Sewage treatment system

Abstract

The utility model relates to a sewage treatment system, which adopts an aeration tank shared water inlet system, that is, a plurality of anaerobic reactors jointly provide inlet water for each aeration tank; when any aeration tank breaks down, the water inflow of the failed aeration tank can be reduced, meanwhile, the water inflow of other aeration tanks in normal operation can be correspondingly increased, and by dynamically balancing the loads of the aeration tanks, the whole sewage treatment system can still maintain an efficient operation state, and it is ensured that the sewage treatment efficiency and the water quality meet the requirements; rapid response and load balance of the sewage treatment system under the condition that the aeration tank breaks down are achieved, the production stability is guaranteed, and the reliability and the anti-risk capacity of the sewage treatment system are improved.

Description

A wastewater treatment system Technical Field

[0001] This application relates to the field of wastewater treatment technology, specifically to a wastewater treatment system. Background Technology

[0002] With increasingly stringent environmental standards, the requirements for wastewater discharge are becoming more demanding, especially for key indicators such as chemical oxygen demand (COD), total nitrogen, and ammonia nitrogen. Various manufacturing enterprises (such as paper mills) must invest in effective wastewater treatment systems to ensure compliance with discharge standards; otherwise, they will face hefty fines and production restrictions. The stable operation of wastewater treatment systems is crucial for the sustainable development of enterprises. Against the backdrop of continuously expanding industrial production scale, wastewater generation is also constantly increasing, which requires wastewater treatment systems with higher treatment capacity and stability.

[0003] Existing wastewater treatment systems typically employ two biological treatment units to meet wastewater treatment needs. The aeration tank plays a central role within each biological treatment unit, specifically responsible for treating the wastewater generated by that unit. By allowing the aeration tanks in the two biological treatment units to operate independently, wastewater from different stages or sources can be treated more specifically, improving treatment efficiency and effectiveness. Typically, one biological treatment unit will have two aeration tanks (Aeration Tank A and Aeration Tank B), and these two aeration tanks operate independently as separate units.

[0004] However, this type of wastewater treatment system carries certain risks. A malfunction in any aeration tank can severely threaten the quality of the effluent from the entire biological treatment unit. Key indicators such as chemical oxygen demand (COD), total nitrogen, and ammonia nitrogen in the effluent may fail to meet discharge standards. Current solutions for aeration tank malfunctions primarily involve reducing the influent load. This method works by decreasing the amount of wastewater entering the aeration tank, reducing the workload of the microorganisms, and allowing the microbial system and equipment within the aeration tank to recover under relatively relaxed conditions. However, because aeration tank malfunctions are complex and varied, potentially involving equipment damage, microbial community imbalance, or sudden changes in water quality, simply reducing the influent load cannot precisely target specific malfunctions for rapid repair. This makes the recovery period unpredictable, ranging from half a month to a month or even longer. During this recovery period, due to the reduced wastewater treatment capacity, companies are forced to reduce production to ensure the normal operation of the entire production process, meet effluent quality standards, and avoid environmental risks, thus impacting their profits. Summary of the Invention

[0005] In view of the above problems, this application provides a wastewater treatment system that solves the problem of reduced wastewater treatment capacity of the entire wastewater treatment system when the aeration tank fails.

[0006] To achieve the above objectives, the inventors provide a wastewater treatment system comprising a first biochemical unit; the first biochemical unit includes an aeration tank A, an aeration tank B, and a plurality of anaerobic reactors; each of the aeration tanks A and each of the anaerobic reactors is provided with a first inlet pipe leading to the aeration tank A; each of the aeration tanks B and each of the anaerobic reactors is provided with a second inlet pipe leading to the aeration tank B; each anaerobic reactor is connected to a corresponding first inlet pipe and second inlet pipe, and each of the first inlet pipe and second inlet pipe is provided with a first valve and a second valve, respectively.

[0007] In some embodiments, one end of each first inlet pipe is connected to the corresponding second inlet pipe, and the other end is connected to aeration tank A; one end of each second inlet pipe is connected to the corresponding anaerobic reactor, and the other end is connected to aeration tank B; the second valve is located between the second inlet pipe and the other end of the second inlet pipe.

