Membrane bioreactor and system based on piezoelectric vibration

Abstract

The invention relates to the technical field of sewage treatment, and discloses a membrane bioreactor and system based on piezoelectric vibration. The membrane component in the MBR comprises a composite membrane material and a membrane frame, the composite membrane material comprises a piezoelectric material and an MBR membrane material, the MBR membrane material is used for realizing solid-liquid separation; the piezoelectric material is used for driving the MBR membrane material to vibrate; and the membrane frame is used for fixing the two ends of the membrane filaments in the composite membrane material and providing membrane filament water producing and backwashing water channels and cable channels, so that the whole membrane component with certain mechanical strength is formed. The MBR membrane material is driven to vibrate through piezoelectric vibration, so that membrane pollution is inhibited, and the water production efficiency and the cleaning efficiency of the membrane are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a membrane bioreactor and system based on piezoelectric vibration. Background Art

[0002] Membrane bioreactors (MBRs) combine biodegradation with membrane separation technology, greatly improving the effluent quality of sewage treatment while effectively increasing volumetric load. Therefore, MBRs have been widely used in the field of sewage treatment. However, in actual operation, MBR membrane materials face severe challenges in performing the critical task of mud-water separation. Various pollutants in sewage, such as colloids and microbial flocs, easily accumulate on the surface and internal pores of the MBR membrane, causing clogging of the membrane pores, leading to increased transmembrane pressure (TMP), decreased flux, reduced water production, and increased energy consumption. Therefore, how to improve the anti-pollution and cleaning capabilities of MBR membrane materials and ensure the efficient operation of MBRs has become a focus of current attention. Summary of the Invention

[0003] In view of this, the present invention provides a membrane bioreactor and system based on piezoelectric vibration to solve the membrane fouling problem of the membrane bioreactor.

[0004] In a first aspect, the present invention provides a membrane bioreactor based on piezoelectric vibration, wherein the membrane assembly in the membrane bioreactor MBR comprises: a composite membrane material and a membrane frame;

[0005] The composite membrane material includes piezoelectric material and MBR membrane material; the MBR membrane material is used to achieve solid-liquid separation; the piezoelectric material is used to drive the MBR membrane material to vibrate; and the membrane frame is used to fix the composite membrane material.

[0006] The MBR provided by this embodiment is based on a composite membrane material comprising piezoelectric material and MBR membrane material. The piezoelectric material is used to drive the MBR membrane material to vibrate, thereby reducing the adhesion and accumulation of pollutants on the surface of the MBR membrane material and reducing the degree of MBR membrane pollution. Compared with traditional MBR membrane components, it effectively inhibits the deep adhesion of pollutants, significantly improves the membrane's anti-pollution ability, increases the membrane flux recovery rate, reduces the flux attenuation rate, extends the service life and maintenance cycle of the MBR membrane, reduces the frequency of chemical cleaning and replacement of the MBR membrane material, and reduces operating costs and energy consumption costs.

[0007] In an optional embodiment, the composite method between the piezoelectric material and the MBR membrane material in the composite membrane material includes any one of the outer end fixed type, the core sheath composite type, and the structural fusion type; when the composite method is the outer end fixed type, the piezoelectric material is wrapped on the outside of at least one MBR membrane filament in the MBR membrane material; when the composite method is the core sheath composite type, each composite membrane filament in the composite membrane material contains piezoelectric fibers and MBR membrane filaments; when the composite method is the structural fusion type, the composite membrane material is made by mixing the piezoelectric material and the MBR membrane material in a preset proportion to form a spinning solution during the spinning process.

[0008] Through the above implementation methods, three composite methods between piezoelectric materials and MBR membrane materials are provided in MBR. Among them, the external end fixed type wraps the piezoelectric material on the outside of the MBR membrane. The external end fixed type has low processing cost and low process difficulty, but the vibration transmission attenuation is large, and it can be used in small-scale, batch production scenarios such as small-scale decentralized MBR; the core-sheath composite membrane has high strength and high vibration transmission efficiency, and can be used in scenarios with high pollutant load, frequent membrane cleaning, or higher membrane strength, such as treating high-load industrial wastewater; the structural fusion type has uniform vibration transmission, higher overall membrane flux, and more uniform mass transfer, and can be used in scenarios such as municipal sewage treatment plants.

[0009] In an optional embodiment, when the composite method is a core-sheath composite method, in each composite membrane yarn, one or more MBR membrane yarns are wrapped around the outside of the piezoelectric fiber.

[0010] Through the above implementation, since multiple MBR membrane filaments tightly surround the piezoelectric fibers, the vibration can act evenly on the entire composite membrane filament, causing the MBR membrane filament to vibrate more fully and enhancing the transmission of the vibration effect, thereby reducing the adhesion of pollutants on the membrane surface and improving the membrane's anti-pollution performance.

[0011] In an optional embodiment, the membrane frame further includes a water production pipe and a circuit pipe;

[0012] A water production pipe is used to collect the effluent from the membrane module and / or the inlet and outlet water for backwashing;

[0013] The circuit tube is used for the power supply circuit of the integrated composite membrane material and receives the piezoelectric drive signal to control the vibration of the piezoelectric material.

[0014] Through the above-described embodiment, the water-permeate pipe effectively collects treated water from the membrane assembly, preventing the disordered flow of effluent within the membrane assembly. Furthermore, the water-permeate pipe is used for backwashing the inlet and outlet water. This backwash effectively removes contaminants from the membrane surface and interior, preventing further fouling and extending the membrane's service life. In the MBR, the circuit tube integrates the power supply circuit, thereby receiving the piezoelectric drive signal to drive the piezoelectric material to vibrate, thereby controlling the vibration of the composite membrane material.

[0015] In an optional embodiment, the membrane bioreactor further comprises a support frame and an aeration device;

[0016] Support frame for fixing membrane modules;

[0017] The aeration device is arranged at the bottom of the support frame and is used to provide dissolved oxygen and perform gas flushing on the membrane assembly.

[0018] Through the above-described embodiment, the support frame can provide stable support for the membrane assembly, ensuring that the membrane assembly maintains a fixed position in the MBR, preventing displacement or shaking of the membrane assembly due to factors such as water flow during MBR operation, ensuring stable operation of the membrane assembly and facilitating installation and maintenance. The aeration device can provide sufficient dissolved oxygen into the reactor to meet the metabolic needs of microorganisms. In addition, the aeration device is used to flush the membrane assembly with gas in the MBR, further effectively reducing the adhesion of contaminants on the membrane surface and preventing membrane fouling.

[0019] In a second aspect, the present invention provides a membrane bioreactor system based on piezoelectric vibration, the system comprising: a transmembrane pressure difference sensor, a control device, and a membrane bioreactor based on piezoelectric vibration as in any embodiment of the first aspect.

[0020] Transmembrane pressure difference sensor, used to detect the transmembrane pressure difference of the membrane assembly in the membrane bioreactor;

[0021] A control device is used to control the vibration of the composite membrane material based on the transmembrane pressure difference.

