Two-stage AAO biochemical pool structure

Abstract

The utility model relates to the technical field of sewage treatment, and discloses a two-stage AAO biochemical pool structure which comprises at least two biochemical pools, a water inlet channel and a plurality of water inlet pipes, and the at least two biochemical pools are arranged at intervals; the biochemical pool comprises a pool body and a top plate, the top plate covers the pool body in a sealing mode, a sewage treatment cavity is defined between the pool body and the top plate, and a water inlet and a water outlet are formed in the side wall of the pool body at intervals; the sewage treatment cavity comprises an anaerobic zone, an anoxic zone I, an aerobic zone I, an anoxic zone II and an aerobic zone II which are communicated in sequence, the water inlet is communicated with the anaerobic zone, and the water outlet is communicated with the aerobic zone II; the water inlet channel is arranged on the bottom surface of the top plate and is respectively communicated with the anaerobic zone, the anoxic zone I and the anoxic zone II through a plurality of water inlet pipes. By changing the arrangement position and arrangement mode of the water inlet channel, the construction cost can be reduced when the number of the biochemical pools needs to be increased, and meanwhile, the space utilization rate of the biochemical pools is increased.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a two-stage AAO biochemical tank structure. Background Technology

[0002] Currently, the biological treatment tanks of existing underground wastewater treatment plants in my country generally adopt a two-stage AAO process with two independently operating compartments and multiple inlets. This process optimizes carbon source distribution and improves denitrification efficiency by sequentially introducing wastewater into the anaerobic zone, anoxic zone I, aerobic zone I, anoxic zone II, and aerobic zone II. The inlet channel is laid in a pipe gallery between the two compartments, distributing water to the anaerobic zone, anoxic zone I, and anoxic zone II through multiple inlet pipes.

[0003] With the widespread application of underground wastewater treatment plants, phased construction (civil engineering based on long-term scale, equipment based on short-term scale) has become the mainstream. Because regulations require short-term operating units to be divided into at least two independently operating compartments, the total number of compartments often exceeds three when long-term treatment units are added. In this case, the traditional two-compartment biological treatment tank with multiple inlet points requires an additional intermediate pipe gallery to lay the inlet channels, leading to a significant increase in construction costs and reduced space utilization. Therefore, there is an urgent need to develop a two-stage AAO biological treatment tank structure suitable for multi-compartment scenarios to address the shortcomings of traditional processes in terms of scalability and economy. Utility Model Content

[0004] The purpose of this invention is to provide a two-stage AAO biochemical pool structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this application provides a two-stage AAO biochemical pool structure, comprising: at least two biochemical pools, an inlet channel, and multiple inlet pipes, wherein the at least two biochemical pools are spaced apart;

[0006] The biochemical tank includes: a tank body and a top plate, the top plate covering the top of the tank body, a sewage treatment chamber defined between the tank body and the top plate, and an inlet and an outlet spaced apart on the side wall of the tank body;

[0007] The wastewater treatment chamber includes an anaerobic zone, an anoxic zone I, an aerobic zone I, an anoxic zone II, and an aerobic zone II connected in sequence. The inlet is connected to the anaerobic zone, and the outlet is connected to the aerobic zone II.

[0008] The water inlet channel is located on the bottom surface of the top plate, and the water inlet channel is connected to the anaerobic zone, the anoxic zone I, and the anoxic zone II respectively through multiple water inlet pipes.

[0009] As a preferred technical solution, each of the water inlet pipes is connected to a control water valve.

[0010] As a preferred technical solution, the anaerobic zone, the anoxic zone I, the aerobic zone I, the anoxic zone II, and the aerobic zone II are arranged in a ring-like sequence.

[0011] As a preferred technical solution, the two-stage AAO biochemical tank structure also includes an aeration channel and multiple aeration pipes. The aeration channel is located on the bottom surface of the top plate, and the aeration channel is connected to the aerobic zone I and the aerobic zone II respectively through the multiple aeration pipes.