[0008] In some embodiments, the first biochemical unit further includes a secondary sedimentation tank A and a sludge well A corresponding to aeration tank A, and a secondary sedimentation tank B and a sludge well B corresponding to aeration tank B.

[0009] The aeration tank A and the corresponding secondary sedimentation tank A are provided with a first effluent pipe leading to the secondary sedimentation tank A, so that the secondary sedimentation tank A receives the sewage discharged from the aeration tank A and separates the activated sludge and clarified water through gravity sedimentation; the sludge well A is connected to the secondary sedimentation tank A to collect the activated sludge discharged from the secondary sedimentation tank A; the sludge well A is provided with at least one first sludge return pipe, which leads to the aeration tank A, and is equipped with a first sludge return pump to regulate the return of activated sludge to the aeration tank A.

[0010] The aeration tank B and the corresponding secondary sedimentation tank B are equipped with a second effluent pipe leading to the secondary sedimentation tank B, so that the secondary sedimentation tank B receives the sewage discharged from the aeration tank B and separates the activated sludge from the clarified water through gravity sedimentation; the sludge well B is connected to the secondary sedimentation tank B to collect the activated sludge discharged from the secondary sedimentation tank B; the sludge well B is equipped with at least one second sludge return pipe, which leads to the aeration tank B, and a second sludge return pump is installed on the second sludge return pipe to regulate the return of activated sludge to the aeration tank B.

[0011] In some embodiments, at least one first sludge return pipe is connected to a second sludge return pipe via a connecting pipe, and the connecting pipe is equipped with a sludge valve.

[0012] In some embodiments, the aeration tank A is provided with at least one first internal return pipe, one end of which is connected to the inlet end of the aeration tank A; the other end of which is connected to the outlet end of the aeration tank A; and a first internal return pump is provided on the first internal return pipe; and / or

[0013] The aeration tank B is provided with at least one second internal return pipe. One end of the second internal return pipe is connected to the inlet end of the aeration tank B, and the other end is connected to the outlet end of the aeration tank B. A second internal return pump is provided on the second internal return pipe.

[0014] In some embodiments, the wastewater treatment system further includes a second biochemical unit, which includes an aeration tank C, and at least one of the anaerobic reactors is connected to a third inlet pipe leading to the aeration tank C, the third inlet pipe being provided with a third valve.

[0015] In some embodiments, the lower part of aeration tank A and / or aeration tank B is provided with a fourth water inlet pipe leading to the upper part of aeration tank C, and the fourth water inlet pipe is provided with a fourth valve.

[0016] In some embodiments, the aeration tank A is provided with at least one first internal return pipe, one end of which is connected to the inlet end of the aeration tank A; the other end of which is connected to the outlet end of the aeration tank A; and a first internal return pump is provided on the first internal return pipe; and / or

[0017] The aeration tank B is provided with at least one second internal return pipe. One end of the second internal return pipe is the inlet end, which is connected to the lower part of the aeration tank B; the other end is the outlet end, which is connected to the upper part of the aeration tank B. A second internal return pump is provided on the second internal return pipe.

[0018] One end of the fourth inlet pipe is connected to at least one first internal return pipe and / or a second internal return pipe; the other end leads to the aeration tank C.

[0019] Unlike existing technologies, the above-mentioned solution employs a shared influent system for the aeration tanks, meaning multiple anaerobic reactors jointly supply influent to each aeration tank. When any aeration tank malfunctions, the influent flow to that faulty tank is reduced, while the influent flow to other normally operating aeration tanks is increased accordingly. By dynamically balancing the load on each aeration tank, the entire wastewater treatment system maintains high-efficiency operation, ensuring wastewater treatment efficiency and compliance with water quality standards. This solution, through a flexible water volume control mechanism, achieves rapid response and load balancing in the event of aeration tank malfunctions, guaranteeing production stability and enhancing the reliability and resilience of the wastewater treatment system.

[0020] The above description of the utility model is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0021] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this utility model and other related contents, and should not be considered as limitations on this application.