[0022] Through the system provided in this embodiment, the transmembrane pressure difference sensor can continuously detect the transmembrane pressure difference of the membrane assembly in the MBR and obtain the working status information of the membrane assembly in real time. By monitoring the transmembrane pressure difference, early signs of membrane contamination can be discovered in a timely manner. For example, when the transmembrane pressure difference gradually increases, it may mean that pollutants have accumulated on the membrane surface. At this time, the control device controls the vibration of the membrane material based on the transmembrane pressure difference to achieve precise regulation of the vibration of the membrane material. For example, when the transmembrane pressure difference increases, the vibration intensity of the composite membrane material is increased, etc., to reduce the adhesion of pollutants on the membrane surface, reduce the transmembrane pressure difference, improve the flux and separation performance of the membrane assembly, extend the service life of the membrane assembly, and realize the automated control of the MBR operation.

[0023] In an optional embodiment, the control device includes: a signal processor and a piezoelectric driver;

[0024] A signal processor is used to perform signal processing on the transmembrane pressure difference to obtain a processed transmembrane pressure difference; and determine vibration data of the membrane assembly based on the processed transmembrane pressure difference;

[0025] The piezoelectric driver is used to determine a piezoelectric driving signal of the composite membrane material based on the vibration data; and to control the vibration of the composite membrane material based on the piezoelectric driving signal.

[0026] Through the above-described embodiment, the signal processor can effectively process the raw signal collected by the transmembrane pressure differential sensor, removing noise and interference, and improving signal quality and accuracy. The processed transmembrane pressure differential signal more accurately reflects the actual operating status of the membrane assembly, providing reliable data support for subsequent determination of vibration data. For example, in complex sewage environments, noise interference may cause deviations in the raw transmembrane pressure differential signal. The signal processor can make the processed transmembrane pressure differential signal more accurate and reliable through operations such as filtering and amplification. Furthermore, the signal processor calculates the most appropriate vibration frequency based on the processed transmembrane pressure differential. For example, when the transmembrane pressure differential is low, the signal processor can lower the target vibration frequency to reduce energy consumption; when the transmembrane pressure differential is high, the target vibration frequency can be increased to effectively reduce membrane fouling. The piezoelectric driver can accurately generate the corresponding piezoelectric drive signal (including amplitude, waveform, etc.) based on the vibration data determined by the signal processor. In the control device, the coordinated operation of the signal processor and the piezoelectric driver can optimize the operating performance of the MBR membrane assembly, allowing the membrane assembly to operate in optimal conditions.

[0027] In an optional embodiment, the piezoelectric driver is further used to detect the load impedance of the membrane bioreactor and / or the resonant frequency of the piezoelectric material in the membrane bioreactor; and send the load impedance and / or the resonant frequency to the signal processing;

[0028] The signal processor is further configured to adjust the vibration data based on the load impedance and / or the resonant frequency, and send the adjusted vibration data to the piezoelectric driver.

[0029] Through the above implementation mode, the change of the load impedance in the MBR reflects the operating status of the membrane assembly. The signal processor detects the MBR load impedance in real time through the piezoelectric driver, and promptly discovers abnormal conditions of the membrane assembly (such as increased membrane pollution, etc.), thereby adjusting the vibration data to optimize the vibration frequency of the membrane assembly. For example, when the load impedance increases, the signal processor appropriately increases the target vibration frequency, enhances the anti-pollution ability of the membrane assembly, reduces the adhesion of pollutants on the membrane surface, improves the adaptability of the system, and ensures that the membrane assembly operates efficiently under complex working conditions.

[0030] In an optional embodiment, the vibration data includes the amplitude of the vibration of the membrane assembly in the membrane bioreactor; the amplitude is determined based on one or more of the contamination level of the wastewater to be treated, the thickness of the membrane filaments, and the material of the membrane filaments.

[0031] Through the above-mentioned embodiment, the amplitude of the membrane assembly in the membrane bioreactor generated by the piezoelectric driver can be determined based on the degree of sewage pollution, the thickness of the membrane filaments, and the material of the membrane filaments. For example, when the concentration of pollutants (including activated sludge, etc.) in the unit where the MBR membrane assembly is located is high, more pollutants will adhere to the surface of the membrane assembly, increasing the risk of membrane pollution. In this case, generating a piezoelectric drive signal with a larger amplitude can make the composite membrane material vibrate more strongly, more effectively shake off the pollutants on the membrane surface, prevent pollutants from accumulating on the membrane surface, reduce membrane pollution, and maintain the flux and separation performance of the membrane assembly. On the contrary, when the degree of pollution of the sewage to be treated is reduced, generating a piezoelectric drive signal with a smaller amplitude can not only meet the demand for preventing membrane pollution, but also avoid unnecessary energy consumption, achieve energy-saving operation of the system, and enhance the flexibility of the system.

[0032] In an optional embodiment, the vibration data includes a waveform of vibration of a membrane module in a membrane bioreactor; the waveform is determined based on the properties of the wastewater to be treated and / or the cleaning requirements.

[0033] Through the above-mentioned implementation, different types of sewage contain pollutants of different properties and concentrations, and the way and degree of contamination to the membrane assembly are also different. For example, sewage containing more particulate pollutants and sewage containing pollutants such as colloids and organic matter have very different attachment methods and cleaning difficulties on the membrane surface. Determining the waveform of the piezoelectric drive signal according to the properties and cleaning requirements of the sewage to be treated can enable the composite membrane material to produce a more targeted vibration mode. For particulate pollutants, a pulsed waveform can be generated, and the particles can be shaken off by instantaneous strong vibration; for organic pollution, a continuous and stable waveform can be generated, which continuously acts on the membrane surface to destroy the binding force between the organic matter and the membrane, thereby more effectively removing different types of pollutants and improving the cleaning effect of the membrane assembly. In this way, the waveform of the piezoelectric drive signal determined based on the cleaning requirements of the sewage to be treated enables the system to adapt to different operating conditions and improves the degree of automation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 2 is a schematic structural diagram of a membrane assembly in a membrane bioreactor based on piezoelectric vibration according to an embodiment of the present invention;

[0036] Figure 2This is a schematic structural diagram of an MBR in which the composite membrane material is fixed at the outer end according to an embodiment of the present invention;

[0037] Figure 3 Schematic diagram of a composite membrane yarn in a core-sheath composite manner according to an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of a membrane filament preparation process of a structural fusion composite membrane material according to an embodiment of the present invention;

[0039] Figure 5 1 is a schematic structural diagram of a membrane bioreactor system based on piezoelectric vibration according to an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the interaction between the internal components in a membrane bioreactor control system based on piezoelectric vibration. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0042] First, the application scenarios of the embodiments of the present application are exemplarily introduced.

