Mainstream anaerobic ammonia oxidation quick start and efficient stable operation method

Abstract

The invention relates to a mainstream anaerobic ammonia oxidation quick start and efficient stable operation method, which uses an immersed anaerobic ammonia oxidation granular sludge membrane biological composite reactor comprising an upflow anaerobic sludge blanket (UASB), and an MBR is immersed in the upper part of the upflow anaerobic sludge blanket (UASB); the height-diameter ratio of the UASB is 4-6, and the overall length of the MBR is 1 / 2-1 / 3 of the height of the UASB. The granulation of the sludge is realized through the UASB, and the enrichment capacity, the sedimentation performance and the stability of the sludge are improved; in the operation process of the mainstream Anammox, the complete retention of sludge functional bacteria is realized by adopting the operation of gradually shortening the hydraulic retention time and improving the nitrogen load and through the biological complete interception effect of the immersed MBR. In the granulation process of the sludge, the settling performance of the sludge is improved, a large amount of flocculent sludge is prevented from being in direct contact with membrane filaments, the membrane pollution problem in the membrane assembly is relieved, meanwhile, water flow shearing force generated around the membrane assembly can effectively wash pollutants on the surface of the membrane assembly, and the membrane pollution problem is further controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of novel sewage denitrification, and in particular to a method for rapid startup and efficient and stable operation of mainstream anaerobic ammonia oxidation. Background Art

[0002] Anaerobic ammonium oxidation (Anammox) is an environmentally friendly autotrophic biological denitrification process that not only has a good denitrification effect, but also can reduce a considerable part of the operating costs and greenhouse gas emissions. Compared with the traditional nitrification-denitrification process, the Anammox process can save 100% of the organic carbon source and air aeration volume, reduce the sludge yield by 80-90%, and reduce greenhouse gas emissions by 90%. Therefore, the Anammox process has good application prospects and market potential in treating high ammonia nitrogen or low carbon / nitrogen ratio (COD: TN) wastewater. However, anaerobic ammonium oxidizing bacteria (AnAOB) grow slowly and are extremely sensitive to environmental conditions, resulting in a long process startup cycle and poor operating stability. In particular, in the mainstream Anammox process, AnAOB is more difficult to enrich in the face of low temperature and low substrate environment, which has become a key factor restricting its widespread application. Therefore, optimizing the reactor design and operation method has become an important strategy to promote the rapid startup and stable operation of the mainstream Anammox process, which is of great significance for promoting the practical application of this technology. Summary of the invention

[0003] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a method for rapid startup and efficient and stable operation of mainstream anaerobic ammonium oxidation, which is suitable for rapid startup of mainstream anaerobic ammonium oxidation process.

[0004] The technical solution adopted by the present invention to solve the technical problem is: In the first aspect, the present invention provides a method for rapid start-up and efficient and stable operation of mainstream anaerobic ammonium oxidation, the method uses an immersed anaerobic ammonium oxidation granular sludge membrane bioreactor, the composite reactor includes an upflow anaerobic sludge bed UASB, and an MBR is immersed on the upper part of the upflow anaerobic sludge bed UASB; the height-to-diameter ratio of the UASB is 4-6, the MBR is placed on the top of the UASB, and the overall length of the MBR is 1 / 2-1 / 3 of the height of the UASB; the process of the operation method is: 1) Inoculating aerobic activated sludge from a sewage treatment plant into the submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor, the mixed liquor suspended solids concentration is 3.25-4.0 g / L, and the mixed liquor volatile suspended solids concentration is 2.49-3.0 g / L; 2) Mainstream start: Under constant temperature of 20±1℃, set NH4 + -N and NO2 --N concentration was 30±2 mg / L, and the hydraulic retention time was set to 20 hours. Under the premise of keeping the influent ammonia nitrogen concentration unchanged, the reactor continued to operate at this hydraulic retention time. The sludge granulation and membrane filtration in the reactor were combined to achieve rapid and effective enrichment of AnAOB, and the effluent NH4 + -N and NO2 - -N concentration decreased simultaneously, while the effluent NO3 - -N concentration gradually increased. When the average total nitrogen removal rate (NRE) exceeded 70% and the proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm in the system exceeded 50%, the reactor granulated the sludge, achieving the rapid and successful start-up of the mainstream Anammox process at a lower ammonia nitrogen concentration, and initially domesticated anaerobic ammonium oxidation granular sludge. 3) Stable operation: By gradually shortening the hydraulic retention time and correspondingly increasing the inlet flow rate of UASB, different degrees of turbulence effects can be generated around the membrane components. The turbulence effect is based on not causing particle disintegration and being able to flush pollutants on the surface of the membrane components. Gradually shortening the hydraulic retention time can increase the influent nitrogen load. When the total nitrogen removal efficiency is stabilized at more than 80wt% for four consecutive days at a certain hydraulic retention time, stable and efficient denitrification performance is achieved. Mature anaerobic ammonium oxidation granular sludge is domesticated in the system, and the proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm is not less than 60%, achieving stable operation.

