Accurate carbon source adding system applied to multi-cycle AAO biochemical pool

Abstract

The utility model relates to the technical field of sewage treatment, and discloses an accurate carbon source adding system applied to a multi-cycle AAO biochemical pool. The system comprises a second guide plate assembly, a propeller and a feeding assembly, the second guide plate assembly is arranged at the bottom of the anoxic tank, the top end is positioned above the liquid level, and a flow channel for liquid circulation can be formed in the anoxic tank; the propeller is mounted in the anoxic tank and is used for providing a power source for the carbon source and mud-water mixed circulation; and the feeding assembly is provided with a plurality of carbon source feeding ports which are uniformly distributed along the flow channel direction of the anoxic tank. Relevant flow and nitrate nitrogen concentration numerical signals are obtained through an electromagnetic flowmeter arranged at the water inlet end of the AAO pool and nitrate nitrogen analyzers arranged at the outlets of the anoxic pool and the aerobic pool respectively and fed back to a PLC system, a dosing pump is controlled to feed a carbon source into the biochemical pool in real time, and a liquid circulation flow guide structure is constructed, so that the concentration of nitrate nitrogen in the biochemical pool is controlled. Efficient mixing and reaction contact of a carbon source and sewage in the anoxic tank are realized, the utilization rate of the carbon source is increased, the denitrification efficiency is improved, and stable and standard reaching of effluent is guaranteed.

Description

A precise carbon source dosing system for multi-cycle AAO biochemical ponds Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically a carbon source precision dosing system applied to a multi-cycle AAO biochemical tank. Background Technology

[0002] In the biological treatment of urban and industrial wastewater, biological nitrogen and phosphorus removal processes widely adopt an anaerobic-anoxic-aerobic (AAO) structure. The anoxic tank, as the primary site of denitrification, directly impacts the stability and compliance of the effluent quality. To improve denitrification efficiency, external carbon sources (such as sodium acetate, glucose, ethanol, etc.) are typically added to the anoxic tank to supplement the electron donors required for the metabolism of denitrifying microorganisms.

[0003] However, existing technologies for adding carbon sources to anoxic tanks typically suffer from the following problems: The addition method is simplistic, relying solely on manual experience to concentrate the dosage at the anoxic tank inlet or a fixed location. This leads to excessive consumption or retention of the carbon source over a short distance, making it difficult to cover the entire anoxic section of the water. The accuracy is low, and the labor intensity is high. Furthermore, this method cannot adjust the dosage in a timely manner according to changes in actual water quality and quantity, resulting in either excessive or insufficient dosage, which significantly impacts the effluent quality and cost of the wastewater treatment plant. Additionally, existing systems usually add agitators inside the anoxic tank to generate vortices to mix the carbon source and wastewater. However, the water flow becomes locally stagnant or short-circuited, causing the carbon source to "agglomerate" or form "blind spots" within the tank. This results in low contact efficiency between microorganisms and the carbon source, thus limiting the denitrification effect. Summary of the Invention

[0004] To overcome the technical problems existing in the carbon source addition methods of the prior art, this utility model provides a carbon source precision addition system for multi-circulation AAO biological tanks. By constructing a liquid circulation guide structure and distributed carbon source addition ports, it realizes efficient mixing and reaction contact between carbon source and sewage in the anoxic tank, improves carbon source utilization, enhances denitrification efficiency, and ensures stable effluent compliance.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] This utility model discloses a carbon source precision dosing system for a multi-cycle AAO biochemical tank. The system includes a second guide plate assembly, a propeller, and a dosing assembly. The biochemical tank includes an anaerobic tank, an anoxic tank, and an aerobic tank arranged in sequence. The second guide plate assembly is set at the bottom of the anoxic tank and can form a flow channel for liquid circulation in the anoxic tank. The propeller is installed in the anoxic tank and is used to provide a power source for liquid circulation. The dosing assembly is provided with multiple carbon source dosing ports evenly distributed along the flow channel of the anoxic tank.