[0022] In the accompanying drawings of the instruction manual:

[0023] Figure 1 is a schematic diagram of the wastewater treatment system structure according to a specific embodiment;

[0024] Figure 2 is a schematic diagram of the wastewater treatment system structure described in the specific embodiment;

[0025] Figure 3 is an enlarged view of point A in Figure 2;

[0026] Figure 4 is a schematic diagram of the wastewater treatment system structure described in the specific embodiment;

[0027] Figure 5 is a schematic diagram of the wastewater treatment system structure described in the specific embodiment;

[0028] Figure 6 is a schematic diagram of the wastewater treatment system structure described in the specific embodiment;

[0029] Figure 7 is an enlarged view of section B in Figure 6.

[0030] The reference numerals used in the above figures are explained as follows:

[0031] 10. Aeration tank A;

[0032] 101. First inlet pipe; 102. First valve; 103. First outlet pipe; 104. First internal return pipe; 105. First internal return pump;

[0033] 20. Aeration tank B;

[0034] 201. Second inlet pipe; 202. Second valve; 203. Second outlet pipe; 204. Second internal return pipe; 205. Second internal return pump;

[0035] 30. Anaerobic reactor;

[0036] 40. Secondary sedimentation tank A;

[0037] 50. Secondary sedimentation tank B;

[0038] 60. Sludge Well A;

[0039] 601. First sludge return pipe; 602. First sludge return pump; 603. Connecting pipe; 604. Sludge valve;

[0040] 70. Sludge Well B;

[0041] 701. Second sludge return pipe; 702. Second sludge return pump;

[0042] 80. Aeration tank C;

[0043] 801, Third water inlet pipe; 802, Third valve; 803, Fourth water inlet pipe; 805, Fourth valve. Detailed Implementation

[0044] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0045] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0046] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0047] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0048] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0049] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0050] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0051] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0052] Unless otherwise expressly specified or limited, the terms "installation," "connection," "communication," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "communication" can be a fixed connection, a detachable connection, or an integral setting; it can be a direct connection or an indirect connection through an intermediate medium; it can be a relationship of two components combined together, an interaction relationship between two components, or a connection within two structures. Those skilled in the art to which this application pertains can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0053] Wastewater treatment systems typically include at least one biological treatment unit. The aeration tank is central to this unit, and its operation directly impacts whether the discharged water meets standards. It primarily works by introducing air into the wastewater, providing oxygen to microorganisms and promoting their decomposition and transformation of pollutants such as organic matter and nitrogen. In this process, microorganisms use oxygen to oxidize and decompose organic matter into carbon dioxide and water, while simultaneously converting ammonia nitrogen into harmless substances like nitrate nitrogen. Different aeration tanks vary in their design and function, differing in the types and quantities of microorganisms used and the treatment process, but all aim to purify wastewater.

[0054] In existing wastewater treatment systems, aeration tanks are independent, meaning each aeration tank has its own influent and effluent systems, treating wastewater from specific sources or with specific properties. For example, in a biological unit with two aeration tanks and five anaerobic reactors 30, three of the anaerobic reactors 30 supply influent to one aeration tank, and the other two supply influent to the other. When an aeration tank malfunctions due to complex reasons such as equipment damage, microbial community imbalance, or sudden changes in water quality, and cannot be quickly repaired, it will pose a significant threat to the quality of the discharged water, potentially causing key indicators such as chemical oxygen demand (COD), total nitrogen, and ammonia nitrogen to exceed discharge standards. Currently, the industry's conventional technical approach to dealing with such malfunctions is to directly reduce the water flow to the corresponding anaerobic reactor 30, lowering the influent load of the aeration tank. This reduces the amount of wastewater entering the aeration tank, alleviating the metabolic pressure on the microorganisms, creating relatively relaxed conditions for equipment maintenance and microbial system recovery, thereby gradually restoring the normal treatment function of the aeration tank and ensuring that the discharged water quality meets standards. However, this method cannot precisely address specific problems, and the recovery period is difficult to control, lasting from half a month to a month or even longer, further exacerbating the contradiction between production losses and environmental risks. At the same time, this method reduces the amount of wastewater treated, requiring companies to adjust their production processes and implement measures such as production cuts, directly resulting in losses in production profits and exacerbating the contradiction between production losses and environmental risks.

