A quick start-up device and method for anaerobic ammonium oxidation process

Abstract

The invention discloses a rapid start-up device and method for an anaerobic ammonium oxidation process, which mainly includes a traditional anaerobic ammonium oxidation reactor, an anaerobic dynamic membrane bioreactor and a dynamic membrane backwashing automatic control system; the traditional anaerobic ammonium oxidation reactor mainly includes an inlet tank, an inlet pump, a reactor body I, an outlet tank I, an exhaust unit and a water bath circulation unit; the anaerobic dynamic membrane bioreactor mainly includes an intermediate inlet pump, a reactor body II, a dynamic membrane assembly, a pressure gauge, an outlet pump, an outlet tank II and a backwashing air pump; the outlet water of the traditional anaerobic ammonium oxidation reactor is connected to the anaerobic dynamic membrane bioreactor pipeline through the intermediate inlet pump; the dynamic membrane backwashing automatic control system is connected to the intermediate inlet pump, the pressure gauge, the outlet pump and the backwashing air pump. The advantages of the invention are mainly reflected in: it can reduce the substrate concentration in the outlet water to the maximum extent, reduce the startup drug consumption; realize the effective enrichment of the bacterial flora, and accelerate the start-up of the anaerobic ammonium oxidation process; the construction cost is low, and the operation and control are simple.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment, relates to biological denitrification of wastewater, and particularly relates to a rapid start-up device and method for an anaerobic ammonia oxidation process. Background Art

[0002] Anaerobic ammonium oxidation is a new type of biological denitrification process that can oxidize ammonia nitrogen into nitrogen gas under anaerobic conditions using nitrite as an electron acceptor, thereby achieving the simultaneous removal of two nitrogen pollutants. Compared with traditional biological denitrification processes, anaerobic ammonium oxidation has the advantages of good denitrification effect, no need for oxygen and external organic carbon source, low operating cost, etc., and has broad prospects for industrial application. However, the doubling time of anaerobic ammonium oxidizing bacteria is long, resulting in a long start-up time for the anaerobic ammonium oxidation process, which limits its large-scale industrial application. At present, relevant studies have shown that anaerobic ammonium oxidation sludge can be mixed with other activated sludges as inoculated sludge to quickly start the anaerobic ammonium oxidation process. However, for the start-up of large-scale industrial anaerobic ammonium oxidation processes, limited anaerobic ammonium oxidation bacteria are still the biggest limiting factor.

[0003] Bioreactors for enriching anaerobic ammonium-oxidizing bacteria include upflow anaerobic sludge blanket reactors (UASB), expanded anaerobic granular sludge beds (EGSB), and sequencing batch bioreactors (SBR), but there is still a phenomenon of strain loss during the enrichment culture process. This undoubtedly further prolongs the startup time of the anaerobic ammonium oxidation process. In addition, during the startup of the anaerobic ammonium oxidation process, due to the small number of anaerobic ammonium-oxidizing bacteria in the reactor, there are still a large amount of residual ammonia nitrogen and nitrite nitrogen in the reactor effluent. Reusing them to the front section of the reactor will cause large fluctuations in the influent, which is not conducive to the stable operation of the reactor and increases the complexity of operation monitoring. Therefore, how to achieve effective enrichment of anaerobic ammonium-oxidizing bacteria, reduce the concentration of ammonia nitrogen and nitrite nitrogen in the effluent, and minimize the startup time of the anaerobic ammonium oxidation process is a key issue that needs to be solved for the large-scale industrial application of the anaerobic ammonium oxidation process. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a rapid start-up device and method for an anaerobic ammonium oxidation process, which can achieve effective enrichment and retention of the bacterial flora and rapid start-up of the anaerobic ammonium oxidation process; avoid substrate loss, minimize the concentration of ammonia nitrogen and nitrite nitrogen in the effluent, and save the cost of drug consumption in the startup phase; at the same time, the startup device has low construction cost and simple operation and control.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A quick start device for an anaerobic ammonium oxidation process comprises a conventional anaerobic ammonium oxidation reactor, an anaerobic dynamic membrane bioreactor and a dynamic membrane backwashing automatic control system, wherein the anaerobic dynamic membrane bioreactor comprises a reactor body II with a dynamic membrane assembly, the outlet water of the conventional anaerobic ammonium oxidation reactor is connected to the reactor body II pipeline via an intermediate water inlet pump, the outlet water of the dynamic membrane assembly is connected to the outlet water tank II pipeline via an outlet water pump, a pressure gauge is arranged on the connecting pipeline, and the dynamic membrane assembly is also connected to a backwashing air pump; the dynamic membrane backwashing automatic control system is respectively connected to the intermediate water inlet pump, the pressure gauge, the outlet water pump and the backwashing air pump, and determines whether to start the backwashing air pump to perform air backwashing on the dynamic membrane assembly according to the pressure gauge.

