Short-cut nitrification continuous aeration device

Abstract

The utility model discloses a short-cut nitrification continuous aeration device which comprises a reaction unit and an aeration unit, the reaction unit comprises a front pool and a circulating mechanism, and the circulating mechanism is communicated with the upper part and the bottom of the front pool and is used for driving liquid at the upper part of the front pool to flow to the bottom of the front pool; the aeration unit comprises an aeration tank, a water inlet mechanism, an aeration mechanism and a reflux mechanism, the water inlet mechanism is communicated with the upper part of the front tank and the aeration tank, liquid in the front tank can flow into the aeration tank through the water inlet mechanism, the aeration mechanism is arranged in the aeration tank for aeration, and the reflux mechanism is communicated with the bottom of the aeration tank and the bottom of the front tank. Compared with the prior art, the short-cut nitrification continuous aeration device provided by the utility model has the advantages that the circulating mechanism is arranged in the reaction tank, and the aeration unit is externally connected to the reaction tank, so that the concentrations of nitrite and free ammonia are jointly diluted by using internal and external reflux, and the inhibition effect of the nitrite and the free ammonia on heterotrophic microorganisms is relieved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a short-range nitrification continuous aeration device. Background Art

[0002] Anaerobic fermentation of food waste produces effluent with high COD and ammonia nitrogen contents, and insufficient raw water alkalinity. Traditional biological denitrification methods are commonly used in China to treat this type of wastewater. These methods employ continuous aeration by increasing the volume of the pre-anoxic tank and nitrification stage, adding carbon sources to adjust the C / N ratio, or intermittent aeration using processes similar to Sequential Batch Reactors (SBRs). However, these methods suffer from unstable treatment results due to various factors, including fluctuations in water quality parameters. These methods also make it difficult to achieve stable and coordinated levels of ammonia nitrogen, pH, and DO, and the process systems are less resistant to shock loads.

[0003] Given this, the use of a short-cut nitrification process can effectively circumvent problems such as insufficient carbon source and alkalinity. Through short-cut nitrification and denitrification under oxygen-limited conditions, it effectively degrades the high ammonia nitrogen content in the biogas slurry, achieving an ammonia nitrogen removal rate exceeding 90%. However, since ammonia-oxidizing bacteria are autotrophic microorganisms, and the high concentrations of nitrite and free ammonia in the system under oxygen-limited conditions inhibit the metabolism of heterotrophic bacteria, resulting in a low COD removal rate. Furthermore, a large amount of organic matter remains undegraded in the effluent, resulting in a TOC removal rate of approximately 60%. This, coupled with the poor biodegradability of the raw water, exacerbates the difficulty of the back-end biochemical process. Utility Model Content

[0004] The purpose of the utility model is to overcome the above technical deficiencies and propose a short-range nitrification continuous aeration device to solve the technical problem in the prior art that the effluent from anaerobic fermentation of food waste using a short-range nitrification process is treated, and the high concentration of nitrite and free ammonia inhibits the metabolism of heterotrophic bacteria, resulting in a low removal rate of substances such as COD and TOC.

[0005] In order to achieve the above technical purpose, the present invention adopts the following technical solutions:

[0006] The utility model provides a short-range nitrification continuous aeration device, which is characterized by comprising:

[0007] The reaction unit includes a pre-tank and a circulation mechanism, wherein the circulation mechanism connects the upper and bottom parts of the pre-tank and is used to drive the liquid in the upper part of the pre-tank to flow to the bottom part of the pre-tank;

[0008] The aeration unit includes an aeration tank, a water inlet mechanism, an aeration mechanism and a reflux mechanism. The water inlet mechanism connects the upper part of the front tank and the aeration tank. The liquid in the front tank can flow into the aeration tank through the water inlet mechanism. The aeration mechanism is arranged in the aeration tank for aeration. The reflux mechanism connects the bottom of the aeration tank and the bottom of the front tank to drive the liquid at the bottom of the aeration tank to flow back to the bottom of the front tank.

