Membrane antifouling method and membrane antifouling system based on magnetic tip array electrode and application

Abstract

The application relates to a membrane anti-fouling method and system based on a magnetic needle array electrode and application, which disperses a particle material with magnetic conductivity and electrical conductivity on a membrane surface or a region adjacent to the outside of the membrane, under the action of a parallel gradient magnetic field, the particle material self-assembles to form a needle array vertical to the membrane surface; the needle array is used as a cathode, and an electric field is applied outside the membrane body, so that an enhanced local electric field is generated at the needle tip. With the tip effect of the needle structure and the electrostatic repulsion of the electric field, the negatively charged pollutants are repelled before approaching the membrane surface, the migration of the negatively charged pollutants in the water body to the membrane surface and into the membrane hole can be effectively inhibited, so that the purposes of relieving membrane pollution, delaying membrane flux attenuation and improving the operation stability of the membrane separation process are achieved. The application has the advantages of simple structure and strong controllability and is suitable for anti-fouling application in various membrane separation processes.

Description

Technical Field

[0001] This invention relates to the field of water treatment and membrane separation technology, specifically to a membrane antifouling method and system based on magnetostrictive needle array electrodes and its application, applicable to membrane devices such as microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Background Technology

[0002] Membrane separation technology is a process that uses membrane materials as selective separation media to achieve substance separation under the influence of external driving forces such as pressure difference, concentration difference, or potential difference. Due to its advantages such as high separation efficiency, continuous operation, small footprint, and ease of modular integration, it has been widely used in drinking water treatment, industrial wastewater treatment, seawater desalination, advanced wastewater treatment, and water resource reuse. Based on different membrane pore structure characteristics and separation mechanisms, membrane separation processes mainly include microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. Microfiltration and ultrafiltration are mainly used to remove suspended solids, colloidal particles, and microorganisms from water, while nanofiltration and reverse osmosis can further remove dissolved organic matter and inorganic salts. During membrane separation operation, pollutants commonly present in raw water, such as natural organic matter, colloidal particles, bacteria, and their metabolites, easily migrate to the membrane surface and undergo adsorption and deposition under the combined influence of transmembrane pressure difference, concentration polarization effect, and physicochemical forces on the membrane surface. Some pollutants may also enter the membrane pores under pressure and gradually form blockages, thus forming a fouling layer on the membrane surface or inside the membrane pores.

[0003] The consequences of membrane fouling are serious and multifaceted, mainly manifested in the following aspects:

[0004] 1) Flux Decline and Increased Energy Consumption: The fouling layer increases mass transfer resistance, leading to a continuous decline in membrane flux (the amount of water produced per unit time per unit membrane area). To maintain water production, it is often necessary to increase the operating pressure, which significantly increases the system's energy consumption.

[0005] 2) Deterioration of separation performance: Fouling may change the hydrophilicity and hydrophobicity, charge properties, etc. of the membrane surface, affecting its selectivity, resulting in a decrease in desalination rate and retention rate, and a deterioration in effluent quality.

[0006] 3) Shortened membrane life and increased operating costs: Fouling exacerbates physical blockage and chemical erosion of the membrane, leading to irreversible damage to the membrane material and shortening its service life. At the same time, frequent physical or chemical cleaning to restore performance not only increases the cost of chemicals and labor, but the waste liquid generated may also cause secondary pollution problems.

[0007] 4) Reduced system stability: The unpredictability and non-uniformity of membrane fouling make the membrane system unstable and increase the difficulty of automatic control, which restricts its large-scale, long-term and reliable engineering applications.

[0008] Therefore, membrane fouling is considered a key common technical bottleneck restricting the further development and promotion of membrane separation technology. Solving the membrane fouling problem is not only about passively cleaning the fouled membrane, but also about actively and continuously inhibiting the migration and adhesion of pollutants to the membrane surface during operation.

[0009] To address membrane fouling, existing technologies have proposed various control and mitigation methods, mainly including operating condition regulation, physical cleaning, chemical cleaning, and membrane material or surface modification. Operating condition regulation methods typically slow down the accumulation of pollutants on the membrane surface by reducing operating pressure, increasing cross-flow velocity, changing operating modes, or optimizing hydraulic conditions. However, these methods often come at the cost of reduced treatment efficiency or increased system energy consumption, and they are unlikely to fundamentally prevent pollutant migration to the membrane surface. Physical cleaning methods, such as backwashing and ultrasonic cleaning, mainly rely on hydraulic shear force or mechanical force to remove loose fouling layers from the membrane surface, and their effectiveness in removing pollutants that have already entered the membrane pores or have strong adsorption interactions with the membrane surface is limited. Chemical cleaning methods typically involve adding chemical agents such as acids, alkalis, oxidants, or complexing agents to dissolve or decompose pollutants. While this can restore membrane flux to some extent, frequent cleaning can easily lead to membrane material aging, decreased mechanical strength, and even structural damage. Furthermore, it also presents problems such as high chemical consumption, high operating costs, and secondary pollution. Membrane material or surface modification methods often introduce hydrophilic groups, antifouling coatings, or functional fillers during membrane preparation or post-treatment stages to reduce the interaction between pollutants and the membrane surface. However, these methods are typically complex and costly, and the modified layers are prone to peeling or performance degradation during long-term operation. Furthermore, most of the aforementioned membrane fouling control methods are passive prevention or post-treatment strategies, making it difficult to continuously and effectively regulate pollutant migration behavior during membrane separation operation and failing to inhibit the enrichment and deposition of pollutants on the membrane surface at the source.

[0010] In recent years, electro-assisted membrane separation technology has attracted attention as an "active fouling suppression" strategy. Its basic principle is to use an external electric field to cause charged pollutants in the water to move directionally under the influence of the electric field force, thus moving them away from the membrane surface. Considering that most organic matter, colloids, and microorganisms in nature have negatively charged surfaces, a common strategy is to set the membrane surface or its adjacent area as a cathode (negatively charged), preventing negatively charged pollutants from approaching through electrostatic repulsion.