[0005] Furthermore, during stable operation, the nitrogen removal efficiency of the system was 0.4 kg N / (m 3 d) or above.

[0006] Furthermore, during the entire experimental operation, the transmembrane pressure difference was tested in real time. It took 32 days for the system transmembrane pressure difference to reach 35 kPa, which can alleviate membrane fouling.

[0007] Furthermore, the inlet diameter of the UASB is 8 mm, the height of the UASB is 45 cm, and the inner diameter is 10 cm. In the stable operation stage, the hydraulic retention time is controlled at 16 h, 12 h, 10 h, 8 h, 6 h, 4 h, and 3 h, respectively, and the corresponding inlet flow rates are 8.29×10 -6 m / s, 1.04×10 -5 m / s, 1.38×10 -5 m / s, 1.66×10 -5 m / s, 2.07×10 -5 m / s, 2.76×10 - 5 m / s, 4.15×10 -5 m / s and 5.53×10 -5 m / s.

[0008] Furthermore, the MBR is an O-type hollow fiber membrane module or a modified O-type hollow fiber membrane module.

[0009] In a second aspect, the present invention provides a submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor coupling device, comprising a water inlet system, a submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor, a water bath circulation system, a water seal structure and a water outlet system; The water inlet system includes a water inlet box 1, a water inlet pipe 2 and a water inlet pump 3, and the water outlet system includes a water outlet 16, a water outlet pipe 17, a water outlet pump 18 and a water outlet box 19; The composite reactor comprises an upflow anaerobic sludge blanket UASB, and an MBR is immersed in the upper part of the upflow anaerobic sludge blanket UASB; the height-to-diameter ratio of the UASB is 4-6, the MBR is placed on the top of the UASB, and the overall length of the MBR is 1 / 2-1 / 3 of the height of the UASB; The UASB is used to achieve granulation of sludge, and the MBR is used to achieve complete retention of microorganisms. The UASB includes an inner tube and an outer tube, and a water bath circulation system 6 is provided between the inner tube and the outer tube. The water bath circulation system consists of a water bath inlet 7, a water bath outlet 8, a water bath water inlet pipe 9, a water bath water inlet pump 10, a water bath pool 11 and a temperature controller 12. The column space of the inner tube is a main reaction zone, and a gas exhaust port 13 is provided at the upper part of the main reaction zone. The gas exhaust port is connected by an exhaust pipe 14, and the exhaust pipe is connected to a water seal structure 15. An outlet 16 of an O-type membrane assembly is provided at the upper part of the main reaction zone, and the outlet 16 is connected to an outlet pipe 17, and water is sucked by an outlet pump 18, and the sucked water is sent to an outlet tank 19. A pressure gauge 20 is connected in front of the outlet pump to record the membrane pollution situation. The lower part of the UASB is a funnel-shaped sludge hopper, and a water inlet is provided at the bottom of the sludge hopper. The water inlet is connected to the water inlet tank through a water inlet pump and a water inlet pipe.