[0055] Referring to Figures 1-7, to ensure the normal operation of the entire production process and the compliance of effluent quality with standards, and to avoid environmental risks, this application provides a wastewater treatment system applicable to the treatment of various types of domestic and industrial wastewater, particularly suitable for papermaking wastewater treatment. A shared influent system for aeration tanks is proposed, where multiple anaerobic reactors 30 jointly supply influent to each aeration tank. When any aeration tank malfunctions, the influent flow to that faulty tank can be reduced, while the influent flow to other normally operating aeration tanks can be increased accordingly. By dynamically balancing the load of each aeration tank, the entire wastewater treatment system can maintain efficient operation, ensuring wastewater treatment efficiency and compliance with water quality standards. This scheme, through a flexible water volume control mechanism, achieves rapid response and load balancing of the wastewater treatment system in the event of aeration tank malfunctions, ensuring production stability and improving the reliability and resilience of the wastewater treatment system.

[0056] The following describes an embodiment of a wastewater treatment system with reference to Figure 1, which includes a first biochemical unit; the first biochemical unit includes an aeration tank A10, an aeration tank B20, and several anaerobic reactors 30;

[0057] Each aeration tank A10 is provided with a first inlet pipe 101 leading to each of the anaerobic reactors 30; each aeration tank B20 is provided with a second inlet pipe 201 leading to each of the anaerobic reactors 30; each anaerobic reactor 30 is connected to the corresponding first inlet pipe 101 and second inlet pipe 201, and each first inlet pipe 101 and second inlet pipe 201 is provided with a first valve 102 and a second valve 202.

[0058] The aforementioned aeration tanks A10 and B20 independently treat wastewater from all anaerobic reactors 30 in the first biological treatment unit. Each anaerobic reactor 30 is connected to a corresponding first inlet pipe 101 and second inlet pipe 201, supplying water to aeration tanks A10 and B20 through their respective first inlet pipes 101 and second inlet pipes 201. That is:

[0059] Each anaerobic reactor 30 is provided with a first inlet pipe 101 corresponding to an aeration tank A10, which is used to transport the wastewater treated by the anaerobic reactor 30 to the aeration tank A10.

[0060] Each anaerobic reactor 30 is equipped with a second inlet pipe 201 corresponding to the aeration tank B20, which is used to transport the wastewater treated by the anaerobic reactor 30 to the aeration tank B.

[0061] In some embodiments, the first biochemical unit has three anaerobic reactors 30 (R1, R2, R3), and the connectivity is as follows:

[0062] R1 is connected to aeration tank A10 through the first inlet pipe 101 and to aeration tank B20 through the second inlet pipe 201.

[0063] R2 is connected to aeration tank A10 through the first inlet pipe 101 and to aeration tank B20 through the second inlet pipe 201.

[0064] R3 is connected to aeration tank A10 through the first inlet pipe 101 and to aeration tank B20 through the second inlet pipe 201.

[0065] A first valve 102 is installed on the first inlet pipe 101 leading to aeration tank A to control the water supply from the corresponding anaerobic reactor 30 to aeration tank A; a second valve 202 is installed on the second inlet pipe 201 leading to aeration tank B to control the water supply from the corresponding anaerobic reactor 30 to aeration tank B.

[0066] The first valve 102 and the second valve 202 are adjusted to appropriate openings according to the load of aeration tanks A10 and B20, enabling multiple anaerobic reactors 30 to supply water to aeration tanks A10 and B20 in parallel, thus distributing the treatment load. When aeration tank A malfunctions (e.g., equipment shutdown, microbial system imbalance), its influent flow needs to be reduced or cut off. The first valve 102 corresponding to aeration tank A from some or all of the anaerobic reactors 30 is closed or adjusted to reduce the water flow to aeration tank A. Simultaneously, the second valve 202 corresponding to aeration tank B from some or all of the anaerobic reactors 30 is adjusted to transfer the water originally planned for aeration tank A to aeration tank B, allowing aeration tank B to bear a greater load. The reverse is also true when aeration tank B20 malfunctions. This dynamic water allocation avoids a decrease in the overall system's treatment capacity due to a single aeration tank malfunction, ensuring that the quality of the discharged water consistently meets standards.

