A device and method for high-rate denitrification of low-ammonia-nitrogen wastewater in tropical regions through short-cut nitrification / anaerobic ammonia oxidation

Abstract

The application provides a device and method for high-rate denitrification of low-ammonia-nitrogen wastewater in tropical areas through short-cut nitrification / anaerobic ammonia oxidation, and belongs to the technical field of biological wastewater treatment and is used for treating low-ammonia-nitrogen wastewater in tropical areas. The device comprises a water inlet tank, a double-zone biological reactor and a water collection tank. The method is as follows: floc sludge is pretreated in the reactor by adding hydroxylamine and controlling the sludge age, so as to maintain the activity of ammonia-oxidizing bacteria and inhibit the activity of nitrite-oxidizing bacteria; after the pretreatment, anaerobic ammonia-oxidizing granular sludge is inoculated into the reactor, and aeration is carried out at the upper part of the reactor to provide an aerobic environment for the ammonia-oxidizing bacteria in the floc sludge; the granular sludge is settled at the lower part of the reactor, and the nitrite generated by the floc sludge at the upper part is returned to the lower part, so as to realize anaerobic ammonia oxidation denitrification. In the application, two kinds of functional microorganisms are placed in suitable environments, the growth of nitrite-oxidizing bacteria is controlled, the short-cut nitrification / anaerobic ammonia oxidation rate is improved, and high-rate denitrification of low-ammonia-nitrogen wastewater is realized.

Description

Technical Field

[0001] This invention belongs to the field of wastewater biological treatment technology, and more specifically, relates to an apparatus and method for high-rate denitrification of low ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation. Background Technology

[0002] Currently, most urban wastewater treatment plants commonly use traditional biological nitrogen removal technology. However, these technologies generally face several problems: firstly, high energy consumption, which is particularly prominent in an era of increasing energy shortages; and secondly, large land area requirements, as traditional wastewater treatment plants have relatively low nitrogen removal rates and require long treatment times.

[0003] Short-cut nitrification / anaerobic ammonium oxidation (PN / A) for low-ammonia nitrogen wastewater is a low-carbon, low-energy nitrogen removal technology, but its application still faces the following challenges: First, there is a conflict in the dissolved oxygen requirements of ammonia-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing bacteria (AnAOB), which limits the rate of anaerobic ammonium oxidation when oxygen is supplied for short-cut nitrification. Second, it is difficult to effectively inhibit the growth of nitrite-oxidizing bacteria (NOB) while stably achieving the short-cut nitrification process, resulting in reduced nitrogen removal efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide an apparatus and method for high-rate denitrification of low ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, which can effectively inhibit NOB growth while leveraging the potential of two functional microorganisms, thereby achieving high-rate denitrification.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] A method for high-rate denitrification of low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonium oxidation includes the following steps: Low-ammonia nitrogen wastewater is fed into a two-zone bioreactor from an inlet tank via an inlet peristaltic pump; flocculent sludge is added to the two-zone bioreactor; the pretreatment stage includes the addition of hydroxylamine; the aeration pump is started to continuously aerate the sludge through aeration heads and control a relatively short sludge age; granular sludge is added to the two-zone bioreactor, and aeration is performed in the upper part of the two-zone bioreactor using an aeration pump and aeration heads; a return peristaltic pump is started, and the mixture at the top is returned to the granular sludge in the lower part of the two-zone bioreactor through a return valve via a bottom inlet; a portion of the flocculent sludge is discharged through a sludge discharge valve; and the treated water is discharged through an outlet valve connected to a collection tank.

[0007] As one of the preferred technical solutions, the runtime adjustment operation in this invention is as follows:

[0008] 1) First, inoculate the flocculent sludge into the dual-zone bioreactor, and control the sludge concentration at 3000mg / L~3500mg / L;

[0009] 2) Entering the pretreatment stage, start the inlet peristaltic pump to pump low ammonia nitrogen wastewater with a concentration of 35.0 mg / L~55.0 mg / L from the inlet tank into the inlet valve of the dual-zone bioreactor. At the same time, hydroxylamine is added to control the concentration of hydroxylamine in the dual-zone bioreactor to 5 mg / L.