[0012] As a preferred technical solution, multiple aerators are provided at the bottom of both the aerobic zone I and the aerobic zone II, and the aerators are connected to the aeration channel through the aeration pipe.

[0013] As a preferred technical solution, the wastewater treatment chamber further includes a first regulating zone, which is located between the anoxic zone I and the aerobic zone I, and is connected to both the anoxic zone I and the aerobic zone I. The bottom of the first regulating zone is provided with multiple aerators and multiple propellers, and the aerators are connected to the aeration channel through the aeration pipe.

[0014] As a preferred technical solution, the wastewater treatment chamber further includes a second regulating zone, which is located between the anoxic zone II and the aerobic zone II, and both ends of the second regulating zone are connected to the anoxic zone II and the aerobic zone II, respectively. The bottom of the second regulating zone is provided with multiple aerators and multiple propellers, and the aerators are connected to the aeration channel through the aeration pipe.

[0015] As a preferred technical solution, the biochemical tank further includes a mixed liquor return channel and a return pump. The mixed liquor return channel is located inside the sewage treatment chamber and is connected to the aerobic zone II and the anoxic zone I, respectively.

[0016] The reflux pump is located in the mixed liquor reflux channel, and the reflux pump is used to pump the mixed liquor in the aerobic II zone to the anoxic I zone.

[0017] As a preferred technical solution, the two-stage AAO biological treatment tank structure also includes a through-wall pump, which is used to pump the treated sludge into the anaerobic zone.

[0018] The two-stage AAO biological treatment tank structure provided by the above technical solution has the following advantages compared with the prior art: the inlet channel is set on the bottom surface of the top plate of the biological treatment tank, and the inlet channel is connected to the anaerobic zone, anoxic zone I and anoxic zone II through the inlet pipe, so as to introduce the sewage in the inlet channel into the tank body. This replaces the practice of setting the inlet channel in the middle pipe gallery in the traditional two-stage AAO biological treatment tank structure. When it is necessary to add biological treatment tank compartments in the future, the inlet channel can be built without the need to build a new middle pipe gallery, which effectively reduces the construction cost and increases the space utilization rate of the biological treatment tank. Attached Figure Description

[0019] The present application will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present application. Furthermore, unless specifically indicated, the drawings are intended only to conceptually represent the composition or structure of the described objects and may contain exaggerated representations, and the drawings are not necessarily drawn to scale.

[0020] Figure 1 This is a top view of the biochemical tank of this utility model located below the top plate;

[0021] Figure 2 This is a top view of the biochemical tank of this utility model located below the top plate;

[0022] Figure 3 This is a cross-sectional view of part AA of the present invention;

[0023] The components include: 1. Biological treatment tank; 11. Tank body; 110. Inlet; 111. Outlet; 112. Anaerobic zone; 113. Anoxic zone I; 114. Aerobic zone I; 115. Anoxic zone II; 116. Aerobic zone II; 117. First regulating zone; 118. Second regulating zone; 119. Mixed liquor return channel; 12. Top plate; 2. Inlet channel; 3. Aeration channel; 4. Aeration pipe; 5. Aerator; 6. Flow promoter; 7. Intermediate pipe gallery. Detailed Implementation

[0024] Preferred embodiments of this application will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary, and should not be construed as limiting the scope of protection of this application.

[0025] First, it should be noted that the directions such as top, bottom, upward, and downward mentioned in this article are defined relative to the directions in the various accompanying figures. They are relative concepts and therefore can change depending on their different positions and practical applications. Therefore, these or other directions should not be interpreted as restrictive terms.

[0026] It should be noted that the term "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude the plural.

[0027] Furthermore, it should be noted that any single technical feature described or implied in the embodiments herein, or any single technical feature shown or implied in the accompanying drawings, can still be combined among these technical features (or their equivalents) to obtain other embodiments of this application not directly mentioned herein.