[0011] However, existing electro-assisted technologies have fundamental limitations. Specifically, the electrode structures commonly used in existing electro-assisted membrane separation technologies are mostly flat or regularly shaped electrodes. The electric field distribution generated near the membrane is relatively uniform, and the local electric field strength is limited, resulting in insufficient repulsion of pollutants. At the same time, the spatial layout between the electrode and the membrane module is usually relatively fixed, making it difficult to construct a high-intensity, controllable local electric field region near the membrane surface, thus limiting the effectiveness of the electric field in suppressing fouling.

[0012] Furthermore, current technologies lack effective means to construct high-intensity, non-uniform local electric fields in situ and controllably near the membrane surface. Some studies have attempted to introduce conductive or magnetic materials into membrane separation systems to improve electric field distribution or enhance external field effects, but these methods mostly employ material fixation, monolithic doping, or simple filling, making it difficult to construct functional structures with ordered structures, tunable morphologies, and significant field enhancement effects in situ near the membrane module. Consequently, their inhibitory effect on membrane fouling remains limited.

[0013] In summary, the fundamental challenges of existing membrane fouling control technologies, especially the most promising active electro-assisted fouling suppression technology, lie in three aspects: First, in terms of capability, they cannot create a sufficiently strong local repulsive force field near the membrane surface; second, in terms of methodology, they lack sophisticated means to construct the required functional structures in situ; and third, in terms of synergy, they have failed to achieve deep integration of multiple physical fields to generate new functions. These technical problems interact and collectively result in existing solutions failing to meet the increasingly demanding requirements of water treatment in terms of fouling suppression effect, long-term stability, operating cost, and system intelligence.

[0014] Therefore, how to further enhance the ability of the electric field to regulate pollutant migration behavior in membrane separation systems and overcome the limitations of existing electro-assisted membrane separation technologies in terms of electric field distribution and efficiency remains an important technical problem that urgently needs in-depth research in this field. Specifically, a novel membrane antifouling technology is urgently needed that can not only solve the membrane fouling problem caused by pollutant deposition on the membrane surface and within the membrane pores during membrane separation, but also overcome the bottlenecks of electro-assisted antifouling technologies, such as uniform electric field distribution, limited local electric field strength, and insufficient ability to regulate pollutant migration behavior. Summary of the Invention

[0015] To address the problems of insufficient electric field strength, uneven distribution, and limited antifouling efficiency caused by electrode morphology in existing electro-assisted membrane fouling technologies, this invention aims to provide a novel cross-physical field synergistic solution. The primary objective of this invention is to provide a membrane antifouling method that can dynamically construct a needle-structured electrode array with a tip-enhancing effect in situ on or near the membrane surface, thereby generating a strong, directional local electric field. This enables more efficient and precise active control of pollutant migration behavior, fundamentally alleviating membrane fouling. Secondly, it provides a system for implementing this method. The ultimate goal is to significantly enhance the repulsive effect of the electric field on pollutants using this method and system, achieving efficient, active, and long-term suppression of membrane fouling, while possessing advantages such as low operating energy consumption, controllable structure, and strong adaptability. This application's solution to the membrane fouling problem has significant theoretical and engineering value for improving the efficiency, stability, and economy of membrane separation processes.

[0016] The first aspect of this application discloses a membrane antifouling method based on a magnetostrictive needle array electrode, comprising the following steps: S1, loading a plurality of magnetically conductive particles onto the working surface of the membrane body or in the flow channel space near the working surface; S2, applying an external magnetic field to the membrane body to magnetize the magnetically conductive particles, and inducing the magnetically conductive particles to form a plurality of needle-like structural units that extend perpendicular to the working surface and have pointed ends away from the working surface based on magnetic dipole interaction, the plurality of needle-like structural units forming and maintaining under magnetic confinement and jointly constituting a needle array; S3, connecting the needle array as a cathode to the circuit, and setting an anode outside the membrane body, applying a working electric field so that the needle array generates a locally enhanced electric field under the working electric field based on the tip effect formed by the tip, thereby generating an electrostatic repulsion effect on contaminants in the fluid to be treated.

[0017] In step S1 above, the magnetically conductive particles are at least one of the following: ferromagnetic metal particles, composite particles of magnetic oxides and conductive materials, magnetically conductive particles with a core-shell structure, or magnetic carbon-based composite particles. Magnetically conductive particles refer to micron- or nano-sized particles that can be loosely or discretely distributed in the absence of an external magnetic field, but can be magnetized and generate magnetic dipole interactions under the influence of an external magnetic field. These particles possess both magnetic permeability and conductivity, allowing the same material to both respond to a magnetic field to complete structural construction and respond to an electric field to perform electrode functions, achieving a deep coupling between material function and field effect. Preferably, they are metal particles with magnetic response characteristics, such as iron, cobalt, nickel, and iron(II,III) oxide, which are attracted by a magnetic field, or other magnetically conductive materials modified or modified with these metals as the core. In another embodiment, they are metal particles modified or modified to improve the conductivity of the magnetically conductive metal particles, such as composite particles formed by modifying the surface of nZVI with metals such as copper, palladium, or gold. Modification methods include, but are not limited to, electroplating, electroless plating, and spraying processes. In step S2 above, the needle-shaped structural unit is a chain-like aggregate formed by magnetically conductive particles stacked in a direction perpendicular to the working surface of the membrane body under the interaction of magnetic dipoles, and it is cone-shaped with a large end near the root of the membrane body and a small end away from the membrane body.