[0067] The anaerobic reactor 30 is connected to the first inlet pipe 101 and the second inlet pipe 201 directly or indirectly. In some embodiments, one end of each first inlet pipe 101 is connected to the corresponding anaerobic reactor 30, and the other end leads to the aeration tank A10; one end of each second inlet pipe 201 is connected to the corresponding anaerobic reactor 30, and the other end leads to the aeration tank B20. In some embodiments, the anaerobic reactor 30 is provided with a main outlet pipe corresponding to the first inlet pipe 101 and the second inlet pipe 201, and one end of the first inlet pipe 101 and the second inlet pipe 201 are respectively connected to the main outlet pipe, and the other end leads to the corresponding aeration tank A10 and aeration tank B20. Referring to Figure 1, in some embodiments, one end of each first inlet pipe 101 is connected to the corresponding second inlet pipe 201, and the other end is connected to the aeration tank A10; one end of each second inlet pipe 201 is connected to the corresponding anaerobic reactor 30, and the other end is connected to the aeration tank B20; the second valve 202 is located between the second inlet pipe 201 and the other end of the second inlet pipe 201.

[0068] The aeration tanks A10 and B20 described in this application do not limit the form in which the microorganisms exist. They can be activated sludge aeration tanks, biofilm aeration tanks (such as aerated biological filters), etc. The following description uses the activated sludge aeration tank as an example.

[0069] As shown in Figure 2, in the activated sludge aeration tank, microorganisms exist in the form of suspended activated sludge. Wastewater is mixed with activated sludge, and organic matter is degraded by aeration to supply oxygen.

[0070] Specifically, the first biochemical unit also includes a secondary sedimentation tank A40 and a sludge well A60 corresponding to the aeration tank A10, and a secondary sedimentation tank B50 and a sludge well B70 corresponding to the aeration tank B20.

[0071] The aeration tank A10 and the corresponding secondary sedimentation tank A40 are provided with a first effluent pipe 103 leading to the secondary sedimentation tank A40, so that the secondary sedimentation tank A40 receives the mixed liquor (high dissolved oxygen mixed liquor, including sewage, activated sludge, etc., hereinafter referred to as mixed liquor) discharged from the aeration tank A10, and separates the activated sludge from the clarified water through gravity sedimentation; the sludge well A60 is connected to the secondary sedimentation tank A40 to collect the activated sludge discharged from the secondary sedimentation tank A40; the sludge well A60 is provided with at least one first sludge return pipe 601, which leads to the aeration tank A10, and the first sludge return pipe 601 is provided with a first sludge return pump 602 to regulate the return of activated sludge to the aeration tank A10 through the first sludge return pump 602;

[0072] The aeration tank B20 and the corresponding secondary sedimentation tank B50 are provided with a second effluent pipe 203 leading to the secondary sedimentation tank B50, so that the secondary sedimentation tank B50 receives the mixed liquor discharged from the aeration tank B20 and separates the activated sludge and clarified water by gravity sedimentation; the sludge well B70 is connected to the secondary sedimentation tank B50 to collect the activated sludge discharged from the secondary sedimentation tank B50; the sludge well B70 is provided with at least one second sludge return pipe 701, which leads to the aeration tank B20, and a second sludge return pump 702 is provided on the second sludge return pipe 701 to regulate the return of activated sludge to the aeration tank B20.

[0073] In some embodiments, the first sludge return pipe 601 and the second sludge return pipe 701 each have three pipes, namely A-1#, A-2#, A-3#, B-1#, B-2#, B-3#.

[0074] The connection relationships between sludge wells A60 and B70 and aeration tanks A10 and B20 are as follows:

[0075] Sludge well A60 is connected to aeration tank A10 through the first sludge return pipes 601 of A-1#, A-2#, and A-3#, and a first sludge return pump 602 is provided on A-1#, A-2#, and A-3# respectively;

[0076] Sludge well B70 is connected to aeration tank B20 through second sludge return pipes 701 of B-1#, B-2#, and B-3#, and second sludge return pumps 702 are respectively installed on B-1#, B-2#, and B-3#.

