A modular wastewater treatment device based on MABR membranes

Abstract

The application relates to the sewage treatment technical field and provides a modular sewage treatment device based on MABR membranes, which comprises a shell, an oxygen supply assembly, a main spiral frame, an auxiliary spiral frame, a transmission assembly, hollow MABR membrane filaments and a gas return assembly. The lower part of the shell is provided with a water inlet pipe, the upper part of the shell is provided with a water outlet pipe, the main spiral frame and the auxiliary spiral frame are rotationally arranged in the shell at intervals, the transmission assembly is arranged at the top of the shell and is in transmission connection with the main spiral frame and the auxiliary spiral frame respectively, the hollow MABR membrane filaments are wound on the auxiliary spiral frame, the oxygen supply assembly and the gas return assembly are arranged at the two ends of the shell respectively, one end of the hollow MABR membrane filaments is connected with the oxygen supply assembly, and the other end of the hollow MABR membrane filaments is connected with the gas return assembly. The axial flow of water flow is realized through spiral stirring, the flow speed of sewage relative to the membranes is increased in the axial direction, the ammonia nitrogen removal efficiency of MABR and the removal efficiency of COD of sewage are improved, and the purpose of online cleaning of the membranes can be achieved.

Description

Technical Field

[0001] This application belongs to the field of wastewater treatment technology, and more specifically, relates to a modular wastewater treatment device based on a MABR membrane. Background Technology

[0002] MABR (Membrane Aerated Biofilm Reactor) is a membrane wastewater treatment technology that combines gas separation membrane technology with biofilm technology. The MABR hollow fiber membrane module allows oxygen to be transferred from one side of the membrane to the other through diffusion, without generating bubbles. Oxygen is transferred from the inside to the outside of the membrane through the permeable membrane, and the direction of mass transfer diffusion is opposite to that of COD / ammonia nitrogen. The MABR membrane bioreactor transfers oxygen through an oxygen concentration gradient, thus offering energy savings compared to traditional MBR membrane reactors. The biofilm-based process allows for a high specific biomass concentration, enabling high volumetric reaction rates. Currently, MABR membrane reactors are being gradually applied in several engineering projects.

[0003] There are several problems with the application of this technology.

[0004] 1) In MABR (Multi-Layer Biofilm Reactor), the mass transfer of gas from the membrane to oxygen on the biofilm surface, and the rate of mass transfer, are limited by the biofilm thickness. Biofilms in wastewater treatment systems are typically thicker than the oxygen permeation depth, usually ranging from 50 μm to 150 μm, and oxygen transfer is further restricted under high carbon loading rates. To reduce biofilm thickness and improve the mass transfer efficiency of biofilm reactors, a patent with publication number CN108025257B was described. However, this technology only reduces the thickness of the biological boundary layer at localized locations on the membrane, and does not simultaneously reduce the boundary layer thickness across the entire membrane system. This is because the arrangement of non-circular fiber bundles enhances the eddy currents of the liquid surrounding the fiber bundles, but only locally enhances mixing, thus reducing the boundary layer thickness on localized fibers. In actual operation, it has been found that biofilm thickness restricts wastewater treatment efficiency; both excessively thin and excessively thick biofilms are detrimental to microbial decomposition of COD.

[0005] 2) Currently, many wastewater treatment plants have generally low influent C / N ratios, resulting in insufficient carbon sources. Internal carbon sources alone may not be sufficient to meet nitrogen removal requirements, thus necessitating the addition of external carbon sources. This is described in patent publication number CN113023889A. However, this technology is still within the scope of supplementing carbon sources and does not consider how to leverage the inherent nitrogen removal efficiency of the MABR membrane reactor itself.

[0006] 3) In practical applications of MABR module treatment units, there are problems such as the large number of membranes used and the large footprint of equipment or membrane tanks. The problems are: a) insufficient contact mixing between wastewater containing pollutants and the biofilm attached to the carrier medium; b) increasing the equipment volume to prevent short-circuiting, resulting in an increase in the footprint; c) increasing the amount of membranes used to improve treatment efficiency; d) considering equipment maintenance, adding spare membrane modules and corresponding membrane tanks.

[0007] In existing MABR membrane treatment devices, deactivated sludge or foreign pollutants adhere to the membrane reactor and are not easily removed. The equipment must be stopped and cleaned offline, which inevitably causes inconvenience to the entire wastewater treatment process.

