A double MBR membrane tank group sewage treatment system and its working method

Abstract

The present invention discloses a double MBR membrane pool group sewage treatment system and a working method thereof, comprising a first MBR membrane pool, a second MBR membrane pool, a post-treatment unit and a multi-stage channel switch. The two MBR membrane pools are regulated by a plurality of valves in cooperation with the multi-stage channel switch, so that the first MBR membrane pool and the second MBR membrane pool can be connected in parallel, in series, or online backwashed, or a single group of MBR membranes can be operated. The system can be adjusted according to the characteristics of water quality to be treated or the treatment volume under different conditions, thereby improving the working efficiency and working stability of the MBR membrane. Meanwhile, when a single group of the double MBR membrane pools is working, the MBR membrane in abnormal working state can be lifted out of the membrane pool by a suspension machine beside the membrane pool for offline cleaning. The system has good adaptability in the treatment of high-concentration and large-volume wastewater, such as wastewater treatment in the brewing industry.

Description

Technical Field

[0001] The invention belongs to the field of sewage treatment, and in particular relates to a double MBR membrane tank group sewage treatment system and a working method thereof. Background Art

[0002] MBR membrane is a commonly used technical device in the existing sewage treatment field, and plays a vital role in the sewage treatment process. However, due to the presence of a small amount of solid particles such as sludge in the sewage, or easily precipitated substances such as calcium ions and magnesium ions in the sewage to be treated, the MBR membrane is prone to surface scaling after a period of use, and backwashing or even offline cleaning is required before the MBR membrane can work normally again. In a sewage treatment process with only a single set of MBR membranes, when the MBR membrane is backwashed or cleaned offline, the entire sewage treatment production line will be severely restricted, and the sewage treatment process may not even be completed normally.

[0003] In order to solve the problem of substandard sewage treatment caused by the failure of a single group of MBR membranes to operate normally, Patent ZL201821255878.X has designed an integrated device with a two-way backwashing function. The device realizes the alternating use of MBR membranes in sewage treatment by installing two groups of MBR membranes in parallel in the process route, avoiding the problem of no normal operation of MBR membranes in the water treatment process route caused by backwashing or offline cleaning of a single group of MBR membranes during water treatment. In addition, the device also realizes the function of backwashing another group of MBR membranes with water purified by one group of MBR membranes through valve design, reducing the impact of the MBR membrane backwashing process on the entire process route. The deposition of particles on the membrane surface or scaling of calcium ions, magnesium ions, etc. can be reduced by increasing the number of backwashing of a single group of MBR membranes, thereby reducing the number of offline cleanings of the MBR membranes. Compared with the sewage treatment system with a single group of MBR membranes, the device not only improves the operating stability of the sewage treatment process route, but also reduces the number of offline cleanings of the MBR membranes, thereby increasing their service life.

[0004] However, due to the high purchase cost of MBR membranes, although the system achieved the stability of the sewage treatment process by connecting two sets of MBR membranes in parallel, it increased the sewage treatment cost. Although the design of using the water purified by one set of membranes to backwash the other set of membranes extended the service life of the MBR membranes to a certain extent, it did not bring into play the functions of the two sets of MBR membranes well. Especially when the MBR membranes are in poor condition, the sewage treated by one set of MBR membranes may not be suitable for direct backwashing of the other set of membranes, which will cause blockage inside the fibers of the MBR membranes. In addition, when treating sewage with complex components or high organic matter concentration, the equipment cannot further increase the utilization efficiency of the MBR membranes by realizing the series operation of the two sets of MBR membranes. Summary of the invention

[0005] The technical problem solved by the present invention is: in view of the above-mentioned shortcomings of the existing double-group MBR membrane in sewage purification and treatment, a novel double-MBR membrane pool sewage treatment system and its working method are provided to improve the treatment effect of sewage with high organic matter concentration and increase the working efficiency of the MBR membrane.

[0006] The present invention is implemented by the following technical solutions:

[0007] A double MBR membrane tank group sewage treatment system, comprising a first MBR membrane tank, a second MBR membrane tank, a post-processing unit and a multi-stage channel switch;

[0008] The inlet pipeline of the first MBR membrane pool and the inlet pipeline of the second MBR membrane pool are respectively provided with an inlet valve, the outlet pipeline of the first MBR membrane pool and the outlet pipeline of the second MBR membrane pool are respectively connected to the post-processing unit, and a multi-stage channel switch is respectively provided between the first MBR membrane pool and the post-processing unit and between the second MBR membrane pool and the post-processing unit, and the first MBR membrane pool and the second MBR membrane pool are also connected to each other through their own multi-stage channel switches;

[0009] The multi-stage channel switch comprises an interface valve and a channel gate, wherein the interface valve is provided with a plurality of interfaces, and the channel gate and the interface valve are arranged to move relative to each other to connect and switch the interfaces on the interface valve.