[0077] Referring to Figures 2 and 3, in some embodiments, to allow for the free addition and subtraction of activated sludge, a connecting pipe 603 is provided between the first sludge return pipe 601 and the second sludge return pipe 701, so as to add or subtract activated sludge from aeration tanks A10 and B20 through the first sludge return pipe 601 and the second sludge return pipe 701. Specifically, at least one first sludge return pipe 601 and the second sludge return pipe 701 are connected by the connecting pipe 603, and the connecting pipe 603 is equipped with a sludge valve 604. In embodiments where both the first sludge return pipe 601 and the second sludge return pipe 701 have three sections, a connecting pipe 603 is added between the first sludge return pipe 601 of A-3# and the second sludge return pipe 701 of B-1#, and a sludge valve 604 is provided on the connecting pipe 603. If one of the aeration tanks, A10 and B20, malfunctions and the activated sludge has poor activity, sludge can be returned and adjusted from the other aeration tank through the added connecting pipe 603. This allows the activated sludge from the other aeration tank to be quickly transferred to the malfunctioning aeration tank, thus achieving rapid recovery of the abnormal aeration system.

[0078] Referring to Figure 4, in some embodiments, to further reduce the total nitrogen content in the wastewater, the aeration tank A10 is provided with at least one first internal return pipe 104, one end of which is connected to the inlet of the aeration tank A10; the other end is connected to the outlet of the aeration tank A10, and a first internal return pump 105 is provided on the first internal return pipe 104; and / or

[0079] The aeration tank B20 is provided with at least one second internal return pipe 204. One end of the second internal return pipe 204 is connected to the inlet end of the aeration tank B20, and the other end is connected to the outlet end of the aeration tank B20. A second internal return pump 205 is provided on the second internal return pipe 204.

[0080] The aforementioned first internal return pipe 104 and second internal return pipe 204 can be installed according to the needs of aeration tank A10 and aeration tank B20. They can coexist or be installed individually. The aforementioned first internal return pump 105 and second internal return pump 205 are used to adjust the flow rate of the corresponding internal return pipe, which can dynamically adjust the denitrification intensity in the corresponding aeration tank to adapt to the needs of different influent loads or treatment stages.

[0081] Since the first internal return pipe 104 and the second internal return pipe 204 have the same function—reducing the total nitrogen content in wastewater—for ease of explanation, the layout and principle of the first internal return pipe 104 will be further explained here.

[0082] During operation of aeration tank A10, the aerobic section of aeration tank A10 converts ammonium nitrogen in the water into nitrate and nitrite through a digestion reaction. The first internal return pipe 104, driven by the first internal return pump 105, draws the mixture containing nitrate and nitrite in aeration tank A10 from the outlet end. After being transported through the first internal return pipe 104, it is sprayed out from the inlet end, so that part of the mixture at the outlet end of aeration tank A10 is returned to the anoxic section at the inlet end of aeration tank A10. Under anoxic conditions, microorganisms further convert nitrate and nitrite in the water into nitrogen gas through denitrification and remove it from the water, thereby significantly reducing the total nitrogen content in the water and achieving the purpose of denitrification.

[0083] Ideally, the outlet and inlet ends should be arranged diagonally, in a ring, or in an S-shape within aeration tank A10 and / or aeration tank B20 to maximize the circulation path length. Specifically, guide walls can be added within aeration tank A10 and / or aeration tank B20. The main function of the guide walls is to guide the flow direction of the water, forming a fixed circulation path in conjunction with the internal return pipe. In this way, the mixed liquor within the aeration tank can circulate along a predetermined path, sequentially passing through the anoxic and aerobic sections.

[0084] Referring to Figure 5, in some embodiments, to more specifically treat wastewater from different stages or sources and improve treatment efficiency and effectiveness, the wastewater treatment system includes a second biological treatment unit in addition to the first biological treatment unit. That is, the wastewater treatment system further includes a second biological treatment unit, which includes an aeration tank C80. To allow for flexible adjustment of the operating efficiency of the three aeration tanks, in this embodiment, at least one of the anaerobic reactors 30 is connected to a third inlet pipe 801 leading to the aeration tank C80, and the third inlet pipe 801 is equipped with a third valve 802. The third valve 802 is used to regulate the flow of water from the anaerobic reactor 30 to the aeration tank C80. If the load on the aeration tank C80 of the second biological treatment unit is low, while the loads on the aeration tanks A10 and B20 of the first biological treatment unit are high, the effluent from the anaerobic reactor 30 can be adjusted to flow to the aeration tank C80 of the second biological treatment unit, balancing the loads of the first and second biological treatment units, allowing both units to operate at high efficiency simultaneously.