[0008] Therefore, how to increase the relative flow rate between the membrane and wastewater within a minimal space, thereby improving ammonia nitrogen removal efficiency, is an urgent problem to be solved. Summary of the Invention

[0009] The purpose of this application is to provide a modular wastewater treatment device based on a MABR membrane to solve the technical problem of low wastewater treatment efficiency in the prior art.

[0010] To achieve the above objectives, the technical solution adopted in this application is as follows: a modular wastewater treatment device based on a MABR membrane is provided, comprising: a shell and a single wastewater treatment module, wherein the single wastewater treatment module comprises: an oxygen supply component, a main spiral frame, a secondary spiral frame, a transmission component, hollow MABR membrane fibers, and a return gas component; an inlet pipe is provided at the lower part of the shell, and an outlet pipe is provided at the upper part of the shell; the main spiral frame and the secondary spiral frame are rotatably arranged at intervals within the shell; the transmission component is arranged at the top of the shell and is respectively connected to the main spiral frame and the secondary spiral frame; the hollow MABR membrane fibers are wound on the secondary spiral frame; the oxygen supply component and the return gas component are respectively arranged at both ends of the shell; one end of the hollow MABR membrane fiber is connected to the oxygen supply component, and the other end of the hollow MABR membrane fiber is connected to the return gas component.

[0011] In one embodiment, at least two secondary screw carriers are provided at equal arc intervals with the main screw carrier as the center.

[0012] In one embodiment, the main screw frame includes a main shaft and a main screw rod disposed on the main shaft, and the auxiliary screw frame includes a secondary shaft and an auxiliary screw rod disposed on the secondary shaft. The two ends of the main shaft and the secondary shaft are respectively rotatably disposed on the two ends of the housing, and at least two main screw rods and two auxiliary screw rods are provided.

[0013] In one embodiment, the transmission assembly includes a motor, a driving gear, a driven gear, a main drive wheel, and a secondary drive wheel. The driven gear and the main drive wheel are spaced apart on the main shaft. The driving gear is mounted on the output shaft of the motor and meshes with the driven gear. The secondary drive wheel is mounted on the secondary shaft, and the main drive wheel and the secondary drive wheel mesh.

[0014] In one embodiment, the oxygen supply assembly includes an oxygen generator, an air supply pipe, an air pump, a top air collection box, an air inlet distribution pipe, and a top rotating cavity. The two ends of the air supply pipe are respectively connected to the oxygen generator and the top air collection box. The air pump is mounted on the air supply pipe. The top air collection box is rotatably mounted on the main shaft. Each of the top rotating cavities is mounted on the main shaft or the secondary shaft. Each of the top rotating cavities is provided with an air inlet pipe extending into the housing. The air inlet pipe is connected to one end of the hollow MABR membrane fiber. The top rotating cavity is rotatably connected to the air inlet distribution pipe.

[0015] In one embodiment, a rotating air collection box is provided on the main shaft, a top air collection box is rotatably mounted on the rotating air collection box, and a pressure gauge is provided on the air supply pipe.

[0016] In one embodiment, the top rotating cavity is rotatably disposed on the top of the housing via a bearing, and the top rotating cavity is fixedly connected to the auxiliary drive wheel or the main drive wheel via a key and keyway.

[0017] In one embodiment, the gas return assembly includes: a bottom gas collection box, a gas return pipe, and a bottom rotating cavity. The bottom rotating cavity is rotatably disposed at the bottom of the housing and fixedly connected to each of the main shafts or secondary shafts. The bottom of the bottom rotating cavity is connected to the bottom gas collection box through the gas return pipe. The top of the bottom rotating cavity is provided with a gas return pipe extending into the housing, and the gas return pipe is connected to the other end of the hollow MABR membrane fiber.

[0018] In one embodiment, the bottom rotating cavity is rotatably disposed at the bottom of the housing via a bearing.

[0019] In one embodiment, the housing contains at least two of the individual wastewater treatment modules.