[0010] In the double MBR membrane tank group sewage treatment system in the above scheme, a switching valve is provided on the pipeline connecting the multi-stage channel switch of the first MBR membrane tank and the multi-stage channel switch of the second MBR membrane tank.

[0011] In the double MBR membrane tank group sewage treatment system in the above scheme, pumps are provided on the liquid outlet pipelines of the first MBR membrane tank and the second MBR membrane tank.

[0012] In the double MBR membrane tank group sewage treatment system in the above scheme, the pump is a bidirectional water pump.

[0013] In the double MBR membrane pool group sewage treatment system in the above scheme, four interfaces are provided on the interface valve of the multi-stage channel switch, two of which are respectively connected to the post-treatment unit and the liquid outlet pipe of the corresponding MBR membrane pool, another interface is connected back to the liquid inlet of the corresponding MBR membrane pool, and the last interface is interconnected with the corresponding interface on the multi-stage channel switch of the other MBR membrane pool.

[0014] In the double MBR membrane tank group sewage treatment system in the above scheme, the interface valve is an annular structure, the interfaces are respectively arranged on the outer wall of the annulus of the interface valve, and the channel gate is a multi-section entity passing through the interface valve, on which sections are provided with channels for switching the interfaces on the interface valve.

[0015] In a double MBR membrane tank group sewage treatment system of the present invention, each section of the channel gate is provided with at least one of a channel connecting the liquid outlet pipeline of the corresponding MBR membrane tank with the post-treatment unit, a channel connecting the liquid inlet pipeline of the corresponding MBR membrane tank with another MBR membrane tank, and a channel connecting the liquid outlet pipeline of the corresponding MBR membrane tank with another MBR membrane tank.

[0016] In the double MBR membrane pool sewage treatment system in the above scheme, the channel gate is also provided with a segment that blocks all interfaces on the interface valve.

[0017] The present invention also discloses a working method of the double MBR membrane tank group sewage treatment system in the above scheme, including the following working modes:

[0018] In parallel mode, the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool are controlled, and the liquid outlet pipeline of the first MBR membrane pool and the liquid outlet pipeline of the second MBR membrane pool are connected in parallel to the post-processing unit through the multi-stage channel switches, respectively, and the first MBR membrane pool and the second MBR membrane pool are disconnected;

[0019] Series mode, controlling the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool, opening the switching valve between the first MBR membrane pool and the second MBR membrane pool, wherein the liquid outlet pipeline of the first MBR membrane pool is connected to the switching valve through its multi-stage channel switch, and then connected to the liquid inlet pipeline of the second MBR membrane pool through the multi-stage channel switch of the second MBR membrane pool, and the liquid outlet pipeline of the second MBR membrane pool is connected to the post-processing unit through its multi-stage channel switch, and the first MBR membrane pool, the second MBR membrane pool and the post-processing unit are connected in series in sequence;

[0020] In the online backwashing mode, the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool are controlled respectively, and the outlet pipeline of the first MBR membrane pool is connected to the post-processing unit through its multi-stage channel switch, and then the post-processing unit is connected to the outlet pipeline of the second MBR membrane pool through the multi-stage channel switch of the second MBR membrane pool, and the pump on the outlet pipeline of the second MBR membrane pool is controlled to transport in reverse, and the first MBR membrane pool, the post-processing unit and the second MBR membrane pool are connected in series in sequence, and the second MBR membrane pool is backwashed online by the clean water purified by the post-processing unit.

[0021] The working method of the double MBR membrane tank group sewage treatment system in the above scheme also includes the following working modes:

[0022] Offline cleaning mode, controlling the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool respectively, closing the liquid inlet valve of the multi-stage channel switch of any MBR membrane pool, controlling its multi-stage channel switch to block all interfaces, and performing offline cleaning on the filter membrane in the MBR membrane pool.

[0023] The double MBR membrane pool sewage treatment system adopted in the present invention can realize the series and parallel operation of the first MBR membrane pool and the second MBR membrane pool, online backwashing or single membrane pool offline cleaning and other operations through a multi-stage channel switch, which is specifically achieved by the following means.

[0024] When the concentration of organic pollutants in the sewage to be treated is low, the parallel working mode is adopted, and the parallel operation of the first MBR membrane pool and the second MBR membrane pool is used to improve the MBR membrane treatment rate and the use efficiency of the double MBR membrane. In the parallel working mode, after the sewage is pre-treated by the MBR membrane pool front unit, the first liquid inlet valve and the second liquid inlet valve are opened, and the sewage before treatment passes through the first liquid inlet valve and the second liquid inlet valve and enters the first MBR membrane pool and the second MBR membrane pool for membrane filtration treatment respectively. Driven by the first pump and the second pump, the sewage after membrane filtration enters the multi-stage channel switch of the first MBR membrane pool and the second MBR membrane pool respectively. By adjusting and controlling the multi-stage channel switch, the sewage after membrane filtration of the first MBR membrane pool and the second MBR membrane pool enters the post-treatment unit for post-treatment after membrane filtration. After the post-treatment is completed, it can be discharged up to standard. The two groups of MBR membrane pools are connected in parallel to treat sewage at the same time, which improves the treatment efficiency.

