Cyclic intermittent low-dissolved oxygen aeration device

Abstract

The utility model discloses a kind of cyclic intermittent low-dissolved oxygen aeration devices, it is related to sewage treatment technical field, including adjustable frequency blower, air pipe and intelligent controller, the biochemical pool box is internally provided with anaerobic zone, anoxic zone and aerobic / anoxic zone, the anaerobic zone, anoxic zone and aerobic / anoxic zone are all equipped with dissolved oxygen measuring instrument and agitator, the output of adjustable frequency blower is equipped with air pipe, the air pipe one end is connected aerobic / anoxic zone, the aerobic / anoxic zone is internally provided with aerator and sludge return pump;The utility model device can be realized with continuous aeration 3 hours, aerobic / anoxic zone dissolved oxygen is controlled in 2-3mg·L ‑1 Between, and stop aeration 0.5 hours, aerobic / anoxic zone dissolved oxygen is controlled in 0.5mg·L ‑1 Inside mode, realize with cyclic aeration / stop aeration operating mode to control biochemical pool box 4 in cyclic intermittent low-dissolved oxygen operating environment.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a circulating intermittent low dissolved oxygen aeration device. Background Technology

[0002] Biochemical reaction tanks are core facilities in fields such as wastewater treatment that utilize the metabolic processes of microorganisms to treat organic matter or produce target products.

[0003] In biological reactors, different bacterial species, such as ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), and denitrifying bacteria (DNB), have different optimal dissolved oxygen (DO) concentration ranges. Sustained high DO levels are detrimental to the denitrification reaction of microorganisms in the reactor. Optimizing the aeration mode has a significant impact on the denitrification effect. By controlling the DO concentration, different denitrification pathways can be adjusted and enhanced. Different aeration modes directly affect the DO in the reactor, thus affecting the denitrification effect. Therefore, this invention proposes a circulating intermittent low dissolved oxygen aeration device to address the shortcomings of existing technologies. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this invention is to provide a circulating intermittent low dissolved oxygen aeration device, which can control the dissolved oxygen in the aerobic / anoxic zone to 2-3 mg·L⁻¹ with continuous aeration for 3 hours. -1 During this period, and after stopping aeration for 0.5 hours, the dissolved oxygen in the aerobic / anoxic zone was controlled at 0.5 mg·L⁻¹. -1 The method involves using a cyclical aeration / stop operation mode to control the low dissolved oxygen environment within the biological tank 4.

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

[0006] A circulating intermittent low dissolved oxygen aeration device includes a frequency-adjustable blower, an air pipe, and an intelligent controller. The frequency-adjustable blower and intelligent controller are both located outside a biological treatment tank. The biological treatment tank contains an anaerobic zone, an anoxic zone, and an aerobic / anoxic zone. Each of the anaerobic, anoxic, and aerobic / anoxic zones is equipped with a dissolved oxygen meter and a stirrer. An air pipe is located at the output end of the frequency-adjustable blower, with one end connected to the aerobic / anoxic zone. The air pipe is equipped with a diamond-shaped valve, a vent valve, and a gas flow meter. The frequency-adjustable blower, dissolved oxygen meter, diamond-shaped valve, and vent valve are all electrically connected to the intelligent controller. An aerobic / anoxic zone contains an aerator and a sludge return pump. A sludge return pipe is located outside the biological treatment tank, with one end connected to the sludge return pump. The anaerobic and anoxic zones are connected to the sludge return pipe via a first return branch pipe and a second return branch pipe, respectively.

[0007] A further improvement is made in that: an inlet pipe is connected to one side of the anaerobic zone, and an inlet flow meter and an inlet eccentric hemispherical valve are installed on the inlet pipe; an outlet pipe is connected to one side of the aerobic / anoxic zone, and an outlet flow meter and an outlet eccentric hemispherical valve are installed on the outlet pipe.

[0008] A further improvement is that a first water-passing through-wall pipe is provided on the partition wall between the anaerobic zone and the anoxic zone, and a second water-passing through-wall pipe is provided on the partition wall between the anoxic zone and the aerobic / anoxic zone.

[0009] A further improvement is that the sludge return pipe is equipped with a sludge return main valve and a sludge return flow meter.

[0010] Further improvements include: an anaerobic zone reflux valve is installed on the first reflux branch pipe, and an anoxic zone reflux valve is installed on the second reflux branch pipe.

[0011] Further improvements include: the aerator is provided in multiple sets, and the agitator is provided in multiple sets.