[0043] Membrane Bio-Reactor (MBR) has greatly improved the effluent quality of sewage treatment and significantly increased the volumetric load by effectively coupling biodegradation with membrane separation. Therefore, MBR has a wide range of applications in the field of sewage treatment. However, the MBR membrane material in the MBR is very susceptible to blockage by pollutants such as colloids and microbial flocs when performing mud and water separation tasks. Once blockage occurs, the transmembrane pressure difference (TMP) will rise, which will cause a series of problems in the MBR, such as a gradual decrease in membrane flux, a significant decrease in water production, and a significant increase in energy consumption, which will seriously affect the efficient and stable operation of the MBR.

[0044] In related technologies, the main technical means for cleaning membrane materials in MBR is chemical cleaning, which involves stopping the machine to soak the membrane with chemicals such as sodium hypochlorite and citric acid, and performing auxiliary flushing through aeration and backwashing. This method has problems such as high energy consumption, frequent shutdowns, and residual chemicals. Other technical means include ultrasonic membrane cleaning and mechanical vibration membrane frames. Among them, ultrasonic membrane cleaning relies on high-frequency sound waves (>20kHz) to produce a cavitation effect in the liquid, requiring an external transducer, resulting in high energy consumption, and severe attenuation of the sound wave energy in the liquid, resulting in insufficient energy actually received by the membrane surface.

[0045] In light of this, the present invention provides a membrane bioreactor and system based on piezoelectric vibration to address membrane fouling issues in membrane bioreactors. Specifically, the MBR membrane material in the MBR is combined with a piezoelectric material. The piezoelectric material vibrates to drive the MBR material, achieving cleanliness of the MBR membrane assembly.

[0046] Figure 1 This is a schematic diagram of the structure of a membrane component in a membrane bioreactor based on piezoelectric vibration provided in an embodiment of the present application. Figure 1 In the embodiment, the membrane assembly in the MBR based on piezoelectric vibration includes: a composite membrane material 101 and a membrane frame 102.

[0047] The composite membrane material 101 includes a piezoelectric material and an MBR membrane material; the MBR membrane material is used to achieve solid-liquid separation; the piezoelectric material is used to drive the MBR membrane material to vibrate; and the membrane frame 102 is used to fix the composite membrane material 101 .

[0048] In one possible implementation, MBR membrane materials are primarily used in membrane bioreactors to achieve solid-liquid separation, intercepting microorganisms, suspended solids, and macromolecular organic matter in wastewater, ensuring that the treated water meets high water quality standards. Exemplary MBR membrane materials can include hollow fiber membranes, flat membranes, and the like.

[0049] In one possible implementation, a piezoelectric material is a functional material that converts mechanical energy into electrical energy. Piezoelectric materials have a piezoelectric effect, that is, when subjected to external forces such as pressure or tension, they generate electric charges. Conversely, when an electric field is applied, they deform. The composite membrane material in the embodiment of the present application mainly utilizes its inverse piezoelectric effect, and by applying an electrical signal, it causes vibration, thereby driving the MBR membrane material combined with it to vibrate. For example, when an alternating voltage is applied to a common piezoelectric ceramic material, it will produce telescopic deformation on a microscopic scale. This deformation is transmitted to the MBR membrane material, causing the MBR membrane to vibrate. In the MBR in the embodiment of the present application, the mechanical deformation characteristics of the piezoelectric material when subjected to an electric field are utilized to drive the MBR membrane material to vibrate, thereby reducing membrane pollution. Exemplarily, the piezoelectric material can be a piezoelectric ceramic sheet, etc. This application does not make specific settings for the specific implementation of the piezoelectric material, and it can be limited according to actual conditions.

[0050] In one possible implementation, composite membrane material 101 is a novel material composed of a piezoelectric material and an MBR membrane material, combining the vibration characteristics of the piezoelectric material with the solid-liquid separation performance of the MBR membrane material. Methods for combining the piezoelectric material and the MBR membrane material in the composite membrane material include, but are not limited to, external end-fixed, core-sheath composite, and structural fusion. The methods for combining composite membrane material 101 will be described in subsequent embodiments and are not detailed here.

[0051] In one possible implementation, the film frame 102 serves as a structural component for fixing the composite film material 101. The film frame 102 can be designed according to the shape, size, quantity, etc. of the composite film material 101, and the composite film material is fixed to the film frame 102 by welding, bolts, or other connection methods.

[0052] Optionally, the membrane frame 102 is divided into an upper and lower membrane frame, which fix the two ends of the membrane wire respectively. For example, multiple membrane wires can be arranged in parallel and sealed with glue to form a membrane assembly as a whole.

[0053] Optionally, the membrane frame 102 may be made of corrosion-resistant materials to avoid being damaged by the environment inside the MBR.

[0054] The MBR provided by this embodiment is based on a composite membrane material 101 comprising a piezoelectric material and an MBR membrane material. The piezoelectric material is used to drive the MBR membrane material to vibrate, thereby reducing the deposition and adsorption of pollutants on the surface of the MBR membrane material and reducing the degree of membrane pollution in the MBR. Compared with traditional MBR membrane components, it effectively inhibits the deep adhesion of pollutants, significantly improves the anti-pollution ability of the membrane, increases the membrane flux recovery rate, reduces the flux attenuation rate, extends the service life and maintenance cycle of the MBR membrane, reduces the frequency of chemical cleaning and replacement of the MBR membrane material, and reduces operating costs, energy consumption costs, and chemical costs.

[0055] In some embodiments, the membrane frame 102 further includes a water production pipe and a circuit pipe.

[0056] The water production pipe is used to collect the effluent from the membrane module and / or the inlet and outlet water for backwashing.

[0057] In one possible implementation, the membrane module's effluent refers to the water obtained after filtration. Backwash inlet and outlet water refer to the inlet water during backwashing and the outlet water after backwashing. The produced water pipe is typically constructed of corrosion-resistant, high-pressure-resistant plastic pipes, such as polyvinyl chloride (PVC) or random copolymer polypropylene (PPR).

[0058] For example, in a sewage treatment plant's MBR, the water pipe collects the clean water filtered by the membrane modules (the effluent from the membrane modules) and transports it to a disinfection tank for disinfection. It is then used as recycled water for urban greening irrigation or industrial cooling. During backwashing, the water pipe also serves as the inlet and outlet channel for backwash water, directing it to the membrane modules for flushing and then discharging the wastewater.

[0059] The circuit tube is used for integrating the power supply circuit of the composite membrane material 101 and receiving the piezoelectric driving signal to control the vibration of the piezoelectric material.

[0060] In one possible implementation, a piezoelectric drive signal is transmitted to the piezoelectric material, causing the piezoelectric material to vibrate according to set requirements, thereby achieving relevant functional control of the membrane assembly, such as reducing membrane contamination through vibration.

[0061] In one possible implementation, the circuit tube is typically made of a material with excellent insulation and flexibility, such as polytetrafluoroethylene (PTFE) or silicone rubber. The wires within the tube are typically multi-strand copper wires to ensure good conductivity and signal transmission. One end of the circuit tube is connected to the output of the control device, and the other end is connected to the electrode of the piezoelectric material in the composite membrane.