[0025] When the pollutant concentration in the sewage is high and a single set of MBR membrane filtration treatment cannot achieve the sewage discharge standard, the series working mode is adopted, and the first MBR membrane pool and the second MBR membrane pool are connected in series to perform two membrane filtration treatments, so as to achieve efficient use of the MBR membrane and deep purification of sewage. In the series working mode, the first liquid inlet valve is opened, the second liquid inlet valve is closed, and the switching valves interconnected between the two MBR membrane pools are opened, and the two sets of multi-stage channel switches are adjusted and controlled. After the sewage passes through the first liquid inlet valve, it enters the first MBR membrane pool to complete the membrane filtration. Driven by the first pump, it enters the multi-stage channel switch of the first MBR membrane pool. After the sewage enters the multi-stage channel switch of the second MBR membrane pool through the switching valve after the liquid outlet of the first MBR membrane pool, it enters the liquid inlet pipeline of the second MBR membrane pool, and the sewage in the first MBR membrane pool is subjected to membrane filtration treatment again by the second MBR membrane pool. After the sewage completes the membrane filtration in the second MBR membrane pool, it enters the post-treatment unit through the multi-stage channel switch of the second MBR membrane pool again, and after the post-treatment is completed, it meets the discharge standard.

[0026] The connection mode of the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool in the present invention is symmetrically installed with the switching valves connected to each other as the center. In the series working mode, the series connection from the second MBR membrane pool to the first MBR membrane pool can be achieved by swapping the valves and multi-stage channel switches corresponding to the first MBR membrane pool and the second MBR membrane pool.

[0027] When the system of the present invention has been running for a period of time and one of the MBR membrane pools needs to be backwashed, an online backwashing mode is adopted to backwash the clogged membrane pool filter membrane online. In the online backwashing mode, the first liquid inlet valve is opened, the second liquid inlet valve is closed, the multi-stage channel switch of the two groups of MBR membrane pools is adjusted and controlled, and the switching valves interconnected between the two MBR membrane pools are closed. After the sewage is purified by the first MBR membrane pool, it enters the treatment unit after passing through the multi-stage channel switch, and the sewage is completely purified into clean water. The second pump of the second MBR membrane pool is controlled to reversely transport, and the clean water treated by the post-treatment unit is introduced into the outlet pipeline of the second MBR membrane pool and reversely enters the second MBR membrane pool to backwash the filter membrane inside the second MBR membrane pool. After the backwashing is completed inside the second MBR membrane pool, the sewage is discharged from the water inlet pipeline of the second MBR membrane pool into the front unit of the MBR membrane pool as sewage circulation treatment, so that the backwashing operation of the second MBR membrane pool is completed under the condition that the first MBR membrane pool works normally. The filter membrane in the MBR membrane pool is backwashed by the completely treated clean water, which is not easy to cause the filter membrane to be blocked, and the backwashing cleaning effect is better.

[0028] When the first MBR membrane pool needs to be backwashed while the second MBR membrane pool is operating normally, the second MBR membrane pool can be backwashed online by switching the valves and multi-stage channel switches corresponding to the first MBR membrane pool and the second MBR membrane pool.

[0029] After the system of the present invention has been running for a long period of time, when any of the membrane pools in the double MBR membrane pools needs to be cleaned offline, an offline cleaning operation is adopted, and the internal filter membrane material is taken out for offline cleaning by closing one of the MBR membrane pools. The first liquid inlet valve and the multi-stage channel switch of the first MBR membrane pool are closed, and the filter membrane material in the first MBR membrane pool is taken out for cleaning. At this time, the membrane filtration operation of the second MBR membrane pool is completely unaffected. Conversely, the filter membrane material in the second MBR membrane pool can also be cleaned offline.

[0030] The present invention has the following beneficial effects:

[0031] The dual MBR membrane pool group sewage treatment system of the present invention realizes the functions of parallel connection, series connection, single group online backwashing and single group offline cleaning of the dual MBR membrane pools in the sewage treatment process by arranging corresponding multi-stage channel switches for the two MBR membrane pools. Under any operating conditions, it can ensure that at least one group of MBR membranes works normally in the sewage treatment process. In addition, according to the sewage volume and the concentration of pollutants, the dual groups of MBR membrane pools in the process route can be connected in series to obtain two membrane filtration effects, or connected in parallel to improve the membrane filtration rate. In addition, the MBR filter membrane is thoroughly backwashed by the treated clean water, thereby improving the online continuous working life of the MBR filter membrane and maximizing the utilization efficiency of the MBR membrane.

[0032] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the double MBR membrane tank group sewage treatment system in the embodiment.

[0034] Figure 2 It is a schematic diagram of the structural decomposition of the multi-stage channel switch in the embodiment.

[0035] Figure 3 This is a schematic diagram of the parallel mode operation of the double MBR membrane tank group sewage treatment system in Example 1.