[0010] 3) Start the aeration pump to continuously aerate the sludge through the aeration head for 1 hour, and control the dissolved oxygen concentration of the dual-zone bioreactor to 4mg / L~6mg / L; after the aeration stage is completed, wash the sludge after the flocculent sludge settles.

[0011] 4) Repeat steps 2) to 3) for a pretreatment period of 7 days, during which half of the reaction volume of sludge is discharged daily, and the sludge age is controlled at 2 days.

[0012] 5) Inoculate the anaerobic ammonia oxidation granular sludge into the above-mentioned dual-zone bioreactor, and control the granular sludge concentration at 5000mg / L-9000mg / L;

[0013] 6) Start the inlet peristaltic pump to pump low ammonia nitrogen wastewater with a concentration of 35.0 mg / L to 55.0 mg / L from the inlet tank into the inlet valve of the dual-zone bioreactor;

[0014] 7) After the water intake is completed, start the reflux peristaltic pump and reflux the mixture at the top through the bottom inlet to the lower granular sludge via the reflux valve of the dual-zone bioreactor. At the same time, start the aeration pump and aeration head. Control the dissolved oxygen concentration at the top of the dual-zone bioreactor to 0.01 mg / L~0.5 mg / L through the upper sensor and upper dissolved oxygen detection instrument.

[0015] 8) The aerobic stage lasts 60 to 25 minutes. The aeration time should be adjusted according to the ammonia nitrogen concentration in the effluent, which should be 2 mg / L to 3 mg / L.

[0016] 9) Five minutes before the end of aeration, discharge some of the flocculent sludge through the sludge discharge valve, and control the sludge age of the flocculent sludge to be 1 to 3 days.

[0017] 10) After the flocculent sludge has settled for 10 minutes, drain the treated water through the outlet valve connected to the collection tank. The drainage volume should be 60% to 65% of the total reactor volume.

[0018] 11) Repeat steps 6) to 10) The dual-zone bioreactor operates in sequencing batch mode to achieve high-rate denitrification through short-cut nitrification / anaerobic ammonia oxidation based on stable NOB control.

[0019] A device for high-rate denitrification of low ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation includes an inlet tank, a dual-zone bioreactor, and a collection tank connected in sequence. The inlet tank is connected to the inlet valve of the dual-zone bioreactor, and the dual-zone bioreactor is connected to the collection tank via an outlet valve.

[0020] As one of the preferred technical solutions, in this invention, the water inlet tank is equipped with a first vent valve.

[0021] As one of the preferred technical solutions, in this invention, the dual-zone bioreactor is equipped with an inlet peristaltic pump, an inlet valve, a return peristaltic pump, a return valve, a bottom inlet, a sludge discharge valve, an outlet valve, an upper sensor, an upper dissolved oxygen detector, a lower sensor, a lower dissolved oxygen detector, an aeration head, a gas flow meter, and an aeration pump.

[0022] As one of the preferred technical solutions, in this invention, the water collection tank is equipped with a second vent valve.

[0023] As one of the preferred technical solutions, in this invention, the reflux valve is connected to the bottom water inlet, and a reflux peristaltic pump is provided in the middle.

[0024] As one of the preferred technical solutions, in this invention, the upper sensor is connected to an upper dissolved oxygen detection instrument, and the lower sensor is connected to a lower dissolved oxygen detection instrument to display the dissolved oxygen concentration in real time.

[0025] As one of the preferred technical solutions, in this invention, the aeration pump is connected in sequence to the gas flow meter and the aeration head.