[0009] In some embodiments, the pre-tank has a liquid inlet, which is located at the bottom of the pre-tank; the volume ratio of the pre-tank to the aeration tank is 1:4.5 to 1:5.5.

[0010] In some embodiments, the circulation mechanism includes a lifting pipe, a first return pipe, a first water distributor and an air supply pipe. The lower end of the lifting pipe is located at the upper part of the front tank, the upper end of the lifting pipe extends above the front tank and is connected to the upper end of the first return pipe. The lower end of the first return pipe is connected to the first water distributor. The water distributor is arranged at the bottom of the front tank, and the air outlet end of the air supply pipe is connected to the part of the lifting pipe below the liquid surface.

[0011] In some embodiments, the circulation mechanism also includes a gas-liquid separator, which is located above the front tank. The top of the gas-liquid separator has an air outlet, the upper end of the lifting pipe is connected to the middle of the gas-liquid separator, and the upper end of the first reflux pipe is connected to the bottom of the gas-liquid separator.

[0012] In some embodiments, the circulation mechanism further includes a second return pipe and an exhaust pipe, the upper end of the second return pipe is connected to the air outlet, the lower end of the second return pipe faces the front tank, and the lower end of the exhaust pipe is connected to the second return pipe.

[0013] In some embodiments, the water inlet mechanism includes an overflow pipe, the upper end of the overflow pipe is connected to the upper part of the front tank, and the lower end of the overflow pipe is located in the aeration tank. The liquid in the front tank can overflow into the aeration tank through the overflow pipe.

[0014] In some embodiments, the water inlet mechanism further includes a second water distributor, which is located at the bottom center of the aeration tank, and the lower end of the overflow pipe is connected to the second water distributor.

[0015] In some embodiments, the aeration mechanism includes an air inlet pipe and a plurality of cyclone aerators. The cyclone aerators are located at the bottom of the aeration tank and are arranged in a plurality of concentric circles surrounding the second water distributor. The air inlet pipe is connected to each cyclone aerator.

[0016] In some embodiments, the air inlet pipeline includes an annular tube, a radial tube and an air guide tube. The multiple annular tubes correspond one-to-one to the concentric circles and are arranged directly above the concentric circles. The radial tubes connect the annular tubes. The air guide tubes correspond one-to-one to the cyclone aerator. The upper end of the air guide tube is connected to the annular tube, and the lower end thereof is connected to the cyclone aerator.

[0017] In some embodiments, the reflux mechanism includes a third reflux pipe and a reflux pump. The third reflux pipe connects the bottom of the aeration tank and the bottom of the front tank. The reflux pump is arranged on the third reflux pipe to drive the liquid at the bottom of the aeration tank to flow back to the bottom of the front tank.

[0018] Compared with the existing technology, the short-range nitrification continuous aeration device provided by the utility model is provided with a circulation mechanism in the reaction tank, and an aeration unit is connected to the outside of the reaction tank. The internal and external reflux are used to jointly dilute the concentration of nitrite and free ammonia, thereby relieving the inhibitory effect of nitrite and free ammonia on heterotrophic microorganisms, allowing heterotrophic microorganisms to fully play the role of sewage treatment, improving the removal rate of substances such as COD and TOC, and reducing the difficulty of back-end biochemical treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a short-range nitrification continuous aeration device provided by an embodiment of the present utility model;

[0020] Figure 2 yes Figure 1 Top view of the middle aeration unit;

[0021] Figure 3 yes Figure 1 Schematic diagram of the local structure of the aeration mechanism. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] In order to solve the technical problem that high concentrations of nitrite and free ammonia inhibit the metabolism of heterotrophic bacteria in the effluent after anaerobic fermentation of food waste using a short-range nitrification process, the utility model provides a short-range nitrification continuous aeration device, which can use internal and external reflux to jointly dilute the concentrations of nitrite and free ammonia, eliminate the inhibitory effects of nitrite and free ammonia on heterotrophic microorganisms, enable heterotrophic microorganisms to fully play their role in sewage treatment, improve the removal rate of substances such as COD and TOC, and reduce the difficulty of back-end biochemical treatment.