[0018] Specifically, the magnetically conductive particles are magnetized in a magnetic field where the magnetic field lines are generally perpendicular to the working surface of the membrane. Their internal magnetic domains align along the magnetic field direction, making each particle a microscopic magnet with a horizontal magnetic moment. Two magnetized particles attract each other through magnetic dipole interaction. According to magnetic dipole interaction, the interaction energy is lowest and exhibits the strongest attraction when the two magnetic moments are in the same direction and along the line connecting them. Therefore, the particles initially tend to connect end-to-end along the horizontal magnetic field direction, forming short horizontal chains. Within the confined flow channel space above and on the membrane surface, numerous short horizontal chains aggregate in three-dimensional space. Due to spatial constraints and the tendency to minimize the total system energy, these short horizontal chains undergo lateral magnetic attraction and assembly. Ultimately, they connect and overlap, growing and extending in a direction perpendicular to the membrane surface (i.e., along the membrane surface normal), forming a stable vertical chain structure, i.e., a chain aggregate. The magnetic torque provided by the parallel gradient magnetic field always acts on these chains, keeping their magnetic moments horizontal, thus locking the vertical orientation of the chains, resisting disturbances such as water flow shear, and achieving structural stability.

[0019] This application utilizes a non-intuitive method—a parallel gradient magnetic field—to indirectly and stably construct a needle array through ingenious magnetic dipole interactions and spatial constraints. Each needle-like structural unit extends in a direction perpendicular to the membrane's working surface. This "orthogonal orientation" construction logic (horizontal magnetic field, vertical structure) is the essence of the inventive concept, achieving controllable construction from a horizontal magnetic field to a vertical structure, a concept readily apparent to those not skilled in the art.

[0020] Meanwhile, the method provided in this application achieves good structural stability and self-healing potential in the needle array. Specifically, the magnetic torque applied by the parallel gradient magnetic field to the vertical needle array is a dynamic restoring force; when the needle array tilts slightly due to water flow impact, the magnetic torque will "correct" it; even if a small number of particles fall off, they may be "captured" and integrated into the array under the action of the strong parallel gradient magnetic field and gradient force, exhibiting self-healing characteristics, which are not found in loose structures formed under fixed electrodes or simple vertical magnetic fields.

[0021] It is important to emphasize that the so-called needle-like structures in this application are not solid needles, but rather chain-like aggregates (or linear assemblies) formed by particles connected by magnetic dipole attraction. During the construction process, the region near the membrane working surface has a high particle concentration and magnetic flux density, making it easier for particles to be attracted and adhere to the root of the formed chains. This results in a larger accumulation of particles at the base of the chains, with a coarser diameter (larger end). As the chains grow upwards (away from the membrane surface), the number of particles that can be captured decreases, and the ends of the chains are usually terminated by a single or a few particles, thus having the finest diameter and forming a sharp "small end" or tip. This spontaneous tapering is beneficial to the mechanical stability of the structure in the fluid.

[0022] The small end (i.e., the tip, usually a single nanoparticle) has an extremely small radius of curvature, providing an ideal geometric basis for the subsequent "tip effect" of the electric field. The conical structure (thick at the root and thin at the top) makes the chain aggregate less prone to breakage under the force of fluid, and has better mechanical robustness than columnar chains of equal diameter.

[0023] According to the method disclosed in the first aspect of this application, in step S2, the external magnetic field is provided by a magnetic confinement device, which includes permanent magnets or electromagnets arranged in an attractive mode on opposite sides of the membrane body or its associated devices in a direction perpendicular to the working surface of the membrane body. This results in the formation of an external magnetic field on the outside of the membrane body with magnetic field lines generally parallel to the filtration direction and perpendicular to the working surface of the membrane body.

[0024] In this application, "attraction mode" refers to a specific configuration that generates a parallel gradient magnetic field. More precisely, it can be described as follows: two permanent magnets are placed above and below the membrane or membrane module, respectively, with opposite poles facing each other (e.g., the S pole of the upper magnet facing down and the N pole of the lower magnet facing up). In this "attraction" configuration, magnetic field lines bend from one magnet edge to the other in the central region between the two magnets, generating a roughly horizontal (parallel to the membrane filtration direction and perpendicular to the membrane surface) gradient magnetic field in that region (i.e., where the membrane module is located). This arrangement simply and effectively establishes the required parallel gradient magnetic field environment in the membrane area, making the requirement to "apply a parallel gradient magnetic field" concrete and feasible, significantly reducing system operating energy consumption and improving economic efficiency. Furthermore, the electromagnet scheme provides the flexibility of adjustable magnetic field strength, facilitating optimization for different water qualities or pollution levels.

[0025] According to the membrane antifouling method disclosed in the first aspect of this application, in step S3, an external electrode is directly connected to the bottom of the needle array to connect the needle array as a cathode to the circuit. Alternatively, the working surface of the membrane body is modified to become a conductive film and serve as a conductive substrate for the needle array, so that the needle array can be connected as a cathode to the circuit. That is, to achieve electrical connection of the needle array, one method is to connect an external electrode to the bottom of the needle array (near the bottom of the membrane surface), which can be understood as connecting wires to the bottom of the needle array, relying on the mutual contact between metal particles to transfer charge. Another method is to modify the working surface of the membrane body, for example, by depositing carbon nanotubes to make it a conductive film, serving as a conductive substrate for the electrode of the needle array, and then connecting the conductive film with wires to realize the needle array as a cathode to the circuit. Both of these designs solve the engineering problem of how to provide reliable electrical connection for the non-fixed particle array "grown" on the membrane surface, especially by modifying the membrane surface to make the membrane body a conductive film.

[0026] The second aspect of this application also discloses a membrane antifouling system for implementing the membrane antifouling method disclosed in the first aspect, comprising: a plurality of magnetically conductive particles loaded in particle form on the working surface of a membrane body; a magnetic confinement device configured to apply an external magnetic field to the membrane body to magnetize the magnetically conductive particles, and based on magnetic dipole interaction, inducing the magnetically conductive particles to form a plurality of needle-like structural units extending perpendicular to the working surface and having pointed ends away from the working surface, the plurality of needle-like structural units being held together under magnetic confinement and collectively constituting a needle array; an electric field application device comprising a cathode connection terminal, an anode, and a power source, wherein the cathode connection terminal is electrically connected to the needle array to use the entire needle array as a cathode, the anode is disposed outside the membrane body, and the power source is used to apply a working electric field between the cathode and the anode.