[0026] A device for high-rate denitrification of low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation includes an inlet tank, a dual-zone bioreactor, and a collection tank. The inlet tank is equipped with a first vent valve. The dual-zone bioreactor is equipped with an inlet peristaltic pump, an inlet valve, a return peristaltic pump, a return valve, a bottom inlet, a sludge discharge valve, an outlet valve, an upper sensor, an upper dissolved oxygen detector, a lower sensor, a lower dissolved oxygen detector, an aeration head, a gas flow meter, and an aeration pump. The collection tank is equipped with a second vent valve. The return valve is connected to the bottom inlet, and a return peristaltic pump is installed in the middle. The upper sensor is connected to the upper dissolved oxygen detector, and the lower sensor is connected to the lower dissolved oxygen detector. The aeration pump is connected to the gas flow meter and the aeration head in sequence.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] (1) This invention provides a method that can effectively inhibit NOB activity and maintain the stability of short-cut nitrification / anaerobic ammonium oxidation system, which can save aeration energy consumption and reagent costs.

[0029] (2) This invention provides a high-rate denitrification method for short-cut nitrification / anaerobic ammonia oxidation process in low ammonia nitrogen wastewater, which shortens the treatment time.

[0030] (3) The present invention uses a dual-zone bioreactor with a relatively large height-to-diameter ratio, which helps to reduce the system's floor space. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the device for high-rate denitrification of low ammonia nitrogen wastewater in tropical regions using short-cut nitrification / anaerobic ammonia oxidation, as described in this invention.

[0032] In the diagram: 1. Inlet tank; 2. Dual-zone bioreactor; 3. Collection tank; 11. First vent valve; 21. Inlet peristaltic pump; 22. Inlet valve; 23. Return peristaltic pump; 24. Return valve; 25. Bottom inlet; 26. Sludge discharge valve; 27. Outlet valve; 28. Upper sensor; 29. ​​Upper dissolved oxygen detector; 210. Lower sensor; 211. Lower dissolved oxygen detector; 212. Aeration head; 213. Gas flow meter; 214. Aeration pump; 31. Second vent valve. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] The method of this invention effectively inhibits NOB growth by adding hydroxylamine during pretreatment and controlling a shorter sludge age, maintaining AOB activity to stably achieve short-cut nitrification. Utilizing the difference in settling properties, flocs and granules are separated in the dual-zone bioreactor 2. Aeration is performed in the upper part of the dual-zone bioreactor 2 via aeration pump 214 and aeration heads 212, providing an aerobic environment for AOB growth in the floc sludge, oxidizing ammonia nitrogen to nitrite nitrogen. Simultaneously, the growth of NOB in the floc sludge is controlled by maintaining a shorter floc sludge age, a higher ammonia nitrogen concentration in the upper part of the dual-zone bioreactor 2, and a low dissolved oxygen environment. The anaerobic ammonia oxidation granular sludge settles in the lower part of the dual-zone bioreactor 2. Anaerobic ammonia oxidation denitrification is achieved by recirculating the nitrite nitrogen produced by the upper floc sludge to the lower part.

[0035] Based on simple control and convenient operation, this invention creatively solves the technical problem of the conflict between AOB bacteria and AnAOB bacteria in terms of dissolved oxygen demand, as well as the technical challenge of effectively inhibiting NOB bacteria activity to achieve a stable short-cut nitrification process.

[0036] Example 1

[0037] like Figure 1As shown, a device for high-rate denitrification of low ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation is disclosed. The device includes an inlet tank 1, a dual-zone bioreactor 2, and a collection tank 3 connected in sequence. The inlet tank 1 is connected to the dual-zone bioreactor 2 via an inlet peristaltic pump 21, and the dual-zone bioreactor 2 is connected to the collection tank 3 via an outlet valve 27.

[0038] The inlet tank 1 is equipped with a first vent valve 11, and the dual-zone bioreactor 2 is equipped with an inlet peristaltic pump 21, an inlet valve 22, a return peristaltic pump 23, a return valve 24, a bottom inlet 25, a sludge discharge valve 26, an outlet valve 27, an upper sensor 28, an upper dissolved oxygen detector 29, a lower sensor 210, a lower dissolved oxygen detector 211, an aeration head 212, a gas flow meter 213, and an aeration pump 214. The collection tank 3 is equipped with a second vent valve 31.

