High-nitrogen wastewater treatment system

Abstract

The utility model discloses a high-nitrogen wastewater treatment system which comprises a water inlet unit, a first biochemical pool, a second biochemical pool, a third biochemical pool, an MBR (Membrane Bioreactor) unit and a water production unit, the water inlet unit is used for supplying high-nitrogen wastewater to the first biochemical pool; when the concentration of organic matters in inlet water is relatively high, the first biochemical pool is used as a hydrolysis acidification pool for a hydrolysis acidification reaction of wastewater; when the concentration of organic matters in influent water is relatively low, the anaerobic tank is used for a denitrification nitrogen removal reaction of wastewater; the second biochemical tank is used as an aerobic tank and is used for nitration reaction of wastewater; the third biochemical tank is used as an anoxic tank when the concentration of organic matters in inlet water is relatively high; when the concentration of organic matters in inlet water is relatively low and the COD value or the NH3-N value of the outlet water of the aerobic tank is higher than the outlet water standard of the aerobic tank, the aerobic tank is used as a second aerobic tank, and when the COD value and the NH3-N value of the outlet water of the aerobic tank meet the outlet water standard of the aerobic tank, the aerobic tank is used as a second anoxic tank. The system is low in operation cost, simple in technological process and stable in effluent quality, and meanwhile, the deep denitrification effect can be achieved.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, specifically to a high-nitrogen wastewater treatment system. Background Technology

[0002] The main sources of high-nitrogen wastewater include the chemical and pharmaceutical industries. Wastewater generated by these industries typically contains high concentrations of total nitrogen and other organic matter. High-nitrogen wastewater has the following main characteristics:

[0003] (1) Wastewater usually contains high levels of organic nitrogen and ammonia nitrogen, and has a high COD value.

[0004] (2) It contains a wide variety of recalcitrant biological substances at high concentrations, and some wastewater contains a large amount of toxic and harmful substances of various types, making it difficult to treat.

[0005] (3) Water quality fluctuates greatly. Taking chemical wastewater as an example, the wastewater flow, concentration, composition and other water quality will fluctuate with the actual production situation of the enterprise. The quality of the discharged wastewater is extremely unstable, which increases the difficulty of subsequent treatment processes.

[0006] Currently, high-nitrogen wastewater is mainly treated using biological pretreatment methods, such as A / O, A 2 The process involves processes such as A / O followed by deep treatments including activated carbon adsorption and oxidation ponds. Traditional A / O or A... 2 When the / O process is used to treat high-nitrogen wastewater, for raw water containing a small amount of carbon source, most of the carbon source is removed in the aerobic zone, resulting in insufficient carbon source returned to the anoxic zone, thus affecting the denitrification efficiency. For raw water containing a higher amount of carbon source, the aeration rate in the aerobic tank needs to be increased, which to some extent leads to an increase in operating costs. Therefore, there is currently no high-nitrogen wastewater treatment method that has low operating costs, a simple process flow, and stable effluent quality. Summary of the Invention

[0007] To address the aforementioned problems, this utility model provides a high-nitrogen wastewater treatment system.

[0008] The technical solution adopted in this utility model is:

[0009] A high-nitrogen wastewater treatment system includes an influent unit, a first biological treatment tank, a second biological treatment tank, a third biological treatment tank, an MBR unit, and a product water unit. The influent unit supplies high-nitrogen wastewater to the first biological treatment tank and monitors the influent organic matter concentration. When the influent organic matter concentration is high, the first biological treatment tank acts as a hydrolysis acidification tank for the hydrolysis and acidification reaction of the wastewater; when the influent organic matter concentration is low, it acts as an anoxic tank for the denitrification reaction of the wastewater. The second biological treatment tank acts as an aerobic tank for the nitrification reaction of the effluent from the first biological treatment tank. The third biological treatment tank acts as an anoxic tank when the influent organic matter concentration is high, for the denitrification reaction of the first biological treatment tank. The process involves denitrification of the effluent from the aerobic tank. When the influent organic matter concentration is low, and the COD or NH3-N value of the aerobic tank effluent is higher than the aerobic tank effluent standard, it serves as a second aerobic tank for secondary nitrification of the effluent from the second biological treatment tank. When the COD and NH3-N values ​​of the aerobic tank effluent meet the aerobic tank effluent standard, it serves as a second anoxic tank for secondary denitrification of the effluent from the second biological treatment tank. The MBR unit includes an MBR membrane tank and MBR membrane modules installed in the MBR membrane tank for separating wastewater that has undergone biological reactions. The permeate unit includes permeate pipes and permeate pumps for discharging permeate from the MBR unit.

