A membrane fouling control device and method for a sewage treatment membrane bioreactor

Abstract

The present invention discloses a membrane fouling control device and method for a sewage treatment membrane bioreactor. By utilizing the characteristics of each process unit of sewage treatment and through device improvement and process optimization, the present invention gives full play to the ability of facultative quorum quenching bacteria to degrade quorum sensing signal molecules. On the one hand, it degrades the quorum sensing signal molecules in the influent sewage to reduce the concentration of quorum sensing signal molecules in the downstream process. On the other hand, when the activity of quorum quenching bacteria in the MBR weakens, it uses the carbon source in the sewage to restore the activity, and continuously maintains the high activity of quorum quenching bacteria in this way. Finally, the efficient control of MBR membrane fouling is realized, the additional treatment cost of quorum quenching bacteria is significantly reduced, and it has good economic and environmental benefits. This method can be used in biological treatment systems for organic wastewater such as municipal sewage, industrial wastewater, and landfill leachate.

Description

Technical Field

[0001] The present invention belongs to the field of sewage treatment, and relates to a pollution control device and method, in particular to a membrane pollution control device and method for a sewage treatment membrane bioreactor. Background Art

[0002] With the shortage of water resources and the aggravation of water pollution, the national emission limit standards for sewage pollutants are becoming increasingly strict. The membrane bioreactor (MBR) has many advantages such as good effluent quality and less land occupation, and is gradually becoming a technology widely used in the fields of urban domestic sewage, high-concentration and difficult-to-treat industrial wastewater, and even rural domestic sewage treatment. In China, the market demand for MBR is growing rapidly, with an annual growth rate of nearly 1 time or even several times. However, membrane pollution caused by extracellular polymeric substances (EPS) during the biological treatment process is a difficult problem restricting the further wide promotion of MBR. In order to reduce membrane pollution and maintain membrane flux, the MBR membrane module requires a very high aeration rate, and the specific energy consumption of MBR is several times higher than that of the conventional activated sludge process. Therefore, one of the biggest disadvantages of the current wastewater MBR treatment technology is high energy consumption. Research on the formation and regulation of inhibiting MBR membrane pollution is of great significance for promoting the development of MBR and energy conservation and consumption reduction in sewage treatment plants.

[0003] Microbial quorum sensing and quenching phenomena provide a new method for controlling MBR membrane pollution. Quorum sensing (QS) is a process by which bacteria secrete and sense QS signal molecules to perceive the density of the bacterial population and then start to regulate the expression of specific genes to control many physiological functions of bacteria, such as the synthesis and secretion of EPS, and the formation of biofilms. The most common QS signal molecule in the activated sludge system is acyl-homoserine lactones (AHLs). At the same time, microorganisms also have a quorum sensing quenching mechanism. Bacteria can secrete quorum sensing quenching enzymes to degrade QS signal molecules, thereby inhibiting the formation of biofilms.

[0004] Scholars at home and abroad have conducted a large number of studies on quorum sensing quenching to control the formation of membrane fouling. In 2009, the team of Chung-Hak Lee first discovered that directly adding QS signal molecule degrading enzymes to the MBR could effectively delay membrane fouling. To overcome the high cost of enzymes, some teams immobilized quorum sensing quenching enzymes on carriers to reduce the concentration of AHLs and alleviate membrane fouling. Quorum sensing quenching bacteria can secrete enzymes that decompose AHLs signal molecules, and their successful isolation provides the possibility for the large-scale application of quorum sensing quenching bacteria in MBR membrane fouling. The research found that the significant reduction in the content of polysaccharides and proteins in the sludge EPS of the quorum sensing quenching bacteria addition group compared to the control group was the main reason for slowing down membrane fouling. However, how to stably maintain the long-term activity of quorum sensing quenching bacteria in the membrane bioreactor has become a limiting factor hindering the wide application of this technology. The technology of embedding and immobilizing microorganisms is a method that uses chemical or physical means to localize free microorganisms in a limited carrier space and keep them active and reusable. This method of immobilizing bacteria can purify and maintain highly efficient bacterial strains, so it has the advantages of high treatment efficiency, easy reaction control, high purity and efficiency of bacterial strains, and high biological concentration. Most technologies only focus on the application preparation methods of quorum sensing quenching bacteria, but during the long-term operation process, quorum sensing quenching bacteria will be lost from the carrier and the quorum sensing quenching activity will decrease. At present, there is no way to continuously achieve the stable and efficient control of MBR membrane fouling from the perspective of reactor device design.