[0062] In the embodiments of this application, the water production pipe effectively collects water treated by the membrane assembly, preventing the disordered flow of the effluent within the membrane assembly. Furthermore, the water production pipe is used for backwashing the inlet and outlet water. This backwash effectively removes contaminants from the membrane surface and interior, preventing further membrane fouling and extending the membrane's service life. In the MBR, the circuit tube is used to integrate the power supply circuit, thereby receiving a piezoelectric drive signal to drive the piezoelectric material to vibrate, thereby controlling the vibration of the composite membrane material 101.

[0063] In some embodiments, the membrane bioreactor further comprises a support frame and an aeration device.

[0064] Support frame, used to fix the membrane assembly.

[0065] In the embodiment of the present application, the support frame can provide stable support for the membrane assembly, ensuring that the membrane assembly maintains a fixed position in the MBR, avoiding displacement or shaking of the membrane assembly due to factors such as the impact of water flow during the operation of the MBR, ensuring stable operation of the membrane assembly, and facilitating installation and maintenance.

[0066] The aeration device is arranged at the bottom of the support frame and is used to provide dissolved oxygen and perform gas flushing on the membrane assembly.

[0067] In one possible implementation, the aeration device is a device installed at the bottom of the support frame. Its main function is to introduce air into the water body to provide dissolved oxygen required for microbial growth. At the same time, the membrane assembly is flushed with gas through the flow of air to remove pollutants on the membrane surface, slow down the rate of membrane pollution, and improve the filtration performance and service life of the membrane assembly.

[0068] For example, the aeration device may be a microporous aerator, a perforated tube aerator, a jet aerator, etc. The aerators may be distributed along the bottom of the support frame in a grid or strip pattern. By adjusting the number, spacing, and aeration intensity of the aerators, the water in the entire membrane tank can obtain sufficient dissolved oxygen and the membrane assembly surface can be effectively flushed with gas.

[0069] In some embodiments, the composite method between the piezoelectric material and the MBR membrane material in the composite membrane material 101 includes any one of an outer end fixed type, a core-sheath composite type, and a structural fusion type.

[0070] In a possible implementation, when the composite method is an outer end fixed type, the piezoelectric material is wrapped around the outside of at least one MBR membrane wire in the MBR membrane material.

[0071] Optionally, piezoelectric material is arranged at one end (middle or end) or multiple ends of the MBR membrane yarn, and the piezoelectric material is wrapped around the outside of the MBR membrane yarn.

[0072] Exemplarily, liquid piezoelectric material is coated on the surface of the MBR membrane to form a wrapping layer, and the piezoelectric material is partially wrapped on the outside of the MBR membrane.

[0073] For example, the MBR membrane is inserted into the piezoelectric material sleeve through a piezoelectric material sleeve that is adapted to the size of the MBR membrane, thereby partially wrapping the piezoelectric material around the outside of the MBR membrane.

[0074] Figure 2The diagram below is a structural diagram of an MBR with composite membrane material fixed at the outer end. Figure 2 In the composite membrane material, the MBR membrane filaments are polyvinylidene fluoride (PVDF) hollow fiber membrane filaments 1. The upper and lower membrane frames fix multiple PVDF hollow fiber membrane filaments 1 arranged in parallel. The ends of the PVDF hollow fiber membrane filaments 1 are connected to the water production pipes 2 in the upper and lower membrane frames. The water production pipes 2 are responsible for collecting the filtered water produced by the PVDF hollow fiber membrane filaments 1 and the inlet and outlet water of the backwash. The water production direction and the backwash outlet direction are as follows: Figure 2 As shown. PZT-5H piezoelectric ceramic sheets 3 (i.e., piezoelectric material) are installed at the upper and lower ends of each PVDF hollow fiber membrane filament 1, near the outer side of the membrane frame. They are bonded to the ends of the PVDF hollow fiber membrane filament 1 using conductive silver glue. The electrodes of the PZT-5H piezoelectric ceramic sheets 3 are connected to an external control device 4 via an insulating conductor. In addition, an aeration device 5 is installed at the bottom of the MBR support frame to provide dissolved oxygen (DO) and perform gas flushing of the membrane assembly. The aeration device 5 is connected to the control device 4, which controls the aeration device.

[0075] In a possible implementation, when the composite method is a core-sheath composite method, each composite membrane filament in the composite membrane material 101 includes a piezoelectric fiber and an MBR membrane filament.

[0076] Optionally, within each composite membrane, one or more MBR membrane filaments surround the piezoelectric fibers. In other words, the piezoelectric fibers serve as the core layer of the composite membrane, while the MBR membrane filaments serve as the sheath. This allows vibrations to be evenly distributed throughout the composite membrane, allowing the MBR membrane filaments to vibrate more fully and enhance the transmission of the vibration effect, thereby reducing the adhesion of contaminants to the membrane surface and improving the membrane's anti-fouling properties.

[0077] The surrounding method may be surrounding with adhesive material, bundling, etc.

[0078] For example, each composite membrane yarn comprises a flexible piezoelectric fiber (core) and one or more hollow fiber membranes (sheaths). The one or more hollow fiber membranes are secured around the outside of the flexible piezoelectric fiber using adhesive material and bundling to form a composite membrane yarn. The number of MBR membrane yarns in each composite membrane yarn is not set and can be limited based on actual conditions.

[0079] Figure 3 The figure is a schematic diagram of a composite membrane yarn with a core-sheath composite method. Figure 3In the embodiment, the core layer 7 is a flexible piezoelectric fiber, such as lead zirconate titanate (PZT) ceramic particles / polydimethylsiloxane (PDMS) matrix, with nickel-plated electrodes on the surface, axial polarization, and a driving direction perpendicular to the length; the sheath layer is 6 (optional) hollow fiber membrane filaments 6 (MBR membrane material), such as PVDF material, and the 6 membrane filaments are in a regular hexagon surrounding the core layer. A certain flexible adhesive is applied in the gap between the core layer 7 and the hollow fiber membrane filaments 6 and in the gap between the hollow fiber membrane filaments 6 to buffer the vibration stress and prevent the core-sheath cross-section from separating. At the same time, a fixed coil 8 is used to reinforce the outside of the sheath at regular intervals to avoid the risk of peeling due to long-term vibration fatigue of the adhesive, and to transmit vibration to a certain extent. For example, the fixed coil 8 can be made of materials such as polyvinyl ether (PTE) or PTFE.

[0080] In a possible implementation, when the composite method is a structural fusion type, the composite membrane material 101 is prepared by mixing the piezoelectric material and the MBR membrane material in a preset ratio to form a spinning solution during the spinning process.

[0081] Optionally, during the preparation of the composite membrane material 101, the piezoelectric material and the MBR membrane material are first mixed in a predetermined ratio to form a spinning solution. The spinning solution is then spun, polarized, and modified to form the composite membrane material 101. The composite membrane material 101 produced in this manner exhibits both piezoelectric and filtration properties. The ratio of the piezoelectric material to the MBR membrane material can be set based on actual conditions and is not limited herein.