[0020] The beneficial effects of the modular wastewater treatment device based on MABR membrane provided in this application are as follows: The transmission component drives the main spiral frame and the auxiliary spiral frame wound with hollow MABR membrane fibers to rotate, thereby realizing axial flow of water. In the axial direction, the flow velocity of wastewater relative to the MABR membrane fibers is increased to improve the ammonia nitrogen removal efficiency of MABR. At the same time, the transmission component controls the rotation speed of the main spiral frame and the auxiliary spiral frame, which can control the scouring effect of water flow on the membrane fibers, realize online adjustment of sludge thickness, improve the mass transfer efficiency between MABR membrane fibers and wastewater, improve the membrane's COD removal efficiency, and achieve the purpose of online membrane cleaning. The hollow MABR membrane fibers are wound on the spiral frame, causing the curvature of the membrane fibers to change to different degrees. In actual operation, it has been found that oxygen flows out through the surface of MABR membrane fibers, which will create turbulence on the membrane surface, which can also be used to control the thickness of the sludge layer on the membrane surface. The single wastewater treatment module is used to realize modular application, and the treatment capacity is not limited by usage. It can be increased or decreased by adding or removing the quantity, with high space utilization and convenient maintenance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the structure of a modular wastewater treatment device based on a MABR membrane provided in an embodiment of this application;

[0023] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0024] Figure 3 for Figure 1 Enlarged view of point B in the middle;

[0025] Figure 4 A top view of the main drive gear and the driven gear in the modular wastewater treatment device based on MABR membrane provided in the embodiments of this application;

[0026] Figure 5 A schematic diagram of the structure of hollow MABR membrane filaments wound around a secondary spiral frame in a modular wastewater treatment device based on a MABR membrane provided in the embodiments of this application;

[0027] Figure 6 A schematic diagram of the main structure of multiple individual wastewater treatment modules in a modular wastewater treatment device based on a MABR membrane provided in the embodiments of this application;

[0028] Figure 7A top view of multiple individual wastewater treatment modules in a modular wastewater treatment device based on a MABR membrane provided in the embodiments of this application;

[0029] Figure 8 Comparison of COD removal in effluent from a modular wastewater treatment device based on a MABR membrane, provided in the embodiments of this application;

[0030] Figure 9 A comparison diagram of ammonia nitrogen removal in effluent from a modular wastewater treatment device based on a MABR membrane, provided in an embodiment of this application.

[0031] The following are the labeling elements in the figure:

[0032] 1. Housing; 2. Main screw frame; 3. Secondary screw frame; 4. Hollow MABR membrane fiber; 5. Inlet pipe; 6. Outlet pipe; 7. Main shaft; 8. Main screw rod; 9. Secondary shaft; 10. Secondary screw rod; 11. Motor; 12. Drive gear; 13. Driven gear; 14. Main drive wheel; 15. Secondary drive wheel; 16. Oxygen generator; 17. Air supply pipe; 18. Air pump; 19. Top air collection box; 20. Air inlet distribution pipe; 21. Top rotating chamber; 22. Air inlet pipe; 23. Rotating air collection box; 24. Pressure gauge; 25. Bearing; 26. Sealing ring; 27. End cap; 28. Bottom air collection box; 29. ​​Return air collection pipe; 30. Bottom rotating chamber; 31. Return air pipe. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0034] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0035] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] like Figures 1-5 As shown, a modular wastewater treatment device based on a MABR membrane, according to an embodiment of this application, will now be described. This modular wastewater treatment device based on a MABR membrane includes: a housing 1 and individual wastewater treatment modules.

[0038] The shell 1 is the main body of the sewage treatment unit. According to the process requirements, the shell 1 is a sealed shell, and its top can be equipped with a sealable and openable top cover. The lower part of the shell 1 is equipped with an inlet pipe 5, and the upper part of the shell 1 is equipped with an outlet pipe 6. Sewage enters the shell 1 from the inlet pipe 5, is treated by the individual sewage treatment module, and is discharged from the outlet pipe 6.

[0039] The individual wastewater treatment module includes: an oxygen supply component, a main spiral frame 2, a secondary spiral frame 3, a transmission component, hollow MABR membrane fibers 4, and a gas return component. The main spiral frame 2 and the secondary spiral frame 3 are rotatably arranged within the housing 1, with the axes of the main spiral frame 2, the secondary spiral frame 3, and the housing 1 all aligned in the same direction. The transmission component is located at the top of the housing 1 and is connected to both the main spiral frame 2 and the secondary spiral frame 3, driving them to rotate and thus creating an axially flowing water flow.

[0040] In this embodiment, hollow MABR membrane fibers 4 are wound on the secondary spiral frame 3. During the rotation of the main spiral frame 2 and the secondary spiral frame 3, the hollow MABR membrane fibers 4 are driven to rotate synchronously, thereby increasing the flow velocity of wastewater relative to the membrane fibers.