[0010] Furthermore, it also includes an aeration unit, which is used to provide oxygen to the second and third biological tanks.

[0011] Furthermore, the aeration unit includes a blower and a biological aeration duct. The blower is connected to the second biological tank and the third biological tank respectively through the biological aeration duct. Aeration valves are provided on the aeration ducts connecting the second biological tank and the third biological tank respectively.

[0012] Furthermore, the first biochemical tank, the second biochemical tank, the third biochemical tank, and the MBR membrane tank are connected by an overflow weir.

[0013] Furthermore, the MBR membrane tank is connected to the second biological treatment tank through the first sludge return pipe, the second biological treatment tank and the third biological treatment tank are connected through the third sludge return pipe, and the second biological treatment tank and the third biological treatment tank are respectively connected to the first biological treatment tank through the second sludge return pipe.

[0014] Furthermore, sludge return valves are installed on the sludge return pipes connecting the first, second, and third biological treatment tanks.

[0015] Furthermore, a first submersible agitator and a second submersible agitator are distributed at the bottom of the first and third biochemical pools.

[0016] Furthermore, both the second and third biological treatment tanks are equipped with aerators.

[0017] Furthermore, the water inlet unit is equipped with an online water inlet monitoring unit, which includes an online COD monitor, an online NH3-N monitor, an online TN monitor, and an online pH monitor.

[0018] Furthermore, an online biochemical monitoring unit is installed at the end of the second biological treatment tank. The online biochemical monitoring unit includes a DO monitor, a sludge concentration meter, a COD online monitor, an NH3-N online monitor, and a TN online monitor.

[0019] The beneficial effects of this utility model are:

[0020] 1. By using the first biological treatment tank as an anoxic tank or a hydrolysis acidification tank, and the third biological treatment tank as an aerobic tank or anoxic tank, based on the concentration of organic matter in the influent and the effluent from the aerobic tank, the process flow is shortened, the number of reaction tanks is reduced, and the system footprint is lowered, thereby achieving efficient wastewater treatment and reducing operating costs.

[0021] 2. By setting up a first biological treatment tank and a third biological treatment tank, the system has a strong adaptability to fluctuations in influent, and can achieve deep denitrification, thereby improving the quality and stability of the effluent. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the high-nitrogen wastewater treatment system of this utility model.

[0023] Figure 2 This is the first flow chart of the high-nitrogen wastewater treatment system of this utility model.

[0024] Figure 3 This is the second flow chart of the high-nitrogen wastewater treatment system of this utility model.

[0025] Figure 4 This is the third flow chart of the high-nitrogen wastewater treatment system of this utility model.

[0026] In the diagram: 1. Inlet unit, 2. First biological treatment tank, 3. Second biological treatment tank, 4. Third biological treatment tank, 5. MBR membrane tank, 6. Permeate unit, 7. Inlet online monitoring unit, 8. Biological online monitoring unit, 9. First submersible mixer, 10. Second submersible mixer, 11. Blower, 12. Biological aeration duct, 13. First aerator, 14. First overflow weir, 15. Second overflow weir, 16. Third overflow weir, 17. Fourth overflow weir, 18. Fifth overflow weir, 19. First sludge return pipe, 20. Second sludge return pipe, 21. Third sludge return pipe, 22. Second aerator, 121. First aeration valve, 122. Second aeration valve, 191. First sludge return valve, 201. Second sludge return valve, 202. Third sludge return valve, 211. Fourth sludge return valve. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solution of this utility model will be clearly and completely described below in conjunction with the accompanying drawings and a preferred embodiment.