[0005] The present invention attempts to find a device and method that can utilize the characteristics of each process unit of sewage treatment, through device improvement and process optimization, to restore the activity of quorum sensing quenching bacteria using the carbon source in sewage when the activity of quorum sensing quenching bacteria weakens, and thus continuously maintain the high activity of quorum sensing quenching bacteria. Therefore, this technical method can be stably and highly strengthened to achieve efficient membrane fouling control in the MBR reactor, and solve the problems of high energy consumption and cleaning in the MBR reactor. At the same time, it can maintain the activity of quorum sensing quenching bacteria for a long time while ensuring the treatment efficiency, significantly reduce the external treatment cost of quorum sensing quenching bacteria, and has good economic and environmental benefits.

[0006] Therefore, separating quorum sensing quenching bacteria that adapt to different process characteristics of sewage, and continuously restoring the number of bacteria in the quorum sensing quenching bacteria carrier through device improvement. On the one hand, it can enable the quorum sensing quenching bacteria to continuously secrete QQ enzymes, and on the other hand, it can maintain the long-term stability of the quorum sensing quenching bacteria carrier, and ultimately achieve the efficient control of MBR membrane fouling, which is the key point of the present invention. Summary of the Invention

[0007] The object of the present invention is to address the problem of membrane fouling in the sewage MBR treatment process, and to provide a facultative quorum sensing quenching bacteria controlled MBR membrane fouling method and its application device in the sewage treatment process. By immobilizing facultative quorum sensing quenching bacteria on carriers and utilizing the characteristics of different process sections in sewage treatment, the present invention mainly improves the influent unit and the MBR unit in the sewage treatment process, realizes the degradation of QS signal molecules in each process section by quorum sensing quenching bacteria, and stably maintains its high activity, so as to achieve efficient control of MBR membrane fouling and recycling of quorum sensing quenching bacteria.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] A sewage treatment membrane bioreactor membrane fouling control device, comprising a grille, a grit chamber, a selector tank, a biochemical tank, an aerobic MBR tank, a hydrocyclone separator, an automatic control system, a control center and a screw rotating cylinder connected in sequence according to the sewage treatment process; one end of the selector tank is respectively connected to the first screw rotating cylinder and the second screw rotating cylinder, the water outlet of the selector tank is connected to the water inlet of the biochemical tank, the other end of the first screw rotating cylinder is connected to the aerobic MBR tank, a membrane module is installed in the aerobic MBR tank, the side stream of the aerobic MBR tank is connected to the top of the hydrocyclone separator through a pump, the bottom of the hydrocyclone separator is connected to the other end of the second screw rotating cylinder, and an automatic control system is arranged in the aerobic MBR tank and connected to the control center. The above "connection" can be directly connected or indirectly connected through a pipeline.

[0010] Further, the screw rotating cylinder is tubular, with a rotating shaft inside, and spiral blades on the rotating shaft form a propeller, and the quorum sensing quenching bacteria carrier is transported by the propeller. The rotating shaft is driven by a motor.

[0011] Further, the bottom of the selector tank is conical, the upper part is a cylindrical structure, the water outlet end is a screen structure, the screen aperture is greater than 1 mm and less than the quorum sensing quenching bacteria carrier, and the bottom of the selector tank is connected to the water inlet end of the first screw rotating cylinder.