[0007] Preferably, the conventional anaerobic ammonium oxidation reactor mainly comprises an inlet tank, an inlet pump, a reactor body I, an outlet tank I, an exhaust unit, a thermostatic tank and a water bath circulation pump, wherein the exhaust unit, the thermostatic tank and the water bath circulation pump are shared by the conventional anaerobic ammonium oxidation reactor and the anaerobic dynamic membrane bioreactor.

[0008] Preferably, the effective volume ratio of the conventional anaerobic ammonium oxidation reactor to the anaerobic dynamic membrane bioreactor is 1:5-10.

[0009] Preferably, the conventional anaerobic ammonium oxidation reactor is an upflow anaerobic sludge blanket reactor (UASB), an anaerobic expanded granular sludge bed (EGSB) or a sequencing batch reactor (SBR).

[0010] Preferably, the dynamic membrane assembly is rectangular or cylindrical, and the membrane material is nylon mesh or stainless steel mesh; the pore size of the membrane material is 30-50 μm.

[0011] Preferably, the outlet pump of the anaerobic dynamic membrane bioreactor is controlled by constant flow; the membrane flux of the dynamic membrane module is 10-60L / m 2 / h, the effluent turbidity is 0.01-5.0NTU.

[0012] The present invention also provides a quick start method based on the quick start device of the anaerobic ammonium oxidation process, wherein the wastewater first enters a conventional anaerobic ammonium oxidation reactor, reacts in the conventional anaerobic ammonium oxidation reactor, and then the effluent enters an anaerobic dynamic membrane bioreactor for another reaction, and the dynamic membrane backwashing automatic control system obtains the pressure data of the pressure gauge in real time. When the pressure gauge value is greater than 40 kPa, the intermediate water inlet pump and the water outlet pump are first stopped, and then the backwashing air pump is turned on for air backwashing; the air backwashing intensity is 5-12 N m 3 / h, the air washing time is 30-180 seconds; when the air backwashing is finished, first stop the backwashing air pump, then start the intermediate water inlet pump and the water outlet pump to resume normal operation.

[0013] Preferably, in the startup stage of the anaerobic ammonium oxidation process, the inoculum sludge of the conventional anaerobic ammonium oxidation reactor is a mixture of mature anaerobic ammonium oxidation sludge and ordinary activated sludge; the inoculum sludge of the anaerobic dynamic membrane bioreactor is one or more of aerobic nitrification sludge, denitrification sludge and methanogenic sludge.

[0014] Preferably, the influent matrix of the conventional anaerobic ammonium oxidation reactor comprises ammonia nitrogen, nitrite nitrogen, inorganic salts and trace elements; wherein the molar ratio of ammonia nitrogen to nitrite nitrogen is 1:1-1.32; the nitrite nitrogen concentrations in the influent and effluent of the conventional anaerobic ammonium oxidation reactor are 126-280 mg N / L and 30-100 mg N / L, respectively.

[0015] Preferably, when the residual substrate in the effluent of the conventional anaerobic ammonium oxidation reactor is far lower than the treatment load of the anaerobic dynamic membrane bioreactor, the load is increased by increasing the influent substrate or shortening the hydraulic retention time to fully supply the substrate required for the proliferation of anaerobic ammonium oxidizing bacteria.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] ① It can avoid the loss of substrate, minimize the concentration of substrate in the effluent, and save the cost of drug consumption in the startup phase.

[0018] ② Realize effective enrichment and retention of bacterial flora and achieve rapid start-up of anaerobic ammonium oxidation process.

[0019] ③Low construction cost and easy operation and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structural principle of the present invention; wherein, the solid arrow represents the direction of water flow; and the hollow arrow represents the direction of air flow. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0022] like Figure 1 As shown, the device mainly includes a traditional anaerobic ammonium oxidation reactor 1, an anaerobic dynamic membrane bioreactor 2 and a dynamic membrane backwashing automatic control system 3.

[0023] Among them, the conventional anaerobic ammonium oxidation reactor 1 selects an upflow anaerobic sludge blanket reactor (UASB), which mainly includes an inlet tank 11, an inlet pump 12, a reactor body I 13, an outlet tank I 14, an exhaust unit 15, a thermostatic tank 16 and a water bath circulation pump 17. The anaerobic dynamic membrane bioreactor 2 mainly includes an intermediate inlet pump 21, a reactor body II 22, a dynamic membrane assembly 23, a pressure gauge 24, an outlet pump 25, an outlet tank II 26 and a backwash air pump 27. The effective volume ratio of the conventional anaerobic ammonium oxidation reactor 1 to the anaerobic dynamic membrane bioreactor 2 is 1:5.5.