[0028] See Figure 1 This application provides a high-nitrogen wastewater treatment system, including an influent unit 1, a first biological treatment tank 2, a second biological treatment tank 3, a third biological treatment tank 4, an MBR unit 5, a product water unit 6, and an aeration unit.

[0029] The water inlet unit 1 includes an inlet pipe and an online water inlet monitoring unit 7 installed on the inlet pipe. The online water inlet monitoring unit 7 includes an online COD monitor, an online NH3-N monitor, an online TN monitor, and an online pH monitor; these are used to monitor the COD value, ammonia nitrogen content, total nitrogen content, and pH value of the inlet water, respectively.

[0030] The first biological treatment tank 2 serves as a hydrolysis acidification tank or anoxic tank. It is equipped with an online DO monitor to monitor the dissolved oxygen content in the tank water. A first submersible agitator 9 is located at the bottom of the first biological treatment tank 2.

[0031] The second biological treatment tank 3 serves as an aerobic tank and is equipped with an online biological monitoring unit 8. This unit includes a DO monitor, a sludge concentration meter, a COD online monitor, an NH3-N online monitor, and a TN online monitor, used to detect dissolved oxygen content, sludge concentration, COD value, ammonia nitrogen content, and total nitrogen content in the tank water, respectively. A second aerator 22 is installed at the bottom of the second biological treatment tank 3.

[0032] The third biological treatment tank 4 serves as either an aerobic or anoxic tank. The third biological treatment tank 4 is equipped with an online DO monitoring instrument, and the bottom of the third biological treatment tank 4 is equipped with a first aerator 13 and a second submersible mixer 10.

[0033] An MBR unit includes an MBR membrane tank and an MBR membrane module disposed within the membrane tank.

[0034] The water production unit 6 includes a water production pipe and a water production pump, which is connected to the MBR membrane module through the water production pipe.

[0035] The first biochemical tank 2 is connected to the second biochemical tank 3 and the third biochemical tank 4 through the first overflow weir 14 and the second overflow weir 15 respectively. The second biochemical tank 3 is connected to the third biochemical tank 4 and the MBR membrane tank 5 through the third overflow weir 16 and the fourth overflow weir 17 respectively. The third biochemical tank 4 is connected to the MBR membrane tank 5 through the fifth overflow weir 18.

[0036] The MBR membrane tank 5 is connected to the second biochemical tank 3 through the first sludge return pipe 19, and the first sludge return pipe 19 is equipped with a first sludge return valve 191.

[0037] The second biological treatment tank 3 and the third biological treatment tank 4 are connected to the first biological treatment tank 2 through a second sludge return pipe 20. The second sludge return pipe 20 includes a second return main pipe, a second sludge return branch pipe B connecting to the third biological treatment tank 4, and a second sludge return branch pipe A connecting to the second biological treatment tank 3. A second sludge return valve 201 and a third sludge return valve 202 are respectively installed on the second sludge return branch pipe A and the second sludge return branch pipe B. The second biological treatment tank 3 is connected to the third biological treatment tank 4 through a third sludge return pipe 21, and a fourth sludge return valve 211 is installed on the third sludge return pipe 21.

[0038] The aeration unit includes a blower 11 and a biochemical aeration duct 12. The biochemical aeration duct 12 includes a first aeration duct and a second aeration duct. The blower 11 is connected to a first aerator 13 and a second aerator 22 through the first aeration duct and the second aeration duct, respectively. A first aeration valve 121 and a second aeration valve 122 are respectively provided on the first aeration duct and the second aeration duct.