[0041] The oxygen supply component and the air return component are respectively located at both ends of the shell 1. One end of the hollow MABR membrane fiber 4 is connected to the oxygen supply component, and the other end of the hollow MABR membrane fiber 4 is connected to the air return component. Oxygen supplied by the oxygen supply component enters the hollow MABR membrane fiber 4, and the oxygen inside the hollow MABR membrane fiber 4 permeates into the wastewater, forming an aerobic zone on the surface of the membrane fiber, while other areas form anoxic and anaerobic spaces. At the same time, oxygen that is not used in time is recovered through the air return component for reuse in the next cycle, reducing costs.

[0042] In this embodiment, the transmission assembly drives the main spiral frame 2 and the auxiliary spiral frame 3, which is wound with hollow MABR membrane fibers 4, to rotate, thereby achieving axial flow of water. In the axial direction, the flow velocity of sewage relative to the membrane is increased to improve the ammonia nitrogen removal efficiency of the MABR membrane fibers. At the same time, the transmission assembly controls the rotation speed of the main spiral frame 2 and the auxiliary spiral frame 3, which can control the scouring effect of the water flow on the membrane fibers, realize online adjustment of sludge thickness, improve the mass transfer efficiency between the membrane fibers and sewage, improve the membrane's COD removal efficiency, and achieve the purpose of online membrane cleaning. The hollow MABR membrane fibers 4 are wound on the spiral frame, causing the curvature of the membrane fibers to change to different degrees. In actual operation, it has been found that oxygen flows out through the surface of the MABR membrane, which will create turbulence on the membrane surface, which can also be used to control the thickness of the sludge layer on the membrane surface. The single sewage treatment module is used to realize modular application, and the treatment capacity is not limited by usage. It can be increased or decreased by adding or removing the quantity, with high space utilization and convenient maintenance.

[0043] In this embodiment, as Figure 1 and Figure 4 As shown, at least two secondary spiral frames 3 are arranged at equal arc intervals with the main spiral frame 2 as the center. The secondary spiral frames 3 are symmetrically arranged with respect to the main spiral frame 2. The secondary spiral frames 3 can have one or two turns, as shown in the figure, where the secondary spiral frames 3 have two turns. The main spiral frame 2 and the secondary spiral frame 3 closest to the main spiral frame 2 rotate in opposite directions. Similarly, the rotation directions of two adjacent secondary spiral frames 3 are opposite. This is to achieve different flow directions of wastewater, with the water flow in adjacent sections forming up-and-down flows in different axial directions, thereby increasing the wastewater retention time. At the same time, along with the up-and-down flow of wastewater along the axial direction, turbulence is formed in the area between the membrane fibers, increasing the contact time between wastewater and activated sludge, and further increasing the wastewater retention time.

[0044] In this embodiment, as Figure 1 As shown, the main spiral frame 2 includes a main shaft 7 and main spiral rods 8 mounted on the main shaft 7. The secondary spiral frame 3 includes a secondary shaft 9 and secondary spiral rods 10 mounted on the secondary shaft 9. The two ends of the main shaft 7 and the secondary shaft 9 are respectively rotatably mounted on the two ends of the housing 1. At least two main spiral rods 8 are provided on the main shaft 7, and at least two secondary spiral rods 10 are provided on each secondary shaft 9. This is to facilitate the winding of the hollow MABR membrane fibers 4 and to drive the flow of wastewater. The specific number can be increased according to needs to form a multi-channel spiral frame. There is space between the two main spiral rods 8 or the two secondary spiral rods 10. In this embodiment, both the main spiral rods 8 and the secondary spiral rods 10 are made of high-strength corrosion-resistant wire. When at least two layers (four rods) of secondary spiral rods 10 are provided on the secondary shaft 9, the hollow MABR membrane fibers 4 are wound in layers on the secondary spiral rods 10. In this embodiment, the spiral amplitude of the main spiral rod 8 is greater than that of the secondary spiral rod 10.