[0012] Furthermore, an aeration device is installed at the bottom of the membrane module, the top of the membrane module is connected to a suction pump, and a transmembrane pressure difference sensor is arranged on the suction pump; the transmembrane pressure difference sensor, the suction pump and the pump are all connected to the automatic control system; a dissolved oxygen DO probe and a pH probe can also be installed in the aerobic MBR tank, and the dissolved oxygen DO probe and the pH probe are both connected to the automatic control system.

[0013] A sewage treatment membrane bioreactor membrane fouling control method using the above device, comprising the following steps:

[0014] After the sewage is pretreated by a grille and a grit chamber, it enters a selection tank which contains a quorum quenching bacteria carrier. The quorum sensing signal molecules in the influent are removed under the action of the quorum quenching bacteria. The effluent from the selection tank is treated in a biochemical tank and then enters an aerobic MBR tank. The quorum quenching bacteria carrier in the selection tank is transported to the aerobic MBR tank through a first spiral cylinder to control membrane fouling by using the quorum quenching bacteria carrier. The quorum quenching bacteria carrier and the mud-water mixture in the aerobic MBR tank enter a cyclone separation tank. After separation in the cyclone separation tank, the quorum quenching bacteria carrier is transported back to the selection tank through a second spiral cylinder, and the sludge is refluxed to the aerobic MBR tank. The effluent from the aerobic MBR tank enters the next-level process unit.

[0015] Further, the residence time of the quorum quenching bacteria carrier in the selection tank is 12 - 24 h.

[0016] Further, the quorum quenching bacteria in the quorum quenching bacteria carrier are facultative bacteria. The dosage in the aerobic MBR tank, that is, the mass ratio of the quorum quenching bacteria to the volume of the aerobic MBR tank is 2 - 5%, and the residence time is 20 - 30 days.

[0017] Further, the linkage between the aerobic MBR tank and the cyclone separation tank is controlled by an automatic control system; there is a transmembrane pressure difference sensor in the aerobic MBR tank for on-line monitoring. The value of the transmembrane pressure difference sensor is recorded, the average membrane fouling rate is calculated, and the low value and high value of the average membrane fouling rate are set. When the average membrane fouling rate is higher than the high value, the water inflow of the cyclone separation tank is increased, and the residence time of the quorum quenching bacteria carrier in the aerobic MBR tank is reduced to improve the activity of the quorum quenching bacteria carrier through the selection tank. The water at the inlet end of the cyclone separation tank enters the side pipe through a pump to adjust the water volume.

[0018] Even further, all control indicators are controlled by the automatic control system, and the equipment operation data can be monitored and recorded online in the control center.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) By utilizing the facultative quorum sensing quenching bacteria characteristics, through process optimization and device design, a selection pool is set after the influent section to exert its anaerobic characteristics, and its aerobic characteristics are exerted in the aerobic MBR pool. A cyclone separation pool is set on the side stream to separate the quorum sensing quenching bacteria carriers and then return them to the selection pool. This design maximally and continuously maintains the activity of the facultative quorum sensing quenching bacteria. On the one hand, the facultative quorum sensing quenching bacteria can secrete QQ enzyme in the aerobic MBR pool to interfere with the QS effect and control membrane fouling. On the other hand, when the activity of the facultative quorum sensing quenching bacteria in the aerobic MBR pool decreases, the abundant organic matter in the influent can quickly revive the quorum sensing quenching bacteria and greatly improve their activity. At the same time, the facultative quorum sensing quenching bacteria are fixed in the carriers, which can protect them from the impact of toxic pollutants and stably maintain the activity of the quorum sensing quenching bacteria for a long time.

[0021] (2) In the wastewater biological treatment system, the facultative quorum sensing quenching bacteria can decompose the QS signal molecules in multiple process links, and maximally slow down the potential of membrane fouling. Research shows that whether it is the influent of the sewage treatment plant or the aerobic MBR pool with a high sludge concentration, there are relatively high concentrations of QS signal molecules, which will greatly increase the potential of EPS secretion and biofilm formation and exacerbate membrane fouling. The present invention respectively aims at the QS signal molecules in the influent and the aerobic MBR reactor, and through process optimization, stably realizes the decomposition of the QS signal molecules, which can greatly slow down membrane fouling.