[0007] As a further improvement to the above scheme, the dosing component includes a carbon source tank, a carbon source dosing pump, a main pipe, and branch pipes; the input end of the carbon source dosing pump is connected to the inside of the carbon source tank, the output end is connected to one end of the main pipe, the other end of the main pipe is connected to one end of multiple branch pipes, and the other ends of the multiple branch pipes extend into the anoxic pool to form the carbon source dosing port.

[0008] As a further improvement to the above scheme, the dosing assembly also includes an inlet electromagnetic flow meter, a first nitrate nitrogen analyzer, a second nitrate nitrogen analyzer, and a PLC control unit. The inlet electromagnetic flow meter is installed at the inlet of the anaerobic tank to collect the sewage flow rate entering the entire biological treatment tank. The probes of the first and second nitrate nitrogen analyzers are respectively installed at the outlet of the anoxic tank and the outlet of the aerobic tank to detect the nitrate nitrogen concentration in the sewage at the corresponding installation locations. The inlet electromagnetic flow meter, the first nitrate nitrogen analyzer, the second nitrate nitrogen analyzer, and the carbon source dosing pump are all electrically connected to the PLC control unit. The PLC control unit is used to control the start and stop of the carbon source dosing pump based on the sewage flow rate and the collected nitrate nitrogen concentration data.

[0009] As a further improvement to the above scheme, the second guide plate assembly includes a straight plate and two arc-shaped plates erected at the bottom of the anoxic pool; the straight plate is set in the middle of the anoxic pool, and the two arc-shaped plates are respectively located at both ends of the straight plate along the length direction, thereby forming a waist-shaped flow channel.

[0010] As a further improvement to the above scheme, both arc-shaped plates are U-shaped structures with extended ends in the horizontal plane, with the head end of each arc-shaped plate pointing towards the tail end of the other arc-shaped plate; two thrusters are provided, located between the two arc-shaped plates respectively; the negative pressure side of each thruster points towards the head end of one arc-shaped plate, and the positive pressure side points towards the tail end of the other arc-shaped plate.

[0011] As a further improvement to the above scheme, the carbon source injection port is located in the region facing the negative pressure side of the propeller.

[0012] As a further improvement to the above scheme, each guide plate in the second guide plate assembly is inserted into the installation groove opened at the bottom of the anoxic pool to achieve detachable installation with the anoxic pool; the installation groove is also provided with a limiting component for stabilizing the guide plate; multiple branch pipes are respectively mounted above the anoxic pool through support seats, and the pipe openings of the branch pipes extend into the anoxic pool to form the carbon source addition port.

[0013] As a further improvement to the above solution, the limiting component includes a rubber sealing gasket that is laid on the inner wall of the mounting groove and can form an interference fit with the guide plate.

[0014] As a further improvement to the above scheme, each of the guide plates in the second guide plate assembly is a brick or cast-in-place wall structure, which is integrally fixed to the bottom of the anoxic pool; among them, multiple branch pipes are pre-embedded inside the wall structure of the arc plate, and the pipe openings are located at the ends of the arc plate and connected to the space inside the anoxic pool.

[0015] As a further improvement to the above scheme, a first guide plate assembly and a third guide plate assembly are respectively installed in the anaerobic tank and the aerobic tank; the first guide plate assembly includes baffles that are staggered along both sides of the bottom of the anaerobic tank to form a unidirectional bent flow channel in the anaerobic tank; the third guide plate assembly is installed in the aerobic tank with the same structure as the second guide plate assembly and can form a flow channel for liquid circulation in the aerobic tank.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. This utility model sets up a guide plate in the anoxic tank to form a closed annular flow channel. Through the coupling effect of the mechanical thrust of the propeller and the guide structure, the sewage in the tank can be stably and directionally circulated. Multiple carbon source dosing ports are distributed along the flow channel, which helps to draw the carbon source into the mainstream area and diffuse it rapidly, effectively improving the contact efficiency between the carbon source and sewage and microorganisms, and enhancing the denitrification reaction effect.