[0010] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1) The method of the present invention is to construct a submerged anaerobic ammonium oxidation granular sludge membrane bioreactor (SGSMBR) by coupling an upflow anaerobic sludge blanket (UASB) with a membrane bioreactor (MBR). On the one hand, the UASB realizes the granulation of sludge, improves the enrichment capacity, sedimentation performance and stability of sludge; on the other hand, in the operation process of mainstream Anammox, by gradually shortening the hydraulic retention time and increasing the nitrogen load, the biological complete interception effect of the submerged MBR is used to achieve the complete retention of sludge functional bacteria, avoiding the problem of sludge functional bacteria being lost with the effluent at a high flow rate. In addition, in the process of sludge granulation, its sedimentation performance is improved, avoiding the direct contact between a large amount of flocculent sludge and membrane fibers, and to a certain extent, the membrane fouling problem (especially biological fouling) in the membrane assembly is alleviated. At the same time, the water flow shear force generated around the membrane assembly can effectively flush the pollutants on the surface of the membrane assembly, further controlling the membrane fouling problem.

[0011] 2) The composite reactor of the present invention is an integrated independent body, which integrates the sludge granulation and the complete interception of membrane organisms, and fully utilizes the advantages of both, thereby further enhancing the rapid start-up and stable operation efficiency of mainstream anaerobic ammonium oxidation. In addition, it significantly reduces the occupied area during the operation of mainstream Anammox.

[0012] 3) During the operation of the present invention, the sludge is granulated and settled to gather at the bottom, avoiding the direct interaction between flocculent sludge and membrane fibers, and alleviating the membrane pollution problem. At the same time, as the flow rate around the module increases, the turbulence effect is enhanced, and the generated water flow shear force can effectively flush the pollutants on the surface of the membrane module, thereby further controlling the membrane pollution. The SGSMBR has a certain membrane self-cleaning function.

[0013] 3) The lower part of the reactor of the present invention is provided with a sludge hopper, and the mass transfer efficiency between the sludge and the substrate is significantly enhanced by the ascending water inlet mode of the main body and the gradual increase in flow rate. Thus, the activity of the functional bacteria is effectively improved. The present invention is designed with partitions, and adopts a continuous water inlet and continuous water outlet operation mode of the membrane module. The system control is simple, and the water quality of the outlet water through the main body is stable and can meet the national emission standards. Therefore, it can be directly discharged and is also easy to recycle and reuse.

[0014] 5) The water bath circulation system provided by the device of the present invention can effectively isolate the adverse effects of external temperature changes on the activity of functional bacteria in the reactor, and create a constant temperature and stable living environment for these key microorganisms, thereby ensuring that they can function efficiently and stably. At the same time, the water bath system has a temperature regulation function, which is simple and quick to operate, and improves the efficiency and reliability of the experiment or production process. In addition, the water bath temperature control of the device provides convenience for studying the operation of the Anammox process under different temperature conditions and its impact on the bacterial community. The application of this coupling device in the mainstream Anammox process not only provides new ideas for improving the startup and operation performance of the process, but also provides an effective solution for alleviating membrane fouling problems, which will greatly promote the engineering application of the mainstream Anammox process in the field of sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor provided in an embodiment of the present invention; Figure 1 Middle: 1 water inlet tank; 2 water inlet pipe; 3 water inlet pump; 4 UASB; 5 MBR; 6 water bath circulation system; 7 water bath inlet; 8 water bath outlet; 9 water bath inlet pipe; 10 water bath inlet pump; 11 water bath; 12 temperature controller; 13 exhaust port; 14 exhaust pipe; 15 water seal structure; 16 water outlet; 17 water outlet pipe; 18 water outlet pump; 19 water outlet tank; 20 pressure gauge.

[0016] Figure 2 This is a SEM microscopic morphology of mature anaerobic ammonium oxidation sludge cultured in the submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor provided in an embodiment of the present invention; Figure 3 A diagram of turbulence effects in a submerged anaerobic ammonium oxidation granular sludge membrane bioreactor provided in an embodiment of the present invention.