[0082] Figure 4 This is a schematic diagram of the membrane filament preparation process of a structural fusion composite membrane material. Figure 4 As shown in FIG, the process includes material pretreatment, spinning solution preparation, double-hole needle spinning, post-treatment, poling and packaging.

[0083] Among them, material pretreatment is used to pretreat the MBR membrane material and piezoelectric material used in the spinning solution configuration. Among them, pretreatment includes drying of the MBR membrane material and modification of the piezoelectric material. The MBR membrane material needs to be dried before use or during certain processing processes. This is because the MBR membrane material may contain a large amount of water or solvent during the preparation process. Excessive water will affect the performance of the membrane, such as pore structure, pore size distribution, mechanical strength, etc. The purpose of drying is to remove the water or solvent in the MBR membrane material to a certain degree of dryness to ensure the stability and performance consistency of the membrane during subsequent use. Piezoelectric material modification is to improve the piezoelectric properties, mechanical properties, stability, etc. of the piezoelectric material to meet the needs of different application scenarios. There are many ways to modify piezoelectric materials, such as by doping with other elements or compounds, changing the microstructure of the material, surface treatment, etc., to adjust the crystal structure, electrical properties, etc. of the piezoelectric material, thereby improving its performance indicators.

[0084] Taking the MBR membrane material as PVDF powder and the piezoelectric material as BaTiO3 nanoparticles as an example, during the material pretreatment process, the PVDF powder is placed in a vacuum oven to dry to remove hygroscopic moisture and prevent bubbles in the spinning solution; the BaTiO3 nanoparticles are immersed in KH550 silane coupling agent ethanol solution to enhance the interface bonding with PVDF.

[0085] The spinning solution configuration is used to realize the configuration of the spinning solution based on the MBR membrane material and the piezoelectric material after material pretreatment. The spinning solution includes a core liquid and a sheath liquid. Among them, the core liquid is used to form the hollow channel of the composite membrane material, and the sheath liquid is composed of the piezoelectric material and the MBR membrane material. Exemplarily, the core liquid can be a soluble polymer solution (such as a 10% PEG-4000 aqueous solution). In the process of configuring the sheath liquid, the dried PVDF and the modified BaTiO3 are first added to the DMAC / acetone solvent, and then mechanical stirring, ultrasonic treatment and ball milling are carried out in sequence to achieve mixed dispersion.

[0086] Double-hole needle spinning is used to form hollow preformed fibers based on the core and sheath liquids in the spinning solution. For example, during the double-hole needle spinning process, by controlling the needle structure, voltage, receiving distance, flow rate, and other factors, the sheath liquid envelops the core liquid, causing it to be stretched in the electric field, forming a hollow preformed fiber.

[0087] Post-processing is used to dissolve the core liquid and control the voids in the hollow preformed fibers, resulting in hollow molded fibers. Specifically, the hollow preformed fibers obtained by the double-hole needle spinning step are first placed in deionized water for 48 hours to dissolve the PEG core liquid and form through-hole hollow channels. They are then treated with acetone vapor to expand the interfiber pores. After freezing, vacuum drying is performed to prevent pore structure collapse, resulting in the hollow molded fibers.

[0088] Polarization and encapsulation are used to activate and hydrophobically encapsulate the hollow fiber to produce a composite membrane material. Specifically, a DC electric field is applied at a preset temperature (above the preset temperature) to activate the piezoelectricity of the composite membrane material and perform hydrophobic encapsulation, improving the membrane surface hydrophobic angle and further enhancing anti-fouling performance.

[0089] In the embodiments of the present application, three composite methods between piezoelectric materials and MBR membrane materials are provided in the MBR. Among them, the external end fixed type wraps the piezoelectric material on the outside of the MBR membrane. The external end fixed type has low processing cost and low process difficulty, but the vibration transmission attenuation is large, and it can be used in small-scale, batch production scenarios such as small-scale decentralized MBR; the core-sheath composite membrane has high strength and high vibration transmission efficiency, and can be used in scenarios with high pollutant load, frequent membrane cleaning or high membrane strength, such as treating high-load industrial wastewater; the structural fusion type has uniform vibration transmission, higher overall membrane flux and more uniform mass transfer, and can be used in scenarios such as municipal sewage treatment plants.

[0090] Figure 5 This is a schematic diagram of the structure of a membrane bioreactor system based on piezoelectric vibration. Figure 5 As shown, the system includes: a transmembrane pressure difference sensor 501, a control device 502 and a Figure 1 The membrane components shown are based on piezoelectric vibration membrane bioreactor MBR503.

[0091] The transmembrane pressure difference sensor 501 is used to detect the transmembrane pressure difference of the membrane assembly in the membrane bioreactor.

[0092] In one possible implementation, a transmembrane pressure differential sensor is an instrument used to measure the pressure differential across the membrane assembly in an MBR (Mechanical Bioreactor) system. During the membrane separation process, the membrane's selective permeability creates a pressure differential across the membrane, which is known as the transmembrane pressure differential. A transmembrane pressure differential sensor monitors this pressure differential in real time. For example, transmembrane pressure differential sensors typically use pressure sensing elements, such as capacitive pressure sensors, strain gauge pressure sensors, or piezoelectric pressure sensors, to measure pressure.

[0093] The control device 502 is used to control the vibration of the composite membrane material based on the transmembrane pressure difference.

[0094] In one possible implementation, the control device 502 is responsible for receiving data from various monitoring devices, such as transmembrane pressure differential sensors, and controlling and adjusting relevant devices in the system according to a preset control strategy. In this embodiment of the present application, the control device 502 controls the vibration of the composite membrane material based on the transmembrane pressure differential data measured by the transmembrane pressure differential sensor to control membrane fouling and optimize membrane module performance.

[0095] In one possible implementation, the control device 502 is further configured to control the vibration of the composite membrane material in the MBR at preset time intervals. For example, the control device activates the piezoelectric vibration every two hours. This regular vibration of the composite membrane material helps prevent the accumulation of contaminants on the membrane surface and maintains membrane permeability.

[0096] by Figure 2 For example, when control device 2 detects a transmembrane pressure differential (TMP) greater than 20 kPa or every two hours of operation, it activates a piezoelectric vibration system with a frequency of 50 Hz, an amplitude of approximately 20 μm, and a sinusoidal vibration pattern for two minutes. Furthermore, when the piezoelectric material vibrates, the flushing aeration disc in aeration device 5 is simultaneously activated for aeration and flushing. This, combined with the shear force of rising bubbles, removes contaminants from the membrane surface. During backwashing, both the vibration and aeration systems are activated simultaneously.

[0097] Through the system provided in this embodiment, the transmembrane pressure difference sensor 501 can continuously detect the transmembrane pressure difference of the membrane assembly in the MBR and obtain the working status information of the membrane assembly in real time. By monitoring the transmembrane pressure difference, early signs of membrane contamination can be discovered in a timely manner. For example, when the transmembrane pressure difference gradually increases, it may mean that pollutants have accumulated on the membrane surface. At this time, the control device 502 controls the vibration of the membrane material based on the transmembrane pressure difference to achieve precise regulation of the vibration of the membrane material. For example, when the transmembrane pressure difference increases, the vibration intensity of the composite membrane material is increased, etc., which reduces the adhesion of pollutants on the membrane surface, reduces the transmembrane pressure difference, improves the flux and separation performance of the membrane assembly, extends the service life of the membrane assembly, and realizes automated control of the MBR operation.