[0036] Figure 4 This is a schematic diagram of the series mode operation of the double MBR membrane tank group sewage treatment system in Example 2.

[0037] Figure 5 This is a schematic diagram of the online backwashing mode operation of the double MBR membrane tank group sewage treatment system in Example 3.

[0038] Numbers in the figure: 1-first liquid inlet valve, 2-second liquid inlet valve, 3-first MBR membrane tank, 4-second MBR membrane tank, 5-first pump, 6-second pump, 7-first multi-stage channel switch, 8-second multi-stage channel switch, 9-switching valve, 10-post-processing unit, 71-interface valve, 72-channel gate, 721-first channel module; 722-second channel module; 723-third channel module; 724-fourth channel module. DETAILED DESCRIPTION

[0039] Now, a double MBR membrane tank group sewage treatment system of the present invention is further explained in combination with the embodiments and the accompanying drawings. Obviously, this implementation case is only used as a further explanation of the double MBR membrane tank group sewage treatment system designed by the present invention, so that technicians in the field can more fully understand the technical means adopted by the present invention, and does not constitute any form of limitation on the technical design of the present invention. Any invention or utility model made based on the design principle of the present invention without creative labor should be protected by the present invention.

[0040] See Figure 1 and Figure 2 The double MBR membrane tank group sewage treatment system shown in the figure is a specific implementation scheme of the present invention, which specifically includes a first liquid inlet valve 1, a second liquid inlet valve 2, a first MBR membrane tank 3, a second MBR membrane tank 4, a first pump 5, a second pump 6, a first multi-stage channel switch 7, a second multi-stage channel switch 8, a switching valve 9 and a post-processing unit 10, etc.

[0041] Among them, the first MBR membrane pool 3 and the second MBR membrane pool 4 are two membrane pools that constitute the double membrane pool group sewage treatment system. The first MBR membrane pool 3 and the second MBR membrane pool 4 are respectively provided with a first liquid inlet valve 1 and a second liquid inlet valve 2 on the liquid inlet pipelines, and the liquid outlet pipelines are respectively connected with the post-treatment unit 10 through parallel pipelines. The post-treatment unit 10 is a unit for further purifying the water after membrane filtration treatment. According to different types of sewage, corresponding purification units can be set. The water passing through the post-treatment unit 10 can be directly discharged as clean water. In addition, the first MBR membrane pool 3 and the second MBR membrane pool 4 are also connected with an MBR membrane pool front unit (not shown in the figure) before the liquid inlet pipeline. For the collection of the treated sewage, preliminary sedimentation, intermediate aeration treatment and preliminary filtration before entering the MBR membrane pool group, the MBR membrane pool front unit is connected to the liquid inlet pipelines of the first MBR membrane pool 3 and the second MBR membrane pool 4 through two parallel pipelines. Both the post-treatment unit 10 and the pre-MBR membrane tank unit are existing sewage treatment technologies, and those skilled in the art can make conventional selections according to the types of sewage to be treated. The specific types are not described in detail in this embodiment.

[0042] A first multi-stage channel switch 7 and a second multi-stage channel switch 8 are respectively provided between the liquid outlet pipeline of the first MBR membrane pool 3 and the post-processing unit 10, and between the liquid outlet pipeline of the second MBR membrane pool 4 and the post-processing unit 10. At the same time, the first MBR membrane pool 3 and the second MBR membrane pool 4 are also directly connected to each other through the connecting pipeline of the first multi-stage channel switch 7 and the second multi-stage channel switch 8, and a switching valve 9 is provided on the pipeline connecting the first multi-stage channel switch 7 and the second multi-stage channel switch 8. The first multi-stage channel switch 7 and the second multi-stage channel switch 8 have multiple groups of interface switching modes, which can respectively realize the series connection and parallel connection between the first MBR membrane pool 3, the second MBR membrane pool 4 and the post-processing unit 10.

[0043] A first pump 5 and a second pump 6 are respectively arranged on the outlet pipes of the first MBR membrane pool 3 and the second MBR membrane pool 4, as the conveying power for the sewage to pass through the respective membrane pools for membrane filtration treatment. The first pump 5 and the second pump 6 in this embodiment are both bidirectional water pumps, and the direction of the water flow through the respective membrane pools can be controlled by changing the direction of the motor driving the water pump.

[0044] The first multi-stage channel switch 7 and the second multi-stage channel switch 8 in this embodiment have the same structure, and the first multi-stage channel switch 7 is taken as an example for specific description below.

[0045] Specific as Figure 2 As shown, the first multi-stage channel switch 7 includes an interface valve 71 and a channel gate 72. Four interfaces a, a1, a2 and a3 are provided on the interface valve 71. The first multi-stage channel switch 7 is connected with the inlet and outlet pipelines of the first MBR membrane pool 3, the second multi-stage channel switch 8 and the post-processing unit 10 through the above four interfaces. The channel gate 72 is relatively movable with the interface valve 71, and is provided with a plurality of channels for connecting and switching the two interfaces on the interface valve 71. By moving the channel gates of the two multi-stage channel switches, the interfaces on the interface valve are switched and connected accordingly, so as to achieve the switching control of the working relationship between the entire double MBR membrane pool group.