[0012] The beneficial effects of this invention are as follows: The intelligent controller of this invention adjusts the frequency of the adjustable frequency blower, the opening degree of the diamond valve, and the opening degree of the vent valve in real time according to the dissolved oxygen level in the biological tank. By changing the air volume, the dissolved oxygen in the biological tank 4 is controlled. The device can control the dissolved oxygen in the aerobic / anoxic zone 403 to 2-3 mg·L⁻¹ after continuous aeration for 3 hours. -1 During this period, and after stopping aeration for 0.5 hours, the dissolved oxygen in the aerobic / anoxic zone 403 was controlled at 0.5 mg·L⁻¹. -1 The method of internal control is used to achieve a cyclical aeration / stop operation mode to control the low dissolved oxygen environment in the biological tank 4.

[0013] During the aeration-stopping period, the entire biological treatment tank is in a state of oxygen deficiency, forming a second-stage anoxic environment. This significantly prolongs the denitrification reaction time. Furthermore, due to the use of intermittent low dissolved oxygen aeration, it is conducive to short-cut nitrification, short-cut denitrification, and anaerobic ammonia oxidation reactions, enabling the achievement of TN emission standards without the addition of carbon sources. Attached Figure Description

[0014] Figure 1 This is a top view of the structure of this utility model;

[0015] Figure 2 This is a top view schematic diagram of the reflux system structure of this utility model.

[0016] The components include: 1. Adjustable frequency blower; 2. Air pipe; 3. Intelligent controller; 4. Biological tank body; 401. Anaerobic zone; 402. Anoxic zone; 403. Aerobic / Anoxic zone; 5. Dissolved oxygen meter; 6. Agitator; 7. Diamond valve; 8. Vent valve; 9. Gas flow meter; 10. Aerator; 11. Sludge return pump; 12. Sludge return pipe; 13. First return branch pipe; 14. Second return branch pipe; 15. Inlet pipe; 16. Inlet flow meter; 17. Inlet eccentric hemispherical valve; 18. Outlet pipe; 19. Outlet flow meter; 20. Outlet eccentric hemispherical valve; 21. First through-wall pipe; 22. Second through-wall pipe; 23. Sludge return main valve; 24. Sludge return flow meter; 25. Anaerobic zone return valve; 26. Anoxic zone return valve. Detailed Implementation

[0017] To deepen the understanding of this utility model, the following detailed description will be provided in conjunction with embodiments. These embodiments are only used to explain this utility model and do not constitute a limitation on the scope of protection of this utility model.

[0018] according to Figure 1-2 As shown in the figure, this embodiment proposes a circulating intermittent low dissolved oxygen aeration device, including a frequency-adjustable blower 1, an air pipe 2, and an intelligent controller 3. The frequency-adjustable blower 1 and the intelligent controller 3 are both located outside the biological treatment tank 4. The biological treatment tank 4 is equipped with an anaerobic zone 401, an anoxic zone 402, and an aerobic / anoxic zone 403. Dissolved oxygen meters 5 and stirrers 6 are installed in each of the anaerobic zone 401, anoxic zone 402, and aerobic / anoxic zone 403. An air pipe 2 is located at the output end of the frequency-adjustable blower 1, and one end of the air pipe 2 is connected to the aerobic / anoxic zone. In the anoxic zone 403, the air pipe 2 is equipped with a diamond valve 7, a vent valve 8, and a gas flow meter 9. The adjustable frequency blower 1, dissolved oxygen meter 5, diamond valve 7, and vent valve 8 are all electrically connected to the intelligent controller 3. The aerobic / anoxic zone 403 is equipped with an aerator 10 and a sludge return pump 11. The outside of the biological tank 4 is equipped with a sludge return pipe 12, one end of which is connected to the sludge return pump 11. The anaerobic zone 401 and the anoxic zone 402 are connected to the sludge return pipe 12 through a first return branch pipe 13 and a second return branch pipe 14, respectively.