[0027] According to the membrane antifouling system disclosed in the second aspect of this application, an external electrode is directly connected to the bottom of the needle array, and the needle array is used as a cathode connected to the circuit; or, the working surface of the membrane body is modified to make the membrane body a conductive membrane, which serves as a conductive substrate for the needle array, so that the needle array is used as a cathode connected to the circuit.

[0028] According to the membrane antifouling system disclosed in the second aspect of this application, the magnetically conductive particles are replaceable, so that the radius of curvature of the tip of the needle-shaped structure unit can be adjusted based on the particle size of the magnetically conductive particles, thereby controlling the local enhanced electric field at the tip of the needle-shaped structure unit when a working electric field is applied; and / or, the strength of the external magnetic field is adjustable, so that the length of the needle-shaped structure unit can be adjusted based on the change in the strength of the external magnetic field, thereby controlling the local enhanced electric field at the tip of the needle-shaped structure unit when a working electric field is applied.

[0029] The method for constructing a needle array electrode based on the magnetostrictive effect and its membrane antifouling system in this application cleverly utilizes a magnetic field as a dynamic, non-contact "assembly tool" to guide micro- and nano-particles with magnetic and electrical conductivity to spontaneously arrange themselves into a "needle-like" or "chain-like" array structure perpendicular to the membrane surface near the membrane surface. Then, the in-situ formed structure is used as a cathode to apply an electric field, and its sharp geometric tip generates a very strong local electric field enhancement effect (i.e., "tip effect"), thereby exerting a strong electrostatic repulsion force on negatively charged pollutants and achieving efficient and active membrane fouling suppression.

[0030] Based on the above description, and addressing the problems of contaminants easily depositing on the membrane surface and entering the membrane pores during existing membrane separation processes, as well as the limited local electric field strength of existing electric-assisted antifouling technologies, this application provides a membrane antifouling method and system that utilizes the synergistic effect of magnetic and electric fields. Specifically, it induces a magnetically conductive material to form a needle-like arrangement structure with a tip effect in situ on the working surface of the membrane or in a region adjacent to the working surface of the membrane body using a magnetic field. The local electric field enhancement effect generated by this structure under the action of an electric field significantly repels negatively charged contaminants, thereby effectively mitigating membrane fouling and delaying membrane flux decay.

[0031] The phrase "the entire array of needles as a cathode" refers to all needle-like structural units being electrically connected in parallel via a conductive film or mutual contact, collectively forming a single electrode (cathode) with a composite three-dimensional morphology. When a negative voltage is applied to this needle array cathode, charge accumulates on the conductor surface. According to the principles of electrostatics, the surface charge density of a conductor is inversely proportional to its radius of curvature. Consequently, at the needle tip, the charge is highly concentrated, generating an extremely high local surface charge density. Compared to the average electric field, the local electric field intensity at the needle tip in this application's structure is significantly amplified.

[0032] Based on the design of using the entire needle array as the cathode in this application, a high local electric field can be obtained at the tip by applying only a normal, safe, low voltage. This field strength far exceeds that of traditional flat plate electrodes at the same voltage, thus achieving a strong electrostatic repulsion force against pollutants with extremely low energy consumption. Furthermore, it provides an in-situ, dynamic means of controlling the pollution suppression efficiency. Specifically, by replacing particles of different sizes or adjusting the magnetic field strength, the morphology of the needle array can be changed in real time, thereby actively controlling the intensity of the local electric field. This means that the system can adapt to water quality with different pollution loads, enhancing the electric field when pollution is severe and reducing energy consumption when pollution is mild—a smart characteristic that fixed electrode systems cannot achieve.

[0033] More importantly, based on the high-intensity, non-uniform electric field generated by the tip, a powerful "electrostatic repulsion barrier" is constructed above the membrane surface, which can effectively repel negatively charged pollutants that try to approach, resulting in extremely high antifouling efficiency.

[0034] The third aspect of this application also discloses a membrane filtration device, including a membrane module having a membrane body and a flow channel space formed by the corresponding membrane body, the membrane body having a working surface for separation filtration; and further including a membrane antifouling system disclosed in the second aspect of this application, the membrane antifouling system being associated with the membrane body.

[0035] The fourth aspect of this application discloses the application of a membrane antifouling method disclosed in the first aspect of this application, or a membrane antifouling system disclosed in the second aspect of this application, or a membrane filtration device disclosed in the third aspect of this application in water treatment.

[0036] Beneficial effects: In the membrane antifouling method and system based on magnetostrictive needle array electrodes of the present invention, magnetically conductive particles can be induced to form a needle array extending perpendicular to the membrane surface under the action of a parallel gradient magnetic field. Under the combined action of magnetic field orientation constraint and the magnetic and conductive properties of the material, the needle array is stably and orderly distributed in the membrane surface region. By applying an electric field from the outside as the entire needle array as a cathode, a significantly enhanced local electric field is formed at the needle tip, thereby achieving directional control of the electric field distribution near the membrane surface. This results in a continuous electrostatic repulsion effect on negatively charged organic pollutants, colloidal particles, and microorganisms in the water, causing them to be repelled before they approach the membrane surface. Ultimately, this effectively inhibits the migration of pollutants to the membrane surface and their entry into the membrane pores, thereby alleviating membrane fouling, delaying membrane flux decay, and improving the operational stability of the membrane separation process.

[0037] The following describes in detail the membrane antifouling method and membrane antifouling system based on magnetostrictive needle array electrodes of the present invention, with reference to the embodiments shown in the accompanying drawings and the reference numerals. Attached Figure Description

[0038] Figure 1 A flowchart illustrating the steps of the membrane antifouling method of the present invention is shown.

[0039] Figure 2 An experimental flow chart of the water treatment system is shown.

[0040] Figure 3 A schematic diagram of a membrane filtration device equipped with the membrane antifouling system of the present invention is shown.