[0045] like Figure 1As shown, the transmission assembly includes a motor 11, a driving gear 12, a driven gear 13, a main drive wheel 14, and a secondary drive wheel 15. The driven gear 13 and the main drive wheel 14 are spaced apart on the main shaft 7 located outside the housing 1. The driving gear 12 is mounted on the output shaft of the motor 11 and meshes with the driven gear 13. The motor 11 is mounted on the top of the housing 1 via a bracket. The secondary drive wheel 15 is mounted on a secondary shaft 9, and the main drive wheel 14 and the secondary drive wheel 15 mesh. When the motor 11 operates, it drives the driving gear 12 to rotate, which in turn drives the driven gear 13 to rotate. The rotation of the driven gear 13 drives the main shaft 7 to rotate, which in turn drives the driving wheel 15 to rotate, thus driving the secondary shaft 9. The main shaft 7 and the secondary shaft 9 rotate in opposite directions, thereby enabling the sewage to flow axially up and down via the main screw carrier 2 and the secondary screw carrier 3.

[0046] like Figures 1-3 As shown, in this embodiment, the oxygen supply assembly includes an oxygen generator 16, an air supply pipe 17, an air pump 18, a top air collection box 19, an air inlet distribution pipe 20, and a top rotating chamber 21. The oxygen supply assembly is located on the top of the housing 1. Specifically, the two ends of the air supply pipe 17 are connected to the oxygen generator 16 and the top air collection box 19, respectively. The air pump 18 is mounted on the air supply pipe 17. The top air collection box 19 is rotatably mounted on the main shaft 7; that is, when the main shaft 7 rotates, the top air collection box 19 remains stationary. Each top rotating chamber 21 is mounted on either the main shaft 7 or the secondary shaft 9. Each top rotating chamber 21 has an air inlet pipe 22 extending into the housing 1. The air inlet pipe 22 is connected to one end of the hollow MABR membrane fiber 4. The top rotating chamber 21 is rotatably connected to the air inlet distribution pipe 20. Oxygen generated by oxygen generator 16 enters the top gas collection box 19 through the action of air pump 18. The top gas collection box 19 then introduces oxygen into the corresponding top rotating chamber 21 through each air inlet distribution pipe 20, and then into the hollow MABR membrane fiber 4 through the air inlet pipe 22 on the top rotating chamber 21. The number of air inlet distribution pipes 20 is the same as the number of top rotating chambers 21.

[0047] Specifically, a rotating gas collection box 23 is provided on the main shaft 7, and a top gas collection box 19 is rotatably mounted on the rotating gas collection box 23 via a bearing 25. A pressure gauge 24 is provided on the air supply pipe 17. The pressure gauge 24 is used to detect the oxygen supply pressure, thereby regulating the speed of the motor 11 to control the scouring effect of the water flow on the membrane fibers, realize online adjustment of sludge thickness, improve the mass transfer efficiency between the membrane fibers and wastewater, improve the membrane's COD removal efficiency for wastewater, and achieve the purpose of online membrane cleaning.

[0048] In this embodiment, the top rotating cavity 21 is rotatably mounted on the top of the housing 1 via a bearing 25. The top rotating cavity 21 is positioned on the axis of the auxiliary drive wheel 15, and is fixedly connected to the auxiliary drive wheel 15 or the main drive wheel 14 via a key and keyway. One end of the top rotating cavity 21 extends into the housing 1, allowing the intake pipe 22 to extend into the housing 1, enabling the intake pipe 22 to rotate synchronously with the hollow MABR membrane fiber 4. The other end of the top rotating cavity 21 is rotatably and sealingly connected to the intake distribution pipe 20 via a sealing ring 26 and an end cap 27. During actual operation, the top rotating cavity 21 rotates synchronously with the secondary shaft 9, while the intake distribution pipe 20 remains relatively stationary.

[0049] In this embodiment, as Figure 1 and Figure 3 As shown, the return gas assembly includes: a bottom gas collection box 28, a return gas collection pipe 29, and a bottom rotating cavity 30. The structure of the bottom rotating cavity 30 is the same as that of the top rotating cavity 21. The bottom rotating cavity 30 is rotatably disposed at the bottom of the housing 1 and fixedly connected to each main shaft 7 or secondary shaft 9. The bottom of the bottom rotating cavity 30 is connected to the bottom gas collection box 28 through the return gas collection pipe 29. The number of return gas collection pipes 29 is the same as the number of bottom rotating cavities 30. The top of the bottom rotating cavity 30 is provided with a return gas pipe 31 extending into the housing 1. The return gas pipe 31 is connected to the other end of the hollow MABR membrane fiber 4. In this embodiment, the bottom rotating cavity 30 is installed in the same way as the top rotating cavity 21. Both are rotatably mounted on the housing 1 via two spaced-apart bearings 25. The top part of the bottom rotating cavity 30 extends into the housing 1 and is sealed by a sealing ring 26 to prevent sewage from flowing out of the housing 1. This also facilitates the synchronous rotation of the return gas pipe 31 and the hollow MABR membrane filaments 4. The bottom of the bottom rotating cavity 30 is rotatably connected to the return gas collection pipe 29 via an end cap 27 and a sealing ring 26. During operation, the air inlet distribution pipe 20 and the return gas pipe 31 are stationary, while the top rotating cavity 21 and the bottom rotating cavity 30 rotate synchronously with the secondary shaft 9. In this embodiment, during the oxygen permeation process of the hollow MABR membrane filaments 4, a small lateral flow of sewage can be achieved on the membrane surface. Accompanied by the up-and-down flow of sewage along the axial direction, turbulence is formed in the membrane surface area, increasing the contact time between sewage and activated sludge and increasing the sewage retention time.