[0018] 2. This utility model, by configuring a flow meter, a nitrate nitrogen analyzer and a PLC control system, enables precise adjustment of carbon source addition, which helps the wastewater treatment system operate stably and improves treatment efficiency.

[0019] 3. The extended design of the arc-shaped guide plate at the head of this utility model can create a hydraulic pressure difference. When the propeller is set on its negative pressure side, the liquid forms a stable circulation direction in the anoxic pool, preventing short-circuiting of the water and dead zones of sedimentation at the edges and corners. On this basis, the carbon source injection port is preferentially arranged in the upstream area of ​​the negative pressure side of the propeller. The negative pressure suction force allows the carbon source to quickly enter the center of the flow channel and be agitated and refined by the impeller, effectively avoiding the deposition of carbon source on the pool wall or bottom, and improving the uniformity of carbon source distribution and reactivity.

[0020] 4. This utility model designs the second guide plate assembly as a detachable modular structure or a brick / cast wall-type fixed structure, which can be flexibly arranged according to the actual working conditions during the construction period, and is also easy to replace or adjust according to the operation conditions in the future, with strong adaptability and maintainability. Attached Figure Description

[0021] Figure 1 is a top view of the biochemical pool with flow circulation and distributed carbon source addition in an embodiment of this utility model.

[0022] Figure 2 is a top view of the anoxic tank in an embodiment of this utility model (the arrows in the figure indicate the direction of fluid circulation).

[0023] Figure 3 is a three-dimensional structural diagram of the biochemical pool with flow circulation and distributed carbon source addition in an embodiment of this utility model.

[0024] Figure 4 is a schematic diagram of the connection between the PLC control unit and various components in an embodiment of this utility model.

[0025] Figure 5 is a three-dimensional structural diagram of the mounting groove at the bottom of the anoxic pool in an embodiment of this utility model.

[0026] Figure 6 is a schematic diagram of the distribution of carbon source injection ports when the guide plate in the embodiment of this utility model adopts a brick or cast-in-place wall structure.

[0027] In the diagram: 1. Anaerobic tank; 2. Anoxic tank; 3. Aerobic tank; 41. First guide plate assembly; 411. Baffle plate; 412. Mixer; 42. Second guide plate assembly; 421. Straight plate; 422. Arc plate; 4221. Head end; 4222. Tail end; 43. Third guide plate assembly; 5. Propeller; 6. Dosing assembly; 61. Carbon source tank; 62. Carbon source dosing pump; 63. Main pipe; 64. Branch pipe; 65. Electromagnetic flow meter at the inlet; 66. First nitrate nitrogen analyzer; 67. Second nitrate nitrogen analyzer; 68. PLC control unit; 7. Mounting slot; 8. Support base. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Please refer to Figures 1 to 4. This embodiment provides a carbon source precision dosing system for multi-cycle AAO biochemical ponds. The system includes a second guide plate assembly 42, a propeller 5, and a dosing assembly 6.

[0030] The biological treatment tank includes an anaerobic tank 1, an anoxic tank 2, and an aerobic tank 3, which are arranged in sequence and connected to each other. Components such as transfer pumps or solenoid valves (not shown in the figure) can be installed at the connection points between the tanks to transport sewage to the next stage at appropriate times.

[0031] The second guide plate assembly 42 is set at the bottom of the anoxic pool 2, with its top end above the liquid surface, and can form a flow channel for liquid circulation in the anoxic pool 2; the propeller 5 is installed in the anoxic pool 2 and is used to provide a power source for liquid circulation; the dosing assembly 6 is provided with multiple carbon source dosing ports that are evenly distributed along the flow channel direction of the anoxic pool 2.