[0022] (3) The linkage intelligent control between the aerobic MBR pool and the cyclone separation pool provides a guarantee for the intelligent early warning and control of membrane fouling. The present invention can feedback control the residence time of the quorum sensing quenching bacteria carriers and the quorum sensing quenching activity according to the transmembrane pressure difference and the average rate of membrane fouling in the aerobic MBR pool, effectively guaranteeing the efficient operation of the aerobic MBR pool.

[0023] (4) Based on the control of membrane fouling by quorum sensing quenching bacteria, the aeration in the aerobic MBR pool can be reduced, and the membrane cleaning frequency can be greatly reduced, thereby greatly reducing the operating cost. Compared with the commonly used carriers, the operating cost is lower, and it has more significant economic and environmental benefits.

[0024] (5) It has a wide application prospect. This technology can be used for the membrane fouling control of the MBR process for municipal domestic sewage, providing new ideas and opening up new ways for the development of low-consumption and high-efficiency MBR treatment technology. At the same time, it can also be used for the membrane fouling control of the MBR process for industrial wastewater, landfill leachate, etc., providing a broader prospect for the popularization and application of the MBR technology. Description of the Drawings

[0025] Figure 1 : The principle flow chart of a specific example of the device of the present invention.

[0026] Among them, 1 is a grille, 2 is a grit chamber, 3 is a selector tank, 4 is a biochemical tank, 5 is an aerobic MBR tank, 6 is a hydrocyclone separation tank, 7 is a dissolved oxygen DO probe, 8 is a transmembrane pressure difference sensor, 9 is a suction pump, 10 is a pH probe, 11 is a membrane module, 12 is a pump, 13 is a quorum sensing quenching bacteria carrier, 14 is an automatic control system, 15 is a control center, 16 is a first spiral cylinder, and 17 is a second spiral cylinder.

[0027] Figure 2 : Variation of quorum sensing signal molecule concentration of different carriers with time.

[0028] Control: No addition, Vacant beads: Sterile carrier; QQ beads-fresh: Freshly prepared quorum sensing quenching bacteria carrier; QQ beads-MBR: Quorum sensing quenching bacteria carrier that has been operating for some time; QQ beads-refresh: Quorum sensing quenching bacteria carrier after activation in the selector tank.

[0029] Figure 3 : Variation of TMP of different mode MBRs.

[0030] C-MBR: Conventional MBR operating without addition; V-MBR: MBR with addition of sterile carrier; QQ-MBR: MBR with addition of quorum sensing quenching bacteria carrier; QQ-refresh: MBR with quorum sensing quenching bacteria carrier coupled in the selector tank. Specific embodiments

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] Referring to Figure 1 , which is a specific example of the device of the present invention. The membrane fouling control device of the sewage treatment membrane bioreactor includes a grille 1, a grit chamber 2, a selector tank 3, a biochemical tank 4, an aerobic MBR tank 5, a hydrocyclone separation tank 6, an automatic control system 14, a control center 15, and a spiral cylinder connected in sequence according to the sewage treatment process; one end of the selector tank is respectively connected to the first spiral cylinder 16 and the second spiral cylinder 17, the outlet of the selector tank is connected to the inlet of the biochemical tank, the other end of the first spiral cylinder is connected to the aerobic MBR tank, the aerobic MBR tank is equipped with a membrane module, the side stream of the aerobic MBR tank is connected to the top of the hydrocyclone separation tank through a pump 12, the bottom of the hydrocyclone separation tank is connected to the other end of the second spiral cylinder, and an automatic control system is arranged in the aerobic MBR tank and connected to the control center.