[0024] It should be noted that the short-range nitrification continuous aeration device described in the present invention is used for, but not limited to, treating the effluent after anaerobic fermentation of food waste. For the sake of convenience, in the present invention, only the application of the short-range nitrification continuous aeration device to treat the effluent after anaerobic fermentation of food waste is used as an example for explanation. The principle of applying the short-range nitrification continuous aeration device to sewage treatment is essentially the same as the principle of applying it to treat the effluent after anaerobic fermentation of food waste, and they will not be elaborated here.

[0025] See also Figure 1 , Figure 1 This is a structural diagram of the XX device in one embodiment of the present invention. The XX device includes a reaction unit 1 and an aeration unit 2.

[0026] The reaction unit 1 includes a pre-tank 11 and a circulation mechanism 12. The circulation mechanism 12 connects the top and bottom of the pre-tank 11 and is used to drive the liquid in the top of the pre-tank 11 to the bottom of the pre-tank 11. The circulation mechanism 12 has the effect of disturbing and diluting the liquid in the pre-tank 11, preventing the local concentration of nitrite and free ammonia from being too high, which would inhibit the metabolism of heterotrophic microorganisms.

[0027] Aeration unit 2 includes an aeration tank 21, a water inlet mechanism 22, an aeration mechanism 23, and a return mechanism 24. The water inlet mechanism 22 connects the upper portion of the pre-tank 11 with the aeration tank 21, allowing liquid in the pre-tank 21 to flow into the aeration tank 21 through the water inlet mechanism 22. The aeration mechanism 23 is located within the aeration tank 21 for aeration. The return mechanism 24 connects the bottom of the aeration tank 21 with the bottom of the pre-tank 11, driving liquid from the bottom of the aeration tank 21 back to the bottom of the pre-tank 11. This also serves to disturb and dilute the liquid in the pre-tank 11, preventing localized high concentrations of nitrite and free ammonia, which could inhibit the metabolism of heterotrophic microorganisms.

[0028] In some embodiments, the pre-tank 11 has a liquid inlet, which is located at the bottom of the pre-tank 11. That is, the sewage to be treated flows into the bottom of the pre-tank 11, and then flows into the aeration tank 21 from the top of the pre-tank 11 through the water inlet mechanism 22. The top of the aeration tank 21 has an outlet for discharging the sewage after aeration treatment. The liquid at the bottom of the aeration tank 21 flows back into the pre-tank 11 through the reflux mechanism 24 to dilute the concentration of nitrite and free ammonia in the pre-tank 11. In this embodiment, the volume ratio of the pre-tank 11 to the aeration tank 21 is 1:4.5 to 1:5.5. The volume ratio of the pre-tank to the aeration tank in the traditional short-range nitrification process is 1:3 to 2:3, and the dilution effect is improved by increasing the volume of the aeration tank 21.

[0029] In some embodiments, the circulation mechanism 12 includes a lifting pipe 121, a first return pipe 122, a first water distributor 123, and an air supply pipe 124, that is, the circulation mechanism 12 uses the air lift principle to drive the liquid in the upper part of the pre-tank 11 to flow to the bottom. The lower end of the lifting pipe 121 is located at the upper part of the pre-tank 11, the upper end of the lifting pipe 121 extends to the top of the pre-tank 11 and is connected to the upper end of the first return pipe 122, the lower end of the first return pipe 122 is connected to the first water distributor 123, and the water distributor 123 is arranged at the bottom of the pre-tank 11 for dispersing the water flow. The air outlet end of the air supply pipe 124 is connected to the part of the lifting pipe 121 below the liquid surface.

[0030] Air is supplied to the lifting pipe 121 through the air supply pipe 124, driving the liquid in the upper part of the pre-tank 11 to flow upward along the lifting pipe 121, and then flows into the first return pipe 122 after flowing to the top of the lifting pipe 121, and then flows to the first water distributor 123 through the first return pipe 122, and is mixed with the liquid at various places at the bottom of the pre-tank 11 through the first water distributor 123. The circulation mechanism 12 plays the role of disturbing and diluting the liquid at the bottom of the pre-tank 11 with the liquid in the upper part of the pre-tank 11. In other embodiments, the circulation mechanism 12 can also use other methods to drive liquid circulation, such as using a water pump.