[0098] In a possible implementation, the control device 502 is further configured to control the vibration of the composite membrane material in the MBR based on the load impedance of the MBR.

[0099] Optionally, the load impedance of the MBR refers to the load impedance of the membrane assembly. Here, the load impedance of the membrane assembly can be the load impedance of each membrane filament, or the load impedance corresponding to multiple membrane filaments, which is not specifically limited in this application. For example, the load impedance of the MBR can be measured in real time using an impedance sensor.

[0100] Optionally, the control device 502 compares the acquired load impedance with a preset impedance range. If the load impedance exceeds the preset impedance range, the control device 502 controls the composite membrane material in the MBR to vibrate.

[0101] In the embodiments of the present application, during operation of a membrane bioreactor, the load impedance of the membrane assembly varies with the degree of contamination of the MBR membrane material. For example, when the load impedance increases, it indicates that the membrane assembly may be contaminated to a certain extent, resulting in increased resistance. In this case, the vibration frequency or amplitude of the composite membrane material is increased by the control device 502 to enhance the cleaning effect on the membrane surface and reduce the load impedance.

[0102] In a possible implementation, the control device 502 may adopt various types of controllers, such as a programmable logic controller (PLC), a single chip microcomputer, and the like.

[0103] In a possible implementation, the control device 502 is also used to control the aeration volume, aeration mode, backwash volume, aeration cycle, etc. of the aeration device.

[0104] The aeration capacity of the aeration device refers to the amount of air introduced into the water body through the aeration device per unit time, usually expressed in cubic meters per hour (m 3 The aeration volume is measured in units of 1 / h. The aeration volume directly affects the dissolved oxygen content in the water, the metabolic activity of microorganisms, and the removal effect of pollutants. Aeration methods include but are not limited to forced aeration and mechanical aeration. Backwash volume refers to the amount of water used to backwash the membrane components during the backwash process, generally measured in cubic meters (m3). 3 ) or liters (L). Aeration cycle refers to the time cycle during which the aeration device starts aeration and stops aeration.

[0105] In some embodiments, the control device 502 includes a signal processor and a piezoelectric driver.

[0106] The signal processor is used to perform signal processing on the transmembrane pressure difference to obtain a processed transmembrane pressure difference; and determine vibration data of the membrane assembly based on the processed transmembrane pressure difference.

[0107] In one possible implementation, a signal processor processes and analyzes the signals collected by the sensor. Specifically, the signal processor amplifies, filters, and performs analog-to-digital conversion on the raw electrical signals transmitted from the transmembrane pressure differential sensor, removing noise and interference from the signal and improving its quality and accuracy.

[0108] Optionally, the signal processor includes but is not limited to electronic components such as amplifiers and filters to process the signal collected by the transmembrane pressure difference sensor. The amplifier is used to enhance the strength of the signal, and the filter is used to filter out noise in the signal.

[0109] In one possible implementation, vibration data includes, but is not limited to, the membrane assembly's vibration frequency, amplitude, waveform, and duty cycle. The vibration frequency refers to the number of times the membrane assembly completes vibrations per unit time, typically measured in Hertz (Hz). It determines the speed of the membrane assembly's vibration. Different frequencies have varying effects on the removal of contaminants from the membrane surface and the stresses applied to the membrane. Higher frequencies may be more effective in removing tiny particles. The amplitude refers to the maximum distance the membrane assembly deviates from its equilibrium position during vibration, typically measured in millimeters (mm) or micrometers (μm). The amplitude reflects the intensity of the vibration; a larger amplitude generates greater force, facilitating the removal of larger particles or sticky substances attached to the membrane surface. The waveform refers to the shape of the membrane assembly's vibration over time. Common waveforms include sine, square, and triangular waves. Different waveforms have different characteristics. For example, sine wave vibration is relatively stable and causes relatively little damage to the membrane; square wave vibration may, in certain circumstances, have a stronger impact and facilitate the removal of stubborn contaminants.

[0110] In a possible implementation, the signal processor determines the vibration data of the current membrane assembly based on the processed transmembrane pressure difference and according to different vibration data corresponding to different transmembrane pressure difference ranges.

[0111] In one possible implementation, the signal processor determines the vibration data of the current membrane assembly based on a proportional-integral-derivative (PID) control algorithm according to the processed transmembrane pressure difference and a preset transmembrane pressure difference.

[0112] The piezoelectric driver is used to determine a piezoelectric driving signal of the composite membrane material based on the vibration data; and to control the vibration of the composite membrane material based on the piezoelectric driving signal.

[0113] In a possible implementation, the signal processor is further configured to determine vibration data of the current membrane assembly based on the load impedance of the MBR 503 .

[0114] Optionally, the signal processor determines the vibration data based on a relationship between the load impedance and the vibration data of the membrane assembly, specifically the load impedance of the current MBR 503. A mathematical model between the load impedance and the vibration data can be established using statistical methods or machine learning algorithms, and the signal processor determines the vibration data based on the mathematical model.

[0115] In one possible implementation, a piezoelectric driver includes a drive circuit. The drive circuit generates a corresponding electrical signal based on a control signal input from a control device. The electrical signal drives the piezoelectric material to produce noticeable vibrations. The drive circuit can control the output voltage, maximum current, frequency range, waveform (e.g., sine wave, square wave, pulse wave, etc.), frequency, and amplitude of the electrical signal. Exemplarily, the drive circuit includes a drive power supply, a waveform generator, and the like.

[0116] In an embodiment of the present application, the signal processor can effectively process the original signal collected by the transmembrane pressure difference sensor 501, remove noise and interference, and improve the quality and accuracy of the signal. The processed transmembrane pressure difference signal can more truly reflect the actual working state of the membrane assembly and provide reliable data support for the subsequent determination of vibration data. For example, in a complex sewage environment, noise interference may cause deviations in the original transmembrane pressure difference signal, and the signal processor can make the processed transmembrane pressure difference signal more accurate and reliable through operations such as filtering and amplification. Furthermore, the signal processor calculates the most appropriate vibration data, such as the frequency, amplitude, waveform, etc. of the vibration based on the processed transmembrane pressure difference. For example, when the transmembrane pressure difference is small, the signal processor can reduce the vibration frequency and reduce energy consumption; when the transmembrane pressure difference is large, the vibration frequency is increased to effectively reduce membrane pollution. The piezoelectric driver can accurately generate the corresponding piezoelectric drive signal (including amplitude, waveform, etc.) according to the target vibration frequency determined by the signal processor. In the control device 502, based on the coordinated work of the signal processor and the piezoelectric driver, the operating performance of the MBR 503 membrane assembly can be optimized, so that the membrane assembly can operate in an optimal state.