[0017] Figure 4 This is a genus-level microbial community analysis diagram of the inoculation sludge, startup stage sludge (sludge on the 47th day in the reactor), and mature stage Anammox sludge (sludge on the 133rd day in the reactor) in Example 1. DETAILED DESCRIPTION

[0018] The present invention is further explained below in conjunction with the embodiments and drawings, but this is not intended to limit the scope of protection of the present application.

[0019] The invention discloses a submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor coupling device (see Figure 1 ), including water inlet system, submerged anaerobic ammonium oxidation granular sludge membrane bioreactor, water bath circulation system, water seal structure and water outlet system; The water inlet system includes a water inlet box 1, a water inlet pipe 2 and a water inlet pump 3, and the water outlet system includes a water outlet 16, a water outlet pipe 17, a water outlet pump 18 and a water outlet box 19; The composite reactor comprises an upflow anaerobic sludge blanket UASB 4, and an MBR 5 is immersed in the upper part of the upflow anaerobic sludge blanket UASB; the height-to-diameter ratio of the UASB is 4-6, the MBR is placed on the top of the UASB, and the overall length of the MBR is 1 / 2-1 / 3 of the height of the UASB; The UASB is used to achieve sludge granulation, and the MBR is used to achieve complete retention of microorganisms, wherein the MBR is an O-type hollow fiber membrane module and is immersed in the UASB.

[0020] UASB includes an inner tube and an outer tube, and a water bath circulation system 6 is provided between the inner tube and the outer tube. The water bath circulation system consists of a water bath inlet 7, a water bath outlet 8, a water bath water inlet pipe 9, a water bath water inlet pump 10, a water bath pool 11 and a temperature controller 12. The column space of the inner tube is the main reaction zone, and a gas exhaust port 13 is provided at the top of the main reaction zone, and the gas exhaust port is connected by an exhaust pipe 14, and the exhaust pipe is connected to a water seal structure 15; a water outlet 16 of an O-type membrane assembly is provided at the top of the main reaction zone, and the water outlet 16 is connected to a water outlet pipe 17, and water is sucked by a water outlet pump 18, and the sucked water is sent to a water outlet tank 19, and a pressure gauge 20 is connected in front of the water outlet pump to record the membrane contamination.

[0021] The lower part of the UASB is a funnel-shaped sludge hopper, and a water inlet is provided at the bottom of the sludge hopper. The water inlet is connected to the water inlet tank through a water inlet pump and a water inlet pipe.

[0022] The UASB achieves sludge granulation, improves sludge stability and sedimentation performance; the granulated sludge shows higher bacterial activity, stability and impact resistance. Then, through the complete interception of MBR microorganisms, the complete interception of functional bacteria is achieved, and the biomass and activity of functional bacteria in the reactor are increased.

[0023] During the operation of the submerged anaerobic ammonium oxidation granular sludge membrane bioreactor, the sludge is granulated by UASB, which improves the sedimentation performance of the sludge and avoids large-scale contact between the flocculent sludge and the membrane bioreactor, thus effectively alleviating membrane fouling. At the same time, the control of the inlet flow rate produces different degrees of turbulence around the membrane assembly, further controlling the membrane fouling problem and greatly saving the cost of cleaning and replacing the membrane assembly.

[0024] The device of the present invention is also equipped with a water bath circulation system to provide a suitable temperature living environment for the microorganisms in the reaction zone, avoiding the adverse effects of fluctuating temperatures in the environment on the sludge, thereby ensuring the accuracy of the experimental process.