[0031] In some embodiments, the circulation mechanism 12 further includes a gas-liquid separator 125, which is located above the pre-tank 11. The gas-liquid separator 125 is a hollow container with a gas outlet at the top. The upper end of the riser 121 is connected to the middle of the gas-liquid separator 125, and the upper end of the first return pipe 122 is connected to the bottom of the gas-liquid separator 125. The gas-liquid mixture in the riser 121 flows into the gas-liquid separator 125, the gas is discharged from the gas outlet at the top, and the liquid flows out from the first return pipe 122 at the bottom, thereby achieving gas-liquid separation.

[0032] In some embodiments, the circulation mechanism 12 further includes a second return pipe 126 and an exhaust pipe 127. The upper end of the second return pipe 126 is connected to the gas outlet, and the lower end of the second return pipe 126 faces the pre-tank 11. The lower end of the exhaust pipe 127 is connected to the second return pipe 126. Some unbroken bubbles in the gas-liquid separator 125 may be discharged from the gas outlet. By providing the second return pipe 126, these bubbles are broken in the second return pipe 126, and the liquid flows back into the pre-tank 11, while the gas is discharged through the exhaust pipe 127.

[0033] In some embodiments, the aeration tank 21 is typically a cylindrical tank. The water inlet mechanism 22 includes an overflow pipe 221. The upper end of the overflow pipe 221 is connected to the upper portion of the pre-tank 11, and the lower end of the overflow pipe 221 is located within the aeration tank 21. Liquid within the pre-tank 11 can overflow into the aeration tank 21 through the overflow pipe 221. In other embodiments, a water pump can be used to drive liquid from the pre-tank 11 into the aeration tank 21. However, it is preferred to collect liquid from the top of the pre-tank 11, as this location provides a more complete reaction.

[0034] In some embodiments, the water inlet mechanism 22 further includes a second water distributor 222, which is located at the bottom center of the aeration tank 21. The lower end of the overflow pipe 221 is connected to the second water distributor 222, so that the liquid that has completed the reaction in the pre-tank 11 enters the bottom center of the aeration tank 21.

[0035] See Figure 2 and Figure 3The aeration mechanism 23 includes an air inlet pipe 231 and multiple cyclone aerators 232. The cyclone aerators 232 are located at the bottom of the aeration tank 21 and arranged in multiple concentric circles around the second water distributor 222. The air inlet pipe 231 connects to each cyclone aerator 232. By arranging the cyclone aerators 232 in multiple circles around the second water distributor 222, the liquid flowing out of the second water distributor 222 is fully aerated, ensuring the effectiveness of the aeration treatment.

[0036] In some embodiments, the air inlet line 231 includes an annular tube 2311, radial tubes 2312, and an air guide tube 2313. The multiple annular tubes 2311 correspond one-to-one to the concentric circles formed by the cyclone aerators 232 and are arranged directly above the concentric circles. The radial tubes 2312 connect to each annular tube 2311, and from the outside to the inside, the inner diameter of the relevant 2312 is reduced to maintain sufficient air pressure. The air guide tube 2313 corresponds one-to-one to the cyclone aerator 232, and the upper end of the air guide tube 2313 is connected to the annular tube 2311, and the lower end is connected to the cyclone aerator 232. The external air supply device is connected to the outermost annular tube 2311, and supplies air to each cyclone aerator 232 through the annular tube 2311, radial tubes 2312, and air guide tube 2313.

[0037] In some embodiments, the reflux mechanism 24 includes a third reflux pipe 241 and a reflux pump. The third reflux pipe 241 connects the outer wall of the bottom of the aeration tank 21 and the bottom of the pre-tank 11. The reflux pump is installed on the third reflux pipe 241 to drive the liquid outside the bottom of the aeration tank 21 back to the bottom of the pre-tank 11. This disturbs and dilutes the liquid in the pre-tank 11, preventing localized high concentrations of nitrite and free ammonia, which could inhibit the metabolism of heterotrophic microorganisms.