[0046] Specifically, on the first multi-stage channel switch 7, interfaces a2 and a3 are respectively connected to the liquid outlet pipelines of the post-processing unit 10 and the first MBR membrane pool 3, interface a1 is connected back to the liquid inlet of the corresponding MBR membrane pool, interface a is interconnected with the corresponding interface b on the second multi-stage channel switch 8, and the interface setting of the second multi-stage channel switch 8 corresponds to the same connection method of the second MBR membrane pool as the first multi-stage channel switch 7.

[0047] The interface valve 71 in this embodiment is a square ring structure, and the four interfaces thereon are respectively provided on the outer walls of the four ring bodies of the interface valve 71. The channel gate 72 adopts a columnar entity structure matching the cross section of the inner ring of the interface valve 71, and is divided into four module sections. The height of each module section corresponds to the thickness of the interface valve 71, and three of the module sections are respectively provided with channels for switching the interfaces on the interface valve 71. When the corresponding module section moves to align with the interface valve 71 up and down, the channel on the channel gate 72 realizes different communication paths between the interfaces on the interface valve 71, and the other module section is not provided with a channel, which is used to block all interfaces on the interface valve 71. The surfaces where the channel gate 72 and the interface valve 71 contact are respectively provided with sealing rings at the positions of the corresponding channel ports and interfaces to ensure the sealing performance of the channel and the interface after docking. The movement of the channel gate 72 can be precisely controlled by a servo motor to ensure that each module section on the channel gate 72 is precisely aligned with the interface valve 71.

[0048] Specifically, no channel is set on the first channel module 721 on the channel gate 72. In order to block the interface on the interface valve 71, the channel set on the second channel module 722 connects the interface a2 and the interface a3 on the interface valve 71, and connects the liquid outlet pipeline of the first MBR membrane pool 3 with the post-processing unit 10. The channel set on the third channel module 723 connects the interface a2 and the interface a on the interface valve 71, and connects the liquid outlet pipeline of the first MBR membrane pool 3 with the second MBR membrane pool 4. Two groups of channels are set on the fourth channel module 724, which connect the interface a2 and the interface a3 on the interface valve 71, and the interface a1 and the interface a in pairs, so that the liquid outlet pipeline of the first MBR membrane pool 3 is connected to the post-processing unit 10, and the liquid inlet pipeline of the first MBR membrane pool 3 is connected to the second MBR membrane pool 4.

[0049] Specific as Figure 1 As shown, the connection mode between the first MBR membrane pool 3 and the first multi-stage channel switch 7 is exactly the same as the connection mode between the second MBR membrane pool 4 and the second multi-stage channel switch 8, and they are arranged symmetrically with the switching valves connected to each other as the center. The four interfaces on the second multi-stage channel switch 8 are b, b1, b2 and b3 respectively. Figure 1 , 3 -5 and specific embodiments describe in detail the specific working method of the double MBR membrane tank group sewage treatment system.

[0050] Embodiment 1

[0051] After pretreatment in the MBR membrane pool front unit, if the pollutant concentration in the wastewater to be treated is low, the first MBR 3 membrane pool and the second MBR 4 membrane pool are connected in parallel to treat the wastewater, such as Figure 3As shown in the figure, by controlling the multi-stage channel switches of the first MBR membrane pool 3 and the second MBR membrane pool 4 respectively, the liquid outlet pipeline of the first MBR membrane pool 3 and the liquid outlet pipeline of the second MBR membrane pool 4 are connected in parallel to the post-treatment unit 10 through the multi-stage channel switches, and the first MBR membrane pool and the second MBR membrane pool are shut off.

[0052] The specific operation is as follows: open the first liquid inlet valve 1 and the second liquid inlet valve 2, close the switching valve 9, adjust the connection mode of the first multi-stage channel switch 7 and the second multi-stage channel switch 8 to align the second channel modules of their respective channel gates, and the sewage before treatment passes through the first liquid inlet valve 1 and the second liquid inlet valve 2 and enters the first MBR membrane pool 3 and the second MBR membrane pool 4 for membrane filtration treatment respectively. The first pump 5 and the second pump 6 are both in forward rotation at this time, and the sewage after membrane filtration in each MBR membrane pool is output from the outlet pipeline and sent to the first multi-stage channel switch 7 and the second multi-stage channel switch 8 through the interface a2 and the interface b2 respectively. Under the guidance of the channel on the second channel module, the filtered water is transported from the interface a3 and b3 to the post-treatment unit 10 for purification and then discharged in compliance with the standards.

[0053] The parallel treatment method can simultaneously utilize the first MBR membrane pool 3 and the second MBR membrane pool 4 for membrane filtration treatment, has a fast treatment speed, and is suitable for working conditions where the membrane pool is in good condition or the pollutant concentration in the sewage is low.

