63).

5. An AAO process coupled with a bilateral flow sludge treatment system according to claim 1, characterized in that The second side-stream module (7) includes a sludge concentrator (71), an acid production tank (72), a chemical conditioning tank (73), and a dehydrator (74) that are connected in sequence. The secondary sedimentation tank (4) is connected to the sludge concentrator (71). The sludge concentrator (71) is used for separating sludge and water in the secondary sedimentation tank (4) to obtain concentrated sludge and a first filtrate, and the dehydrator (74) is used for separating sludge and water from the conditioned sludge obtained in the conditioning tank to obtain dewatered sludge and a second filtrate containing volatile fatty acids.

6. The AAO process-coupled bilateral flow sludge treatment system according to claim 5, characterized in that, The sludge concentrator (71) is connected to the anaerobic tank (1) and is used for refluxing the first filtrate obtained by the sludge concentrator (71) into the anaerobic tank (1). The dehydrator (74) is connected to the anoxic tank (2) and is used for refluxing the second filtrate obtained by the dehydrator (74) into the anoxic tank (2).

7. An AAO process coupled with a bilateral flow sludge treatment system according to claim 5, characterized in that The acid-producing tank (72) is provided with a pH detector, a temperature detector, a second ORP meter for monitoring the oxidation-reduction potential in the acid-producing tank (72), and a second on-line monitoring device (721) for monitoring data of volatile fatty acids, total nitrogen, and total phosphorus. The chemical conditioning tank (73) is connected to a second chemical storage tank through a second chemical dosing pump (75). The second chemical storage tank stores flocculants and / or coagulants. The control system (5) is electrically connected to the second chemical dosing pump (75). The control system (5) obtains the monitoring data of volatile fatty acids, total nitrogen, and total phosphorus to control the chemical dosage of the second chemical dosing pump (75) for dosing into the acid-producing tank (72).

8. An AAO process coupled with a bilateral flow sludge treatment system according to claim 5, characterized in that The acid-producing tank (72) is further provided with heating equipment and / or heat preservation equipment.

9. An AAO process-coupled double-sided flow sludge treatment system according to claim 1, characterized in that, A pretreatment module (8) is further provided at the front end of the anaerobic tank (1). The pretreatment module (8) includes a grille (81) and a grit chamber (82) arranged in sequence.

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