Spiral symmetric flow anaerobic membrane bio-membrane reactor system

Abstract

The invention discloses a spiral symmetrical flow anaerobic membrane bio-membrane reactor system, which comprises a spiral symmetrical flow anaerobic reactor and a membrane aeration bio-membrane reactor, the spiral symmetrical flow anaerobic reactor is sequentially provided with a water inlet pump, a water inlet pipe, a first anaerobic reaction zone, a second anaerobic reaction zone, a third anaerobic reaction zone, a main gas outlet pipe and a water outlet pipe from bottom to top; the membrane aeration bio-membrane reactor is sequentially provided with a water inlet pump, a water inlet pipe, an MABR third reaction zone, an MABR second reaction zone, an MABR first reaction zone, a membrane assembly, an air inlet assembly and a water outlet pipe from bottom to top. According to the invention, gas-liquid interaction among multiple reaction intervals is realized through the gas pump and the liquid pump, precise regulation and control of gas partial pressure and reflux flow are realized, and the system has the characteristics of enhancing mass transfer driving force, improving methane yield, optimizing denitrification efficiency and the like, so that the system can adopt a green and low-carbon water treatment route, and meanwhile, efficient and intensive reactor combination is realized.

Description

Technical Field

[0001] The invention relates to a spiral symmetrical flow anaerobic membrane biofilm reactor system, belonging to the technical field of wastewater treatment. Background Art

[0002] According to the China Ecological Environment Statistical Yearbook, chemical oxygen demand (COD) emissions from industries like textiles and papermaking in my country reached 58,000 and 52,000 tons, respectively, in 2023. The wastewater from these industries is typically sulfur-rich, high-concentration organic wastewater, containing a variety of aromatic compounds and sodium sulfonates, which produce a large number of polar groups such as sulfonic acid groups (-SO3-). Sulfate concentrations in this wastewater can reach over 600 mg / L, COD concentrations can range from 1,505 to 10,000 mg / L, and total nitrogen concentrations can reach 200 to 1,892 mg / L. This wastewater is difficult to treat and poses a significant threat to humans and the environment without effective treatment.

[0003] Anaerobic reactors are commonly used to treat sulfur-rich, high-concentration organic wastewater. However, during anaerobic digestion, these wastewaters, due to their high sulfur content, tend to produce H2S, which inhibits microbial activity, and due to their high carbon content, tend to produce organic acids, which pose a risk of system acidification. Existing single anaerobic reactors (such as UASB and IC) and the spiral symmetrical flow anaerobic reactor invented by the applicant often suffer from system instability, acidification, and reduced efficiency. Therefore, innovation in the structure and equipment system of anaerobic reactors is particularly critical.

[0004] The increase of ORP can promote the 2- Oxidation process, studies have shown that when ORP is -340mV and 260mV, S 2- The main oxidation products are S 0 and SO4 2- The oxidizing bacteria can use oxygen to oxidize H2S into high-valent sulfides, thereby alleviating the problem of H2S accumulation. At the same time, the increase in ORP can also enable the oxidizing bacteria to oxidize CH4 into CO2, alleviating the problem of dissolved methane accumulation. The introduction of the generated CO2 into the anaerobic reactor can regulate the three-stage anaerobic process and improve the efficiency of the anaerobic reactor. Based on this, the applicant integrated the existing invention patent spiral symmetric flow anaerobic reactor (SSSAB, invention patent authorization number: ZL201210054218.6) with the membrane aeration biofilm reactor, innovating new technologies, new ideas, and new processes to obtain an efficient and stable treatment system, thereby inventing the spiral symmetric flow anaerobic membrane biofilm reactor system.

[0005] Studies have shown that methane-oxidizing bacteria in MABR can oxidize CH4 and H2S, alleviating the accumulation of dissolved methane and hydrogen sulfide. The sulfide produced during the process can also selectively inhibit nitrite-oxidizing bacteria, allowing ammonia-oxidizing bacteria to stably oxidize ammonia nitrogen to NO.2- , to achieve long-term stable operation of the ammonia oxidation process in MABR.