[0050] like Figure 6 and 7 As shown, in this embodiment, the housing 1 contains at least two individual wastewater treatment modules, and the specific number can be increased according to the size of the housing 1. The purpose of this is to improve space utilization by increasing or decreasing the number of modules, and the modular design facilitates maintenance and replacement. This individual wastewater treatment module can be used as a membrane module for small-scale integrated wastewater treatment or as a component of a membrane treatment system for large-scale wastewater treatment projects, making its application more flexible.

[0051] In this embodiment, the modular wastewater treatment device based on MABR membrane has the following positive and beneficial effects:

[0052] 1. By rotating the main spiral frame 2 and the auxiliary spiral frame 3 in opposite directions, the relative velocity between the wastewater and the hollow MABR membrane fibers 4 is increased, thereby improving the mass transfer efficiency and achieving the best removal effect of COD and ammonia nitrogen.

[0053] 2. The hollow MABR membrane fibers 4 increase the spatial density of the membrane fibers through winding, while effectively ensuring the gaps between the membrane fibers, thereby improving the utilization efficiency of the membrane. By adjusting the gap between the screw rods and the helical structure, multi-layer winding of the membrane fibers can be achieved, leaving gaps between the membrane fibers while maximizing the filling of the membrane fibers, thus improving the spatial density and utilization efficiency of the membrane fibers.

[0054] 3. Online adjustment of biofilm thickness is possible. During operation, oxygen supply pressure can be detected via pressure gauge 24. The biofilm thickness is determined by the pressure reading, and the speed of motor 11 is adjusted, thereby adjusting the speed of main shaft 7 and changing the wastewater flow rate. Through the flushing action of the wastewater, the sludge thickness can be adjusted online, achieving online adjustment of activated sludge thickness, improving mass transfer efficiency, and thus improving biochemical efficiency. Simultaneously, while adjusting the biofilm thickness, deactivated sludge on the membrane can be removed online.

[0055] 4. Online sludge removal, avoiding offline shutdown for cleaning. This wastewater treatment device can automatically remove sludge from the membrane fibers during wastewater treatment. By adjusting and increasing the rotation speed of the main shaft 7, the flow speed of wastewater along the axial direction and laterally is increased, achieving online sludge removal through water flow impact.

[0056] 5. The membrane unit exhibits micro-turbulence, which can control the thickness of the surface sludge layer under static or weak motion conditions, thereby reducing the operating energy consumption of the equipment. Specifically, during operation, this structural design can achieve online reduction of the sludge layer thickness under static conditions. The main shaft speed is only activated when a certain pressure setpoint is reached, thus achieving the effect of reducing energy consumption.

[0057] 6. Under conditions of no carbon source addition and low C / N ratio, increasing the relative flow velocity between wastewater and the membrane improves the denitrification efficiency of the MABR membrane fibers. The hollow MABR membrane fibers 4 are rotated, which can accelerate the vertical relative flow velocity between wastewater and the membrane surface, achieving the goal of increasing the flow velocity between wastewater and the membrane surface without increasing the equipment volume, thereby improving the denitrification efficiency of the hollow MABR membrane fibers 4.

[0058] 7. The water flow is evenly distributed and maintains cross-flow over the hollow MABR membrane filaments 4, so that the wastewater has sufficient contact with the surface of the hollow MABR membrane filaments 4, increases the contact time between the wastewater and the membrane filaments, increases the residence time of the wastewater in the shell 1, and improves the biofilm reaction efficiency.