[0038] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A short-range nitrification continuous aeration device, characterized in that: include: A reaction unit, comprising a pre-tank and a circulation mechanism, wherein the circulation mechanism is connected to the upper and lower parts of the pre-tank and is used to drive the liquid in the upper part of the pre-tank to flow to the bottom part of the pre-tank; The aeration unit includes an aeration tank, a water inlet mechanism, an aeration mechanism, and a reflux mechanism. The water inlet mechanism connects the upper part of the pre-tank and the aeration tank, and the liquid in the pre-tank can flow into the aeration tank through the water inlet mechanism. The aeration mechanism is arranged in the aeration tank for aeration. The reflux mechanism connects the bottom of the aeration tank and the bottom of the pre-tank to drive the liquid at the bottom of the aeration tank to flow back to the bottom of the pre-tank.

2. The short-cut nitrification continuous aeration device according to claim 1, characterized in that: The pre-tank has a liquid inlet, which is located at the bottom of the pre-tank; the volume ratio of the pre-tank to the aeration tank is 1:4.5 to 1:5.

5.

3. The short-cut nitrification continuous aeration device according to claim 1, characterized in that: The circulation mechanism includes a lifting pipe, a first return pipe, a first water distributor and an air supply pipe. The lower end of the lifting pipe is located at the upper part of the pre-tank, the upper end of the lifting pipe extends to the top of the pre-tank and is connected with the upper end of the first return pipe, the lower end of the first return pipe is connected with the first water distributor, the water distributor is arranged at the bottom of the pre-tank, and the air outlet end of the air supply pipe is connected to the part of the lifting pipe below the liquid surface.

4. The short-cut nitrification continuous aeration device according to claim 3, characterized in that: The circulation mechanism also includes a gas-liquid separator, which is located above the front tank. The top of the gas-liquid separator has an air outlet, the upper end of the lifting pipe is connected to the middle of the gas-liquid separator, and the upper end of the first reflux pipe is connected to the bottom of the gas-liquid separator.

5. The short-cut nitrification continuous aeration device according to claim 4, characterized in that: The circulation mechanism also includes a second return pipe and an exhaust pipe, the upper end of the second return pipe is connected to the air outlet, the lower end of the second return pipe faces the pre-tank, and the lower end of the exhaust pipe is connected to the second return pipe.

6. The short-cut nitrification continuous aeration device according to claim 1, characterized in that: The water inlet mechanism includes an overflow pipe, the upper end of which is connected to the upper part of the pre-tank, and the lower end of which is located in the aeration tank. The liquid in the pre-tank can overflow into the aeration tank through the overflow pipe.

7. The short-cut nitrification continuous aeration device according to claim 6, characterized in that: The water inlet mechanism further includes a second water distributor, which is located at the bottom center of the aeration tank, and the lower end of the overflow pipe is connected to the second water distributor.

8. The short-cut nitrification continuous aeration device according to claim 7, characterized in that: The aeration mechanism includes an air inlet pipeline and a plurality of cyclone aerators. The cyclone aerators are located at the bottom of the aeration tank and are arranged in a plurality of concentric circles surrounding the second water distributor. The air inlet pipeline is connected to each of the cyclone aerators.

9. The short-cut nitrification continuous aeration device according to claim 8, characterized in that: The air intake pipeline includes an annular tube, a radial tube and an air guide tube. The multiple annular tubes correspond one-to-one to the concentric circles and are arranged directly above the concentric circles. The radial tubes connect the annular tubes. The air guide tubes correspond one-to-one to the cyclone aerator. The upper end of the air guide tube is connected to the annular tube, and the lower end thereof is connected to the cyclone aerator.

10. The short-cut nitrification continuous aeration device according to claim 1, characterized in that: The reflux mechanism includes a third reflux pipe and a reflux pump. The third reflux pipe connects the bottom of the aeration tank and the bottom of the pre-tank. The reflux pump is arranged on the third reflux pipe to drive the liquid at the bottom of the aeration tank to flow back to the bottom of the pre-tank.

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