[0006] In addition, studies have shown that when the CO2 concentration in the digestate is ≥2.0±0.2mmol / L, it can promote CH4 production, while at low CO2 concentrations (0.9mmol / L), it will promote acetate production. Therefore, by regulating the liquid reflux flow rate between the first, second, and third reaction zones of the MABR and the first, second, and third anaerobic reactors of the SSSAB (usually 1:2 to 1:4), and regulating the air flow rate of the SSSAB gas produced into the MABR (usually 0.5 to 2.0L / min), the adaptability and stability of the anaerobic system to sulfur-rich organic wastewater can be improved, thereby improving the carbon removal and denitrification efficiency. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a spiral symmetrical flow anaerobic membrane biofilm reactor system, integrate SSSAB and MABR, realize an efficient and intensive reactor combination, and achieve precise control of the reaction area, gas partial pressure and reflux liquid flow rate, thereby enhancing the mass transfer driving force, improving methane yield and optimizing denitrification efficiency, and realizing a green and low-carbon water treatment route.

[0008] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0009] The application discloses a spiral symmetric flow anaerobic membrane biofilm reactor system, which comprises a spiral symmetric flow anaerobic reactor (SSSAB) and a membrane aerated biofilm reactor (MABR); the bottom of the spiral symmetric flow anaerobic reactor is provided with an SSSAB water inlet pipe, the SSSAB water inlet pipe is connected with an SSSAB water inlet pump, the top of the spiral symmetric flow anaerobic reactor is provided with a three-phase separation zone and an SSSAB water outlet pipe, the SSSAB water outlet pipe is communicated with a sedimentation tank, the gas phase outlet of the three-phase separation zone is connected with a total gas outlet pipe, the total gas outlet pipe is communicated with a gas storage tank through an external gas exhaust valve or an endogenous biogas gas valve, and the middle part of the spiral symmetric flow anaerobic reactor is sequentially provided with a first anaerobic reaction zone, a second anaerobic reaction zone and a third anaerobic reaction zone from bottom to top; the lower parts of the first anaerobic reaction zone, the second anaerobic reaction zone and the third anaerobic reaction zone are respectively provided with a first reflux water inlet pipe, a second reflux water inlet pipe and a third reflux water inlet pipe; and the upper parts of the first anaerobic reaction zone, the second anaerobic reaction zone and the third anaerobic reaction zone are respectively provided with a first gas outlet pipe, a second gas outlet pipe and a third gas outlet pipe.

[0010] Preferably, the upper parts of the first anaerobic reaction zone, the second anaerobic reaction zone and the third anaerobic reaction zone are respectively provided with a first spiral elliptical baffle, a second spiral elliptical baffle and a third spiral elliptical baffle.

[0011] More preferably, the first spiral elliptical baffle, the third spiral elliptical baffle and the second spiral elliptical baffle are symmetrically arranged along the central axis of the spiral symmetric flow anaerobic reactor.

[0012] Preferably, the first backflow pump, the second backflow pump and the third backflow pump are connected with the first backflow inlet pipe, the second backflow inlet pipe and the third backflow inlet pipe through the first backflow valve, the second backflow valve and the third backflow valve respectively.

[0013] Preferably, the air inlet assembly comprises an oxygen gas pump and an endogenous biogas gas pump in communication with the gas storage tank, and the oxygen gas pump and the endogenous biogas gas pump are in communication with the membrane assembly through a tee joint.

[0014] Preferably, the first anaerobic reaction zone, the second anaerobic reaction zone and the third anaerobic reaction zone are located at 2 / 5, 3 / 5 and 4 / 5 of the height of the spiral symmetric flow anaerobic reactor respectively, and are used for hydrolysis acidification, hydrogen production and acetic acid production and methane production respectively.

[0015] Preferably, the MABR third reaction zone, the MABR second reaction zone and the MABR first reaction zone are located at 1 / 3, 2 / 3 and 3 / 3 of the height of the membrane aerated biofilm reactor respectively, and the dissolved oxygen concentration and the oxidation-reduction potential (ORP) of the three reaction zones increase from top to bottom.