[0028] It should also be understood that while the terms "first," "second," etc., are used in this document to describe various types of information, this information should not be limited to these terms, which are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0029] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0030] Please see Figure 1-3 The present application provides a two-stage AAO biochemical pool structure, comprising: at least two biochemical pools 1, an inlet channel 2, and multiple inlet pipes, wherein at least two of the biochemical pools 1 are arranged at intervals.

[0031] The biochemical tank includes: a tank body 11 and a top plate 12. The top plate 12 covers the top of the tank body 11. A sewage treatment chamber is defined between the tank body 11 and the top plate 12. An inlet 110 and an outlet 111 are spaced apart on the side wall of the tank body 11.

[0032] The wastewater treatment chamber includes an anaerobic zone 112, anoxic zone I 113, aerobic zone I 114, anoxic zone II 115, and aerobic zone II 116 connected in sequence. The inlet 110 is connected to the anaerobic zone 112, and the outlet 111 is connected to the aerobic zone II 116.

[0033] The water inlet channel 2 is located on the bottom surface of the top plate 12, and the water inlet channel 2 is connected to the anaerobic zone 112, the anoxic zone I 113 and the anoxic zone II 115 respectively through multiple water inlet pipes.

[0034] In this embodiment, wastewater enters the anaerobic zone 112 through inlet 110 and reacts sequentially in anaerobic zone 112, anoxic zone I 113, aerobic zone I 114, anoxic zone II 115, and aerobic zone II 116, finally flowing out through outlet 111, thereby optimizing the distribution of carbon sources and improving denitrification efficiency. Wastewater is distributed through inlet pipes to the anaerobic zone 112, anoxic zone I 113, and anoxic zone II 115 respectively. The inlet channel 2 is located on the bottom surface of the top plate 12, distributing water to the anaerobic zone 112, anoxic zone I 113, and anoxic zone II 115 through multiple inlet pipes. When an additional biological treatment tank 1 is needed, only an inlet channel 2 needs to be constructed on the bottom surface of the top slab 12 of the newly added biological treatment tank 1, and an inlet pipe needs to be installed to connect the inlet channel 2 with the corresponding anaerobic zone 112, anoxic zone I 113, and anoxic zone II 115. Unlike traditional processes, where the inlet channel 2 is placed in the intermediate pipe gallery 7, adding an additional biological treatment tank 1 requires a corresponding intermediate pipe gallery 7, resulting in high construction costs and significant difficulty. This application, however, is beneficial for reducing construction costs and difficulty when constructing a multi-compartment, two-stage AAO biological treatment tank structure, and also helps to improve the space utilization rate of the biological treatment tank 1.

[0035] In some embodiments, each of the inlet pipes is connected to a control valve. The control valve is used to control the inflow rate to the anaerobic zone 112, the anoxic zone I 113, and the anoxic zone II 115. On the one hand, the microorganisms in different zones have different carbon source requirements; by controlling the valve, the carbon source in the wastewater can be precisely allocated according to the actual needs of each zone. On the other hand, the influent water quality may fluctuate over time; by controlling the valve, the amount of wastewater entering each zone can be flexibly adjusted, enabling the system to adapt to different water quality conditions and maintain a stable treatment effect. Furthermore, in the actual operation of the wastewater treatment plant, adjustments may be made according to different operating requirements and conditions; by controlling the valve to rationally allocate the water volume, it is beneficial to improve the utilization rate and operating efficiency of the equipment.

[0036] In some embodiments, the anaerobic zone 112, the anoxic zone I 113, the aerobic zone I 114, the anoxic zone II 115, and the aerobic zone II 116 are arranged in a ring. On one hand, the ring-shaped arrangement allows for circulating wastewater flow, resulting in smoother and more uniform flow compared to traditional linear arrangements, effectively preventing stagnant zones. Furthermore, the contact between pollutants and microorganisms in the wastewater is more thorough, extending the reaction time and significantly improving treatment efficiency. On the other hand, for the same treatment scale, the ring layout is more compact, reducing the footprint and lowering construction costs.