[0039] The working principle of this utility model is as follows:

[0040] See Figure 2 and Figure 3 High-nitrogen wastewater enters the treatment system through inlet unit 1, and the influent water quality is monitored by inlet online monitoring unit 7. When the influent COD value is low, the first submersible mixer 9 is activated, the first overflow weir 14, the third overflow weir 16, and the fifth overflow weir 18 are lowered, and the second overflow weir 15 and the fourth overflow weir 17 are raised. The high-nitrogen wastewater enters the first biological treatment tank 2 through the inlet pipe. The first biological treatment tank 2 serves as an anoxic tank. After denitrification in the anoxic tank, the wastewater overflows through overflow weir 14 into the second biological treatment tank 3. The second biological treatment tank 3 serves as an aerobic tank. The wastewater undergoes nitrification in the aerobic tank. After the reaction is complete, the wastewater overflows through overflow weir 16 into the third biological treatment tank 4.

[0041] See Figure 2 When the online biochemical monitoring unit 8 displays a COD or NH3-N value higher than the effluent standard of the aerobic tank, the first aeration valve 121 is opened, and the third biochemical tank 4 is adjusted to become the second aerobic tank. Based on the dissolved oxygen content monitored by the DO monitor of the online biochemical monitoring unit 8, the airflow is adjusted. The wastewater undergoes secondary nitrification in the second aerobic tank. After the reaction, the wastewater enters the MBR membrane tank 5 through the fifth overflow weir 18. During this process, the sludge in the third biochemical tank 4 is returned to the front end of the first biochemical tank 2 through the second sludge return pipe 20 and the third sludge return valve 202. The sludge in the MBR membrane tank 5 is returned to the front end of the second biochemical tank 3 through the first sludge return pipe 19 and the second sludge return valve 191. At this time, the second sludge return valve 201 and the fourth sludge return valve 211 are closed, and the MBR permeate is finally discharged from the permeate unit 6.

[0042] See Figure 3When the online biochemical monitoring unit 8 displays that the COD or NH3-N meets the effluent standards of the aerobic tank, the first aeration valve 121 is closed, the second submersible mixer 10 is turned on, and the third biological tank 4 is adjusted to the second anoxic tank. The wastewater undergoes a secondary denitrification reaction in the second anoxic tank. After the reaction, the wastewater overflows into the MBR membrane tank 5 through the fifth overflow weir 18. During this process, the sludge in the second biological tank 3 is returned to the front end of the first biological tank 2 through the second sludge return pipe 20 and the second sludge return valve 201. The sludge in the MBR membrane tank 5 is returned to the front end of the second biological tank 3 through the first sludge return pipe 19 and the first sludge return valve 191. At this time, the third sludge return valve 202 and the fourth sludge return valve 211 are closed, and the MBR permeate is finally discharged from the permeate unit 6.

[0043] See Figure 4 High-nitrogen wastewater enters the treatment system through influent unit 1. The influent water quality is monitored by influent online monitoring unit 7. When the influent COD value is high, the first biological treatment tank 2 is adjusted to a hydrolysis acidification tank, the first submersible mixer 9 is shut off, the second submersible mixer 10 is turned on, the first overflow weir 14 and overflow weir 18 are raised, and the second overflow weir 15, third overflow weir 16, and fourth overflow weir 17 are lowered. The wastewater enters the first biological treatment tank 2 through the influent pipe. In the hydrolysis acidification tank, large molecular organic matter in the wastewater is decomposed into small molecular organic matter. The decomposed wastewater overflows through the second overflow weir 15 into the third biological treatment tank 4. The third biological treatment tank 4 serves as an anoxic tank for denitrification. The wastewater after the reaction overflows through the third overflow weir 16 into the second biological treatment tank 3 for nitrification. After the reaction, the wastewater overflows through the fourth overflow weir 17 into the MBR membrane tank 5. During this process, the sludge in the second biological treatment tank 3 is returned to the front end of the third biological treatment tank 4 through the third sludge return pipe 21 and the fourth sludge return valve 211. The sludge in the third biological treatment tank 4 is returned to the front end of the first biological treatment tank 2 through the second sludge return pipe 20 and the third sludge return valve 202. The sludge in the MBR membrane tank 5 is returned to the front end of the second biological treatment tank 3 through the first sludge return pipe 19 and the first sludge return valve 191. At this time, the second sludge return valve 201 is closed, and the MBR permeate is finally discharged from the permeate unit 6.