[0025] A method for rapid startup and efficient and stable operation of mainstream anaerobic ammonium oxidation according to the present invention comprises the following processes: 1) Inoculating aerobic activated sludge from a sewage treatment plant into the submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor, the mixed liquor suspended solids concentration is 3.25-4.0 g / L, and the mixed liquor volatile suspended solids concentration is 2.49-3.0 g / L; 2) Mainstream start: Under constant temperature of 20±1℃, set NH4 + -N and NO2 - -N concentration was 30±2 mg / L, and the hydraulic retention time was set to 20 hours. Under the premise of keeping the influent ammonia nitrogen concentration unchanged, the reactor continued to operate at this hydraulic retention time. The sludge granulation and membrane filtration in the reactor were combined to achieve rapid and effective enrichment of AnAOB, and the effluent NH4 + -N and NO2 - -N concentration decreased simultaneously, while the effluent NO3 - -N concentration gradually increased. When the average total nitrogen removal rate (NRE) exceeded 70% and the proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm in the system exceeded 50%, the reactor granulated the sludge, achieving the rapid and successful start-up of the mainstream Anammox process at a lower ammonia nitrogen concentration, and initially domesticated anaerobic ammonium oxidation granular sludge. 3) Stable operation: By gradually shortening the hydraulic retention time and correspondingly increasing the inlet flow rate of UASB, different degrees of turbulence effects can be generated around the membrane components. The turbulence effect is based on not causing particle disintegration and being able to flush pollutants on the surface of the membrane components. Gradually shortening the hydraulic retention time can increase the influent nitrogen load. When the total nitrogen removal efficiency is stabilized at more than 80% for four consecutive days at a certain hydraulic retention time, stable and efficient denitrification performance is achieved. Mature anaerobic ammonium oxidation granular sludge is domesticated in the system, and the proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm is not less than 60%, achieving stable operation.

[0026] In the mainstream startup phase of the present invention, the ammonia nitrogen concentration in the influent is kept constant, and the mainstream startup is performed at a lower ammonia nitrogen concentration. During the mainstream startup process, the hydraulic retention time is kept constant at 20 hours. After running for about 45 days, the average total nitrogen removal rate NRE exceeds 70%, and the proportion of anaerobic ammonia oxidation particles with a particle size of more than 200 μm exceeds 50%. The reactor granulates the sludge, and it is considered that the mainstream Anammox process is successfully started. The present invention can achieve rapid startup while maintaining a low ammonia nitrogen concentration. It combines sludge granulation with membrane filtration through the reasonable setting of the reactor structure, realizes the rapid and effective enrichment of AnAOB, and significantly improves the retention rate of functional bacteria, thereby accelerating the rapid startup of the mainstream Anammox process.

[0027] In the present invention, during stable operation, by gradually shortening the hydraulic retention time and correspondingly increasing the inlet flow rate, the degree of turbulence effect around the membrane assembly can be controlled. This turbulence effect will not cause the disintegration of particles, and can flush the pollutants on the surface of the membrane assembly. If the turbulence effect is too small, it will not play a flushing role. If it is too large, it will cause floating and disperse some particles. Gradually shortening the hydraulic retention time can avoid large fluctuations, ensure that the strains can survive stably, and increase the nitrogen load of the influent.

[0028] The method of the present invention can ensure a high total nitrogen removal efficiency under the premise of a high nitrogen removal rate, has better denitrification performance, and realizes efficient denitrification under mainstream conditions (low temperature, low nitrogen concentration). Compared with the prior art of rapid start-up by increasing the influent concentration to form a side stream-like method, it can further shorten the rapid start-up time and operating efficiency.

[0029] In addition, during the entire experimental operation, the present invention uses a pressure gauge to test the transmembrane pressure difference in real time. The transmembrane pressure difference can reach 35 kPa after 32 days, which can effectively alleviate membrane pollution. The sludge granulation and sedimentation in the reactor and the turbulence effect around the membrane assembly (flow rate control under different hydraulic retention times) effectively alleviate membrane pollution, and the control of membrane pollution is achieved during the operation, which greatly reduces the cost caused by modifying the membrane and cleaning and replacing the membrane.

[0030] Example 1 The device of the present invention (such as Figure 1 The device described in the present invention was used to achieve rapid and effective start-up of the mainstream Anammox process. In this embodiment, UASB (45 cm high, 10 cm inner diameter, height-to-diameter ratio of 4.5) was coupled with MBR, where the MBR used an O-type hollow fiber membrane module (pore size of 0.1 μm, surface area of ​​0.02 m 2 ), the membrane module was placed on top of the UASB with a total length of 20 cm, and the inlet diameter of the UASB was 8 mm. A laboratory-scale SGSMBR (working volume 3 L) was constructed.

