Biological denitrification system for coupling vertical-flow short-cut nitrification with anaerobic ammonia oxidation

Abstract

The utility model discloses a biological denitrification system for coupling vertical-flow short-cut nitrification with anaerobic ammonia oxidation. The biological denitrification system comprises a tank body, a sleeve is arranged in the tank body, a gas-collecting hood is mounted at the top of the tank body, an anaerobic zone and an aerobic zone are sequentially arranged in the sleeve from bottom to top, a separation zone is arranged at the top of the sleeve, and a backflow layer is arranged between the outer wall of the sleeve and the inner wall of the tank body; the anaerobic zone is composed of anaerobic ammonia oxidation granular sludge, a water distribution system and an aeration system are sequentially arranged at the bottom of the anaerobic zone, the aeration system is connected with a gas collecting hood through a pipeline, a three-phase separator A and an exhaust pipe are arranged at the top of the anaerobic zone, and an exhaust port in the top end of the exhaust pipe is located in the gas collecting hood. According to the biological denitrification system provided by the utility model, low-consumption and high-efficiency biological denitrification can be realized through a vertical flow type structure, effluent is clear and transparent, a rear sedimentation tank is not needed, the sludge concentration of the system is maintained through regular sludge discharge, sludge backflow is not needed, and the biological denitrification system has the advantages of saving occupied area and investment cost.

Description

Technical Field

[0001] The utility model relates to a biological nitrogen removal system for vertical-flow short-cut nitrification coupled with anaerobic ammonium oxidation, belonging to the technical field of sewage treatment. Background Technique

[0002] The short-cut nitrification / denitrification technology is a newly emerging biological nitrogen removal technology in recent years. Compared with the traditional AO biological nitrogen removal, this technology oxidizes ammonia nitrogen at the nitrite nitrogen stage and converts it into ammonia nitrogen by denitrification and discharges it, omitting the conversion process of intermediate nitrate nitrogen. It can accelerate the reaction process while reducing the aeration and carbon source supply, effectively reducing the operation cost; the anaerobic ammonium oxidation technology is another newly emerging biological nitrogen removal process. This process can save 60% of the aeration volume compared with the traditional process, does not require additional carbon source addition, and has the advantages of short hydraulic retention time, high treatment efficiency, and small floor area. The prerequisite for this process is a stable supply of nitrite nitrogen, and the product of short-cut nitrification is exactly nitrite nitrogen. Therefore, a large number of scholars have also coupled the two processes to achieve a low-consumption and high-efficiency biological nitrogen removal method.

[0003] The short-cut nitrification coupled with anaerobic ammonium oxidation technology has the advantages of saving operation energy consumption, not requiring organic carbon source, and being applicable to high-ammonia-nitrogen wastewater. However, to achieve the stable operation of this process, there are also relatively strict external conditions, such as higher temperature, low C / N, low dissolved oxygen, etc. In the northern or western alpine regions, a large amount of energy is often consumed for heat preservation.

[0004] At present, the commonly used reaction forms are continuous reaction tanks and sequencing batch reactors. In the operation of continuous reaction tanks, there are problems such as difficult precise adjustment of aeration and easy occurrence of over-aeration, which easily leads to a decrease in nitrite yield and affects the treatment effect of the entire reaction; although the sequencing batch reactor can flexibly control the aeration time, there are problems such as small treatment water volume and low treatment efficiency, and it is difficult to effectively treat wastewater on a large scale. Whether it is a continuous or sequencing batch reaction form, there are still various limitations in actual operation. Content of the Utility Model

[0005] In view of the deficiencies in the background technique, the utility model provides a biological nitrogen removal system for vertical-flow short-cut nitrification coupled with anaerobic ammonium oxidation, which can achieve low-consumption and high-efficiency biological nitrogen removal through a vertical-flow structure, the effluent is clear and transparent, no post-precipitation tank is required, the sludge concentration of the system is maintained by regular sludge discharge, and sludge reflux is not required, having the advantages of saving floor area and investment cost.

[0006] To solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A biological nitrogen removal system for vertical-flow short-cut nitrification coupled with anaerobic ammonium oxidation, comprising a tank body, a sleeve is arranged inside the tank body, and a gas collection hood is installed at the top of the tank body;

[0008] Inside the sleeve, an anaerobic zone and an aerobic zone are successively arranged from bottom to top. A separation zone is arranged at the top of the sleeve, and a reflux layer is arranged between the outer wall of the sleeve and the inner wall of the tank.