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

[0017] Firstly, in the present application, the excess dissolved CH4 in the SSSAB is oxidized in the MABR to CO2, which alleviates the problem of excessive VFAs production caused by the accumulation of dissolved CH4 in the SSSAB; the redundant VFAs in the SSSAB are used to solve the problem of inhibition of nitrifying bacteria and nitrite-oxidizing bacteria activity caused by excessive alkalinity in the MABR; the dissolved H2S in the SSSAB is oxidized by sulfur-oxidizing bacteria in the MABR, which solves the problem of microbial activity decline caused by the accumulation of dissolved H2S in the SSSAB; the dissolved H2S in the SSSAB is dissociated into HS - and S 2- in the alkaline environment of the MABR, which further inhibits the nitrite-oxidizing bacteria in the MABR, reduces the production of NO 3- , and solves the problem of instability in the ammonia oxidation process.

[0018] Secondly, in the present application, the backflow rate of the first reaction zone of the MABR is regulated (backflow ratio ≈ 1:4), the ORP of the first anaerobic reaction zone is controlled (about -150-100 mV), and the hydrolysis acidification process is controlled. At the same time, the dissolved H2S in the SSSAB is oxidized to sulfate, which alleviates the problem of microbial activity decline caused by the accumulation of dissolved H2S in the SSSAB.

[0019] Third, the present invention regulates the reflux flow rate of the MABR second reaction zone (reflux ratio ≈ 1:4) to control the ORP of the second anaerobic reaction zone to an appropriate level (approximately -250 to -150 mV), thereby controlling the hydrogen and acetic acid production processes. By introducing CO2 produced by oxidation in the MABR second reaction zone into the second anaerobic reaction zone and regulating the CO2 concentration in the second anaerobic reaction zone (≥ 0.8 mmol / L), both the hydrogenotrophic and acetic acid fermentation methanogenesis pathways are regulated.

[0020] In addition, the alkalinity produced in the second reaction zone of MABR can be used to neutralize the VFAs produced in the second anaerobic reaction zone of SSSAB, which will further increase the alkalinity of the SSSAB bed.

[0021] Fourth, the present invention controls the third anaerobic reaction zone to an appropriate ORP (approximately -400 to -250 mV) by regulating the reflux flow rate of the MABR third reaction zone (reflux ratio ≈1:2). At the same time, the CO2 produced by the oxidation of CH4 in the MABR third reaction zone is introduced into the third anaerobic reaction zone, which can increase the CO2 concentration in the third anaerobic reaction zone (≈0.8 mmol / L), improve the activity of methanogens, and promote the conversion of CO2 by methanogens, thereby promoting the methanogenesis process in the third anaerobic reaction zone. In addition, the third anaerobic reaction zone is the most acidified. The alkalinity generated by the third MABR reaction zone is used to neutralize the large amount of VFAs produced in the third anaerobic reaction zone, solving the problem of methanogen inactivation caused by SSSAB acid accumulation.

[0022] Fifth, the present invention regulates the reflux flow of the first reaction zone of MABR, the second reaction zone of MABR and the third reaction zone of MABR to obtain a suitable carbon-nitrogen ratio in the equipment system (the carbon-nitrogen ratio in MABR is about 10 to 30), thereby promoting the efficient removal of COD and ammonia nitrogen by SSSAB and MABR.

[0023] Sixth, in the present invention, the endogenous biogas generated by SSSAB is introduced into MABR, and the endogenous biogas is used to promote the CH4 oxidation and anaerobic ammonium oxidation process inside the MABR, thereby promoting denitrification.

[0024] Seventh, in the present invention, endogenous biogas and exogenous oxygen are introduced separately or simultaneously by controlling the endogenous biogas pump and the oxygen pump, and the flow rate of endogenous biogas entering the MABR is controlled (≈0.5~2.0L / min), thereby improving the activity of anaerobic bacteria in the MABR, promoting the mass transfer driving force in the MABR, and improving the COD and ammonia nitrogen removal rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the spiral symmetric flow anaerobic membrane biofilm reactor system provided by the present invention. DETAILED DESCRIPTION

[0026] To make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0027] Example

[0028] like Figure 1 , which is a schematic diagram of the spiral symmetric flow anaerobic membrane biofilm reactor system provided in this embodiment, which includes a spiral symmetric flow anaerobic reactor I and a membrane aeration biofilm reactor II.