[0033] Among them, the spiral rotating cylinder is tubular, and a spiral propeller is arranged in the spiral rotating cylinder. The quorum quenching sterilization carrier is transported by the propeller. The bottom of the selection tank 3 is conical, the upper part is a cylindrical structure, and the water outlet end is a screen structure. The aperture of the screen is greater than 1 mm and less than the quorum quenching sterilization carrier. An aeration device is installed at the bottom of the membrane module 11, the top of the membrane module is connected to the suction pump 9, and a transmembrane pressure difference sensor 8 is arranged on the suction pump; the transmembrane pressure difference sensor 8, the suction pump 9, and the pump 12 are all connected to the automatic control system; A dissolved oxygen DO probe 7 and a pH probe 10 can also be installed in the aerobic MBR tank.

[0034] A method for controlling membrane fouling in a sewage treatment membrane bioreactor using the above device, comprising the following steps:

[0035] After the sewage is pretreated by the grille 1 and the grit chamber 2, it enters the selection tank 3. The selection tank contains a quorum quenching sterilization carrier, and the quorum quenching signal molecules in the influent are removed under the action of the quorum quenching sterilization. The effluent from the selection tank is treated by the biochemical tank 4 (anaerobic, anoxic, aerobic or other modified processes) and then enters the aerobic MBR tank 5. The quorum quenching sterilization carrier in the selection tank is transported to the aerobic MBR tank 5 through the first spiral rotating cylinder 16 to complete the degradation of most pollutants, and the quorum quenching sterilization carrier is used to control membrane fouling. The quorum quenching sterilization carrier and the mud-water mixture in the aerobic MBR tank enter the hydrocyclone separation tank 6. Under the action of the tangential shear force in the hydrocyclone separation tank, the quorum quenching sterilization carrier sinks to the bottom. The separated quorum quenching sterilization carrier is transported back to the selection tank through the second spiral rotating cylinder under the action of the vacuum pump, and the sludge is refluxed to the aerobic MBR tank. The effluent from the aerobic MBR tank enters the next-stage process unit.

[0036] The selection tank realizes full contact between the quorum quenching sterilization carrier and the influent through inlet hydraulic mixing. The quorum quenching sterilization can rapidly proliferate using the abundant organic matter in the influent, greatly improving the quorum quenching activity, which is beneficial to the degradation of QS signal molecules in the downstream MBR unit. At the same time, microorganisms in the influent will also secrete QS signal molecules, which play an important role in membrane fouling. The rapid proliferation of the quorum quenching sterilization can also greatly reduce the content of QS signal molecules in the influent, which can further reduce membrane fouling. The residence time of the quorum quenching sterilization carrier in the selection tank is 12 - 24 h.

[0037] The quorum quenching bacteria in the quorum quenching bacteria carrier are facultative bacteria. The dosage in the aerobic MBR tank, that is, the mass ratio of the quorum quenching bacteria carrier to the volume of the aerobic MBR tank is 2-5%, and the residence time is 20-30 days. The quorum quenching bacteria can survive in the relatively anaerobic influent environment, utilize the carbon source therein for rapid reproduction, maintain the quorum quenching activity and degrade the QS signal molecules in the influent. They can also maintain the activity in the aerobic MBR tank and degrade the QS signal molecules in the aerobic MBR tank with sludge, greatly slowing down the membrane fouling.

[0038] The linkage between the aerobic MBR tank 5 and the cyclone separation tank 6 is controlled by the automatic control system 14; in the aerobic MBR tank, there is an online transmembrane pressure difference sensor 8 to monitor and record the value of the transmembrane pressure difference sensor, calculate the average rate of membrane fouling, set the low value and high value of the average rate of membrane fouling. When the average rate of membrane fouling is higher than the high value, increase the water inflow of the cyclone separation tank and reduce the residence time of the quorum quenching bacteria carrier in the aerobic MBR tank to improve the activity of the quorum quenching bacteria carrier through the selection tank. The water at the inlet end of the cyclone separation tank enters the side pipe through a pump to adjust the water volume.

[0039] All control indicators are controlled by the automatic control system, and the equipment operation data can be monitored and recorded online in the control center.

[0040] Example

[0041] Taking the treatment of urban domestic sewage as an example, the wastewater quality indexes are: pH 7-7.5, ammonia nitrogen concentration 30-50 mg / L, COD 100-250 mg / L.