[0054] Embodiment 2

[0055] When the pollutant concentration in the sewage is high, or the MBR membrane pool in the double-membrane pool sewage treatment system is in poor condition, and single membrane filtration cannot achieve sewage discharge standards, the sewage can be treated by connecting the first MBR membrane pool 3 and the second MBR membrane pool 4 in series, such as Figure 4 As shown in the figure, the multi-stage channel switches of the first MBR membrane pool 3 and the second MBR membrane pool 4 are controlled, and the switching valve 9 between the first MBR membrane pool 3 and the second MBR membrane pool 4 is opened, wherein the outlet pipeline of the first MBR membrane pool 3 is connected to the switching valve 9 through its multi-stage channel switch, and then connected to the inlet pipeline of the second MBR membrane pool 4 through the multi-stage channel switch of the second MBR membrane pool 4, and the outlet pipeline of the second MBR membrane pool 4 is connected to the post-treatment unit 10 through its multi-stage channel switch, and the first MBR membrane pool 3, the second MBR membrane pool 4 and the post-treatment unit 10 are connected in series in sequence, and efficient purification of sewage is achieved through two membrane filtrations.

[0056] The specific operation is as follows: open the first liquid inlet valve 1, close the second liquid inlet valve 2, open the switching valve 9, set the connection mode of the first multi-stage channel switch 7 to align with the third channel module of the channel gate, set the connection mode of the second multi-stage channel switch 8 to align with the fourth channel module of the channel gate, the sewage enters the first MBR membrane pool 3 through the first liquid inlet valve 1, completes the first membrane filtration under the positive rotation of the first pump 5, and is introduced into the switching valve 9 through the interface a2-interface a passage of the first multi-stage channel switch 7. After the sewage has been filtered once, it enters the second multi-stage channel switch 8, firstly through the interface b-interface b1 passage to the liquid inlet pipeline of the second MBR membrane pool 4. Driven by the positive rotation of the second pump 6, the sewage enters the second MBR membrane pool 4 and passes through the membrane filtration of the second MBR membrane pool 4 for the second time. After entering the post-treatment unit 10 through the interface b2-interface b3 passage of the fourth channel module of the second multi-stage channel switch 8 for post-treatment, thereby achieving two MBR membrane filtration treatments and standard discharge.

[0057] Figure 4 The series connection sequence from the first MBR membrane pool 3 to the second MBR membrane pool 4 is shown in FIG. In this embodiment, “first” and “second” are only used to distinguish and identify the two groups of MBR membrane pools, and are not limited to the series connection sequence of the technical solution. In actual applications, the series connection sequence can also be adopted. Figure 4 The series sequence from the second membrane pool MBR4 to the first MBR membrane pool 3. Since the first MBR membrane pool 3 and the second MBR membrane pool 4 and their corresponding multi-stage channel switches are in the same connection mode, the first MBR membrane pool 3 can be connected in series behind the second MBR membrane pool 4 to perform double-membrane series membrane filtration operation by swapping the valves and multi-stage switch controls of the two groups of MBR membrane pools.

[0058] The specific operation is as follows: close the first liquid inlet valve 1, open the second liquid inlet valve 2 and the switching valve 9, set the connection mode of the second multi-stage channel switch 8 to align with the third channel module of the channel gate, set the connection mode of the first multi-stage channel switch 7 to align with the fourth channel module of the channel gate, the sewage enters the second MBR membrane pool 4 through the second liquid inlet valve 2, and completes the first membrane filtration under the drive of the second pump 6, and is introduced into the switching valve 9 through the interface b2-interface b passage on the second multi-stage channel switch 8. After the sewage has passed through the membrane filtration once, it enters the first multi-stage channel switch 7, and is first introduced into the liquid inlet pipeline of the second MBR membrane pool 4 through the interface a-interface a1 passage. Driven by the forward rotation of the first pump 5, the sewage after the membrane filtration once passes through the membrane filtration of the first MBR membrane pool 3, and then enters the post-treatment unit 10 through the interface a2-interface a3 passage of the fourth channel module for post-treatment, that is, the two MBR membrane pool series membrane filtrations of the second operation mode are completed.

[0059] In this embodiment, since the sewage to be treated is subjected to two MBR membrane filtrations, the membrane filtration functions of the two groups of MBR membranes can be fully utilized to deeply purify the sewage with high concentrations of pollutants, achieving a better purification effect than a single group of MBR membrane filtration process.

[0060] Embodiment 3

[0061] After the double MBR membrane pool group has been running for a period of time, some particles are enriched or ions are precipitated on the MBR filter membrane. The online backwashing mode can be used to clean the MBR filter membrane. Figure 5 As shown in the figure, by controlling the multi-stage channel switches of the first MBR membrane pool 3 and the second MBR membrane pool 4 respectively, the outlet pipeline of the first MBR membrane pool 3 is connected to the post-treatment unit 10 through its multi-stage channel switch, and then the post-treatment unit 10 is connected to the outlet pipeline of the second MBR membrane pool 4 through the multi-stage channel switch of the second MBR membrane pool 4, the pump on the outlet pipeline of the second MBR membrane pool 4 is controlled to reversely transport, the first MBR membrane pool 3, the post-treatment unit 10 and the second MBR membrane pool 4 are connected in series in sequence, and the second MBR membrane pool is backwashed online by the clean water purified by the post-treatment unit 10.