[0031] The specific operation method is as follows: (1) The sludge inoculated in the experiment was aerobic activated sludge from a sewage treatment plant. The suspended solids concentration of the mixed liquor was 3.25 g / L and the volatile suspended solids concentration of the mixed liquor was 2.49 g / L.

[0032] (2) A continuous water inlet mode was used. The experimental wastewater was simulated wastewater (for the specific configuration process, see Dapena-Mora, A., Van Hulle, SWH, Luis, Campos J., Mendez, R. Vanrolleghem, PA Jetten, M., 2004. Enrichment of Anammox biomass from municipal activated sludge: experimental and modelling results. J. Chem. Technol. Biotechnol. 79: 1421-1428.). The inlet water was stripped with 95% N2 / 5% CO2 for 5 minutes to remove dissolved oxygen.

[0033] (3) The temperature of the reactor is controlled at 20 ± 1 °C. The nitrogen matrix of the influent is ammonia nitrogen (NH4 + -N) and nitrite nitrogen (NO2 - -N) provides, in which the startup phase NH4 + -N and NO2 - -N concentration was set to 30 ± 2 mg / L, and the hydraulic retention time was set to 20 h.

[0034] During the initial operation of the reactor, from day 1 to day 18, the sludge in the SGSMBR undergoes a transformation phase, during which NO2 - -N is basically removed, and denitrification is the dominant process in this stage. Then, 19-25 days later, the system enters a stagnant period, and the effluent NH4 + -N concentration is close to influent NH4 + -N concentration. Outlet NO2 - -N and NO3 - The concentration of -N showed a significant upward trend compared with the previous stage. The stagnation period lasted only about 6 days, which was shorter than that recorded in other literature. The shortening of the stagnation period was conducive to the rapid start-up of the Anammox process. When the reactor was running for 47 days, the effluent NH4 + -N and NO2 - -N was removed simultaneously, and the average total nitrogen removal efficiency reached 75.19%. The proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm was 57.10%, which showed that the mainstream Anammox process was successfully started and anaerobic ammonium oxidation granular sludge was initially domesticated ( Figure 4 The relative abundance of anaerobic ammonium oxidizing bacteria is about 10%. In the SGSMBR, due to the combination of sludge granulation and membrane filtration, the rapid and effective enrichment of AnAOB is achieved, and the retention rate of functional bacteria is significantly improved, thereby accelerating the rapid start-up of the mainstream Anammox process.

[0035] (4) Then, in the temperature operation stage, the nitrogen load was increased by gradually shortening the hydraulic retention time. When the hydraulic retention time in the experiment was controlled at 16 h, 12 h, 10 h, 8 h, 6 h, 4 h and 3 h, the corresponding inlet flow rates were 8.29×10 -6 m / s, 1.04×10 -5 m / s, 1.38×10 -5 m / s, 1.66×10 -5 m / s, 2.07×10 -5 m / s, 2.76×10 - 5 m / s, 4.15×10 -5 m / s and 5.53×10 -5 m / s, the shorter the hydraulic retention time, the greater the flow rate. The simulated flow rate around the membrane module can be controlled at 4.89×10 -7 m / s~1.30×10 -6 m / s range (see Figure 3 ).

[0036] When the hydraulic retention time was 3 h, the total nitrogen removal efficiency remained above 80 wt% for four consecutive days, and the nitrogen removal rate was 0.49 kg N / (m 3 d) Stable and efficient denitrification performance was achieved, and AnAOB was gradually enriched and mature anaerobic ammonium-oxidizing granular sludge was domesticated (the content of functional anaerobic ammonium-oxidizing bacteria was significantly increased), and the proportion of anaerobic ammonium-oxidizing granules with a particle size of more than 200 μm was 68.96%; During the stable operation stage of the reactor (133 days), SGSMBR achieved the best Anammox denitrification performance (TNRE was 88.31%). During the operation, the performance of the reactor did not fluctuate significantly, and the denitrification performance was relatively stable, indicating that SGSMBR has good resistance to hydraulic load shock.