[0037] Please see Figure 2In some embodiments, the two-stage AAO biological treatment tank structure further includes an aeration channel 3 and multiple aeration pipes 4. The aeration channel 3 is located on the bottom surface of the top plate 12, and the aeration channel 3 is connected to the aerobic zone I 114 and the aerobic zone II 116 respectively through the multiple aeration pipes 4. Simultaneously, in some embodiments, multiple aerators 5 are provided at the bottom of both the aerobic zone I 114 and the aerobic zone II 116, and the aerators 5 are connected to the aeration channel 3 through the aeration pipes 4. On the one hand, the aerobic treatment process requires a large amount of oxygen for the survival and metabolism of aerobic microorganisms. The aerators 5 disperse air into tiny bubbles, increasing the contact area between air and wastewater, allowing oxygen to dissolve more effectively in the water, meeting the oxygen requirements of aerobic microorganisms, and ensuring their efficient decomposition of pollutants such as organic matter and ammonia nitrogen in the wastewater. On the other hand, the airflow generated by aeration can create circulation and turbulence in the wastewater within the tank, allowing pollutants, microorganisms, and dissolved oxygen in the wastewater to fully mix and come into contact. To prevent sludge sedimentation, avoid sludge accumulation and anaerobic phenomena, and ensure that microorganisms are evenly distributed in the water, thereby improving treatment efficiency; on the other hand, it facilitates the transfer of pollutants in wastewater to the surface of microorganisms, and also helps to remove microbial metabolites, accelerating the biochemical reaction rate and improving treatment efficiency; in addition, proper aeration can control the performance of activated sludge, avoid sludge bulking due to insufficient dissolved oxygen, and ensure the stable operation of the biological system.

[0038] In some embodiments, the wastewater treatment chamber further includes a first regulating zone 117, which is located between the anoxic zone I 113 and the aerobic zone I 114, and is connected to both the anoxic zone I 113 and the aerobic zone I 114. Multiple aerators 5 and multiple flow promoters 6 are provided at the bottom of the first regulating zone 117, and the aerators 5 are connected to the aeration channel 3 via the aeration pipe 4. The first regulating zone 117 serves two purposes: firstly, it improves the treatment efficiency of the first stage of the biological treatment tank 1; secondly, it provides a more suitable growth environment for microorganisms, promoting the growth and reproduction of different functional microorganisms; and thirdly, when the flow promoters 6 operate in anaerobic conditions, they promote thorough mixing between wastewater and microorganisms, enhance the mass transfer process, ensure sufficient contact between the substrate and microorganisms, and increase the reaction rate. When the aerators 5 operate in aerobic conditions, in addition to providing oxygen, they also act as a mixer, further enhancing the mass transfer effect and improving the efficiency of the aerobic reaction; and fourthly, it enhances process flexibility. Different wastewater qualities require different treatment processes. When the influent ammonia nitrogen content is high, aerator 5 can be turned on, transforming the first regulating zone 117 into an aerobic zone to enhance nitrification and convert more ammonia nitrogen into nitrate nitrogen, providing sufficient substrate for subsequent denitrification in the anoxic zone. When the influent organic matter content is high, requiring more carbon source for denitrification, aerator 5 can be turned off and propeller 6 turned on, transforming the first regulating zone 117 into an anaerobic zone 112 to promote anaerobic fermentation of organic matter, releasing more carbon source and improving denitrification efficiency. Furthermore, wastewater quality may fluctuate over time. By flexibly adjusting the environmental conditions of the first regulating zone 117, water quality fluctuations can be effectively addressed, ensuring the stability and treatment effect of the entire treatment system.