[0117] In a possible implementation, the piezoelectric driver is further used to detect the load impedance and / or the resonant frequency of the membrane bioreactor; and send the load impedance and / or the resonant frequency to the signal processor.

[0118] Exemplarily, the piezoelectric driver further includes a piezoelectric impedance detection unit, and the load impedance of the MBR 503 is obtained through the piezoelectric impedance detection unit.

[0119] Exemplarily, the piezoelectric driver further includes a piezoelectric feedback unit, and the resonant frequency of the MBR 503 is obtained through the piezoelectric feedback unit.

[0120] The signal processor is further configured to adjust the vibration data based on the load impedance and / or the resonant frequency, and send the adjusted vibration data to the piezoelectric driver.

[0121] Optionally, when the load impedance increases, the vibration data is increased, such as by increasing the frequency and amplitude of the membrane assembly vibration. This is because an increase in load impedance indicates that the contamination of the membrane assembly has increased, and the signal processor will be increased accordingly to enhance the cleaning of the membrane assembly. Conversely, if the load impedance decreases, it indicates that the contamination of the membrane assembly has decreased. The signal processor will reduce the vibration data, such as reducing the frequency and amplitude of the membrane assembly vibration. In an embodiment of the present application, the signal processor first determines the vibration data based on the transmembrane pressure difference. When the load impedance changes, the vibration data is adjusted to accurately control the vibration of the membrane assembly.

[0122] In the embodiment of the present application, the change in the load impedance in MBR503 reflects the operating status of the membrane assembly. The signal processor detects the load impedance of MBR503 in real time through the piezoelectric driver, and promptly discovers abnormal conditions of the membrane assembly (such as increased membrane pollution, etc.), thereby adjusting the vibration data to optimize the vibration frequency of the membrane assembly. For example, when the load impedance increases, the signal processor appropriately increases the target vibration frequency, enhances the anti-pollution ability of the membrane assembly, reduces the adhesion of pollutants on the membrane surface, improves the adaptability of the system, and ensures that the membrane assembly operates efficiently under complex working conditions.

[0123] Optionally, the signal processor adjusts the vibration frequency of the membrane assembly when the resonant frequency exceeds a preset frequency range. For example, if the resonant frequency is lower than a minimum value in the preset frequency range, the vibration frequency of the membrane assembly is reduced; if the resonant frequency is greater than a maximum value in the preset frequency range, the vibration frequency of the membrane assembly is increased.

[0124] In an embodiment of the present application, the signal processor can adjust the vibration data based on a PID control algorithm.

[0125] In a possible implementation, the amplitude of the vibration of the membrane assembly in the MBR 503 is determined based on one or more of the contamination level of the wastewater to be treated, the thickness of the membrane fibers, and the material of the membrane fibers.

[0126] Optionally, the amplitude of the membrane assembly in MBR503 refers to the maximum distance that the membrane assembly deviates from its equilibrium position when the membrane assembly generates mechanical vibration under the action of the piezoelectric driver. The unit is usually a length unit, such as micron (μm). It directly describes the physical amplitude of the vibration of the membrane assembly, reflects the intensity of the vibration of the membrane assembly, and is closely related to whether the membrane assembly can effectively remove pollutants.

[0127] Optionally, the amplitude of the membrane assembly in MBR503 is positively correlated with the degree of contamination of the wastewater to be treated. For example, when the degree of contamination of the wastewater to be treated is high, more pollutants will adhere to the surface of the membrane assembly, increasing the risk of membrane contamination. In this case, generating a piezoelectric drive signal with a larger amplitude can cause the composite membrane material to vibrate more strongly, more effectively shaking off pollutants on the membrane surface, preventing pollutants from accumulating on the membrane surface, reducing membrane contamination, and maintaining the flux and separation performance of the membrane assembly. On the contrary, when the degree of contamination of the wastewater to be treated is reduced, generating a piezoelectric drive signal with a smaller amplitude can not only meet the need to prevent membrane contamination, but also avoid unnecessary energy consumption, achieve energy-saving operation of the system, and enhance the flexibility of the system.

[0128] Optionally, the contamination level of the wastewater to be treated can be determined by test data such as turbidity and total organic carbon, or by a contamination level indicator indicated by a user. Exemplarily, the signal processor determines the amplitude of the membrane assembly vibration based on the contamination level indicated by the user.

[0129] Similarly, the voltage value of the piezoelectric drive signal is also determined based on the pollution level of the wastewater to be treated. The voltage value of the piezoelectric drive signal is also positively correlated with the pollution level.

[0130] For example, if the wastewater to be treated is slightly polluted, the amplitude of the membrane assembly in MBR503 can be set to 10 μm and the voltage of the piezoelectric drive signal can be set to 15 V. If the wastewater to be treated is heavily polluted, the amplitude of the membrane assembly in MBR503 can be set to 50 μm and the voltage of the piezoelectric drive signal can be set to 30 V.

[0131] Optionally, when the composite membrane material is composited in an externally fixed manner, the membrane filament thickness may be the thickness of the MBR membrane filament, or the thickness of the MBR membrane filament after wrapping the piezoelectric material. When the composite membrane material is composited in a core-sheath manner, the membrane filament thickness may be the thickness of the piezoelectric fiber in the composite membrane filament, the thickness of the MBR pattern, or the thickness of the composite membrane filament. When the composite membrane material is composited in a structurally fused manner, the membrane filament thickness is the thickness of the composite membrane material.

[0132] The vibration amplitude of the membrane assembly in the MBR503 is positively correlated with the thickness of the membrane filaments. Thicker membrane filaments result in larger vibration amplitudes. Thinner membrane filaments result in smaller vibration amplitudes. This prevents mechanical damage to the membrane assembly, which could lead to breakage. Membrane filament thickness can be characterized by its diameter, radius, and cross-sectional area.

[0133] Optionally, the vibration amplitude of the membrane assembly in MBR 503 is related to the membrane material. If the membrane material is flexible (such as PVDF), the membrane assembly is vibration-resistant, and the vibration amplitude can be appropriately increased. If the membrane material is rigid (such as ceramic membrane), excessive amplitude may cause cracks in the membrane material. Therefore, the vibration amplitude can be appropriately reduced.

[0134] In some embodiments, the waveform of the piezoelectric driving signal is determined based on the properties of the wastewater to be treated and / or the cleaning requirements.

[0135] Exemplarily, the waveform of the piezoelectric driving signal includes but is not limited to a sine wave, a square wave, a triangle wave, a pulse wave, etc. Different waveforms have different spectral characteristics and energy distributions, and have different effects on the vibration effect of the piezoelectric driver.

[0136] In one possible implementation, the cleaning requirements for the treated wastewater include, but are not limited to, rapid stripping and continuous anti-fouling. Rapid stripping refers to the need to clean the membrane assembly in the MBR 503 as quickly as possible. If rapid stripping is the cleaning requirement, the waveform of the piezoelectric drive signal can be a pulse wave. For continuous anti-fouling, the waveform of the piezoelectric drive signal can be a sine wave. With a uniformly distributed sine wave, the force acting on the membrane assembly is relatively uniform throughout the vibration process, preventing localized energy overload or underload, thus ensuring continuous anti-fouling effectiveness.