[0009] The anaerobic zone is composed of anaerobic ammonium oxidation granular sludge. A water distribution system and an aeration system are successively arranged at the bottom of the anaerobic zone. The aeration system is connected to a gas collection hood through a pipeline.

[0010] At the top of the anaerobic zone, a three-phase separator A and an exhaust pipe are arranged. The exhaust port at the top end of the exhaust pipe is located inside the gas collection hood.

[0011] Furthermore, the aerobic zone is composed of a MABR membrane aeration bioreactor. The MABR membrane aeration bioreactor is connected to a fan A through a pipeline. A water distribution system is arranged at the bottom of the aerobic zone, and the water distribution system is connected to a carbon source and an alkalinity inlet.

[0012] Furthermore, a fan B is installed on the pipeline connecting the aeration system and the gas collection hood.

[0013] Furthermore, water inlets are arranged around the water distribution system.

[0014] Furthermore, an overflow weir with a serrated structure is arranged at the open end at the top of the sleeve.

[0015] Furthermore, a three-phase separator B is installed in the separation zone.

[0016] Furthermore, a water outlet is arranged on one side at the top of the tank, and the water outlet is located above the three-phase separator B; a sludge discharge port is arranged on one side at the bottom of the tank.

[0017] Furthermore, an air outlet is arranged at the top of the gas collection hood.

[0018] Furthermore, a heat preservation layer is arranged outside the tank, and the heat preservation layer is made of heat preservation cotton.

[0019] Furthermore, the height-diameter ratio of the tank is 2:1 - 5:1, the diameter ratio of the sleeve to the tank is 2:3 - 4:5, and the volume ratio of the anaerobic zone, aerobic zone, and separation zone is 2:1:1.

[0020] After the utility model adopts the above technical solutions, compared with the prior art, it has the following advantages:

[0021] The utility model adopts a vertical flow structure and is internally provided with multiple three-phase separators. The effluent is clarified without a post-precipitation tank, and the floor area is small. Sludge is regularly discharged through the sludge discharge port at the bottom of the tank, and no additional sludge reflux system is required, saving construction costs and operating costs.

[0022] The anaerobic zone and the aerobic zone react in separate areas, ensuring the adaptability of the bacterial strains to the environment, improving the activity of the bacterial strains and the treatment efficiency of the system. Through the reflux layer, the shortcut nitrification reaction and the anaerobic ammonium oxidation reaction are coupled to achieve low-consumption and high-efficiency biological nitrogen removal;

[0023] The bottom of the anaerobic zone is equipped with an aeration and water distribution system, which can ensure that the anaerobic ammonium oxidation granular sludge meets the rising flow velocity requirements, avoid sludge deflocculation, and at the same time create a negative pressure at the bottom of the tank to achieve the reflux of aerobic effluent to the anaerobic zone. The gas used for aeration comes from the gas collection hood at the top of the system and does not contain oxygen, ensuring the stability of dissolved oxygen in the anaerobic zone;

[0024] The aerobic zone adopts a MABR membrane aerated bioreactor, which has a high oxygen utilization rate, effectively reduces sludge production, and the effluent is clearer. There is a water distribution system at the bottom of the aerobic zone, which can timely supplement the carbon source and alkalinity required by the system to ensure the stable progress of the shortcut nitrification reaction;

[0025] The main reaction zone of the present utility model is completed inside the sleeve, which can reduce the interference of external temperature changes on the system.

[0026] The present utility model will be described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of the present utility model;

[0028] Figure 2 is a schematic structural diagram of the water distribution system at the bottom of the anaerobic zone.

[0029] In the figure, 1 - tank body, 2 - sleeve, 3 - gas collection hood, 4 - anaerobic zone, 5 - aerobic zone, 6 - aeration system, 7 - water inlet, 8 - three-phase separator A, 9 - exhaust pipe, 10 - carbon source and alkalinity inlet, 11 - overflow weir, 12 - three-phase separator B, 13 - water outlet, 14 - gas outlet, 15 - sludge discharge port, 16 - fan A, 17 - fan B. Detailed Embodiments

[0030] For a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described with reference to the drawings.

[0031] As Figure 1 and Figure 2 collectively shown, the present utility model provides a vertical-flow shortcut nitrification coupled with anaerobic ammonium oxidation biological nitrogen removal system, including a tank body 1, a sleeve 2 is arranged inside the tank body 1, and a gas collection hood 3 is installed at the top of the tank body 1.