[0041] Figure 4 (a)-(d) show schematic diagrams comparing the systems in different field domains, where Figure 4 (a) Schematic diagram of a blank control group without an external field applied and without loading magnetic and conductive particles. Figure 4 (b) is a schematic diagram of the control group with magnetically and electrically conductive particles loaded but only an electric field applied. Figure 4 (c) is a schematic diagram of the control group where magnetically conductive particles are loaded but only a magnetic field is applied. Figure 4 (d) is a schematic diagram of a magnetically and electrically conductive particle being loaded with a magnetic field and an electric field being applied simultaneously.

[0042] Figure 5 The paper presents a comparison of the antifouling performance of the antifouling system formed based on the method and system of the present invention with that of other systems in water treatment systems for HA.

[0043] Figure label:

[0044] 1. Membrane filtration device; 2. Magnetic confinement device; 3. Electric field application device; 4. Membrane body; 5. Needle-shaped structural unit; 6. Top cover plate; 7. Membrane shell; 8. Support frame; 9. Fixing frame; 10. Flow channel space; 11. Nitrogen cylinder; 12. Glass container; 13. Electrochemical workstation; 14. Electronic balance; 15. Data collection and display device. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0046] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the attached figures). If the specific posture changes, the directional indications will also change accordingly. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0047] Figure 1 A flowchart illustrating the steps of the membrane antifouling method of the present invention is shown. (Combined with...) Figure 1 As shown, this invention discloses a membrane antifouling method based on a magnetostrictive needle array electrode, which includes the following steps: S1, loading a plurality of magnetically conductive particles onto the working surface of the membrane body 4; S2, applying an external magnetic field to the membrane body 4 to magnetize the magnetically conductive particles, and inducing the magnetically conductive particles to form a plurality of needle-like structural units 5 extending perpendicular to the working surface and with pointed ends away from the working surface based on magnetic dipole interaction, the plurality of needle-like structural units 5 are held together under magnetic confinement and together constitute a needle array; S3, connecting the needle array as a cathode to the circuit, and setting an anode outside the membrane body 4, applying a working electric field so that the needle array generates a locally enhanced electric field under the working electric field based on the tip effect formed by the tip, thereby generating an electrostatic repulsion effect on contaminants in the fluid to be treated.

[0048] The present invention also discloses a membrane antifouling system for implementing the aforementioned membrane antifouling method, comprising: a plurality of magnetically conductive particles, which are loaded in particle form on the working surface of the membrane body 4 or in the flow channel space 10 near the working surface; a magnetic confinement device 2, which is configured to apply an external magnetic field to the membrane body 4 to magnetize the magnetically conductive particles, and based on magnetic dipole interaction, induces the magnetically conductive particles to form a plurality of needle-like structural units 5 extending in a direction perpendicular to the working surface and with pointed ends away from the working surface, the plurality of needle-like structural units 5 forming and holding together under magnetic confinement to constitute a needle array; and an electric field application device 3, which includes a cathode connection end, an anode, and a power source, wherein the cathode connection end is electrically connected to the needle array to use the entire needle array as a cathode, the anode is disposed outside the membrane body 4, and the power source is used to apply a working electric field between the cathode and the anode.

[0049] In the embodiments of the above methods and systems, the membrane body 4 can be a microfiltration membrane, ultrafiltration membrane, nanofiltration membrane, and reverse osmosis membrane, etc., and the membrane module is a membrane structure used to treat polluted water, which can include the membrane body 4 and its support frame 8.

[0050] The magnetic confinement device 2 is disposed on opposite sides of the membrane module or the membrane filtration device 1 attached to the membrane module (or membrane device), and is used to provide an external magnetic field in the region where the membrane module is located. Specifically, the magnetic confinement device 2 may include permanent magnets 2a disposed above and below the filtration device, respectively, to provide a parallel gradient magnetic field with magnetic field lines generally parallel to the membrane filtration direction and perpendicular to the membrane surface, thereby causing the magnetically conductive particles within the device to spontaneously form a micron-sized needle-shaped array. The needle array is confined within the device by the magnetic field and serves as a membrane surface electrode (cathode).

[0051] In a specific embodiment, the magnetically conductive and electrically conductive particle material can be disposed on the working surface of the membrane body or arranged in the adjacent area on the outside of the membrane. Under the action of a parallel gradient magnetic field, the magnetically conductive and electrically conductive particle material undergoes orientation rearrangement under the action of magnetic force, spontaneously forming multiple needle-like structural units 5 extending in a direction perpendicular to the membrane surface (the working surface of the membrane). The needle-like structural units 5 are arranged in an array in the membrane surface area to form a needle array, and remain stable under the constraint of the magnetic field. The electric field application device 3 is used to electrically connect with the needle array, so that the entire needle array acts as a cathode, forming an electric field outside the membrane assembly. Due to the pointed geometric features of the needle array, an enhanced local electric field is formed at its needle tip after the electric field is applied.

[0052] The above structural configuration enables the magnetic field to construct and stabilize the needle-like arrangement, and the electric field to exert electrostatic repulsion on pollutants, thereby achieving effective suppression of membrane fouling.

[0053] In other words, to address the problems of pollutants easily depositing on the membrane surface and entering the membrane pores during existing membrane separation processes, and the limited local electric field strength of existing electric-assisted fouling suppression technologies, this invention provides a membrane fouling suppression method that utilizes the synergistic effect of magnetic and electric fields. This method induces magnetically and electrically conductive particles to form an array of needles with a tip effect (or a "needle-like arrangement structure") in situ. The local electric field enhancement effect generated by this structure under the action of an electric field is utilized to produce a significant electrostatic repulsion effect on negatively charged pollutants, thereby effectively alleviating membrane fouling and delaying membrane flux decay.