[0029] The basic structure of the spiral symmetrical flow anaerobic reactor I can adopt the spiral symmetrical flow anaerobic reactor of Chinese invention patent number: ZL201210054218.6. The bottom of the spiral symmetrical flow anaerobic reactor I is provided with an SSSAB water inlet pipe 2, which is connected to the SSSAB water inlet pump 1. The top of the spiral symmetrical flow anaerobic reactor I is provided with a three-phase separation zone 11 and an SSSAB water outlet pipe 10, which is connected to the sedimentation tank 27. The gas phase outlet of the three-phase separation zone 11 is connected to the main gas outlet pipe 12, which discharges gas through an external exhaust valve 13 or is connected to a gas storage tank 15 through an internal biogas valve 14. The middle part of the rotationally symmetrical flow anaerobic reactor is provided with a first anaerobic reaction zone A, a second anaerobic reaction zone B, and a third anaerobic reaction zone C from bottom to top. The lower parts of the first anaerobic reaction zone A, the second anaerobic reaction zone B, and the third anaerobic reaction zone C are respectively provided with a first return water inlet pipe 24, a second return water inlet pipe 5, and a third return water inlet pipe 18. The upper parts of the first anaerobic reaction zone A, the second anaerobic reaction zone B, and the third anaerobic reaction zone C are respectively provided with a first gas outlet pipe 22, a second gas outlet pipe 8, and a third gas outlet pipe 16.

[0030] The bottom of the membrane aeration biofilm reactor II is provided with a MABR water inlet pipe 29, the MABR water inlet pipe 29 is communicated with the supernatant in the sedimentation tank 27 through a MABR water inlet pump 28, the top of the membrane aeration biofilm reactor II is provided with a MABR water outlet pipe 41, the membrane aeration biofilm reactor II is provided with a membrane assembly 40, the top of the membrane assembly 40 is communicated with the gas inlet assembly outside the membrane aeration biofilm reactor II, the membrane assembly 40 is sequentially provided with a MABR first reaction zone a, a MABR second reaction zone b and a MABR third reaction zone c from top to bottom, the upper part of the MABR first reaction zone a, the MABR second reaction zone b and the MABR third reaction zone c is respectively provided with a first gas pipe 36, a second gas pipe 42 and a third gas pipe 43, the first gas pipe 36, the second gas pipe 42 and the third gas pipe 43 are respectively communicated with the first jet pipe 35, the second jet pipe 33 and the third jet pipe 31 at the end of the first gas outlet pipe 22, the second gas outlet pipe 8 and the third gas outlet pipe 16 through the third gas valve 17, the second gas valve 7 and the first gas valve 23, the lower part of the MABR first reaction zone a, the MABR second reaction zone b and the MABR third reaction zone c is respectively provided with a first reflux water outlet pipe 34, a second reflux water outlet pipe 32 and a third reflux water outlet pipe 30, the first reflux water outlet pipe 34, the second reflux water outlet pipe 32 and the third reflux water outlet pipe 30 are respectively communicated with the first reflux water inlet pipe 24, the second reflux water inlet pipe 5 and the third reflux water inlet pipe 18 through the first reflux pump 26, the second reflux pump 3 and the third reflux pump 20.

[0031] The top of the first anaerobic reaction zone A, the second anaerobic reaction zone B and the third anaerobic reaction zone C is respectively provided with a first spiral elliptical baffle 21, a second spiral elliptical baffle 6 and a third spiral elliptical baffle 9.

[0032] The first reflux pump 26, the second reflux pump 3 and the third reflux pump 20 are respectively connected with the first reflux water inlet pipe 24, the second reflux water inlet pipe 5 and the third reflux water inlet pipe 18 through the first reflux valve 25, the second reflux valve 4 and the third reflux valve 19.