[0032] The anaerobic zone 4 and the aerobic zone 5 are sequentially arranged from bottom to top inside the sleeve 2, and a separation zone is arranged at the top of the sleeve 2. A reflux layer is arranged between the outer wall of the sleeve 2 and the inner wall of the tank body 1.

[0033] The anaerobic zone 4 is composed of anammox granular sludge. A water distribution system and an aeration system 6 are successively arranged at the bottom of the anaerobic zone 4.

[0034] Water inlets 7 are arranged around the water distribution system. The wastewater to be treated enters the water distribution system evenly from the surrounding water inlets 7 after passing through a water distribution package outside the system.

[0035] The aeration system 6 is connected to the gas collection hood 3 through a pipeline, and a blower B17 is installed on the pipeline.

[0036] A three-phase separator A8 and an exhaust pipe 9 are arranged at the top of the anaerobic zone 4. The exhaust port at the top of the exhaust pipe 9 is located inside the gas collection hood 3. The nitrogen gas generated in the anaerobic zone 4 is transported into the top gas collection hood 3 to avoid the impact of the generated nitrogen gas on the aerobic zone microorganisms.

[0037] The water distribution system and the aeration system 6 can provide an appropriate upward flow rate for the formation of granular sludge, avoid the deflocculation of granular sludge, and in order to prevent the dissolved oxygen in the anaerobic zone 4 from being too high, the aeration system 6 draws air from inside the gas collection hood 3.

[0038] The aerobic zone 5 is composed of a MABR membrane aeration bioreactor. The MABR membrane aeration bioreactor is connected to a blower A16 through a pipeline. A biofilm for the growth of microorganisms adheres to the outer surface of the hollow fiber membrane. Air supplies oxygen to the biofilm through the hollow fiber membrane to achieve efficient micro-aeration, and at the same time ensure that the sludge is in a suspended state and will not deposit at the bottom of the tank. A water distribution system is arranged at the bottom of the aerobic zone 5. The water distribution system is connected to a carbon source and alkalinity inlet 10. The water distribution system can evenly distribute the carbon source and alkalinity, and can ensure the stable operation of the shortcut nitrification reaction.

[0039] An overflow weir 11 with a serrated structure is arranged at the top opening end of the sleeve 2.

[0040] A three-phase separator B12 is installed in the separation zone.

[0041] An outlet 13 is arranged on one side of the top of the tank body 1. The outlet 13 is located above the three-phase separator B12.

[0042] A sludge discharge port 15 is arranged on one side of the bottom of the tank body 1.

[0043] An air outlet 14 is arranged at the top of the gas collection hood 3.

[0044] A heat preservation layer is arranged outside the tank body 1. The heat preservation layer uses heat preservation cotton, which keeps warm in winter and insulates heat in summer, reducing the influence of temperature changes on the system.

[0045] In the present utility model, the height-diameter ratio of the tank body 1 is 2:1 - 5:1, the diameter ratio of the sleeve 2 to the tank body 1 is 2:3 - 4:5, the volume ratio of the anaerobic zone 4, aerobic zone 5, and separation zone is 2:1:1. The dissolved oxygen in the anaerobic zone 4 is <0.5 mg / L, the dissolved oxygen in the aerobic zone 5 is 0.5 - 1.2 mg / L, the system temperature is 25°C - 30°C, and sludge is regularly discharged through the sludge discharge port 15 at the bottom of the tank to maintain the system sludge concentration at 3000 - 4000 mg / L.

[0046] The specific working principle of the present utility model:

[0047] The present utility model is divided into three parts: anaerobic zone, aerobic zone, and separation zone from bottom to top. The wastewater uniformly enters the reactor through the bottom water distribution system of the tank. In the anaerobic zone, the uncompletely converted organic nitrogen is completely converted into ammonia nitrogen. Then, through the aerobic zone, a short-cut nitrification reaction occurs to convert ammonia nitrogen into nitrite nitrogen, which is then refluxed to the anaerobic zone again through the reflux system in the pool wall part. Anaerobic ammonium oxidation reaction occurs between ammonia nitrogen and nitrite nitrogen here to generate nitrogen gas and be discharged, realizing biological nitrogen removal.

[0048] Specific wastewater treatment process: The wastewater to be treated uniformly enters the bottom of the anaerobic zone from all around the system. A microporous aeration system is provided at the bottom of the anaerobic zone, and the inlet gas is the oxygen-free gas in the system gas collection hood. The purpose is to provide negative pressure for reflux to ensure the stability of the reflux layer and at the same time provide an upward flow rate for the granular sludge.