[0054] Specifically, the membrane antifouling method and system based on the present invention can induce magnetically conductive and electrically conductive particulate materials to form a needle array extending perpendicular to the membrane surface under the action of a parallel gradient magnetic field. Under the combined effect of magnetic field orientation constraint and the magnetic and conductive properties of the material, the needle array is stably and orderly distributed in the membrane surface region. By applying an electric field from the outside as the entire needle array as a cathode, a significantly enhanced local electric field is formed at the needle tip, thereby achieving directional control of the electric field distribution near the membrane surface. This generates a continuous electrostatic repulsion effect on negatively charged organic pollutants, colloidal particles, and microorganisms in the water, causing them to be repelled before approaching the membrane surface. Ultimately, this effectively inhibits the migration of pollutants to the membrane surface and their entry into the membrane pores, thereby achieving the purpose of alleviating membrane fouling, delaying membrane flux decay, and improving the operational stability of the membrane separation process.

[0055] In the specific embodiments of the above methods and systems, the magnetically conductive particles are at least one of ferromagnetic metal particles, composite particles of magnetic oxides and conductive materials, magnetically conductive particles with a core-shell structure, or magnetic carbon-based composite particles. The combination of magnetic permeability and conductivity allows the same material to both respond to a magnetic field to complete structural construction and respond to an electric field to perform electrode functions, achieving a deep coupling between material function and field effects.

[0056] In the respective specific embodiments of the above methods and systems, the needle-shaped structural unit 5 is a chain-like aggregate formed by magnetically conductive particles stacked in a direction perpendicular to the working surface of the membrane body 4 under the interaction of magnetic dipoles, and is tapered with a large end near the root of the membrane body 4 and a small end away from the membrane body 4.

[0057] Furthermore, in the respective specific embodiments of the above methods and systems, the external magnetic field is provided by the magnetic confinement device 2, which includes permanent magnets 2a or electromagnets arranged in an attraction mode on opposite sides of the membrane body 4 or its attached devices in a direction perpendicular to the working surface of the membrane body 4.

[0058] In addition, in specific embodiments of the above methods and systems, the needle array is connected to the circuit as a cathode by directly connecting an external electrode to the bottom of the needle array, or the working surface of the membrane body is modified to become a conductive film and used as a conductive substrate for the needle array, so that the needle array is connected to the circuit as a cathode.

[0059] More importantly, in the respective specific embodiments of the above methods and systems, the magnetically conductive particles are made replaceable so that the radius of curvature of the tip of the needle-shaped structural unit 5 can be adjusted based on the particle size of the magnetically conductive particles, thereby controlling the local enhanced electric field at the tip of the needle-shaped structural unit 5 when a working electric field is applied; and / or, the strength of the external magnetic field is adjustable so that the length of the needle-shaped structural unit 5 can be adjusted based on the change in the strength of the external magnetic field, thereby controlling the local enhanced electric field at the tip of the needle-shaped structural unit 5 when a working electric field is applied.

[0060] Based on the above description, and addressing the problems of pollutants easily depositing on the membrane surface and entering the membrane pores during existing membrane separation processes, as well as the limited local electric field strength of existing electric-assisted antifouling technologies, this application provides a membrane antifouling method and system that utilizes the synergistic effect of magnetic and electric fields. Specifically, it induces a magnetically conductive material to form a needle-like arrangement structure with a tip effect in situ on the working surface of the membrane body 4 or in a region adjacent to the working surface of the membrane body 4. Utilizing the local electric field enhancement effect generated by this structure under the action of an electric field, a significant electrostatic repulsion effect is achieved against negatively charged pollutants, thereby effectively mitigating membrane fouling and delaying membrane flux decay.

[0061] The third aspect of this application also discloses a membrane filtration device 1, including a membrane housing 7 and a membrane module, the membrane module having a membrane body 4 and a flow channel space 10 formed by the corresponding membrane body 4, the membrane body 4 having a working surface for separation filtration; the membrane filtration device 1 also includes the aforementioned membrane antifouling system, which is associated with the membrane module of the membrane filtration device 1. Specifically, a plurality of magnetically conductive particles are configured and loaded in particle form on the working surface of the membrane body 4 or in the flow channel space 10 near the working surface; the magnetic confinement device 2 is configured to apply an external magnetic field perpendicular to the working surface of the membrane body 4 to magnetize the magnetically conductive particles, and based on the interaction of magnetic dipoles, induce the magnetically conductive particles to form a plurality of needle-like structural units 5 extending perpendicular to the working surface and with pointed ends away from the working surface. The plurality of needle-like structural units 5 are held together under the action of magnetic confinement and together constitute a needle array; the electric field application device 3 includes a cathode connection end, an anode and a power source, wherein the cathode connection end is electrically connected to the needle array to use the entire needle array as a cathode, the anode is disposed outside the membrane body 4, and the power source is used to apply a working electric field between the cathode and the anode.

[0062] The fourth aspect of this application discloses the application of the method disclosed in the first aspect of this application, the system disclosed in the second aspect of this application, or the membrane filtration device 1 disclosed in the third aspect of this application in water treatment.

[0063] The following describes the membrane antifouling method, the membrane antifouling system for implementing the method, the membrane filtration device 1, and the water treatment process of the present invention, using nano-zero valent iron (nZVI) particles as the magnetic and conductive substrate for the in-situ grown needle array and a DC power supply as the external electric field application device 3.

[0064] In this study, nano-zero-valent iron (nZVI) particles with an average particle size of 10 nm were selected as the basis for constructing the needle array. A "magnetic-electric" dual external field coupling device was constructed using commercially available neodymium iron boron (N52) permanent magnets 2a and an adjustable DC power supply. For result verification, a negatively charged humic acid (HA) solution was used as the model pollutant to simulate a real organic pollution system. All materials and equipment involved were readily available from the commercial market.

[0065] In the system for implementing the method of the present invention, the membrane filtration device 1 is a hollow rectangular acrylic cavity, the dimensions of which can be 62 mm in length × 32 mm in width × 48 mm in height, such as... Figure 3 As shown. The magnetic confinement device 2 includes two N52 rectangular permanent magnets 2a, arranged coaxially and parallel to each other in an attractive configuration. The membrane filter device 1, forming a flow channel, is positioned between the two permanent magnets 2a, meaning the entire membrane filter device 1 is placed within the gap between the two permanent magnets 2a, remaining parallel to the magnets. The top cover plate 6 of the membrane filter device 1 has pre-drilled holes as an inlet, and the bottom side has pre-drilled holes as an outlet for collecting water samples. A nitrogen cylinder 11 is also provided as a delivery device to transport the HA solution into the chamber for filtration.