[0059] 8. The individual sewage treatment module ensures orderly sewage flow during operation, preventing short-circuiting of the water flow.

[0060] 9. The oxygen supply component can supply oxygen directly, which makes the oxygen supply efficiency higher; the bottom gas collection box can collect the oxygen that is not used in time and recycle it for the device, and can also adjust the oxygen pressure in the membrane filament to ensure that there is no oxygen loss.

[0061] 10. This device can be used in a modular manner, and there is no limit to the amount of wastewater it can process. The number of individual wastewater treatment modules can be increased or decreased. It has a high space utilization rate and the modular design makes it easy to maintain and replace. Specific implementation method 1:

[0063] Based on the experimental conditions described in the literature "Research and Application of Novel MABR Phosphorus and Nitrogen Removal Technology", and considering the influence of different relative flow velocities on COD removal rate, a comparative experiment was conducted. The influent COD concentration was 160 mg / L; the aeration pressure was 0.1 MPa; the aeration time was 12 h; and the operation time was 10 days. The relative flow velocities between the wastewater and the MABR membrane were compared at 0.01 m / s, 0.02 m / s, and 0.05 m / s, respectively. The COD removal results are as follows: Figure 8 As shown, when the relative flow velocity between water and the membrane is 0.01 m / s, the COD concentration is 50 mg / L, and the removal rate is 68%. When the relative flow velocity between water and the membrane is 0.02 m / s, the COD concentration is 30 mg / L, and the removal rate is 81%. When the relative flow velocity between water and the membrane is 0.05 m / s, the COD concentration is 8 mg / L, and the removal rate is 95%. The COD removal rate of the wastewater treatment device in this embodiment is significantly improved. Specific implementation method 2:

[0065] According to the literature "Research and Application of Novel MABR Phosphorus and Nitrogen Removal Technology", total nitrogen removal is affected by both the C / N ratio and the water flow velocity. As both the C / N ratio and the water flow velocity increase, the total nitrogen removal rate also increases. Based on the experimental conditions described in the literature, considering the effect of different relative flow velocities on ammonia nitrogen removal rate under low C / N ratio conditions, a comparative experiment was conducted. The conditions were: C / N ratio of 3:1; influent ammonia nitrogen concentration of 40 mg / L; aeration pressure of 0.15 MPa; and aeration time of 5 h. The relative flow velocities between the wastewater and the MABR membrane were compared at 0.01 m / s, 0.02 m / s, and 0.05 m / s, respectively. The ammonia nitrogen removal results are as follows: Figure 9As shown, when the relative flow velocity between water and the membrane is 0.01 m / s, the ammonia nitrogen concentration is 12 mg / L, and the removal rate is 70%. When the relative flow velocity between water and the membrane is 0.02 m / s, the ammonia nitrogen concentration is 8 mg / L, and the removal rate is 80%. When the relative flow velocity between water and the membrane is 0.05 m / s, the ammonia nitrogen concentration is 0.5 mg / L, and the removal rate is 98.75%. The ammonia nitrogen removal rate of the wastewater treatment device in this embodiment is significantly improved.

[0066] The results show that the wastewater treatment device in this embodiment can effectively improve the removal efficiency of COD and ammonia nitrogen by increasing the relative flow velocity. Under the condition of a low C / N ratio of 3:1, increasing the relative flow velocity has a more significant effect on the removal of ammonia nitrogen. Furthermore, the relative flow velocity needs to be increased to a certain critical value to achieve the optimal treatment effect. Increasing the relative flow velocity of wastewater to the membrane surface allows for adjustable biofilm thickness and effectively improves the mass transfer efficiency between the membrane and wastewater. Under the same COD and ammonia nitrogen removal rates, fewer membrane fibers are used, the equipment occupies less space, and the investment and operating costs are lower. It can also be modularized, making it suitable for large, medium, and small wastewater treatment devices, and thus more widely applicable.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A modular wastewater treatment device based on MABR membranes, characterized in that, The application relates to a sewage treatment device, which comprises a shell (1) and a single sewage treatment module, wherein the single sewage treatment module comprises an oxygen supply assembly, a main spiral frame (2), a secondary spiral frame (3), a transmission assembly, hollow MABR membrane filaments (4) and a gas return assembly; the lower part of the shell (1) is provided with a water inlet pipe (5), the upper part of the shell (1) is provided with a water outlet pipe (6), the main spiral frame (2) and the secondary spiral frame (3) are arranged in the shell (1) in a spaced rotating mode, the transmission assembly is arranged at the top of the shell (1) and is in transmission connection with the main spiral frame (2) and the secondary spiral frame (3) respectively, the secondary spiral frame (3) is wound with the hollow MABR membrane filaments (4), the oxygen supply assembly and the gas return assembly are arranged at two ends of the shell (1) respectively, one end of the hollow MABR membrane filaments (4) is connected with the oxygen supply assembly, the other end of the hollow MABR membrane filaments (4) is connected with the gas return assembly; the secondary spiral frame (3) is arranged at equal arc distances with the main spiral frame (2) as the center, and the rotation directions of the main spiral frame (2) and the secondary spiral frame (3) close to the main spiral frame (2) are opposite. The main spiral frame (2) comprises a main shaft (7) and a main spiral rod (8) arranged on the main shaft (7), the secondary spiral frame (3) comprises a secondary shaft (9) and a secondary spiral rod (10) arranged on the secondary shaft (9), the two ends of the main shaft (7) and the secondary shaft (9) are arranged in a rotating mode on the two ends of the shell (1) respectively, and the main spiral rod (8) and the secondary spiral rod (10) are arranged in at least two.