[0042] The control of membrane fouling in the wastewater MBR reactor is achieved through the following steps:

[0043] (1) The production conditions of the quorum quenching bacteria carrier are: culturing the facultative quorum quenching bacteria Brucella sp.ZJ1, after culturing in LB medium at 30 °C for 24 h, centrifuging and adding it to the sodium alginate and PVA solutions, then adding it to the CaCl2-H3BO3 solution, dropping while stirring, the dropping speed is 2.0 mL / min. After placing the formed gel particles for 1 h, crosslinking them in the NaSO4 solution to obtain quorum quenching bacteria carriers with a diameter of 2 mm, rinsing them with sterile distilled water multiple times and storing them at 4 °C for standby.

[0044] (2) After the sewage is pretreated by the grille and grit chamber, it enters the selection tank, biochemical tank, and aerobic MBR tank in sequence. The dosing ratio of the quorum quenching bacteria carrier in the aerobic MBR tank is about 2%. Through the hydrocyclone separation tank, the quorum quenching bacteria carrier can be refluxed to the selection tank through the spiral cylinder. In the selection tank, due to the conical structure at the bottom, a large swirl is generated in the water flow, stirring up the quorum quenching bacteria carrier, making the influent and the quorum quenching bacteria carrier mix evenly. The residence time of the quorum quenching bacteria carrier in the selection tank is 12 - 24 h; after passing through the selection tank, the quorum quenching activity of the quorum quenching bacteria carrier increases by 30 - 60% (as Figure 2 shown), and the concentration of AHLs signaling molecules in the influent decreases by 10 - 25%.

[0045] (3) After the quorum quenching bacteria carrier stays in the selection tank, it is transported to the aerobic MBR tank through the spiral cylinder. The sludge concentration in the aerobic MBR tank is about 5000 mg / L, the membrane flux is 20 L / (m 2 ⋅h), the hydraulic retention time is 3 h, and the sludge retention time is 10 days.

[0046] (4) The results show that adding the membrane fouling control efficiency in the aerobic MBR tank is significant. Compared with the conventional MBR reactor, the membrane fouling cycle is extended from 2 - 3 days of the conventional MBR to 6 - 8 days, which is 3 times longer. The membrane fouling cycle of the quorum quenching bacteria carrier coupled with the selection tank + aerobic MBR tank can be extended 5 times to 10 - 13 days (as Figure 3 shown). At the same time, after 60 days of operation, it is found that the quorum quenching activity of the quorum quenching bacteria carrier in the selection tank + aerobic MBR tank remains stable, showing a long-term membrane fouling control effect.

[0047] The above is only one embodiment of the present invention, which does not limit the protection scope of the present invention. Based on the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. A membrane fouling control device for a sewage treatment membrane bioreactor, characterized in that It includes a grille (1), a grit chamber (2), a selector tank (3), a biochemical tank (4), an aerobic MBR tank (5), a hydrocyclone separator (6), as well as an automatic control system (14), a control center (15) and at least two screw rotating cylinders, which are connected in sequence according to the sewage treatment process; one end of the selector tank (3) is respectively connected to the first screw rotating cylinder (16) and the second screw rotating cylinder (17). The outlet end of the selector tank (3) is a screen structure, and the screen aperture is smaller than the quorum quenching bacteria carrier. The bottom of the selector tank (3) is connected to the inlet end of the first screw rotating cylinder (16), and the outlet of the selector tank (3) is connected to the inlet of the biochemical tank (4). The other end of the first screw rotating cylinder (16) is connected to the aerobic MBR tank (5). The quorum quenching bacteria carrier in the selector tank (3) is transported to the aerobic MBR tank (5) through the first screw rotating cylinder (16). The aerobic MBR tank (5) is equipped with a membrane module (11). The side flow of the aerobic MBR tank (5) is connected to the top of the hydrocyclone separator (6) through a pump (12). The bottom of the hydrocyclone separator (6) is connected to the other end of the second screw rotating cylinder (17). After being separated by the hydrocyclone separator (6), the quorum quenching bacteria carrier is transported back to the selector tank (3) through the second screw rotating cylinder (17). The quorum quenching bacteria in the quorum quenching bacteria carrier are facultative bacteria. An automatic control system (14) is arranged in the aerobic MBR tank (5) and is connected to the control center (15).