[0033] The gas inlet assembly comprises an oxygen gas pump 39 and an endogenous biogas pump 37 communicated with the gas storage tank 15, the oxygen gas pump 39 and the endogenous biogas pump 37 are communicated with the membrane assembly 40 through a three-way pipe 38.

[0034] The first anaerobic reaction zone A, the second anaerobic reaction zone B and the third anaerobic reaction zone C are respectively located at 2 / 5, 3 / 5 and 4 / 5 of the height of the spiral symmetric flow anaerobic reactor I, and are respectively used for hydrolysis acidification, hydrogen production and acetic acid production and methane production.

[0035] The MABR third reaction zone c, MABR second reaction zone b, and MABR first reaction zone a are respectively located at 1 / 3, 2 / 3, and 3 / 3 of the height of the membrane aerated biofilm reactor II. The dissolved oxygen concentrations in the three reaction zones increase from top to bottom, and the redox potential increases accordingly.

[0036] The methane oxidizing bacteria in the MABR oxidize the excess dissolved CH4 in the SSSAB into CO2, alleviating the problem of excessive production of volatile fatty acids (VFAs) caused by the accumulation of dissolved CH4 in the SSSAB; the redundant VFAs in the SSSAB are used to solve the problem of excessive alkalinity in the MABR inhibiting the activity of nitrifying bacteria and nitrite oxidizing bacteria. The sulfur oxidizing bacteria in the MABR oxidize the dissolved H2S in the effluent of the SSSAB, solving the problem of decreased microbial activity caused by the accumulation of dissolved H2S in the SSSAB; the dissolved H2S in the SSSAB is dissociated into HS in the alkaline environment of the MABR. - and S 2- , thereby inhibiting nitrite oxidizing bacteria in MABR and reducing NO 3- The production of ammonia can solve the problem of instability in the ammonia oxidation process.

[0037] The reaction liquid from the MABR's first reaction zone flows out through the first reflux effluent pipe and is pumped into the first reflux inlet pipe by the first reflux pump, entering the first anaerobic reaction zone. The reflux ratio is controlled by the first reflux pump. The first anaerobic reaction zone primarily focuses on hydrolysis and acidification, requiring a relatively low ORP. Therefore, by regulating the reflux flow rate in the MABR's first reaction zone (reflux ratio ≈ 1:4), the first anaerobic reaction zone is controlled to an appropriate ORP (approximately -150 to +100 mV), thereby controlling the hydrolysis and acidification process. At the same time, the dissolved H₂S in the SSSAB is oxidized to sulfate, alleviating the problem of decreased microbial activity caused by the accumulation of dissolved H₂S in the SSSAB.

[0038] The reaction liquid of the second reaction zone of the MABR flows out through the second reflux outflow pipe and is pumped into the second reflux inflow pipe by the second reflux pump to enter the second anaerobic reaction zone, and the reflux ratio is controlled by the second reflux pump. The hydrogen-producing and acetic acid-producing bacteria in the second anaerobic reaction zone of the SSSAB account for a relatively large proportion, and part of the methanogens, and the control of the ORP can control the type of acid production. The higher the ORP, the more the propionic acid type fermentation is inhibited, and the more the acetic acid type and butyric acid type fermentation is promoted. Therefore, by adjusting the reflux flow of the second reaction zone of the MABR (reflux ratio ≈ 1:4), the ORP of the second anaerobic reaction zone is controlled to be appropriate (about -250 to -150 mV), and the hydrogen-producing and acetic acid-producing process is controlled. By introducing CO2 produced by oxidation in the second reaction zone of the MABR into the second anaerobic reaction zone, the CO2 concentration in the second anaerobic reaction zone is controlled (≥0.8 mmol / L), and the hydrogenotrophic methanogenesis pathway and acetic acid fermentation methanogenesis pathway are regulated. In addition, the alkalinity produced in the second reaction zone of the MABR is used to neutralize the VFAs produced in the second anaerobic reaction zone of the SSSAB, which will further improve the alkalinity of the SSSAB bed.

