Automatic MBR (Membrane Bioreactor) reflux device and system

Abstract

The utility model relates to the technical field of sewage treatment, in particular to an automatic MBR (Membrane Bioreactor) reflux device and system.The device comprises a transfer pool, a first electromagnetic valve, a controller and a first detection component, the transfer pool is provided with a liquid inlet used for being communicated with an MBR membrane pool and a liquid outlet used for being communicated with a biochemical reaction pool; the first detection assembly is arranged in the transfer pool, electrically connected with the controller and used for monitoring the sludge concentration of the transfer pool, and the first electromagnetic valve is electrically connected with the controller and arranged at the liquid outlet. According to the utility model, the reflux ratio of the MBR process can be automatically controlled, the nitrate concentration of sludge in the MBR membrane tank, which flows back to an anaerobic zone, is optimized, the overhigh nitrate concentration is prevented from inhibiting the activity of phosphorus-accumulating bacteria, the biological phosphorus removal capability of the phosphorus-accumulating bacteria is improved, and the use of chemical phosphorus removal agents is reduced.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and more specifically, to an automated MBR reflux device and system. Background Technology

[0002] MBR, or Membrane Bioreactor, is a modern wastewater treatment technology that combines the advantages of biological treatment and membrane separation, providing an effective solution for efficient wastewater treatment and resource recovery. Its working principle is as follows: Wastewater first enters the reaction tank of the MBR system, where it mixes with activated sludge (microorganisms). The microorganisms in the activated sludge convert the organic matter in the wastewater into their own energy, while producing carbon dioxide and water. The mixture after microbial treatment passes through an ultrafiltration membrane with a pore size of less than 0.1 micrometers to intercept microorganisms and incompletely decomposed large organic molecules, but allows water molecules and some small molecules to pass through. Through the filtration effect of the membrane, clean water is separated, resulting in effluent with extremely high quality standards, even suitable for direct reuse. The activated sludge (containing microorganisms and large molecules that did not pass through the membrane) that is intercepted by the membrane is returned to the reaction tank to continue participating in the wastewater treatment process.

[0003] Chinese patent CN202020549276.6 discloses an MBR membrane system. This system uses a reaction vessel with a lower space, above which the MBR membrane module and aeration components are positioned, creating a lower space with a lower dissolved oxygen content than the MBR membrane module and aeration components. Since sludge containing microorganisms easily accumulates at the bottom of the reaction vessel, the lower space can consume dissolved oxygen. The lower space is connected to a wastewater return pipe, which also connects to the microbial denitrification section. By using the wastewater return pipe in the lower space, water with low dissolved oxygen content or a sludge-water mixture is output to the microbial denitrification section. After consuming dissolved oxygen in the lower space, the water is then transported to the microbial denitrification section. Compared to MBR membrane systems filled with a packing box or those that directly transport water with the output port located at the MBR membrane module, this system allows for better reaction in the microbial denitrification section, saving on the structure of the packing box and improving the reaction efficiency of the microbial denitrification section. However, in actual operation, polyphosphate-accumulating bacteria in the MBR process suffer severe mortality. This is because the reflux liquid in the MBR process has a low sludge content and a high water content, resulting in a very high reflux ratio. This necessitates more reflux to maintain the sludge volume of the entire system, leading to more dissolved nitrates entering the anaerobic zone. Studies have shown that nitrate concentrations above 3 mg / L compete with polyphosphate-accumulating bacteria for carbon sources, inhibiting their growth and phosphorus release. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the low mud content in the reflux mixture of existing MBR membrane systems, and to propose an automated MBR reflux device and system that automatically controls the reflux ratio of the MBR process, optimizes the nitrate concentration in the reflux from the MBR membrane tank to the anaerobic zone, prevents excessively high nitrate concentrations from inhibiting polyphosphate-accumulating bacteria activity, revitalizes the biological phosphorus removal capacity of polyphosphate-accumulating bacteria, and reduces the use of chemical phosphorus removal agents.