[0044] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications are also within the protection scope of the present utility model.

Claims

1. A high-nitrogen wastewater treatment system, characterized in that, It includes an inlet unit (1), a first biological treatment tank (2), a second biological treatment tank (3), a third biological treatment tank (4), an MBR unit, and a product water unit (6). The inlet unit (1) is used to supply high-nitrogen wastewater to the first biological treatment tank (2) and to monitor the concentration of organic matter in the inlet water; The first biological treatment tank (2) serves as a hydrolysis acidification tank when the concentration of organic matter in the influent is high, and is used for the hydrolysis acidification reaction of wastewater; when the concentration of organic matter in the influent is low, it serves as an anoxic tank, and is used for the denitrification reaction of wastewater. The second biological treatment tank (3) serves as an aerobic tank for the nitrification reaction of the effluent from the first biological treatment tank (2); When the influent organic matter concentration is high, the third biological tank (4) serves as an anoxic tank for the denitrification reaction of the effluent from the first biological tank (2); when the influent organic matter concentration is low, and the COD or NH3-N value of the aerobic tank effluent is higher than the aerobic tank effluent standard, it serves as a second aerobic tank for the secondary nitrification reaction of the effluent from the second biological tank (3); when the COD and NH3-N values ​​of the aerobic tank effluent meet the aerobic tank effluent standard, it serves as a second anoxic tank for the secondary denitrification reaction of the effluent from the second biological tank (3). The MBR unit includes an MBR membrane tank (5) and an MBR membrane module installed in the MBR membrane tank for separating wastewater that has undergone biochemical reactions; The water production unit (6) includes a water production pipe and a water production pump, which are used to discharge the water produced by the MBR unit.

2. The high-nitrogen wastewater treatment system according to claim 1, characterized in that, It also includes an aeration unit, which is used to provide oxygen to the second biological tank (3) and the third biological tank (4).

3. The high-nitrogen wastewater treatment system according to claim 2, characterized in that, The aeration unit includes a blower and a biochemical aeration duct. The blower (11) is connected to the second biochemical tank (3) and the third biochemical tank (4) respectively through the biochemical aeration duct. Aeration valves are provided on the aeration ducts connecting the second biochemical tank (3) and the third biochemical tank (4).

4. A high-nitrogen wastewater treatment system according to claim 1 or 2, characterized in that, The first biochemical tank (2), the second biochemical tank (3), the third biochemical tank (4), and the MBR membrane tank (5) are connected by an overflow weir.

5. A high-nitrogen wastewater treatment system according to claim 1 or 2, characterized in that, The MBR membrane tank (5) is connected to the second biological tank (3) through the first sludge return pipe (19). The second biological tank (3) and the third biological tank (4) are connected through the third sludge return pipe (21). The second biological tank (3) and the third biological tank (4) are connected to the first biological tank (2) through the second sludge return pipe (20).

6. A high-nitrogen wastewater treatment system according to claim 5, characterized in that, Sludge return valves are installed on the sludge return pipes connecting the first biological treatment tank (2), the second biological treatment tank (3), and the third biological treatment tank (4).

7. A high-nitrogen wastewater treatment system according to claim 1, characterized in that, The bottom of the first biochemical tank (2) and the third biochemical tank (4) are provided with a first submersible agitator (9) and a second submersible agitator (10).

8. A high-nitrogen wastewater treatment system according to claim 1, characterized in that, Both the second biochemical tank (3) and the third biochemical tank (4) are equipped with aerators.

9. A high-nitrogen wastewater treatment system according to claim 1, characterized in that, The water inlet unit (1) is equipped with an online water inlet monitoring unit (7), which includes an online COD monitor, an online NH3-N monitor, an online TN monitor and an online pH monitor.

10. A high-nitrogen wastewater treatment system according to claim 1, characterized in that, The second biological treatment tank (3) is equipped with a biological online monitoring unit (8) at the end. The biological online monitoring unit (8) includes a DO monitor, a sludge concentration meter, a COD online monitor, an NH3-N online monitor and a TN online monitor.

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