[0062] The specific operation is as follows: open the first liquid inlet valve 1 and the second liquid inlet valve 2, close the switching valve 9, set the connection mode of the first multi-stage channel switch 7 and the second multi-stage channel switch 8 to the second channel module, and control the first pump 5 to rotate forward and the second pump 6 to rotate reversely. After the sewage is filtered and purified by the first MBR membrane pool 3, it is introduced into the post-treatment unit 10 through the interface a2-interface a3 passage of the first multi-stage channel switch 7 for deep purification treatment. The clean water after the deep purification treatment is driven by the reverse rotation of the second pump 6 through the interface b3-b2 passage of the second multi-stage channel switch 8 from the outlet pipeline of the second MBR membrane pool 4, and the filter membrane in the second MBR membrane pool 4 is backwashed. After the backwashing of the second MBR4, the sewage flows back to the MBR membrane front unit through the second liquid inlet valve 2 and is treated again together with the sewage in the MBR membrane front unit.

[0063] The above is an online backwashing of the second MBR membrane pool 4. Since the first MBR membrane pool 3 and the second MBR membrane pool 4 and their corresponding multi-stage channel switches are connected in the same way, the first MBR membrane pool 3 can also be backwashed. During the specific operation, it is only necessary to set the first pump 5 to reverse and the second pump 6 to forward. The water flow route is exactly opposite to the route when the second MBR membrane pool 4 is backwashed.

[0064] During the backwashing operation, the membrane filtration water volume and the backwashing water volume can be adjusted by adjusting the rotation speed of the first pump 5 and the second pump 6, thereby ensuring that the amount of water entering the post-treatment unit 10 is always greater than or equal to the amount of water extracted from the post-treatment unit 10 for backwashing, thereby ensuring that the MBR membrane pool that normally membrane filters sewage can continue to perform MBR membrane filtration operations during the backwashing operation.

[0065] In this embodiment, since the double MBR membrane pool can be backwashed during the normal operation of the system, and the water purified by the post-treatment unit is used for backwashing during the backwashing process, the efficiency of the backwashing can be effectively improved, and the damage of the MBR filter membrane caused by poor backwashing water quality can be avoided, and the long-term continuous and stable operation of the double MBR membrane pool can be ensured. Compared with the MBR membrane sewage purification system in the prior art, the number of backwashing of the MBR membrane can be appropriately increased without affecting the sewage purification efficiency to increase the normal service time of the MBR membrane and reduce the offline cleaning frequency of the MBR membrane.

[0066] Embodiment 4

[0067] When one of the membrane pools in the double MBR membrane pool group has a lot of particle enrichment or ion precipitation after long-term operation, this embodiment can also use the offline cleaning mode to clean the MBR filter membrane, by controlling the multi-stage channel switches of the first MBR membrane pool 3 and the second MBR membrane pool 4, closing the liquid inlet valve of the multi-stage channel switch of any MBR membrane pool, controlling its multi-stage channel switch to block all interfaces, and cleaning the filter membrane in the MBR membrane pool offline, while ensuring the normal operation of the other membrane pool in the process route. .

[0068] The specific operation is as follows: when the first MBR membrane pool 3 needs to be cleaned offline, it is only necessary to close the first liquid inlet valve 1 and align the connection mode of the first multi-stage channel switch 7 with the first channel module of the channel gate, and block and close all the interfaces corresponding to the first MBR membrane pool 3, so as to achieve isolation of the process route of the first MBR membrane pool 3. When the filter membrane material in the first MBR membrane pool 3 is taken out of the membrane pool and cleaned offline, the second MBR membrane pool 4 can perform single membrane pool filtration treatment normally in parallel mode, ensuring that at least one group of MBR membranes in the double MBR membrane pool group sewage treatment system is working normally, so as to achieve the goal of uninterrupted sewage treatment.

[0069] Since the first MBR membrane pool 3 and the second MBR membrane pool 4 and their corresponding multi-stage channel switches have the same connection mode, the second liquid inlet valve 2 of the second MBR membrane pool 4 and the connection mode of the second multi-stage channel switch 8 are aligned with the first channel module of the channel gate. The first MBR membrane pool 3 can normally perform single membrane pool filtration treatment in parallel mode, that is, the second MBR membrane pool 4 can be cleaned offline when the first MBR membrane pool 3 is operating normally. By alternating offline cleaning, the purpose of normal operation of at least one group of MBR membranes and normal operation of the sewage treatment process route can be achieved.