[0049] The wastewater flows upward, passes through the anaerobic zone, and ammonia nitrogen and nitrite nitrogen are converted into ammonia nitrogen and discharged through anaerobic ammonium oxidation granular sludge, realizing biological nitrogen removal. At the same time, a part of the organic nitrogen in the influent is ammoniated to improve the nitrogen removal effect. A three-phase separator is provided at the top of the anaerobic zone, which can separate the anaerobic granular sludge from the water and at the same time transport the generated nitrogen gas to the top gas collection hood to avoid the impact of the generated nitrogen gas on the microorganisms in the aerobic zone.

[0050] The wastewater continues to flow upward and enters the aerobic zone, reacting with the biofilm attached to the surface of the MABR membrane-aerated bioreactor. The microorganisms convert ammonia nitrogen into nitrite nitrogen, providing raw materials for the anaerobic ammonium oxidation reaction. Air permeates oxygen from the inside to the outside through the hollow fiber membrane, reducing sludge production while improving the oxygen utilization rate. A water distribution system is provided at the bottom of the aerobic zone, which can provide carbon source and alkalinity in time when the short-cut nitrification reaction is unstable to ensure the stability of the reaction. An overflow weir is provided at the upper part of the aerobic zone, and the treated water of the reaction flows through the overflow weir and completes reflux in the reflux layer.

[0051] The wastewater continues to flow upward. A three-phase separator is also provided at the upper part of the reactor to separate mud, water, and gas. The effluent is transparent and clear, and the separated gas is briefly collected in the top gas collection hood and then discharged through the gas outlet.

[0052] The above is an example of the best implementation mode of the present utility model, and the parts not described in detail are all common general knowledge in the art. The protection scope of the present utility model shall be subject to the content of the claims, and any equivalent transformation based on the technical disclosure of the present utility model is also within the protection scope of the present utility model.

Claims

1. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system, characterized by: It comprises a tank body (1), the tank body (1) has a sleeve (2) built in it, and a gas collecting hood (3) is installed on the top of the tank body (1); The sleeve (2) is provided with an anaerobic zone (4) and an aerobic zone (5) in sequence from bottom to top, a separation zone is provided at the top of the sleeve (2), and a recirculation layer is provided between the outer wall of the sleeve (2) and the inner wall of the tank body (1); The anaerobic zone (4) is composed of anaerobic ammonium oxidation granular sludge. A water distribution system and an aeration system (6) are sequentially arranged at the bottom of the anaerobic zone (4). The aeration system (6) is connected to the gas collecting hood (3) through a pipeline. A three-phase separator A (8) and an exhaust pipe (9) are provided at the top of the anaerobic zone (4), and the exhaust port at the top of the exhaust pipe (9) is located in the gas collecting hood (3).

2. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: The aerobic zone (5) is composed of a MABR membrane aerated bioreactor, which is connected to a fan A (16) via a pipeline. A water distribution system is provided at the bottom of the aerobic zone (5), and the water distribution system is connected to a carbon source and alkalinity inlet (10).

3. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: A fan B (17) is installed on the connecting pipeline between the aeration system (6) and the air collecting hood (3).

4. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: Water inlets (7) are arranged on all sides of the water distribution system.

5. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: An overflow weir (11) with a sawtooth structure is provided at the top open end of the sleeve (2).

6. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: A three-phase separator B (12) is installed in the separation zone.

7. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 6, characterized in that: A water outlet (13) is provided on one side of the top of the tank body (1), and the water outlet (13) is located above the three-phase separator B (12); and a mud discharge port (15) is provided on one side of the bottom of the tank body (1).

8. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: The top of the air collecting hood (3) is provided with an air outlet (14).

9. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system as claimed in claim 1, characterized in that: The tank body (1) is provided with a heat-insulating layer on the outside, and the heat-insulating layer is made of heat-insulating cotton.

10. A vertical flow short-range nitrification coupled anaerobic ammonium oxidation biological denitrification system according to claim 1, characterized in that: The height-to-diameter ratio of the tank body (1) is 2:1-5:1, the diameter ratio of the sleeve (2) and the tank body (1) is 2:3-4:5, and the volume ratio of the anaerobic zone (4), the aerobic zone (5), and the separation zone is 2:1:1.

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