[0039] The reaction liquid of the third reaction zone of the MABR flows out through the third reflux outflow pipe and is pumped into the third reflux inflow pipe by the third reflux pump to enter the third anaerobic reaction zone, and the reflux ratio is controlled by the third reflux pump. The obligate anaerobes in the third anaerobic reaction zone account for the largest proportion, and the environment needs to be controlled to have a low ORP, and the dissolved oxygen concentration of the reflux liquid in the third reaction zone of the MABR is the lowest, and has less effect on the ORP. Therefore, by adjusting the reflux flow of the third reaction zone of the MABR (reflux ratio ≈ 1:2), the ORP of the third anaerobic reaction zone is controlled to be appropriate (about -400 to -250 mV). At the same time, CO2 produced by oxidation of CH4 in the third reaction zone of the MABR is introduced into the third anaerobic reaction zone, which can increase the CO2 concentration in the third anaerobic reaction zone (≈0.8 mmol / L), improve the activity of methanogens, promote the conversion of CO2 by methanogens, and thus promote the methanogenesis process in the third anaerobic reaction zone. In addition, the third anaerobic reaction zone is the most severely acidified, and the alkalinity produced in the third reaction zone of the MABR is used to neutralize the large amount of VFAs produced in the third anaerobic reaction zone, solving the problem of inactivation of methanogens caused by acid accumulation in the SSSAB.

[0040] By controlling the MABR influent pump to regulate the MABR influent flow, and by controlling the first reflux pump, the second reflux pump and the third reflux pump to regulate the reflux flow of the first reaction zone of the MABR, the second reaction zone of the MABR and the third reaction zone of the MABR, the appropriate carbon-nitrogen ratio in the equipped system (the carbon-nitrogen ratio in the MABR is about 10-30) is obtained, thereby promoting the efficient removal of COD and ammonia nitrogen by the SSSAB and the MABR.

[0041] The endogenous biogas produced by the first anaerobic reaction zone, the second anaerobic reaction zone and the third anaerobic reaction zone is collected by the first spiral-elliptical baffle, the second spiral-elliptical baffle and the third spiral-elliptical baffle respectively, and flows out from the first gas outlet pipe, the second gas outlet pipe and the third gas outlet pipe respectively, and is introduced into the membrane assembly of the MABR third reaction zone, the MABR second reaction zone and the MABR first reaction zone through the first jet pipe, the second jet pipe and the third jet pipe, and the gas flow of the three zones is controlled by the first gas valve, the second gas valve and the third gas valve.

[0042] The gas produced by the SSSAB is mainly CH4, CO2 and H2, and the gas produced by the SSSAB is introduced into the MABR, which can promote the oxidation of CH4 to CO2 by the methane-oxidizing bacteria in the aerobic layer of the MABR, and at the same time, the anaerobic ammonium oxidation bacteria in the anoxic layer and the anaerobic layer can utilize CH4 to reduce ammonia nitrogen and nitrate nitrogen to nitrogen, promote the anaerobic ammonium oxidation process, and promote denitrification.

[0043] The total gas (CH4, H2S, CO2, H2, etc.) produced in the SSSAB is collected by the three-phase separation zone, flows out through the total gas outlet pipe, and the exhaust gas valve and the endogenous biogas valve are used to control the exhaust or collection of biogas, the endogenous biogas produced by the SSSAB is introduced into the gas storage tank for collection, and the endogenous biogas gas pump is used to introduce the endogenous biogas into the three-way joint and into the MABR, and the endogenous biogas gas pump and the oxygen gas pump can be used to introduce the endogenous biogas and the external oxygen respectively or simultaneously, the flow of the endogenous biogas of the SSSAB into the MABR is controlled to be 0.5-2.0 L / min, so as to improve the activity of the anaerobic bacteria in the MABR, promote the mass transfer driving force in the MABR, and improve the removal rates of COD and ammonia nitrogen.