[0039] The operating method of the above-mentioned device for high-rate denitrification of low-ammonia nitrogen wastewater in tropical regions via short-cut denitrification / anaerobic ammonia oxidation is as follows: Low-ammonia nitrogen wastewater is fed into a dual-zone bioreactor 2 from the inlet tank 1 through the inlet peristaltic pump 21, and inoculated flocculent sludge is added to the dual-zone bioreactor 2. The pretreatment stage includes the addition of hydroxylamine, starting the aeration pump 214 to continuously aerate the sludge through the aeration head 212, and controlling a relatively short sludge age; inoculating granular sludge is added to the dual-zone bioreactor 2, and aeration is performed in the upper part of the dual-zone bioreactor 2 using the aeration pump 214 and the aeration head 212; starting the return peristaltic pump 23, and returning the mixture from the top through the return valve 24 to the granular sludge in the lower part of the dual-zone bioreactor 2 through the bottom inlet 25; discharging part of the flocculent sludge through the sludge discharge valve 26; and draining the treated water by connecting it to the collection tank 3 through the outlet valve 27.

[0040] Example 2

[0041] A method for high-rate denitrification of low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonium oxidation is disclosed. The method utilizes the apparatus described in Example 1 for high-rate denitrification of low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonium oxidation. During the experimental process, the synthesized wastewater composition includes: 450 mg / L NaHCO3, 18 mg / L KH2PO4, 14 mg / L CaCl2·2H2O, 90 mg / L MgSO4·7H2O, and 1.25 mg / L trace elements. Trace element solution A contains: 5 g / L EDTA and 22 g / L FeSO4. Throughout the experiment, Fe... 2+The concentration was maintained at 0.08 mM. Trace element solution B contained: 15 g / L EDTA, 0.014 g / L H3BO4, 0.19 g / L NiCl2·6H2O, 0.22 g / L NaMoO4·2H2O, 0.25 g / L CuSO4·5H2O, 0.99 g / L MnCl2·4H2O, and 0.43 g / L ZnSO4·7H2O.

[0042] Test apparatus such as Figure 1 As shown, each reactor is made of acrylic material, and the effective volume of the dual-zone bioreactor 2 is 5L.

[0043] In this invention, the runtime adjustment operation is as follows:

[0044] (1) First, the flocculent sludge is inoculated into a 5L dual-zone bioreactor 2 with a sludge concentration of 3500mg / L.

[0045] (2) Enter the pretreatment stage, start the inlet peristaltic pump 21 to pump the 45mg / L low ammonia nitrogen wastewater in the inlet tank 1 into the inlet valve 22 of the dual-zone bioreactor 2, and add hydroxylamine at the same time to control the concentration of hydroxylamine in the container to 5mg / L.

[0046] (3) Start the aeration pump 214 to continuously aerate the sludge through the aeration head 212 for 1 hour, and control the dissolved oxygen concentration in the reactor to 6 mg / L. After the aeration stage is completed, wash the sludge after the flocculent sludge has settled.

[0047] (4) Repeat steps (2) to (3) for a total of 7 days. During this period, half of the reaction volume of sludge is discharged daily, and the sludge age is controlled to be 2 days.

[0048] (5) The anaerobic ammonia oxidation granular sludge was inoculated into the above-mentioned dual-zone bioreactor 2, and the granular sludge concentration was 8000 mg / L.

[0049] (6) Start the inlet peristaltic pump 21 to pump the 45mg / L low ammonia nitrogen wastewater in the inlet tank 1 into the inlet valve 22 of the dual-zone bioreactor 2.

[0050] (7) After the water intake is completed, start the reflux peristaltic pump 23 and reflux the mixture at the top through the bottom inlet 25 to the lower granular sludge through the reflux valve 24 of the dual-zone bioreactor 2. At the same time, start the aeration pump 214 and aeration head 212 and control the dissolved oxygen concentration at the top of the dual-zone bioreactor 2 to be 0.01mg / L~0.5mg / L through the upper sensor 28 and the upper dissolved oxygen detection instrument 29.