[0005] To achieve the above objectives, this solution provides an automated MBR reflux device, including a transfer tank, a first solenoid valve, a controller, and a first detection component. The transfer tank is provided with an inlet for communicating with the MBR membrane tank and an outlet for communicating with the biochemical reaction tank. The first detection component is located in the transfer tank and electrically connected to the controller to monitor the sludge concentration in the transfer tank. The first solenoid valve is electrically connected to the controller and is located at the outlet.

[0006] In this technical solution, the activated sludge intercepted in the MBR membrane tank is pumped into a transfer tank. The activated sludge is allowed to stand in the transfer tank. The first detection component monitors the sludge concentration in real time and feeds the monitoring information back to the controller. When the sludge concentration in the transfer tank reaches the set value, the controller controls the first solenoid valve to open, and the sludge is transported to the biological reaction tank through the outlet to maintain its sludge volume. This device can optimize the nitrate concentration of the sludge returned from the MBR membrane tank to the anaerobic zone of the biological reaction tank, preventing excessively high nitrate concentrations from inhibiting the activity of polyphosphate-accumulating bacteria, thereby activating the biological phosphorus removal capacity of polyphosphate-accumulating bacteria, reducing the use of chemical phosphorus removal agents, and this process is automated through the controller.

[0007] As a preferred embodiment, the sludge will be concentrated and deposited at the bottom of the transfer tank after a period of settling. In order to facilitate the transportation of the concentrated sludge, the inlet and outlet are respectively located at the bottom of the transfer tank.

[0008] As a preferred embodiment, the first detection component includes an MLSS detection probe and a nitrate concentration detection probe electrically connected to the controller. The MLSS detection probe and the nitrate concentration detection probe are respectively located at the lower part of the transfer tank. The MLSS detection probe and the nitrate concentration detection probe are used to monitor the mixed liquor suspended solids concentration and nitrate concentration of the sludge, respectively. After the monitoring data is sent to the controller, the controller judges the degree of sludge concentration. When the concentration required by the biochemical reaction tank is reached, the controller controls the first solenoid valve to open.

[0009] As a preferred embodiment, in order to avoid blockage of the conveying channel and improve the sludge conveying efficiency, a first peristaltic pump electrically connected to the controller is provided between the first solenoid valve and the inlet. One end of the first peristaltic pump is connected to the inlet, and the other end of the first peristaltic pump is connected to the inlet of the first solenoid valve. When the sludge concentration reaches the required concentration in the biochemical reaction tank, the first solenoid valve is opened and the first peristaltic pump is started. The first peristaltic pump can convey the sludge at the bottom of the transfer tank to the biochemical reaction tank.

[0010] As a preferred embodiment, in order to facilitate the suction of activated sludge intercepted by the membrane in the MBR membrane tank, the inlet is equipped with a second peristaltic pump and a second solenoid valve electrically connected to the controller.

[0011] As a preferred embodiment, in order to monitor the amount of sludge mixture in the transfer tank and avoid excessive sludge being pumped out and causing overflow, the transfer tank is equipped with a level gauge electrically connected to the controller.

[0012] As a preferred embodiment, the nitrate concentration of the sludge flowing out of the outlet is less than 0.3 mg / L, and the mixed liquor suspended solids concentration of the sludge flowing out of the outlet is 6000-8000 mg / L. Sludge at this concentration will not inhibit the activity of polyphosphate-accumulating bacteria and can replenish the amount of activated sludge in the biochemical reaction tank.

[0013] As a preferred embodiment, in order to control the amount of sludge transported, the outlet is equipped with a flow meter electrically connected to the controller. The controller can transport a fixed amount of sludge according to the sludge demand of the biochemical reaction tank. When the flow meter reaches the amount of sludge required by the biochemical reaction tank, it sends a signal to the controller, and the controller then closes the first solenoid valve and the first peristaltic pump.

[0014] To achieve the above objectives, this solution provides an automated MBR reflux system, including the aforementioned automated MBR reflux device, and further including an MBR membrane tank and a biochemical reaction tank connected together. The MBR membrane tank is connected to the inlet, the inlet of the first solenoid valve is connected to the outlet, and the outlet of the first solenoid valve is connected to the biochemical reaction tank.