[0019] Operating principle of this utility model device:

[0020] First, when the wastewater enters the anaerobic zone 401 of the biological treatment tank 4, it merges with the returned sludge inside the anaerobic zone 401. Through low-speed stirring by the agitator 6 inside the anaerobic zone 401, as well as measures such as flow rate adjustment and control of the amount of returned sludge, the dissolved oxygen in the anaerobic zone 401 is controlled at 0.2 mg·L⁻¹. -1In the anaerobic zone 401, microorganisms fully release phosphorus and synthesize energy to store in their bodies, making full preparations for subsequent aerobic over-phosphorus uptake;

[0021] Secondly, the anaerobic wastewater enters the anoxic zone 402 through the through-wall pipe. In the anoxic zone 402, nitrate nitrogen and nitrite nitrogen in the returned sludge undergo denitrification. Within the anoxic zone 402, dissolved oxygen is controlled at 0.2–0.5 mg / L by low-speed stirring with a mixer 6, control of the returned sludge volume, and adjustment of the blower airflow. -1 between;

[0022] Finally, the wastewater treated in the anoxic zone 402 enters the aerobic / anoxic zone 403. In the aerobic / anoxic zone 403, the intelligent controller 3, based on feedback data from the dissolved oxygen meter 5, adjusts in real time the frequency of the adjustable frequency blower 1, the opening of the diamond valve 7, and the opening of the vent valve 8, using continuous aeration for 3 hours to control the dissolved oxygen in the aerobic / anoxic zone 403 at 2-3 mg / L. -1 Between these periods, aeration is stopped for 0.5 hours. During this period, the dissolved oxygen in the aerobic / anoxic zone 403 is controlled at 0.5 mg / L by low-speed stirring with agitator 6. -1 The system employs an internal, repetitive aeration / stop operation mode within the biological treatment tank 4, creating a periodically cyclical, intermittent low dissolved oxygen environment. During periods of aeration stoppage, the entire biological treatment tank 4 is in a state of oxygen deficiency, forming a secondary anoxic condition. This significantly prolongs the denitrification reaction time. Furthermore, the intermittent low dissolved oxygen aeration promotes short-cut nitrification, short-cut denitrification, and anaerobic ammonia oxidation reactions, enabling TN emissions to meet standards without the addition of a carbon source.

[0023] When this invention adopts the intermittent low dissolved oxygen aeration operation mode, short-range nitrification and denitrification reactions will occur in the biological treatment tank, which is beneficial to improving the nitrogen removal efficiency.

[0024] During the aeration period, NH4 + -N first decomposes into NO2 in the nitration reaction. - -N and NO3 - -N, during this period NH4 + -N is gradually reduced, while NO2 - -N and NO3 - -N gradually accumulates, and the reaction formula is shown in equation (1):

[0025] Short-cut nitrification: NH4 + +1.5O2→NO2 - +H₂O+2H + (1);

[0026] During periods of intermittent low dissolved oxygen, NO2- -N undergoes a short-range denitrification reaction with the residual organic matter in the tank, thereby achieving TN removal. The reaction formula is shown in equation (2):

[0027] Short-cut denitrification: 6NO2 - +3CH3OH + 3CO2 → 3N2 + 6HCO3 - +3H2O (2)

[0028] Intermittent low dissolved oxygen processes favor NO2 - The accumulation of NO2 can significantly improve the reactivity of anammox and TN removal efficiency. - Increased concentration can optimize community structure and function, stabilize or increase the relative abundance of major functional microorganisms, increase the relative abundance of hydrolytic bacteria, and significantly improve the denitrification capacity of the system.

[0029] Under intermittent low dissolved oxygen mode, NO2 produced by nitrification reaction during aeration periods - The remaining NH4 in the biological treatment tank during the aeration stop period + Anaerobic ammonia oxidation occurs, which greatly improves the denitrification efficiency, thereby further realizing the removal of TN. The reaction formula is shown in equation (3):

[0030] Anaerobic ammonia oxidation: NH4 + + 1.32NO2 - →N2 + 2H2O (3).

[0031] An inlet pipe 15 is connected to one side of the anaerobic zone 401. The inlet pipe 15 is equipped with an inlet flow meter 16 and an inlet eccentric ball valve 17. An outlet pipe 18 is connected to one side of the aerobic / anoxic zone 403. The outlet pipe 18 is equipped with an outlet flow meter 19 and an outlet eccentric ball valve 20. Wastewater enters the anaerobic zone 401 after passing through the inlet pipe 15 and being monitored and controlled by the inlet flow meter 16 and the inlet eccentric ball valve 17.

[0032] A further improvement is made in that: a first water-passing through-wall pipe 21 is provided on the partition wall between the anaerobic zone 401 and the anoxic zone 402, and a second water-passing through-wall pipe 22 is provided on the partition wall between the anoxic zone 402 and the aerobic / anoxic zone 403. Wastewater that has undergone anaerobic treatment in the anaerobic zone 401 enters the anoxic zone 402 through the first water-passing through-wall pipe 21, and wastewater that has undergone the first stage of anoxic treatment in the anoxic zone 402 enters the aerobic / anoxic zone 403 through the second water-passing through-wall pipe 22.