2. The MABR membrane-based modular wastewater treatment device of claim 1, wherein: The transmission assembly comprises a motor (11), a driving gear (12), a driven gear (13), a main driving wheel (14) and a secondary driving wheel (15), the driven gear (13) and the main driving wheel (14) are arranged in a spaced mode on the main shaft (7), the driving gear (12) is arranged on the output shaft of the motor (11) and is in meshing connection with the driven gear (13), the secondary driving wheel (15) is arranged on the secondary shaft (9), and the main driving wheel (14) and the secondary driving wheel (15) are in meshing connection.

3. The MABR membrane-based modular wastewater treatment device of claim 2, wherein: The oxygen supply assembly comprises an oxygen generator (16), a gas supply pipe (17), a gas pump (18), a top gas collecting tank (19), an air inlet distribution pipe (20) and a top rotating cavity (21), the two ends of the gas supply pipe (17) are connected with the oxygen generator (16) and the top gas collecting tank (19) respectively, the gas pump (18) is arranged on the gas supply pipe (17), the top gas collecting tank (19) is arranged in a rotating mode on the main shaft (7), each top rotating cavity (21) is arranged on the main shaft (7) or the secondary shaft (9), each top rotating cavity (21) is provided with an air inlet pipe (22) extending into the shell (1), the air inlet pipe (22) is connected with one end of the hollow MABR membrane filaments (4), and the top rotating cavity (21) is in rotating connection with the air inlet distribution pipe (20).

4. The MABR membrane-based modular wastewater treatment device of claim 3, wherein: ​ 5. The MABR membrane-based modular wastewater treatment device of claim 4, wherein: The main shaft (7) is provided with a rotating gas collecting box (23), the top gas collecting box (19) is rotatably arranged on the rotating gas collecting box (23), and the gas supply pipe (17) is provided with a pressure detection table (24).

6. The MABR membrane-based modular wastewater treatment device of claim 5, wherein: The top rotating cavity (21) is rotatably arranged on the top of the shell (1) through a bearing (25), and the top rotating cavity (21) is fixedly connected with the auxiliary driving wheel (15) or the main driving wheel (14) through a key and a key groove.

7. The MABR membrane-based modular wastewater treatment device of claim 5, wherein: The gas recovery assembly comprises a bottom gas collecting box (28), a recovery gas collecting pipe (29) and a bottom rotating cavity (30), the bottom rotating cavity (30) is rotatably arranged on the bottom of the shell (1) and is fixedly connected with each main shaft (7) or auxiliary shaft (9), the bottom of the bottom rotating cavity (30) is connected with the bottom gas collecting box (28) through the recovery gas collecting pipe (29), the top of the bottom rotating cavity (30) is provided with a gas recovery pipe (31) extending into the shell (1), and the gas recovery pipe (31) is connected with the other end of the hollow MABR membrane wire (4).

8. The MABR membrane-based modular wastewater treatment device of claim 7, wherein: The bottom rotating cavity (30) is rotatably arranged on the bottom of the shell (1) through a bearing (25).

9. The MABR membrane-based modular wastewater treatment device of any one of claims 1-8, wherein: At least two single sewage treatment modules are arranged in the shell (1).

Images