[0015] As a preferred embodiment, a third peristaltic pump is provided between the MBR membrane tank and the transfer tank. One end of the third peristaltic pump is connected to the MBR membrane tank, and the other end of the third peristaltic pump is connected to the upper part of the transfer tank, so as to return the supernatant of the transfer tank to the MBR membrane tank.

[0016] In this technical solution, the MBR membrane tank and the biological reaction tank are existing technologies in the field of wastewater treatment. Wastewater first enters the biological reaction tank for treatment, where activated sludge degrades the wastewater. Subsequently, the wastewater, along with some still-active sludge, enters the MBR membrane tank for filtration. The filtered water is discharged, while the activated sludge intercepted in the MBR membrane tank is pumped by a second peristaltic pump to a transfer tank for settling. After the sludge is concentrated, it is transported by a first peristaltic pump to the anaerobic section of the biological reaction tank to replenish the lost activated sludge. After the sludge transport is completed, the supernatant in the transfer tank is returned to the MBR membrane tank by a third peristaltic pump for continued filtration.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] 1. The controller in this utility model is electrically connected to the first detection component, the first solenoid valve, the flow meter and the first peristaltic pump respectively, so as to realize the automatic return of MBR sludge and can quantitatively transport sludge according to the amount of sludge required in the biochemical reaction tank.

[0019] 2. By setting up a transfer tank, sludge can be concentrated, thereby reducing the return ratio, optimizing the nitrate concentration returned from the MBR membrane tank to the anaerobic zone, preventing excessively high nitrate concentrations from inhibiting polyphosphate-accumulating bacteria activity, activating the biological phosphorus removal capacity of polyphosphate-accumulating bacteria, and reducing the use of chemical phosphorus removal agents.

[0020] 3. By setting a level gauge to measure the liquid level in the transfer tank and feeding it back to the controller in real time, the excessive sludge in the transfer tank can be prevented from overflowing. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the automated MBR reflux device of this utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the automated MBR reflux system of this utility model;

[0023] Figure 3 This is a flowchart of the automated MBR reflux system of this utility model.

[0024] In the diagram: Transfer tank 1; Outlet 11; First solenoid valve 111; First peristaltic pump 112; Flow meter 113; Inlet 12; Second solenoid valve 121; Second peristaltic pump 122; Controller 2; First detection component 3; Level gauge 4; MBR membrane tank 5; Membrane module 51; Aeration component 52; Chemical dosing component 53; Water collection pipe 54; Biochemical reaction tank 6; Second detection component 61; Third peristaltic pump 7; Fourth peristaltic pump 8; Third solenoid valve 9. Detailed Implementation

[0025] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0026] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0027] The technical solution of this utility model will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0028] Example 1:

[0029] like Figure 1 As shown, this embodiment provides an automated MBR reflux device, including a transfer tank 1, a first solenoid valve 111, a controller 2, and a first detection component 3. The transfer tank 1 is provided with an inlet 12 for communicating with an MBR membrane tank 5 and an outlet 11 for communicating with a biochemical reaction tank 6. The first detection component 3 is located in the transfer tank 1 and electrically connected to the controller 2 to monitor the sludge concentration of the transfer tank 1. The first solenoid valve 111 is located at the outlet 11 and electrically connected to the controller 2.

[0030] In this embodiment, the inlet 12 and the outlet 11 are respectively located at the bottom of the transfer tank 1.

[0031] Specifically, the first detection component 3 includes an MLSS detection probe and a nitrate concentration detection probe that are electrically connected to the controller 2. The MLSS detection probe and the nitrate concentration detection probe are respectively located at the lower part of the transfer tank 1.

[0032] In this embodiment, the transfer tank 1 is a PVC storage tank. The controller 2 can collect the concentration of suspended solids and nitrate concentration of the activated sludge mixture in the transfer tank 1 through the first detection component 3. The controller 2 can also calculate the amount of sludge that needs to be returned. When the concentration reaches the set value, the controller controls the first solenoid valve 111 to open to transport the concentrated activated sludge.

[0033] Specifically, a first peristaltic pump 112 electrically connected to the controller 2 is provided between the first solenoid valve 111 and the liquid outlet 11. One end of the first peristaltic pump 112 is connected to the liquid outlet 11, and the other end of the first peristaltic pump 112 is connected to the inlet of the first solenoid valve 111.