2. The membrane fouling control device for a sewage treatment membrane bioreactor according to claim 1, wherein, The screw rotating cylinder is tubular, with a rotating shaft inside. There are spiral blades on the rotating shaft to form a propeller, and the quorum quenching bacteria carrier is transported by the propeller.

3. The membrane pollution control device for a sewage treatment membrane bioreactor according to claim 1, characterized in that The bottom of the selector tank (3) is conical, and the upper part is a cylindrical structure. The screen aperture is greater than 1 mm.

4. The membrane fouling control device for a sewage treatment membrane bioreactor according to claim 1, characterized in that, An aeration device is installed at the bottom of the membrane module (11). The top of the membrane module (11) is connected to a suction pump (9). A transmembrane pressure difference sensor (8) is arranged on the suction pump (9); the transmembrane pressure difference sensor (8), the suction pump (9), and the pump (12) are all connected to the automatic control system (14).

5. The membrane pollution control device for a sewage treatment membrane bioreactor according to claim 1, characterized in that, A dissolved oxygen DO probe (7) and a pH probe (10) are also installed in the aerobic MBR tank (5), and the dissolved oxygen DO probe (7) and the pH probe (10) are both connected to the automatic control system (14).

6. A method for controlling membrane fouling in a sewage treatment membrane bioreactor, characterized in that, It is implemented by using the device according to any one of claims 1 - 5. The method includes the following steps: After the sewage is pretreated by the grille (1) and the grit chamber (2), it enters the selector tank (3). The selector tank (3) contains a quorum quenching bacteria carrier, and the quorum quenching signal molecules in the influent are removed under the action of the quorum quenching bacteria. After the water outlet of the selector tank (3) is treated by the biochemical tank (4), it enters the aerobic MBR tank (5). The quorum quenching bacteria carrier is used to control membrane fouling. The quorum quenching bacteria carrier and the mud - water mixture in the aerobic MBR tank (5) enter the hydrocyclone separator (6), and the sludge flows back to the aerobic MBR tank (5). The water outlet of the aerobic MBR tank (5) enters the next - level process unit.

7. The method for controlling membrane fouling of a sewage treatment membrane bioreactor according to claim 6, characterized in that, The residence time of the quorum quenching bacteria carrier in the selector tank (3) is 12 - 24 h.

8. The method for controlling membrane fouling of a sewage treatment membrane bioreactor according to claim 6, characterized in that, The dosage of the quorum quenching bacteria carrier in the aerobic MBR tank (5), that is, the mass ratio of the quorum quenching bacteria carrier to the volume of the aerobic MBR tank (5) is 2 - 5%, and the residence time is 20 - 30 days.

9. The method for controlling membrane fouling of a sewage treatment membrane bioreactor according to claim 6, characterized in that The linkage between the aerobic MBR tank (5) and the cyclone separation tank (6) is controlled by the automatic control system (14); there is a transmembrane pressure difference sensor (8) in the aerobic MBR tank (5) for on-line monitoring, recording the value of the transmembrane pressure difference sensor (8), calculating the average membrane fouling rate, setting the low value and high value of the average membrane fouling rate. When the average membrane fouling rate is higher than the high value, increase the water inflow of the cyclone separation tank (6) and reduce the residence time of the quorum quenching bacteria carrier in the aerobic MBR tank (5), so as to improve the activity of the quorum quenching bacteria carrier through the selection tank (3). The water at the inlet end of the cyclone separation tank (6) enters the side pipe through the pump (12) to adjust the water volume.

10. The method for controlling membrane fouling of a sewage treatment membrane bioreactor according to claim 6, wherein, All control indicators are controlled by the automatic control system (14), and the equipment operation data can be monitored and recorded online at the control center (15).

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