[0032] The dosing assembly 6 includes a carbon source tank 61, a carbon source dosing pump 62, a main pipe 63, and branch pipes 64. It may also include an inlet electromagnetic flow meter 65, a first nitrate nitrogen analyzer 66, a second nitrate nitrogen analyzer 67, and a PLC control unit 68. The input end of the carbon source dosing pump 62 is connected to the inside of the carbon source tank 61, and the output end is connected to one end of the main pipe 63. The other end of the main pipe 63 is simultaneously connected to one end of multiple branch pipes 64, and the other ends of the multiple branch pipes 64 extend into the anoxic tank 2 to form the carbon source dosing port.

[0033] An electromagnetic flow meter 65 is installed at the inlet of the anaerobic tank 1 to collect the flow rate of sewage entering the entire biological treatment tank. The probes of the first nitrate nitrogen analyzer 66 and the second nitrate nitrogen analyzer 67 are respectively installed at the outlet of the anoxic tank 2 and the outlet of the aerobic tank 3 to detect the nitrate nitrogen concentration in the sewage at the corresponding installation locations. The electromagnetic flow meter 65, the first nitrate nitrogen analyzer 66, the second nitrate nitrogen analyzer 67, and the carbon source dosing pump 62 are all electrically connected to the PLC control unit 68. The PLC control unit 68 is used to control the opening and closing of the carbon source dosing pump 62 based on the sewage flow rate and the collected nitrate nitrogen concentration data to adjust the carbon source dosing amount.

[0034] The first nitrate nitrogen analyzer 66 and the second nitrate nitrogen analyzer 67 can be commercially available online analyzers; in this embodiment, the Hach NT3 model is selected. The PLC control unit 68 is an S7-300 model. Through programming, the PLC control unit can compare the actual nitrate nitrogen concentration at the end of the anoxic tank 2 with a set value and adjust the carbon source dosage in real time according to an empirical formula. The empirical formula is related to the actual operation data of the wastewater treatment plant and will not be elaborated here.

[0035] The second guide plate assembly 42 includes a straight plate 421 and two arc-shaped plates 422 erected at the bottom of the anoxic tank 2; the straight plate 421 is located in the middle of the anoxic tank 2; the two arc-shaped plates 422 are located at both ends of the straight plate 421 along its length. The two arc-shaped plates 422 and the straight plate 421 form an waist-shaped flow channel in the anoxic tank 2. The straight plate 421 is used to prevent short-circuiting and force the sewage in the tank to flow around it; the arc-shaped plates 422 are used to smoothly change direction and guide the formation of circulation.

[0036] In this embodiment, both arc-shaped plates 422 are U-shaped structures with extended ends 4221 in the horizontal plane, with the end 4221 of each arc-shaped plate 422 pointing towards the end 4222 of the other arc-shaped plate 422. The extended ends 4221 can create a pressure difference, promote uniform circulation direction, and prevent stagnant water zones.

[0037] Two propellers 5 can be installed in the anoxic tank 2, located between two arc-shaped plates 422 respectively; the negative pressure side of each propeller 5 points to the beginning end 4221 of one arc-shaped plate 422, and the positive pressure side points to the end end 4222 of the other arc-shaped plate 422. The carbon source dosing port can be preferentially located in the area facing the negative pressure side of the propeller 5. The suction force of the negative pressure side of the propeller 5 draws sewage in from the beginning end 4221 of the arc-shaped plate 422, enhancing the "pumping" effect from that end, and pushing the sewage out through the impeller and pushing it downstream to the end end 4222 of the other arc-shaped plate 422, which helps to maintain a strong directional circulation.

[0038] In some embodiments, the axis of the thruster 5 is collinear with the extension lines of the ends of the two arc-shaped plates 422 in the vertical plane, naturally coupling the mechanical thrust with the structural guidance and avoiding flow disturbance.

[0039] Referring to Figure 5, in this embodiment, each guide plate in the second guide plate assembly 42 is inserted into the mounting groove 7 opened at the bottom of the anoxic tank 2, thereby achieving detachable installation between the guide plate and the anoxic tank 2. The mounting groove 7 is also equipped with limiting components for stabilizing the guide plates. These limiting components may include rubber sealing gaskets (not shown) laid on the inner wall of the mounting groove 7 and capable of interference fit with the guide plates, and may also include bolts or clips (not shown) set on the mounting groove 7 to assist in fixing the guide plates, thereby increasing the anti-overturning ability of the guide plates and improving their durability. By designing the guide plates as a detachable modular structure, if the flow is not good at a certain point during use, the plate position can be quickly adjusted or the plate type replaced; suitable guide plate components can also be matched for different tank structures.