[0033] The sludge return pipe 12 is equipped with a sludge return main valve 23 and a sludge return flow meter 24. The first return branch pipe 13 is equipped with an anaerobic zone return valve 25, and the second return branch pipe 14 is equipped with an anoxic zone return valve 26. The return system consisting of the first return branch pipe 13, the second return branch pipe 14, the sludge return pipe 12, and the sludge return pump 11 enables the transport of activated sludge from the end of the biological treatment tank 4 to the front end.

[0034] The aerator 10 is provided in multiple sets, and the agitator 6 is provided in multiple sets.

[0035] This invention's intelligent controller adjusts the frequency of the adjustable frequency blower, the opening degree of the diamond valve, and the opening degree of the vent valve in real time according to the dissolved oxygen level in the biological treatment tank 4. By changing the air volume, it controls the dissolved oxygen in the biological treatment tank 4. The device can control the dissolved oxygen in the aerobic / anoxic zone 403 to 2-3 mg·L⁻¹ after 3 hours of continuous aeration. -1 During this period, and after stopping aeration for 0.5 hours, the dissolved oxygen in the aerobic / anoxic zone 403 was controlled at 0.5 mg·L⁻¹. -1 The device achieves a cyclical aeration / stop operation mode to control the biological tank 4 to maintain a low dissolved oxygen environment. During the aeration stop period, the entire biological tank 4 is in a hypoxic state, forming a second-stage hypoxia, which significantly prolongs the denitrification reaction time. Furthermore, the use of intermittent low dissolved oxygen aeration is conducive to the occurrence of short-cut nitrification, short-cut denitrification, and anaerobic ammonia.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A cyclically interrupted low dissolved oxygen aeration device, characterized by: The system includes a frequency-adjustable blower (1), an air pipe (2), and an intelligent controller (3). The frequency-adjustable blower (1) and the intelligent controller (3) are both located outside the biological tank (4). The biological tank (4) is equipped with an anaerobic zone (401), an anoxic zone (402), and an aerobic / anoxic zone (403). Dissolved oxygen meters (5) and stirrers (6) are installed in the anaerobic zone (401), the anoxic zone (402), and the aerobic / anoxic zone (403). An air pipe (2) is installed at the output end of the frequency-adjustable blower (1). One end of the air pipe (2) is connected to the aerobic / anoxic zone (403). The aerobic / anoxic zone (403) is equipped with a rhombus valve (7), a vent valve (8) and a gas flow meter (9). The adjustable frequency blower (1), dissolved oxygen meter (5), rhombus valve (7) and vent valve (8) are all electrically connected to the intelligent controller (3). The aerobic / anoxic zone (403) is equipped with an aerator (10) and a sludge return pump (11). The outside of the biochemical tank (4) is equipped with a sludge return pipe (12). One end of the sludge return pipe (12) is connected to the sludge return pump (11). The anaerobic zone (401) and the anoxic zone (402) are connected to the sludge return pipe (12) through the first return branch pipe (13) and the second return branch pipe (14) respectively.

2. A cyclically interrupted low dissolved oxygen aeration device according to claim 1, characterized in that: The anaerobic zone (401) is connected to an inlet pipe (15) on one side, and an inlet flow meter (16) and an inlet eccentric hemispherical valve (17) are provided on the inlet pipe (15). The aerobic / anoxic zone (403) is connected to an outlet pipe (18) on one side, and an outlet flow meter (19) and an outlet eccentric hemispherical valve (20) are provided on the outlet pipe (18).

3. The cyclically interrupted low dissolved oxygen aeration device according to claim 1, characterized in that: A first water-passing wall pipe (21) is provided on the partition wall between the anaerobic zone (401) and the anoxic zone (402), and a second water-passing wall pipe (22) is provided on the partition wall between the anoxic zone (402) and the aerobic / anoxic zone (403).

4. The cyclically interrupted low dissolved oxygen aeration device according to claim 1, characterized in that: The sludge return pipe (12) is equipped with a sludge return main valve (23) and a sludge return flow meter (24).

5. A cyclically interrupted low dissolved oxygen aeration device according to claim 4, characterized in that: The first reflux branch (13) is equipped with an anaerobic zone reflux valve (25), and the second reflux branch (14) is equipped with an anoxic zone reflux valve (26).

6. The cyclically interrupted low dissolved oxygen aeration device according to claim 1, characterized in that: The aerator (10) is provided in multiple sets, and the agitator (6) is provided in multiple sets.

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