[0070] The working route states of the double MBR membrane tank group sewage treatment system corresponding to the above four embodiments are shown in Table 1 below.

[0071] Table 1

[0072]

[0073] The above embodiments describe the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only illustrate the specific working principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A double MBR membrane tank group sewage treatment system, characterized by: It includes a first MBR membrane tank, a second MBR membrane tank, a post-processing unit and a multi-stage channel switch; The inlet pipeline of the first MBR membrane pool and the inlet pipeline of the second MBR membrane pool are respectively provided with an inlet valve, the outlet pipeline of the first MBR membrane pool and the outlet pipeline of the second MBR membrane pool are respectively connected to the post-processing unit, and a multi-stage channel switch is respectively provided between the first MBR membrane pool and the post-processing unit and between the second MBR membrane pool and the post-processing unit, and the first MBR membrane pool and the second MBR membrane pool are also connected to each other through their own multi-stage channel switches; The multi-stage channel switch comprises an interface valve and a channel gate, wherein the interface valve is a square ring structure, and a plurality of interfaces are arranged on the interface valve. The channel gate adopts a columnar entity structure matching the inner ring section of the interface valve, and is divided into four module sections, and the height of each module section corresponds to the thickness of the interface valve. The channel gate is relatively movable with the interface valve to connect and switch the interfaces on the interface valve; a switching valve is arranged on the pipeline connecting the multi-stage channel switch of the first MBR membrane pool and the multi-stage channel switch of the second MBR membrane pool; The interface valve of the multi-stage channel switch is provided with four interfaces, two of which are respectively connected to the post-processing unit and the liquid outlet pipe of the corresponding MBR membrane pool, another interface is connected back to the liquid inlet of the corresponding MBR membrane pool, and the last interface is interconnected with the corresponding interface on the multi-stage channel switch of another MBR membrane pool.

2. According to the double MBR membrane tank group sewage treatment system of claim 1, pumps are provided on the liquid outlet pipelines of the first MBR membrane tank and the second MBR membrane tank.

3. According to the double MBR membrane pool group sewage treatment system of claim 2, the pump is a bidirectional water pump.

4. According to a double MBR membrane pool group sewage treatment system as described in claim 1, the interface valve is an annular structure, the interfaces are respectively arranged on the outer wall of the annulus of the interface valve, and the channel gate is a multi-section entity passing through the interface valve, and the channel gate is segmented and provided with channels for switching the interfaces on the interface valve.

5. A dual MBR membrane pool sewage treatment system according to any one of claims 1 to 4, wherein each section of the channel gate is provided with at least one of a channel connecting the outlet pipeline of the corresponding MBR membrane pool with the post-treatment unit, a channel connecting the inlet pipeline of the corresponding MBR membrane pool with another MBR membrane pool, and a channel connecting the outlet pipeline of the corresponding MBR membrane pool with another MBR membrane pool.

6. According to the double MBR membrane pool group sewage treatment system of claim 5, the channel gate is also provided with a segment that completely blocks all interfaces on the interface valve.

7. A method for operating a double MBR membrane tank sewage treatment system according to any one of claims 1 to 6, characterized in that The following working modes are included: In parallel mode, the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool are controlled, and the liquid outlet pipeline of the first MBR membrane pool and the liquid outlet pipeline of the second MBR membrane pool are connected in parallel to the post-processing unit through the multi-stage channel switches, respectively, and the first MBR membrane pool and the second MBR membrane pool are disconnected; Series mode, controlling the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool, opening the switching valve between the first MBR membrane pool and the second MBR membrane pool, wherein the liquid outlet pipeline of the first MBR membrane pool is connected to the switching valve through its multi-stage channel switch, and then connected to the liquid inlet pipeline of the second MBR membrane pool through the multi-stage channel switch of the second MBR membrane pool, and the liquid outlet pipeline of the second MBR membrane pool is connected to the post-processing unit through its multi-stage channel switch, and the first MBR membrane pool, the second MBR membrane pool and the post-processing unit are connected in series in sequence; In the online backwashing mode, the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool are controlled respectively, and the outlet pipeline of the first MBR membrane pool is connected to the post-processing unit through its multi-stage channel switch, and then the post-processing unit is connected to the outlet pipeline of the second MBR membrane pool through the multi-stage channel switch of the second MBR membrane pool, and the pump on the outlet pipeline of the second MBR membrane pool is controlled to transport in reverse, and the first MBR membrane pool, the post-processing unit and the second MBR membrane pool are connected in series in sequence, and the second MBR membrane pool is backwashed online by the clean water purified by the post-processing unit.

8. The working method of the double MBR membrane pool sewage treatment system according to claim 7 further comprises the following working modes: Offline cleaning mode, controlling the multi-stage channel switches of the first MBR membrane pool and the second MBR membrane pool respectively, closing the liquid inlet valve of the multi-stage channel switch of any MBR membrane pool, controlling its multi-stage channel switch to block all interfaces, and performing offline cleaning on the filter membrane in the MBR membrane pool.

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