[0037] After 133 days of operation, the inoculated sludge was successfully domesticated from flocculent aerobic activated sludge to mature anaerobic ammonium oxidation granular sludge, and the horizontal microbial community was found to be Figure 4 , among which the relative abundance of anaerobic ammonia-oxidizing bacteria was above 20%.

[0038] During the operation of SGSMBR, the transmembrane pressure difference in the pressure gauge took more than 32 days to reach 35 kPa. Compared with the submerged MBR in the existing literature (TMP reached 35 kPa in 24 days), the membrane fouling problem has been further alleviated. Granulated sludge improves its sedimentation performance and avoids direct contact between a large amount of flocculent sludge and the submerged membrane assembly, thereby alleviating membrane fouling. At the same time, when the water flows through the membrane assembly, the turbulence generated by the turbulent effect brings a certain shear force, which plays a role in hydraulic scouring, helping to remove pollutants on the surface of the membrane assembly, thereby preventing the membrane pores from clogging. As the flow rate increases, the water flow shear force generated can effectively flush the pollutants on the surface of the membrane assembly, thereby further controlling membrane fouling.

[0039] It can be seen from the above embodiments that the present invention can achieve rapid startup of the mainstream anaerobic ammonium oxidation process, and the time required for startup is 47 days. Compared with the existing mainstream anaerobic ammonium oxidation startup process, the startup time is greatly shortened, and stable operation and high denitrification removal effect can be achieved 133 days after startup, and anaerobic ammonium oxidation granular sludge is successfully cultivated, membrane pollution is also alleviated, and the cost of cleaning and replacing membrane components is greatly saved.

[0040] Comparative Example On the basis of Example 1, another coupled reactor of this laboratory, a fixed bed coupled biological nested filler reactor, was started at the same time to run the mainstream Anammox process of this application as a comparative example. The effective working volume of the main body of the coupled reactor in this comparative example is 2.6L, and the height to outer diameter ratio is 2.5. The reactor body is filled with biological nested fillers, which are made of polyethylene. The cross-section of the filler is annular as a whole, and the annular region is porous. The reactor achieves the retention of functional bacteria through the sludge circulation system and biofilm.

[0041] Comparison results of the two groups of reactors: The startup period of the mainstream Anammox process in the comparative example was about 70 days, which was much longer than the startup period of the mainstream Anammox process in Example 1 (47 days). The total nitrogen removal efficiency in the startup phase was 70.26%, and after 133 days of stable operation, the total nitrogen removal efficiency and nitrogen removal rate reached 82.37% and 0.38 kg N / (m 3 ·d), which are lower than 88.31% and 0.49 kg N / (m 3 ·d).

[0042] The sludge granulation and complete retention of functional bacteria achieved in the device of Example 1 of the present invention accelerate the start-up time of the mainstream Anammox process and improve its efficient and stable denitrification performance.

[0043] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A method for rapid startup and efficient and stable operation of mainstream anaerobic ammonium oxidation, characterized in that: The method uses an immersed anaerobic ammonium oxidation granular sludge membrane bioreactor, the composite reactor includes an upflow anaerobic sludge bed UASB, and an MBR is immersed on the upper part of the upflow anaerobic sludge bed UASB; the height-to-diameter ratio of the UASB is 4-6, the MBR is placed on the top of the UASB, and the overall length of the MBR is 1 / 2-1 / 3 of the height of the UASB; the process of the operation method is: 1) Inoculating aerobic activated sludge from a sewage treatment plant into the submerged anaerobic ammonium oxidation granular sludge membrane biocomposite reactor, the mixed liquor suspended solids concentration is 3.25-4.0 g / L, and the mixed liquor volatile suspended solids concentration is 2.49-3.0 g / L; 2) Mainstream start: Under the condition of constant temperature 20±1℃, set NH4 + -N and NO2 - -N concentration was 30±2 mg / L, and the hydraulic retention time was set to 20 hours. Under the premise of keeping the influent ammonia nitrogen concentration unchanged, the reactor continued to operate at this hydraulic retention time. The sludge granulation and membrane filtration in the reactor were combined to achieve rapid and effective enrichment of AnAOB, and the effluent NH4 + -N and NO2 - -N concentration decreased simultaneously, while the effluent NO3 - -N concentration gradually increased. When the average total nitrogen removal rate (NRE) exceeded 70% and the proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm in the system exceeded 50%, the reactor granulated the sludge, achieving the rapid and successful start-up of the mainstream Anammox process at a lower ammonia nitrogen concentration, and initially domesticated anaerobic ammonium oxidation granular sludge. 3) Stable operation: By gradually shortening the hydraulic retention time and correspondingly increasing the inlet flow rate of UASB, different degrees of turbulence effects can be generated around the membrane components. The turbulence effect is based on not causing particle disintegration and being able to flush pollutants on the surface of the membrane components. Gradually shortening the hydraulic retention time can increase the influent nitrogen load. When the total nitrogen removal efficiency is stabilized at more than 80wt% for four consecutive days at a certain hydraulic retention time, stable and efficient denitrification performance is achieved. Mature anaerobic ammonium oxidation granular sludge is domesticated in the system, and the proportion of anaerobic ammonium oxidation particles with a particle size of more than 200 μm is not less than 60%, achieving stable operation.