[0039] In some embodiments, the wastewater treatment chamber further includes a second regulating zone 118, which is located between the anoxic zone II 115 and the aerobic zone II 116. Both ends of the second regulating zone 118 are connected to the anoxic zone II 115 and the aerobic zone II 116, respectively. A plurality of aerators 5 and a plurality of propellers 6 are provided at the bottom of the second regulating zone 118, and the aerators 5 are connected to the aeration channel 3 through the aeration pipe. The second regulating zone 118 operates in the secondary treatment process of the biological treatment tank 1, improving the treatment efficiency of the secondary treatment in the biological treatment tank 1.

[0040] Please see Figure 2In some embodiments, the biological treatment tank 1 further includes a mixed liquor return channel 119 and a return pump. The mixed liquor return channel 119 is disposed within the wastewater treatment chamber and is connected to both the aerobic zone II 116 and the anoxic zone I 113. The return pump is disposed within the mixed liquor return channel 119 and is used to pump the mixed liquor from the aerobic zone II 116 to the anoxic zone I 113. On the one hand, the mixed liquor in the aerobic zone II 116 contains a large amount of organic matter that has been decomposed and metabolized by aerobic microorganisms after aeration and oxygenation. Returning it to the anoxic zone I 113 can provide a rich carbon source for the denitrifying bacteria in the anoxic zone I 113. Furthermore, polyphosphate-accumulating bacteria (PABs) excessively absorb phosphorus under aerobic conditions and release phosphorus under anaerobic conditions. The refluxed mixed liquor contains a certain amount of PPAs, which, when pumped back to the anoxic zone I 113, create an anaerobic environment, promoting the full release of phosphorus by PPAs. This prepares the conditions for subsequent excessive phosphorus absorption in the aerobic zone II 116, thereby improving phosphorus removal efficiency. On the other hand, during the growth and reproduction of microorganisms in the aerobic zone II 116, some microorganisms will be refluxed back to the anoxic zone I 113 with the mixed liquor, helping to replenish the number of microorganisms in the anoxic zone I 113, maintaining the stability and activity of the microbial population in the anoxic zone I 113, and ensuring the continuous and stable progress of various biochemical reactions in the anoxic zone I 113. Moreover, the reflux of the mixed liquor creates a circulation flow between the anoxic zone I 113 and the aerobic zone II 116, which helps to distribute microorganisms more evenly throughout the entire biological treatment tank 1 system. This avoids excessive aggregation or deficiency of microorganisms in local areas, which is beneficial to improving the treatment effect of microorganisms on pollutants in wastewater.

[0041] In some embodiments, the two-stage AAO biological treatment tank structure further includes a through-wall pump, which is used to pump the treated sludge into the anaerobic zone 112. The treated wastewater enters a secondary sedimentation tank for settling, and the settled sludge is pumped into the anaerobic zone 112 using the through-wall pump. This serves two purposes: firstly, it replenishes the microorganisms in the anaerobic zone 112, enhancing the quantity and diversity of the bacterial community; secondly, it provides a usable carbon source for the anaerobic zone 112, improving the utilization rate of carbon sources in the wastewater and enhancing nitrogen and phosphorus removal. Simultaneously, returning the treated sludge to the anaerobic zone 112 redistributes the carbon source, ensuring sufficient carbon for the anaerobic zone 112 to carry out relevant reactions, preventing limited anaerobic reactions due to insufficient carbon sources, and ensuring stable treatment performance of the entire biological system.

[0042] In summary, the two-stage AAO biological treatment tank structure provided in this embodiment innovatively abandons the traditional method of laying multiple inlet pipes in the intermediate pipe gallery 7 for two-stage AAO systems. The construction of biological treatment tanks 1 with more than two compartments does not require the addition of an intermediate pipe gallery 7, significantly reducing construction costs and alleviating the high foundation pit cost pressure of underground sewage treatment plants. It meets recent regulatory requirements while leaving room for future expansion, improving land and facility utilization efficiency. Simultaneously, it effectively shortens the sludge and mixed liquor return pipelines, reduces head loss, lowers the return pump head, and effectively reduces operating power consumption, achieving a win-win situation of energy saving and cost reduction. Furthermore, the addition of an adjustment zone dynamically adjusts the volume of the aerobic and anoxic zones according to the influent water quality and quantity, ensuring the efficient and stable operation of biological treatment tank 1 and enhancing the system's ability to cope with complex influent.