[0137] Exemplarily, the signal processor determines a waveform of vibration of the membrane assembly based on a cleaning requirement indicated by a user.

[0138] In one possible implementation, the properties of the wastewater to be treated refer to physical, chemical, and biological properties of the wastewater that affect membrane fouling. Physical properties include suspended solids (SS) concentration and particle size distribution. Chemical properties include organic matter (e.g., chemical oxygen demand (COD)) concentration and oil concentration. Biological properties include microbial concentration and extracellular polymer content.

[0139] The waveform of the piezoelectric drive signal can be determined based on the properties of the wastewater to be treated. For physical properties, taking wastewater with high suspended solids concentration (such as mining wastewater) as an example, waveforms with steep edges, such as square waves and spike waves, can be used to achieve rapid stripping of high suspended solids. For chemical properties, taking wastewater with oily pollutants as an example, the waveform can be selected as a continuous or unidirectionally enhanced waveform, such as a sine wave or a positive spike wave, to destroy the oil film adsorption through continuous anti-fouling. Taking biological characteristics as an example, for wastewater with high microbial concentration, square waves and composite waves can be used to achieve bidirectional impact and penetrate the biological structure through pulses.

[0140] In the embodiments of the present application, different types of sewage contain pollutants of different properties and concentrations, and the manner and degree of contamination of the membrane components are also different. For example, sewage containing more particulate pollutants and sewage containing pollutants such as colloids and organic matter have very different attachment methods and cleaning difficulties on the membrane surface. Determining the waveform of the piezoelectric drive signal according to the properties and cleaning requirements of the sewage to be treated can enable the composite membrane material to produce a more targeted vibration mode. For particulate pollutants, a pulsed waveform can be generated, and the particles can be shaken off by instantaneous strong vibration; for organic pollution, a continuous and stable waveform can be generated, which continuously acts on the membrane surface to destroy the binding force between the organic matter and the membrane, thereby more effectively removing different types of pollutants and improving the cleaning effect of the membrane component. In this way, the waveform of the piezoelectric drive signal determined based on the properties and cleaning requirements of the sewage to be treated enables the system to adapt to different operating conditions and improves the degree of automation of the system.

[0141] Figure 6 This is a schematic diagram of the interaction between the internal components in a membrane bioreactor control system based on piezoelectric vibration. Figure 6 In the process, the signal processor obtains the transmembrane pressure difference from the transmembrane pressure difference sensor, processes the transmembrane pressure difference, and determines the vibration data based on the processed transmembrane pressure difference. The piezoelectric driver generates a piezoelectric drive signal based on the vibration data to control the vibration of the composite membrane wire, thereby achieving the purpose of cleaning the membrane components in the MBR. In addition, the piezoelectric driver is also used to detect the load impedance and / or resonant frequency in the MBR, and feed it back to the signal processor, so that the signal processor can further adjust the vibration data based on the load impedance and / or resonant frequency, thereby achieving precise control of the vibration of the membrane components in the MBR. Figure 6 As shown, in this system, aeration and backwashing in the MBR are also achieved by controlling the aeration device.

[0142] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A membrane bioreactor based on piezoelectric vibration, characterized in that: The membrane components in the membrane bioreactor MBR include: composite membrane materials and membrane frames; The composite membrane material includes a piezoelectric material and an MBR membrane material; the MBR membrane material is used to achieve solid-liquid separation; the piezoelectric material is used to drive the MBR membrane material to vibrate; and the membrane frame is used to fix the composite membrane material.

2. The membrane bioreactor according to claim 1, characterized in that The composite method between the piezoelectric material and the MBR membrane material in the composite membrane material includes any one of an outer end fixed type, a core sheath composite type, and a structural fusion type; when the composite method is the outer end fixed type, the piezoelectric material is wrapped around the outside of at least one MBR membrane filament in the MBR membrane material; when the composite method is the core sheath composite type, each composite membrane filament in the composite membrane material contains a piezoelectric fiber and an MBR membrane filament; when the composite method is the structural fusion type, the composite membrane material is made by mixing the piezoelectric material and the MBR membrane material in a preset proportion to form a spinning solution during the spinning process.

3. The membrane bioreactor according to claim 2, characterized in that When the composite method is a core-sheath composite method, in each composite membrane yarn, one or more MBR membrane yarns surround the outside of the piezoelectric fiber.

4. The membrane bioreactor according to any one of claims 1 to 3, characterized in that The membrane frame also includes a water production pipe and a circuit pipe; The water production pipe is used to collect the water outlet of the membrane module and / or backwash the inlet and outlet water; The circuit tube is used to integrate the power supply circuit of the composite film material and receive a piezoelectric driving signal to control the vibration of the piezoelectric material.

5. The membrane bioreactor according to any one of claims 1 to 3, characterized in that The membrane bioreactor also includes a support frame and an aeration device; The support frame is used to fix the membrane assembly; The aeration device is arranged at the bottom of the support frame and is used to provide dissolved oxygen and perform gas flushing on the membrane assembly.

6. A membrane bioreactor control system based on piezoelectric vibration, characterized in that: The system comprises: a transmembrane pressure difference sensor, a control device and a membrane bioreactor based on piezoelectric vibration according to any one of claims 1 to 5; The transmembrane pressure difference sensor is used to detect the transmembrane pressure difference of the membrane assembly in the membrane bioreactor; The control device is used to control the vibration of the composite membrane material based on the transmembrane pressure difference.

7. The membrane bioreactor control system according to claim 6, characterized in that: The control device includes: a signal processor and a piezoelectric driver; The signal processor is configured to perform signal processing on the transmembrane pressure difference to obtain a processed transmembrane pressure difference; and determine vibration data of the membrane assembly based on the processed transmembrane pressure difference; The piezoelectric driver is used to determine a piezoelectric driving signal for the composite film material based on the vibration data; and control the vibration of the composite film material based on the piezoelectric driving signal.

8. The membrane bioreactor control system according to claim 7, characterized in that: The piezoelectric driver is further used to detect the load impedance of the membrane bioreactor and / or the resonant frequency of the piezoelectric material in the membrane bioreactor; and send the load impedance and / or the resonant frequency to the signal processor; The signal processor is further configured to adjust the vibration data based on the load impedance and / or the resonant frequency, and send the adjusted vibration data to the piezoelectric driver.

9. The membrane bioreactor control system according to claim 7 or 8, characterized in that: The vibration data includes the amplitude of the vibration of the membrane assembly in the membrane bioreactor; the amplitude is determined based on one or more of the pollution degree of the sewage to be treated, the thickness of the membrane filaments, and the material of the membrane filaments.

10. The membrane bioreactor control system according to claim 7 or 8, characterized in that: The vibration data includes a waveform of vibration of the membrane assembly in the membrane bioreactor; the waveform is determined based on the properties of the wastewater to be treated and / or the cleaning requirements.

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