[0066] Initially, the membrane module, support frame 8, fixing frame 9, magnetic conductive plate, sintering plate, and other accessories are assembled in the cavity of the membrane housing 7. nZVI particles are loaded onto the membrane surface. Then, a magnetic confinement device 2 is constructed using permanent magnets 2a arranged above and below the membrane housing 7 to provide a parallel gradient magnetic field with magnetic field lines generally parallel to the filtration direction and perpendicular to the membrane surface. This causes the nZVI particles on the membrane surface to spontaneously form a micron-line array (i.e., a needle array) as array electrodes. Specifically, the formed micron-line array consists of multiple micron-lines (i.e., needle-like structural units 5) extending parallel to the filtration direction (perpendicular to the membrane surface) and arranged along parallel magnetic field lines to the entire membrane surface, with the multiple micron-lines extending along the filtration direction. The sintering plate serves as a support layer in the filtration system, its purpose being to fix and support the position of the membrane module. It can be understood as providing a platform for the membrane module, and the pores of this platform are much larger than the membrane pores. During filtration, the particles pass through the membrane module first, thus not affecting the filtration effect of the system.

[0067] In this invention, the process by which magnetically conductive and electrically conductive particles form a needle array on the membrane surface or near the working surface of the membrane to suppress membrane fouling is based on a synergistic mechanism of magnetic field-induced orientation, electric field tip enhancement, and electrostatic repulsion. Specifically, the magnetically conductive and electrically conductive particles in a free-dispersed state first undergo orientation rearrangement under the action of a parallel gradient magnetic field, and spontaneously construct a needle array perpendicular to the membrane surface along the direction of the magnetic field. Subsequently, when an electric field is applied from the outside using the needle array as a cathode, the needle tip (tip) generates a significantly enhanced local electric field due to the geometric morphology effect, thereby generating a directional electrostatic repulsion effect on negatively charged organic pollutants, colloidal particles, and microorganisms in the water, inhibiting their migration to the membrane surface and entry into the membrane pores.

[0068] The specific operation process is as follows: Magnetic and conductive particulate material is laid on the membrane surface of the membrane module or its adjacent outer region. The membrane module is then placed between opposing magnetic confinement devices 2, creating a magnetic field in the space containing the membrane module where magnetic field lines are approximately perpendicular to the membrane surface. Under the influence of this magnetic field, the magnetic and conductive particulate material aligns and gradually forms needle-like structures extending perpendicular to the membrane surface. Subsequently, the array of needles is electrically connected to an electric field application device 3, which serves as the cathode. A 2V electric field is then applied outside the membrane module, creating an enhanced local electric field in the needle tip region. During membrane separation operation, the water to be treated flows across the membrane surface. Negatively charged pollutants in the water are repelled under the enhanced electric field, thereby inhibiting their deposition on the membrane surface and their penetration into the membrane pores. Through this process, a functional structure with needle-like arrangement characteristics and an enhanced electric field effect is constructed to achieve continuous suppression of membrane fouling.

[0069] In this invention, a magnetically conductive and electrically conductive needle array is formed in situ on the membrane surface or in the vicinity of the membrane based on this method and used as an electrode. That is, magnetically conductive and electrically conductive particle material can be constructed in situ into a needle array extending perpendicular to the membrane surface, and the needle array is spatially ordered and coupled to an external electric field as a cathode. Each needle-shaped structural unit 5 has a geometrically independent tip region facing the membrane surface. When an electric field is applied outside the membrane module during membrane separation operation and the water to be treated flows along the membrane surface, a significantly enhanced local electric field is formed at the tip of each needle-shaped unit. This field generates a directional electrostatic repulsion effect on negatively charged organic pollutants, colloidal particles, and microorganisms in the water, and continues to exert a repulsion effect along the flow direction. This effectively inhibits the deposition of pollutants on the membrane surface and their penetration into the membrane pores, making the membrane flux retention capacity and operational stability significantly better than conventional membrane separation systems without needle-shaped structures or without an applied electric field.

[0070] In one specific embodiment, the permanent magnet has dimensions of 100×50×25mm, a surface magnetic field strength of 300-450mT, and a distance of 380mm between the two magnets. This ensures that the magnetic field strength of the plane containing the needle-like structural units on the film surface is approximately 4-5mT. Furthermore, the distance between the needle array and the lower magnet is 150mm, and the distance between the needle array and the upper magnet is 230mm. The parameters required for forming the needle array in this embodiment are for reference only; different particle sizes can be adjusted according to actual conditions. In principle, any adjustment that allows the needle array to form on the film surface is acceptable.

[0071] This invention provides a new technical approach for constructing a functional structure with field enhancement effect on a membrane module or membrane filtration device 1 and actively regulating the migration behavior of pollutants, thereby achieving efficient and long-lasting inhibition of membrane fouling during water treatment.

[0072] Effect comparison experiment:

[0073] For comparison, different physical fields were applied to the water treatment systems to create water treatment systems under different physical field systems:

[0074] Specifically, the water treatment system is constructed as follows: Figure 2 As shown, the fluid tube is connected via a conduit to a delivery device (i.e., nitrogen cylinder 11), a glass container 12 for the feed solution, and a membrane filtration device 1. The glass container 12 contains an HA solution (10 mg / L, 250 mL, initial pH = 5.4 ± 0.1). First, the working pressure inside the nitrogen cylinder 11 is adjusted to a predetermined value (0.2 ± 0.01 bar) to increase the filtration rate of the HA solution. The pressurized HA solution is then permeated vertically along the nZVI loading direction and flows out of the fluid tube at a flow rate of 0.76 ml / min. Water samples are collected downstream of the fluid tube at predetermined time intervals. During the treatment process, data is tested using an electrochemical workstation 13, and the treated aqueous solution is measured using an electronic balance 14. The results are calculated and displayed using a data collection and display device 15.