[0034] In this embodiment, the first peristaltic pump 112 delivers the concentrated activated sludge more quickly to prevent clogging of the outlet 11. During this process, the mixed liquid delivered contains a large amount of sludge.

[0035] Specifically, the liquid inlet 12 is equipped with a second peristaltic pump 122 and a second solenoid valve 121 that are electrically connected to the controller 2.

[0036] In this embodiment, the second peristaltic pump 122 can pump out the activated sludge intercepted in the MBR membrane tank 5, and the mixed liquor obtained during this process contains less sludge.

[0037] Specifically, the transfer pool 1 is equipped with a level gauge 4 that is electrically connected to the controller 2.

[0038] In this embodiment, the level gauge 4 is an ultrasonic level gauge.

[0039] Specifically, the outlet 11 is equipped with a flow meter 113 that is electrically connected to the controller 2.

[0040] In this embodiment, the sludge return flow rate can be precisely controlled by the flow meter 113.

[0041] Specifically, the nitrate concentration of the sludge flowing out of the outlet 11 is less than 0.3 mg / L, and the mixed liquor suspended solids concentration of the sludge flowing out of the outlet 11 is 6000-8000 mg / L.

[0042] In this embodiment, sludge at this concentration will not inhibit polyphosphate-accumulating bacteria activity, and the amount of activated sludge in the biochemical reaction tank can be replenished.

[0043] Example 2:

[0044] like Figure 2 , 3 As shown, this embodiment provides an automated MBR reflux system, including the aforementioned automated MBR reflux device, and further including a biochemical reaction tank 6 and an MBR membrane tank 5 connected together. The MBR membrane tank 5 is connected to the inlet 12, the inlet of the first solenoid valve 111 is connected to the outlet 11, and the outlet of the first solenoid valve 111 is connected to the biochemical reaction tank 6.

[0045] In this embodiment, a fourth peristaltic pump 8 and a third solenoid valve 9 are provided between the MBR membrane tank 5 and the biochemical reaction tank 6. The MBR membrane tank 5 is equipped with a membrane module 51 for filtration, and a water collection pipe 54 is connected to the membrane module 51 for collecting filtered clean water. The bottom of the MBR membrane tank 5 is equipped with an aeration component 52 for providing sufficient oxygen to support the growth of aerobic microorganisms and the treatment capacity of activated sludge. The biochemical reaction tank 6 is equipped with a second detection component 61 electrically connected to the controller 2 for detecting the sludge concentration in its anaerobic section. The second detection component 61 includes an MLSS detection probe and a nitrate concentration detection probe.

[0046] In this embodiment, in order to maintain the MBR membrane tank 5, the MBR membrane tank 5 is equipped with a chemical dosing assembly 53, which includes a chemical dosing tank and a chemical dosing pump, for periodically chemically cleaning the membrane module 51 to maintain the water permeability of the membrane and extend the service life of the membrane. The MBR membrane tank 5 is also equipped with a backwashing and maintenance cleaning system (not shown in the figure), which includes a backwashing pump, a backwashing valve, a backwashing water tank, etc., for physically cleaning the membrane module 51 to remove contaminants from the membrane surface.

[0047] Example 3:

[0048] This embodiment is similar to Embodiment 2, except that in this embodiment, a third peristaltic pump 7 is provided between the MBR membrane tank 5 and the transfer tank 1. One end of the third peristaltic pump 7 is connected to the MBR membrane tank 5, and the other end of the third peristaltic pump 7 is connected to the upper part of the transfer tank 1, so as to return the supernatant of the transfer tank 1 to the MBR membrane tank 5.