[0024] Both the reactor body I 13 and the reactor body II 22 are double-layer structures. The dynamic membrane component 23 is in the inner layer of the reactor body II 22. The dynamic membrane component 23 is rectangular, the membrane material is nylon mesh, the pore size is 50 μm, and the membrane area is 0.02 m 2 , membrane flux is 11.3L / m 2 / h.

[0025] The wastewater is sent into the inner layer of the reactor body I 13 (sent in from the bottom) through the water inlet tank 11 and the water inlet pump 12 for anaerobic ammonia oxidation reaction. The effluent after the reaction is sent into the water outlet tank I 14, and then sent into the inner layer of the reactor body II 22 (sent in from the bottom) through the intermediate water inlet pump 21, and the anaerobic ammonia oxidation reaction continues in the inner layer of the reactor body II 22.

[0026] The thermostatic tank 16 delivers water to the outer layer of the reactor body I 13 through the water bath circulation pump 17 to realize the constant temperature control of the reaction process, and the constant temperature water of the outer layer of the reactor body I 13 is then delivered to the outer layer of the reactor body II 22, and finally returns to the thermostatic tank 16 to realize circulation. That is, the conventional anaerobic ammonia oxidation reactor 1 and the anaerobic dynamic membrane bioreactor 2 share the exhaust unit 15, the thermostatic tank 16 and the water bath circulation pump 17.

[0027] After the reaction in the reactor body I 13, the gas generated during the reaction is sent to the exhaust unit 15 and then discharged to the outside or sent to the dynamic membrane assembly 23 for gas washing through the backwashing gas pump 27 during backwashing.

[0028] After the effluent of the reactor body I 13 reacts in the dynamic membrane assembly 23, the effluent is sent to the effluent tank II 26 through the effluent pump 25, and the effluent pressure is monitored by the pressure gauge 24, wherein the effluent pump 25 is a constant flow control, and the effluent turbidity is initially 5.0 NTU and gradually decreases to 0.01 NTU. The gas generated by the reaction is directly discharged into the exhaust unit 15, and then discharged or sent to the dynamic membrane assembly 23 for gas washing through the backwashing gas pump 27 during backwashing.

[0029] The dynamic membrane backwashing automatic control system 3 is connected to the intermediate water inlet pump 21, the pressure gauge 24, the water outlet pump 25 and the backwashing air pump 27 respectively. It determines whether to perform air backwashing on the dynamic membrane assembly 23 according to the pressure gauge 24. When the pressure gauge value is greater than 40 kPa, the intermediate water inlet pump 21 and the water outlet pump 25 are stopped first, and then the backwashing air pump 27 is turned on for air backwashing; the air backwashing intensity is 7 N m 3 / h, the air washing time is 60 seconds; when the air backwashing is finished, the backwashing air pump 27 is stopped first, and then the intermediate water inlet pump 21 and the water outlet pump 25 are turned on to resume normal operation.

[0030] In the present invention, at the start-up stage of the anaerobic ammonium oxidation process, the inoculated sludge of the UASB reactor is a mixture of anaerobic ammonium oxidation sludge and ordinary activated sludge; the influent matrix includes ammonia nitrogen, nitrite nitrogen, inorganic salts and trace elements; the molar ratio of ammonia nitrogen to nitrite nitrogen is 1:1; the nitrite nitrogen concentrations in the influent and effluent of the UASB reactor are 126 mg N / L and 30-35 mg N / L respectively. The inoculated sludge of the anaerobic dynamic membrane bioreactor 2 is a mixed sludge of aerobic nitrification sludge and denitrification sludge.

[0031] After 48 days of enrichment culture, the removal molar ratio of ammonia nitrogen and nitrite nitrogen in dynamic membrane bioreactor 2 was 1.05 ± 0.12 mol mol -1 , removal load is 1.46g / m 3 / h, and the effluent ammonia nitrogen concentration is 0.1mg N / L.