2. The operating method according to claim 1, characterized in that: During stable operation, the nitrogen removal efficiency of the system is 0.4 kg N / (m 3 d) or above.

3. The operating method according to claim 1, characterized in that: During the entire experimental operation, the transmembrane pressure difference was tested in real time. It took 32 days for the transmembrane pressure difference of the system to reach 35 kPa, which can alleviate membrane fouling.

4. The operating method according to claim 1, characterized in that: The inlet diameter of the UASB is 8 mm, the height of the UASB is 45 cm, and the inner diameter is 10 cm. During the stable operation stage, the hydraulic retention time is controlled at 16 h, 12 h, 10 h, 8 h, 6 h, 4 h, and 3 h, respectively, and the corresponding inlet flow rates are 8.29×10 -6 m / s, 1.04×10 -5 m / s, 1.38×10 -5 m / s, 1.66×10 -5 m / s, 2.07×10 -5 m / s, 2.76×10 -5 m / s, 4.15×10 -5 m / s and 5.53×10 -5 m / s.

5. The operating method according to claim 1, characterized in that: The MBR is an O-type hollow fiber membrane component or a modified O-type hollow fiber membrane component.

6. A submerged anaerobic ammonium oxidation granular sludge membrane bioreactor coupling device, characterized in that: It includes a water inlet system, an immersed anaerobic ammonium oxidation granular sludge membrane biocomposite reactor, a water bath circulation system, a water seal structure and a water outlet system; The water inlet system includes a water inlet box, a water inlet pipe and a water inlet pump, and the water outlet system includes a water outlet, a water outlet pipe, a water outlet pump and a water outlet box; The composite reactor comprises an upflow anaerobic sludge blanket UASB, and an MBR is immersed in the upper part of the upflow anaerobic sludge blanket UASB; the height-to-diameter ratio of the UASB is 4-6, the MBR is placed on the top of the UASB, and the overall length of the MBR is 1 / 2-1 / 3 of the height of the UASB; The UASB is used to achieve sludge granulation, and the MBR is used to achieve complete microbial retention. The UASB includes an inner tube and an outer tube, and a water bath circulation system is provided between the inner tube and the outer tube. The water bath circulation system consists of a water bath inlet, a water bath outlet, a water bath water inlet pipe, a water bath water inlet pump, a water bath pool, and a temperature controller. The column space of the inner tube is the main reaction zone, and a gas exhaust port is provided at the top of the main reaction zone. The gas exhaust port is connected by an exhaust pipe, and the exhaust pipe is connected to a water seal structure. The main reaction zone is provided with a water outlet of an O-type membrane assembly at the top, and the water outlet is connected to a water outlet pipe, and water is sucked by a water outlet pump, and the sucked water is sent to a water outlet tank. A pressure gauge is connected in front of the water outlet pump to record membrane pollution. The lower part of the UASB is a funnel-shaped sludge hopper, and a water inlet is provided at the bottom of the sludge hopper. The water inlet is connected to the water inlet tank through a water inlet pump and a water inlet pipe.

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