[0085] Referring to Figure 6, in some embodiments, activated sludge can be replenished to aeration tank C80 through aeration tank A10 and / or aeration tank B20. Specifically, a fourth inlet pipe 803 leading to the upper part of aeration tank C80 is provided at the lower part of aeration tank A10 and / or aeration tank B20, and a fourth valve 805 is provided on the fourth inlet pipe 803. Specifically, it includes:

[0086] A fourth inlet pipe 803 can be provided at the lower part of the aeration tank A10, leading to the upper part of the aeration tank C80. A fourth valve 805 is provided on the fourth inlet pipe 803. When the activated sludge in the aeration tank C80 has poor activity, activated sludge can be adjusted from the aeration tank A10 through the fourth inlet pipe 803. The activated sludge in the aeration tank A10 can be quickly adjusted into the aeration tank C80 by using the fourth inlet pipe 803, so as to achieve rapid recovery of the aeration tank C80.

[0087] Alternatively, a fourth inlet pipe 803 can be provided at the lower part of the aeration tank B20, leading to the upper part of the aeration tank C80. A fourth valve 805 is provided on the fourth inlet pipe 803. When the activated sludge in the aeration tank C80 has poor activity, activated sludge can be adjusted from the aeration tank B20 through the fourth inlet pipe 803. The activated sludge in the aeration tank B20 can be quickly adjusted into the aeration tank C80 using the fourth inlet pipe 803 to achieve rapid recovery of the aeration tank C80.

[0088] A fourth inlet pipe 803 leading to the upper part of aeration tank C80 can also be provided at the lower part of aeration tanks A10 and B20. A fourth valve 805 is provided on the fourth inlet pipe 803. When the activated sludge activity in aeration tank C80 is poor, activated sludge can be adjusted from aeration tanks A10 and B20 through the fourth inlet pipe 803. The activated sludge from aeration tanks A10 and B20 can be quickly adjusted into aeration tank C80 using the fourth inlet pipe 803, thereby achieving rapid recovery of aeration tank C80.

[0089] Referring to Figures 6 and 7, if an internal return pipe is installed, the fourth inlet pipe 803 can be directly connected to the internal return pipe. Specifically, as follows:

[0090] The aeration tank A10 is provided with at least one first internal return pipe 104. One end of the first internal return pipe 104 is the inlet end, which connects to the lower part of the aeration tank A10; the other end is the outlet end, which connects to the upper part of the aeration tank A10. A first internal return pump 105 is provided on the first internal return pipe 104; and / or

[0091] The aeration tank B20 is provided with at least one second internal return pipe 204. One end of the second internal return pipe 204 is the inlet end, which is connected to the lower part of the aeration tank B20; the other end is the outlet end, which is connected to the upper part of the aeration tank B20. A second internal return pump 205 is provided on the second internal return pipe 204.

[0092] One end of the fourth inlet pipe 803 is connected to at least one first internal return pipe 104 and / or a second internal return pipe 204; the other end is connected to the aeration tank C80.

[0093] When the activated sludge in aeration tank C80 has poor activity, the activated sludge in aeration tank A and / or aeration tank B has good activity. When aeration tank A and / or aeration tank B are running, the first internal return pipe 104 and / or the second internal return pipe 204 are driven by the first internal return pump 105 and / or the second internal return pump 205 to draw the mixed liquor in aeration tank A and / or aeration tank B from the inlet end. The activated sludge in aeration tank A10 and aeration tank B20 is quickly transferred to aeration tank C80 through the fourth inlet pipe 803 to achieve rapid recovery of aeration tank C80.