[0043] This specification discloses the present application with reference to the accompanying drawings and also enables those skilled in the art to implement the application, including making and using any device or system, employing suitable materials, and using any combination of methods. The scope of this application is defined by the claimed technical solution and includes other instances that would occur to those skilled in the art. Such other instances shall be considered to fall within the scope of protection defined by the claimed technical solution, provided that they include structural elements that are not different from the literal language of the claimed technical solution, or contain equivalent structural elements that are not substantially different from the literal language of the claimed technical solution.

Claims

1. A two-stage AAO biochemical pool structure, characterized in that, include: At least two biological treatment tanks, an inlet channel, and multiple inlet pipes, with at least two of the biological treatment tanks spaced apart; The biochemical tank includes: a tank body and a top plate, the top plate covering the top of the tank body, a sewage treatment chamber defined between the tank body and the top plate, and an inlet and an outlet spaced apart on the side wall of the tank body; The wastewater treatment chamber includes an anaerobic zone, an anoxic zone I, an aerobic zone I, an anoxic zone II, and an aerobic zone II connected in sequence. The inlet is connected to the anaerobic zone, and the outlet is connected to the aerobic zone II. The water inlet channel is located on the bottom surface of the top plate, and the water inlet channel is connected to the anaerobic zone, the anoxic zone I, and the anoxic zone II respectively through multiple water inlet pipes.

2. The two-stage AAO biochemical pool structure according to claim 1, characterized in that, Each of the aforementioned water inlet pipes is connected to a control water valve.

3. The two-stage AAO biochemical pool structure according to claim 1, characterized in that, The anaerobic zone, the hypoxic zone I, the aerobic zone I, the hypoxic zone II, and the aerobic zone II are arranged in a ring-like sequence.

4. The two-stage AAO biochemical pool structure according to claim 1, characterized in that, It also includes an aeration channel and multiple aeration pipes. The aeration channel is located on the bottom surface of the top plate, and the aeration channel is connected to the aerobic zone I and the aerobic zone II respectively through the multiple aeration pipes.

5. The two-stage AAO biochemical pool structure according to claim 4, characterized in that, Multiple aerators are provided at the bottom of both the aerobic zone I and the aerobic zone II, and the aerators are connected to the aeration channel through the aeration pipe.

6. The two-stage AAO biochemical pool structure according to claim 5, characterized in that, The wastewater treatment chamber further includes a first regulating zone, which is located between the anoxic zone I and the aerobic zone I, and is connected to both the anoxic zone I and the aerobic zone I. The bottom of the first regulating zone is provided with multiple aerators and multiple propellers, and the aerators are connected to the aeration channel through the aeration pipe.

7. The two-stage AAO biochemical pool structure according to claim 6, characterized in that, The wastewater treatment chamber further includes a second regulating zone, which is located between the anoxic zone II and the aerobic zone II. Both ends of the second regulating zone are connected to the anoxic zone II and the aerobic zone II, respectively. The bottom of the second regulating zone is provided with multiple aerators and multiple propellers, and the aerators are connected to the aeration channel through the aeration pipe.

8. The two-stage AAO biochemical pool structure according to claim 7, characterized in that, The biochemical tank also includes a mixed liquor return channel and a return pump. The mixed liquor return channel is located inside the sewage treatment chamber and is connected to the aerobic zone II and the anoxic zone I, respectively. The reflux pump is located in the mixed liquor reflux channel, and the reflux pump is used to pump the mixed liquor in the aerobic II zone to the anoxic I zone.

9. The two-stage AAO biochemical pool structure according to any one of claims 1-8, characterized in that, It also includes a through-wall pump, which is used to pump the treated sludge into the anaerobic zone.

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