Claims

1. A method for quickly starting up a quick start-up device for an anaerobic ammonium oxidation process, the quick start-up device for the anaerobic ammonium oxidation process comprising a conventional anaerobic ammonium oxidation reactor (1), an anaerobic dynamic membrane bioreactor (2) and a dynamic membrane backwashing automatic control system (3), the conventional anaerobic ammonium oxidation reactor (1) comprising a water inlet tank (11), a water inlet pump (12), a reactor body I (13), a water outlet tank I (14), an exhaust unit (15), a thermostatic bath (16) and a water bath circulation pump (17), wherein: The exhaust unit (15), the thermostatic tank (16) and the water bath circulation pump (17) are shared by the conventional anaerobic ammonium oxidation reactor (1) and the anaerobic dynamic membrane bioreactor (2); the anaerobic dynamic membrane bioreactor (2) comprises a reactor body II (22) with a dynamic membrane assembly (23); the effluent of the conventional anaerobic ammonium oxidation reactor (1) is connected to the reactor body II (22) through an intermediate water inlet pump (21); the outlet of the dynamic membrane assembly (23) is connected to the outlet tank II (22) through an outlet pump (25). (26) is connected with a pipeline, and a pressure gauge (24) is arranged on the connecting pipeline, and the dynamic membrane assembly (23) is also connected with a backwashing air pump (27); the dynamic membrane backwashing automatic control system (3) is respectively connected with the intermediate water inlet pump (21), the pressure gauge (24), the water outlet pump (25) and the backwashing air pump (27), and determines whether to start the backwashing air pump (27) to perform air backwashing on the dynamic membrane assembly (23) according to the pressure gauge (24). The effective volume ratio of the conventional anaerobic ammonium oxidation reactor (1) to the anaerobic dynamic membrane bioreactor (2) is 1:5-10. In the start-up stage of the anaerobic ammonium oxidation process, The inoculated sludge of the conventional anaerobic ammonium oxidation reactor (1) is a mixture of mature anaerobic ammonium oxidation sludge and ordinary activated sludge; the inoculated sludge of the anaerobic dynamic membrane bioreactor (2) is one or more of aerobic nitrification sludge, denitrification sludge and methanogenic sludge; the wastewater first enters the conventional anaerobic ammonium oxidation reactor (1), reacts in the conventional anaerobic ammonium oxidation reactor (1), and then the effluent enters the anaerobic dynamic membrane bioreactor (2) to react again, and the dynamic membrane backwashing automatic control system (3) obtains the pressure data of the pressure gauge (24) in real time. When the pressure gauge value is greater than 40 kPa, the intermediate water inlet pump (21) and the water outlet pump (25) are first stopped, and then the backwashing air pump (27) is turned on to perform air backwashing; the air backwashing intensity is 5-12 N m 3 / h, the air washing time is 30-180 seconds; when the air backwashing is finished, the backwashing air pump (27) is stopped first, and then the intermediate water inlet pump (21) and the water outlet pump (25) are turned on to resume normal operation.

2. The rapid start-up method of the rapid start-up device of the anaerobic ammonium oxidation process according to claim 1, characterized in that: The influent matrix of the conventional anaerobic ammonium oxidation reactor (1) comprises ammonia nitrogen, nitrite nitrogen, inorganic salts and trace elements; wherein the molar ratio of ammonia nitrogen to nitrite nitrogen is 1:1-1.32; and the nitrite nitrogen concentrations in the influent and effluent of the conventional anaerobic ammonium oxidation reactor (1) are 126-280 mg N / L and 30-100 mg N / L, respectively.

3. The rapid start-up method of the rapid start-up device of the anaerobic ammonium oxidation process according to claim 1, characterized in that: When the residual substrate in the effluent of the conventional anaerobic ammonium oxidation reactor (1) is much lower than the treatment load of the anaerobic dynamic membrane bioreactor (2), the load is increased by increasing the influent substrate or shortening the hydraulic retention time, thereby fully supplying the substrate required for the proliferation of anaerobic ammonium oxidizing bacteria.

4. The rapid start-up method of the rapid start-up device of the anaerobic ammonium oxidation process according to claim 1, characterized in that: The conventional anaerobic ammonium oxidation reactor (1) is an upflow anaerobic sludge blanket reactor, an anaerobic granular sludge expanded bed or a sequencing batch reactor.

5. The rapid start-up method of the rapid start-up device of the anaerobic ammonium oxidation process according to claim 1, characterized in that: The dynamic membrane component (23) is rectangular or cylindrical, and the membrane material is a nylon mesh or a stainless steel mesh; the pore size of the membrane material is 30-50 μm.

6. The rapid start-up method of the rapid start-up device of the anaerobic ammonium oxidation process according to claim 1, characterized in that: The outlet pump (25) of the anaerobic dynamic membrane bioreactor (2) is controlled by constant flow; the membrane flux of the dynamic membrane assembly (23) is 10-60 L / m 2 / h, and the effluent turbidity is 0.01-5.0 NTU.

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