[0094] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A wastewater treatment system, comprising a first biochemical unit; the first biochemical unit comprising an aeration tank A, an aeration tank B, and a plurality of anaerobic reactors; characterized in that, Each aeration tank A is provided with a first inlet pipe leading to each anaerobic reactor; each aeration tank B is provided with a second inlet pipe leading to each anaerobic reactor; each anaerobic reactor is connected to the corresponding first inlet pipe and second inlet pipe, and each first inlet pipe and second inlet pipe is provided with a first valve and a second valve.

2. The wastewater treatment system according to claim 1, characterized in that, Each of the first inlet pipes has one end connected to the corresponding second inlet pipe and the other end connected to aeration tank A; each of the second inlet pipes has one end connected to the corresponding anaerobic reactor and the other end connected to aeration tank B; the second valve is located between the second inlet pipe and the other end of the second inlet pipe.

3. The wastewater treatment system according to claim 1, characterized in that, The first biochemical unit also includes a secondary sedimentation tank A and a sludge well A corresponding to aeration tank A, and a secondary sedimentation tank B and a sludge well B corresponding to aeration tank B; the aeration tank A and the corresponding secondary sedimentation tank A are provided with a first effluent pipe leading to the secondary sedimentation tank A, so that the secondary sedimentation tank A receives the sewage discharged from the aeration tank A and separates the activated sludge from the clarified water through gravity sedimentation; the sludge well A is connected to the secondary sedimentation tank A to collect the activated sludge discharged from the secondary sedimentation tank A. The sludge well A is provided with at least one sludge return pipe leading to the first sludge return pipe, which leads to the aeration tank A. The first sludge return pipe is equipped with a first sludge return pump to regulate the return of activated sludge to the aeration tank A. The aeration tank B and the corresponding secondary sedimentation tank B are provided with a second effluent pipe leading to the secondary sedimentation tank B, so that the secondary sedimentation tank B receives the wastewater discharged from the aeration tank B and separates the activated sludge from the clarified water through gravity sedimentation. The sludge well B is connected to the secondary sedimentation tank B to collect the activated sludge discharged from the secondary sedimentation tank B. The sludge well B is provided with at least one second sludge return pipe, which leads to the aeration tank B. The second sludge return pipe is equipped with a second sludge return pump to regulate the return of activated sludge to the aeration tank B.

4. The wastewater treatment system according to claim 3, characterized in that, At least one first sludge return pipe is connected to a second sludge return pipe via a connecting pipe, and the connecting pipe is equipped with a sludge valve.

5. The wastewater treatment system according to claim 3, characterized in that, The aeration tank A is provided with at least one first internal return pipe, one end of which is connected to the inlet end of the aeration tank A; the other end of which is connected to the outlet end of the aeration tank A, and a first internal return pump is provided on the first internal return pipe; and / or the aeration tank B is provided with at least one second internal return pipe, one end of which is connected to the inlet end of the aeration tank B; the other end of which is connected to the outlet end of the aeration tank B, and a second internal return pump is provided on the second internal return pipe.

6. The wastewater treatment system according to claim 1, characterized in that, The wastewater treatment system further includes a second biochemical unit, which includes an aeration tank C, and at least one of the anaerobic reactors is connected to a third inlet pipe leading to the aeration tank C, and the third inlet pipe is equipped with a third valve.

7. The wastewater treatment system according to claim 6, characterized in that, The lower part of aeration tank A and / or aeration tank B is provided with a fourth water inlet pipe leading to the upper part of aeration tank C, and the fourth water inlet pipe is provided with a fourth valve.

8. The wastewater treatment system according to claim 7, characterized in that, The aeration tank A is provided with at least one first internal return pipe, one end of which is connected to the inlet of the aeration tank A; the other end of which is connected to the outlet of the aeration tank A. A first internal return pump is provided on the first internal return pipe. And / or the aeration tank B is provided with at least one second internal return pipe, one end of which is the inlet and is connected to the lower part of the aeration tank B; the other end of which is the outlet and is connected to the upper part of the aeration tank B. A second internal return pump is provided on the second internal return pipe. One end of the fourth inlet pipe is connected to at least one first internal return pipe and / or the second internal return pipe; the other end leads to the aeration tank C.

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