[0040] Multiple branch pipes 64 are mounted above the anoxic pool 2 via support bases 8. The pipe openings of the branch pipes 64 extend into the anoxic pool 2 to form carbon source addition ports, and are located between the negative pressure side of the propeller 5 and the first end 4221 of the arc plate 422. Multiple support bases 8 can be fixed to the upper edge of the pool wall of the anoxic pool 2.

[0041] By preferentially placing the two carbon source inlets in the negative pressure side-facing area of ​​the two propellers 5, the suction force of the propellers 5 actively draws the carbon source into the main circulation flow. Upon entering the tank, the carbon source is immediately agitated and sheared by the impellers inside the propellers 5, facilitating uniform diffusion and reducing carbon source adhesion and deposition on the tank walls or bottom. This promotes uniform mixing and rapid diffusion of the carbon source, thereby enhancing the reaction contact efficiency between microorganisms and the carbon source and improving the denitrification effect in the anoxic section.

[0042] Referring to Figure 6, in some embodiments, each guide plate in the second guide plate assembly 42 can be designed as a brick or cast-in-place wall structure, integrally fixed to the bottom of the anoxic pool 2, possessing good structural stability and resistance to water flow impact. Multiple branch pipes 64 can be pre-embedded inside the wall structure of the arc-shaped plate 422, with the pipe openings located at the ends of the arc-shaped plate 422 and communicating with the space within the anoxic pool 2.

[0043] In some embodiments, the anaerobic tank 1 and the aerobic tank 3 may also be respectively provided with a first guide plate assembly 41 and a third guide plate assembly 43. The first guide plate assembly 41 includes baffles 411 staggered along both sides of the bottom of the anaerobic tank 1, thereby forming a unidirectional tortuous flow channel in the anaerobic tank 1. A stirrer 412 can be installed near each baffle 411. The third guide plate assembly 43 is arranged in the aerobic tank 3 with the same structure as the second guide plate assembly 42, and can form a flow channel for liquid circulation in the aerobic tank 3. In this embodiment, there are two aerobic tanks 3, and the same propeller assembly as in the anoxic tank 2 can be installed in the aerobic tank 3.

[0044] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A carbon source precision dosing system for use in multi-cycle AAO biochemical ponds, characterized in that, The system includes a second guide plate assembly (42), a propeller (5), and a dosing assembly (6); the biochemical tank includes an anaerobic tank (1), an anoxic tank (2), and an aerobic tank (3) arranged in sequence; the second guide plate assembly (42) is set at the bottom of the anoxic tank (2), with its top end above the liquid surface, and can form a flow channel for liquid circulation in the anoxic tank (2); the propeller (5) is installed in the anoxic tank (2) and is used to provide a power source for liquid circulation; the dosing assembly (6) is provided with multiple carbon source dosing ports evenly distributed along the flow channel direction of the anoxic tank (2).

2. The carbon source precision dosing system for a multi-cycle AAO biochemical tank according to claim 1, characterized in that, The dosing assembly (6) includes a carbon source tank (61), a carbon source dosing pump (62), a main pipe (63), and branch pipes (64). The input end of the carbon source dosing pump (62) is connected to the inside of the carbon source tank (61), and the output end is connected to one end of the main pipe (63). The other end of the main pipe (63) is connected to one end of multiple branch pipes (64). The other ends of the multiple branch pipes (64) extend into the anoxic pool (2) to form the carbon source dosing port.