[0044] The operation mode of the application is as follows:

[0045] Wastewater is pumped into the SSSAB inlet pipe 2 via the SSSAB inlet pump 1, first entering the first anaerobic reaction zone A. The endogenous biogas produced by anaerobic digestion in this zone is collected by the first spiral elliptical baffle 21. The wastewater then flows upward into the second anaerobic reaction zone B, where the endogenous biogas produced by anaerobic digestion is collected by the second spiral elliptical baffle 6. The wastewater continues to flow upward into the third anaerobic reaction zone C, where the endogenous biogas produced by anaerobic digestion is collected by the third spiral elliptical baffle 9. The endogenous biogas produced by reactions in the first anaerobic reaction zone A, the second anaerobic reaction zone B, and the third anaerobic reaction zone C flows through the first outlet pipe 22, the second outlet pipe 8, and the third outlet pipe 16 to the MABR third reaction zone C, the MABR second reaction zone B, and the MABR first reaction zone A, respectively. The endogenous biogas diffuses outward within the hollow fiber membranes, partially entering the reaction solution to participate in the reaction. This endogenous biogas can be collected separately or simultaneously via the first air valve 23, the second air valve 7, and the third air valve 17. After reacting in the three anaerobic zones, the wastewater flows through the SSSAB outlet pipe 10 to the sedimentation tank 27. Sedimentation tank 27 is regularly drained of sludge. The supernatant from sedimentation tank 27 is pumped into the MABR inlet pipe 29 via the MABR inlet pump 28, entering the MABR. The reaction liquid then flows upward, reacting sequentially in the MABR third reaction zone c, the MABR second reaction zone b, and the MABR first reaction zone a. The reaction liquid from the MABR first reaction zone a, the MABR second reaction zone b, and the MABR third reaction zone c flows out through the first reflux outlet pipe 34, the second reflux outlet pipe 32, and the third reflux outlet pipe 30, respectively, to the first anaerobic reaction zone A, the second anaerobic reaction zone B, and the third anaerobic reaction zone C for further reaction. Each reflux outlet pipe is equipped with an electric reflux pump to control the reflux flow rate. When the reactor is in the startup phase or the operating conditions change, exogenous oxygen is provided to the hollow fiber membranes in the entire MABRⅡ longitudinally through the oxygen pump 39 via the tee 38, and an electric valve is provided to control the air intake flow rate; the total endogenous biogas generated by the SSSAB can be controlled for discharge or collection through the external exhaust valve 13 and the endogenous biogas valve 14, and the endogenous biogas is collected by passing it into the gas storage tank 15. The endogenous biogas collected in the gas storage tank is provided to the hollow fiber membranes in the entire MABR longitudinally through the endogenous biogas pump 37 via the tee 38, and an electric air pump is provided to control the air intake flow rate.