[0051] (8) Aerobic stage (45 minutes), the aeration time is adjusted according to the ammonia nitrogen concentration in the effluent (3 mg / L).

[0052] (9) Five minutes before the end of aeration, some flocculent sludge is discharged through sludge discharge valve 26. The sludge age of the flocculent sludge is 2 days.

[0053] (10) After the flocculent sludge has settled for 10 minutes, the treated water is drained through the outlet valve 27 connected to the water collection tank 3. The drainage volume accounts for 62.5% of the total volume of the reactor.

[0054] (11) Repeat steps (6) to (10), and the dual-zone bioreactor 2 is operated in sequential batch processing mode to achieve high-rate denitrification by short-range nitrification / anaerobic ammonia oxidation on the basis of stable NOB control.

[0055] The experimental results show that in this dual-zone bioreactor system, the influent ammonia nitrogen concentration is 45 mg / L; the volumetric nitrogen removal rate is 1.4 gN / L / d to 1.6 gN / L / d; after pretreatment, the NOB activity is less than 0.01 gN / g-SS / d, achieving stable short-cut nitrification / anaerobic ammonia oxidation; the effluent total nitrogen is 7.3 mg / L to 8.4 mg / L; the ammonia nitrogen concentration is 2.3 mg / L to 3.1 mg / L; and the effluent nitrate nitrogen concentration is less than 4.5 mg / L. The results indicate that the device and method successfully achieved high-rate denitrification of low-ammonia nitrogen wastewater in tropical regions through short-cut nitrification / anaerobic ammonia oxidation.

[0056] Finally, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, characterized in that, The process includes the following steps: Low ammonia nitrogen wastewater is fed into the dual-zone bioreactor (2) from the inlet tank (1) via the inlet peristaltic pump (21); flocculent sludge is added to the dual-zone bioreactor (2); the pretreatment stage includes the addition of hydroxylamine; the aeration pump (214) is started to continuously aerate the sludge through the aeration head (212) and control the sludge age to a short period; granular sludge is added to the dual-zone bioreactor (2); aeration is performed at the top of the dual-zone bioreactor (2) using the aeration pump (214) and the aeration head (212); the return peristaltic pump (23) is started, and the mixture at the top is returned to the granular sludge at the bottom of the dual-zone bioreactor (2) through the return valve (24) via the bottom inlet (25); some flocculent sludge is discharged through the sludge discharge valve (26); the treated water is drained by connecting it to the collection tank (3) through the outlet valve (27). The operation is adjusted as follows: 1) First, inoculate the flocculent sludge into the dual-zone bioreactor (2), and control the sludge concentration at 3000mg / L~3500mg / L; 2) Entering the pretreatment stage, start the inlet peristaltic pump (21) to pump the low ammonia nitrogen wastewater with a concentration of 35.0 mg / L to 55.0 mg / L from the inlet tank (1) into the inlet valve (22) of the dual-zone bioreactor (2). At the same time, hydroxylamine is added to control the concentration of hydroxylamine in the dual-zone bioreactor (2) to 5 mg / L. 3) Start the aeration pump (214) to continuously aerate the sludge through the aeration head (212) for 1 hour, and control the dissolved oxygen concentration of the dual-zone bioreactor (2) to be 4mg / L~6mg / L; after the aeration stage is completed, wash the sludge after the flocculent sludge settles. 4) Repeat steps 2) to 3) for a total of 7 days of pretreatment. During this period, half of the reaction volume of sludge is discharged daily, and the sludge age is controlled to be 2 days. 5) Inoculate the anaerobic ammonia oxidation granular sludge into the above-mentioned dual-zone bioreactor (2), and control the granular sludge concentration at 5000mg / L~9000mg / L; 6) Start the inlet peristaltic pump (21) to pump the low ammonia nitrogen wastewater with a concentration of 35.0 mg / L to 55.0 mg / L from the inlet tank (1) into the inlet valve (22) of the dual-zone bioreactor (2); 7) After the water intake is completed, start the reflux peristaltic pump (23) and reflux the mixture at the top through the bottom inlet (25) to the lower granular sludge via the reflux valve (24) of the dual-zone bioreactor (2). At the same time, start the aeration pump (214) and aeration head (212) and control the dissolved oxygen concentration at the top of the dual-zone bioreactor (2) to be 0.01 mg / L~0.5 mg / L via the upper sensor (28) and upper dissolved oxygen detector (29). 8) The aerobic stage lasts 60 to 25 minutes. The aeration time should be adjusted according to the ammonia nitrogen concentration in the effluent, which should be 2 mg / L to 3 mg / L. 9) Five minutes before the end of aeration, discharge part of the flocculent sludge through the sludge discharge valve (26) to control the sludge age of the flocculent sludge to be 1 to 3 days. 10) After the flocculent sludge has settled for 10 minutes, the treated water is drained through the outlet valve (27) connected to the water collection tank (3). The drainage volume accounts for 60% to 65% of the total volume of the reactor. 11) Repeat steps 6) to 10), the dual-zone bioreactor (2) is operated in sequential batch processing mode to achieve high-rate denitrification by short-range nitrification / anaerobic ammonia oxidation on the basis of stable NOB control.

2. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 1, is characterized in that... The apparatus used in this method includes an inlet tank (1), a dual-zone bioreactor (2), and a collection tank (3) connected in sequence. The inlet tank (1) is connected to the inlet valve (22) of the dual-zone bioreactor (2), and the dual-zone bioreactor (2) is connected to the collection tank (3) through an outlet valve (27).

3. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 2, is characterized in that... The water inlet tank (1) is equipped with a first vent valve (11).

4. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 2, is characterized in that... The dual-zone bioreactor (2) is equipped with an inlet peristaltic pump (21), an inlet valve (22), a return peristaltic pump (23), a return valve (24), a bottom inlet (25), a sludge discharge valve (26), an outlet valve (27), an upper sensor (28), an upper dissolved oxygen detector (29), a lower sensor (210), a lower dissolved oxygen detector (211), an aeration head (212), a gas flow meter (213), and an aeration pump (214).

5. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 2, is characterized in that... The water collection tank (3) is equipped with a second vent valve (31).

6. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 4, is characterized in that... The reflux valve (24) is connected to the bottom inlet (25), and a reflux peristaltic pump (23) is installed in the middle.

7. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 4, is characterized in that... The upper sensor (28) is connected to the upper dissolved oxygen detector (29), and the lower sensor (210) is connected to the lower dissolved oxygen detector (211), displaying the dissolved oxygen concentration in real time.

8. The method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 4, is characterized in that... The aeration pump (214) is connected in sequence to the gas flow meter (213) and the aeration head (212).

9. A method for high-rate nitrogen removal from low-ammonia nitrogen wastewater in tropical regions via short-cut nitrification / anaerobic ammonia oxidation, as described in claim 1, is characterized in that... The apparatus used in this method includes an inlet tank (1), a dual-zone bioreactor (2), and a collection tank (3). The inlet tank (1) is equipped with a first vent valve (11). The dual-zone bioreactor (2) is equipped with an inlet peristaltic pump (21), an inlet valve (22), a reflux peristaltic pump (23), a reflux valve (24), a bottom inlet (25), a sludge discharge valve (26), an outlet valve (27), an upper sensor (28), an upper dissolved oxygen detector (29), a lower sensor (210), and a lower dissolved oxygen detector (210). 211), aeration head (212), gas flow meter (213), aeration pump (214); the water collection tank (3) is equipped with a second vent valve (31), the return valve (24) is connected to the bottom inlet (25), and a return peristaltic pump (23) is set in the middle; the upper sensor (28) is connected to the upper dissolved oxygen detection instrument (29), and the lower sensor (210) is connected to the lower dissolved oxygen detection instrument (211); the aeration pump (214) is connected to the gas flow meter (213) and the aeration head (212) in sequence.

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