3. A carbon source precision dosing system for multi-cycle AAO biochemical ponds according to claim 2, characterized in that, The dosing assembly (6) also includes an inlet electromagnetic flow meter (65), a first nitrate nitrogen analyzer (66), a second nitrate nitrogen analyzer (67), and a PLC control unit (68). The inlet electromagnetic flow meter (65) is installed at the inlet of the anaerobic tank (1) to collect the flow rate of sewage entering the entire biological tank. The probes of the first nitrate nitrogen analyzer (66) and the second nitrate nitrogen analyzer (67) are respectively installed at the outlet of the anoxic tank (2) and the outlet of the aerobic tank (3) to detect the nitrate nitrogen concentration in the sewage at the corresponding installation location. The inlet electromagnetic flow meter (65), the first nitrate nitrogen analyzer (66), the second nitrate nitrogen analyzer (67), and the carbon source dosing pump (62) are all electrically connected to the PLC control unit (68). The PLC control unit (68) is used to control the flow rate of the carbon source dosing pump (62) based on the sewage flow rate and the data collected on the nitrate nitrogen concentration.

4. The carbon source precision dosing system for a multi-cycle AAO biochemical tank according to claim 1, characterized in that, The second guide plate assembly (42) includes a straight plate (421) and two arc-shaped plates (422) erected at the bottom of the anoxic pool (2); the straight plate (421) is set in the middle of the anoxic pool (2), and the two arc-shaped plates (422) are located at both ends of the straight plate (421) along the length direction, thereby forming a waist-shaped flow channel.

5. A carbon source precision dosing system for multi-cycle AAO biochemical ponds according to claim 4, characterized in that, Both arc-shaped plates (422) are U-shaped structures with an extended head end (4221) in the horizontal plane. The head end (4221) of each arc-shaped plate (422) points to the tail end (4222) of the other arc-shaped plate (422). Two thrusters (5) are provided, located between the two arc-shaped plates (422). The negative pressure side of each thruster (5) points to the head end (4221) of one arc-shaped plate (422), and the positive pressure side points to the tail end (4222) of the other arc-shaped plate (422).

6. A carbon source precision dosing system for multi-cycle AAO biochemical ponds according to claim 5, characterized in that, The carbon source injection port is located in the region facing the negative pressure side of the thruster (5).

7. A carbon source precision dosing system for multi-cycle AAO biochemical ponds according to claim 4, characterized in that, Each guide plate in the second guide plate assembly (42) is inserted into the installation groove (7) opened at the bottom of the anoxic pool (2) to achieve detachable installation with the anoxic pool (2); the installation groove (7) is also provided with a limiting component for stabilizing the guide plate; multiple branch pipes (64) are respectively mounted above the anoxic pool (2) through the support base (8), and the pipe opening of the branch pipe (64) extends into the anoxic pool (2) to form the carbon source addition port.

8. A carbon source precision dosing system for a multi-cycle AAO biochemical tank according to claim 7, characterized in that, The limiting component includes a rubber sealing gasket that is laid on the inner wall of the mounting groove (7) and can produce an interference fit with the guide plate.

9. A carbon source precision dosing system for a multi-cycle AAO biochemical tank according to claim 4, characterized in that, Each of the guide plates in the second guide plate assembly (42) is a brick or cast wall structure, which is fixedly connected to the bottom of the anoxic pool (2); among them, multiple branch pipes (64) are pre-embedded inside the wall structure of the arc plate (422), and the pipe openings are located at the end of the arc plate (422) and connected to the space inside the anoxic pool (2).

10. A carbon source precision dosing system for a multi-cycle AAO biochemical tank according to any one of claims 4 to 9, characterized in that, The anaerobic tank (1) and the aerobic tank (3) are respectively equipped with a first guide plate assembly (41) and a third guide plate assembly (43); the first guide plate assembly (41) includes partitions (411) that are staggered along both sides of the bottom of the anaerobic tank (1) to form a unidirectional bent flow channel in the anaerobic tank (1); the third guide plate assembly (43) is set in the aerobic tank (3) with reference to the structure of the second guide plate assembly (42) and can form a flow channel for liquid circulation in the aerobic tank (3).

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