Claims

1. A spiral symmetric flow anaerobic membrane biofilm reactor system, characterized in that: The invention comprises a spiral symmetrical flow anaerobic reactor (I) and a membrane aeration biofilm reactor (II); a SSSAB water inlet pipe (2) is provided at the bottom of the spiral symmetrical flow anaerobic reactor (I), the SSSAB water inlet pipe (2) is connected to the SSSAB water inlet pump (1), a three-phase separation zone (11) and a SSSAB water outlet pipe (10) are provided at the top of the spiral symmetrical flow anaerobic reactor (I), the SSSAB water outlet pipe (10) is communicated with a sedimentation tank (27), a gas phase outlet of the three-phase separation zone (11) is connected to a main gas outlet pipe (12), and the main gas outlet pipe (12) discharges gas through an external gas exhaust valve (13) or discharges gas through an internal biogas valve ( 14) is connected to the gas storage tank (15), and the middle part of the spiral symmetrical flow anaerobic reactor is provided with a first anaerobic reaction zone (A), a second anaerobic reaction zone (B), and a third anaerobic reaction zone (C) in sequence from bottom to top. The lower parts of the first anaerobic reaction zone (A), the second anaerobic reaction zone (B), and the third anaerobic reaction zone (C) are respectively provided with a first return water inlet pipe (24), a second return water inlet pipe (5), and a third return water inlet pipe (18). The upper parts of the first anaerobic reaction zone (A), the second anaerobic reaction zone (B), and the third anaerobic reaction zone (C) are respectively provided with a first gas outlet pipe (22), a second gas outlet pipe (8), and a third gas outlet pipe (16);The bottom of the membrane aerated biofilm reactor (II) is provided with an MABR water inlet pipe (29), and the MABR water inlet pipe (29) is communicated with the supernatant in the sedimentation tank (27) through the MABR water inlet pump (28). The top of the membrane aerated biofilm reactor (II) is provided with a MABR water outlet pipe (41), and a membrane assembly (40) is provided in the membrane aerated biofilm reactor (II). The top of the membrane assembly (40) is communicated with the air inlet assembly outside the membrane aerated biofilm reactor (II). The membrane assembly (40) is provided with a MABR first reaction zone (a), a MABR second reaction zone (b), and a MABR third reaction zone (c) from top to bottom. The upper parts of the MABR first reaction zone (a), the MABR second reaction zone (b), and the MABR third reaction zone (c) are respectively provided with a first air pipe (36), a second air pipe (42), and a third air pipe (43). The first air pipe (36), the second air pipe (42), and the third air pipe (43) are respectively provided. The air pipe (42) and the third air pipe (43) are respectively connected to the first jet pipe (35), the second jet pipe (33), and the third jet pipe (31) at the ends of the first air outlet pipe (22), the second air outlet pipe (8), and the third air outlet pipe (16) through the third air valve (17), the second air valve (7), and the first air valve (23). The lower parts of the first reaction zone (a) of the MABR, the second reaction zone (b), and the third reaction zone (c) of the MABR are respectively provided with a first reflux outlet pipe (34), a second reflux outlet pipe (32), and a third reflux outlet pipe (30). The first reflux outlet pipe (34), the second reflux outlet pipe (32), and the third reflux outlet pipe (30) are respectively connected to the first reflux inlet pipe (24), the second reflux inlet pipe (5), and the third reflux inlet pipe (18) through the first reflux pump (26), the second reflux pump (3), and the third reflux pump (20).

2. The spiral symmetric flow anaerobic membrane biofilm reactor system according to claim 1, characterized in that: A first spiral elliptical baffle (21), a second spiral elliptical baffle (6), and a third spiral elliptical baffle (9) are respectively provided on the tops of the first anaerobic reaction zone (A), the second anaerobic reaction zone (B), and the third anaerobic reaction zone (C).

3. The spiral symmetric flow anaerobic membrane biofilm reactor system according to claim 2, characterized in that: The first spiral elliptical baffle (21), the third spiral elliptical baffle (9) and the second spiral elliptical baffle (6) are symmetrically arranged about the central axis of the spiral symmetrical flow anaerobic reactor.

4. The spiral symmetric flow anaerobic membrane biofilm reactor system according to claim 1, characterized in that: The first reflux pump (26), the second reflux pump (3), and the third reflux pump (20) are connected to the first reflux water inlet pipe (24), the second reflux water inlet pipe (5), and the third reflux water inlet pipe (18) respectively through the first reflux valve (25), the second reflux valve (4), and the third reflux valve (19).

5. The spiral symmetric flow anaerobic membrane biofilm reactor system according to claim 1, characterized in that: The air intake assembly includes an oxygen pump (39) and an endogenous biogas pump (37) connected to a gas storage tank (15). The oxygen pump (39) and the endogenous biogas pump (37) are connected to the membrane assembly (40) via a tee (38).

6. The spiral symmetric flow anaerobic membrane biofilm reactor system according to claim 1, characterized in that: The first anaerobic reaction zone (A), the second anaerobic reaction zone (B), and the third anaerobic reaction zone (C) are respectively located at 2 / 5, 3 / 5, and 4 / 5 of the height of the spiral symmetrical flow anaerobic reactor (I), and are used for hydrolysis and acidification, hydrogen and acetic acid production, and methane production, respectively.

7. The spiral symmetric flow anaerobic membrane biofilm reactor system according to claim 1, characterized in that: The MABR third reaction zone (c), MABR second reaction zone (b), and MABR first reaction zone (a) are respectively located at 1 / 3, 2 / 3, and 3 / 3 of the height of the membrane aerated biofilm reactor (II). The dissolved oxygen concentrations in the three reaction zones increase from top to bottom, and the redox potential increases accordingly.

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