[0049] The working process of this automated MBR reflux system is as follows:

[0050] Wastewater first enters the biochemical reaction tank 6 for treatment. The fourth peristaltic pump 8 and the third solenoid valve 9 are then turned on, allowing the wastewater to enter the MBR membrane tank 5. Under the action of the aeration component 52, the wastewater enters the membrane component 51 for filtration. The filtered water is collected through the collection pipe 54 and discharged. Subsequently, the second peristaltic pump 122 and the second solenoid valve 121 are turned on. At this time, the activated sludge intercepted by the membrane component is pumped to the transfer tank 1 for settling. Once the level gauge 4 detects that the liquid level has reached the designated height, it sends a signal to the controller 2. The controller 2 then controls the second peristaltic pump 122 and the second solenoid valve 121 to close. Meanwhile, the first detection component 3 monitors the mixed liquor suspension of the sludge in real time. Once the sludge concentration reaches the specified values ​​for floating solids and nitrates, controller 2 opens the first solenoid valve 111 and the first peristaltic pump 112, and the sludge is transported to the anaerobic section of the biochemical reactor 6. The second detection component 61 monitors the sludge concentration in the anaerobic section of the biochemical reactor 6 in real time and sends a signal to controller 2. Controller 2 calculates the required amount of sludge and, in conjunction with flow meter 113, closes the first solenoid valve 111 and the first peristaltic pump 112 at any time. After the first solenoid valve 111 and the first peristaltic pump 112 are closed, controller 2 opens the third peristaltic pump 7 to return the remaining supernatant in transfer tank 1 to the MBR membrane tank 5 for further filtration.

[0051] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0052] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An automated MBR reflux device, characterized in that, The system includes a transfer tank (1), a first solenoid valve (111), a controller (2), and a first detection component (3). The transfer tank (1) is provided with an inlet (12) for communicating with the MBR membrane tank (5) and an outlet (11) for communicating with the biochemical reaction tank (6). The first detection component (3) is located in the transfer tank (1) and electrically connected to the controller (2) to monitor the sludge concentration of the transfer tank (1). The first solenoid valve (111) is located at the outlet (11) and electrically connected to the controller (2).

2. The automated MBR reflux device according to claim 1, characterized in that, The inlet (12) and outlet (11) are respectively located at the bottom of the transfer tank (1).

3. An automated MBR reflux device according to claim 2, characterized in that, The first detection component (3) includes an MLSS detection probe and a nitrate concentration detection probe that are electrically connected to the controller (2). The MLSS detection probe and the nitrate concentration detection probe are respectively located at the lower part of the transfer tank (1).

4. An automated MBR reflux device according to claim 2, characterized in that, A first peristaltic pump (112) electrically connected to the controller (2) is provided between the first solenoid valve (111) and the liquid outlet (11). One end of the first peristaltic pump (112) is connected to the liquid outlet (11), and the other end of the first peristaltic pump (112) is connected to the inlet of the first solenoid valve (111).

5. An automated MBR reflux device according to claim 1, characterized in that, The inlet (12) is equipped with a second peristaltic pump (122) and a second solenoid valve (121) that are electrically connected to the controller (2).

6. An automated MBR reflux device according to claim 1, characterized in that, The transfer pool (1) is equipped with a level gauge (4) that is electrically connected to the controller (2).

7. An automated MBR reflux device according to claim 1, characterized in that, The outlet (11) is equipped with a flow meter (113) that is electrically connected to the controller (2).

8. An automated MBR reflux device according to any one of claims 1 to 7, characterized in that, The nitrate concentration of the sludge flowing out of the outlet (11) is less than 0.3 mg / L, and the mixed liquor suspended solids concentration of the sludge flowing out of the outlet (11) is 6000-8000 mg / L.

9. An automated MBR reflux system, characterized in that, The automated MBR reflux device according to any one of claims 1 to 8 further includes a biochemical reaction tank (6) and an MBR membrane tank (5) connected together, wherein the MBR membrane tank (5) is connected to the inlet (12), the inlet of the first solenoid valve (111) is connected to the outlet (11), and the outlet of the first solenoid valve (111) is connected to the biochemical reaction tank (6).

10. An automated MBR reflux system according to claim 9, characterized in that, A third peristaltic pump (7) is also provided between the MBR membrane tank (5) and the transfer tank (1). One end of the third peristaltic pump (7) is connected to the MBR membrane tank (5), and the other end of the third peristaltic pump (7) is connected to the upper part of the transfer tank (1) to return the supernatant of the transfer tank (1) to the MBR membrane tank (5).

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