[0075] Under the same configuration conditions as described above, that is, under the same configuration conditions as the needle array (in nZVI micrometer line array) constructed in this application, by controlling the presence or absence of an external field, a field-free system, an electric field-assisted antifouling system, a magnetic field-assisted antifouling system, and an electromagnetic field antifouling system were constructed respectively. That is, a water treatment system in which no external electric field or magnetic field is applied, a water treatment system in which only an electric field is applied, a water treatment system in which only a magnetic field is applied, and a water treatment system in which both electric field and magnetic field are applied.

[0076] Figure 4 The study showcased water treatment systems under different frameworks, with a blank control group consisting of systems without external fields or material loading. Figure 4 a); Only apply an electric field ( Figure 4 b) and only applying a magnetic field as the experimental control group ( Figure 4 c) Figure 4 d represents the embodiment group of this application in which an electric field and a magnetic field are applied simultaneously.

[0077] Unless otherwise stated, all catalytic experiments were conducted at a pressure of 0.2 ± 0.01 bar on the aforementioned constructed water treatment system.

[0078] The antifouling effects of the water treatment systems under the above systems are as follows:

[0079] Figure 5 The data shows the changes in membrane flux over time under different operating conditions. The blank control group (i.e., the original membrane system without applied magnetic or electric fields and without loaded magnetic or conductive materials) experienced a rapid decrease in flux during the initial stage of operation. As the operating time increased, the membrane flux continued to decline, reaching only 25% of the initial flux at 180 min. This indicates that without external field control and functional structural assistance, pollutant deposition on the membrane surface and penetration into the membrane pores were severe, leading to rapid membrane fouling. These results demonstrate that relying solely on the membrane structure is insufficient to effectively suppress pollutant migration, resulting in poor long-term stability of the membrane separation process.

[0080] In contrast, in systems where only a magnetic field is applied or only a magnetically and electrically conductive material is loaded without an electric field, the membrane flux decay trend is somewhat mitigated, but the overall antifouling effect remains limited. The membrane flux under magnetic field only condition decreased to 48% at 180 min, and under material loading only condition, the membrane flux decreased to 52%, both significantly higher than the blank control group, but still showing a gradual decay trend over time. This indicates that while relying solely on the magnetic field or the steric hindrance effect of the material itself can influence the distribution of pollutants near the membrane surface to some extent, it is difficult to achieve sustained and effective active regulation of the migration behavior of negatively charged pollutants, and its inhibitory effect on membrane fouling remains limited.

[0081] Furthermore, in the system where only an electric field was applied but no magnetic field-induced structure was constructed, the membrane flux retention capacity was significantly better than the control system described above. The membrane flux ultimately maintained approximately 60% of its initial flux after 180 minutes, indicating that the applied electric field has a certain electrostatic repulsion effect on negatively charged organic pollutants, colloidal particles, and microorganisms in the water, which can inhibit the migration of pollutants to the membrane surface to a certain extent, thereby delaying membrane fouling. However, the electrode structure in this system is relatively flat, the electric field distribution is relatively uniform, and the local electric field strength is limited, resulting in an upper limit to the repulsion effect on pollutants, and the membrane flux still gradually decreases with operating time. Compared with the control systems described above, the electromagnetic composite field system constructed in this invention shows the most significant improvement in the operating performance of the membrane separation process. Figure 5As shown, the membrane flux remained at a high level throughout the 180-minute operation, eventually stabilizing at around 70%, significantly higher than the control, magnetic field only, material loading only, and electric field only systems. This indicates that under magnetic field induction, the magnetically and electrically conductive material forms an in-situ array of needles, which, under the action of an applied electric field, act as cathodes, generating a tip effect. This results in a significantly enhanced local electric field at the needle tips, thereby exerting a stronger directional control effect on pollutant migration behavior. This enhanced electric field constructs a repulsive electric field region near the membrane surface, causing negatively charged pollutants in the water to be repelled before approaching the membrane surface, thus effectively inhibiting their deposition on the membrane surface and penetration into the membrane pores.

[0082] The above comparisons demonstrate that the electromagnetic composite field system of this invention exhibits stronger antifouling performance within the same operating time, and its membrane flux decay rate is significantly lower than that of systems using only electric or magnetic fields, exhibiting a clear synergistic enhancement effect. Specifically, under the influence of the needle-shaped magnetically conductive structure induced by the magnetic field, the electric field changes from a uniform distribution to a locally enhanced distribution, significantly amplifying the electrostatic repulsion near the membrane surface, thereby achieving continuous and efficient control over pollutant migration behavior. In conclusion, the electromagnetic composite field system constructed by this invention demonstrates optimal performance in suppressing membrane fouling, delaying flux decay, and improving the long-term operational stability of the membrane separation process.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A membrane antifouling method based on magnetostrictive tip array electrodes, characterized in that, Includes the following steps: S1, several magnetic and conductive particles are loaded on the working surface of the membrane body; S2, an external magnetic field is applied to the corresponding membrane body to magnetize the magnetically conductive particles. Based on the magnetic dipole interaction, the magnetically conductive particles are induced to form multiple needle-like structural units that extend in a direction perpendicular to the working surface and have pointed ends away from the working surface. The multiple needle-like structural units are held together under the magnetic confinement and together form a needle array. S3, the needle array is used as a cathode connected to the circuit, and an anode is set outside the membrane body. A working electric field is applied so that the needle array generates a local enhanced electric field under the working electric field based on the tip effect formed by the tip, which generates an electrostatic repulsion effect on the pollutants in the fluid to be treated. The magnetically conductive particles are at least one of the following: ferromagnetic metal particles, composite particles of magnetic oxide and conductive material, magnetically conductive particles with core-shell structure, or magnetic carbon-based composite particles. In step S2, the external magnetic field is provided by a magnetic confinement device, which includes permanent magnets or electromagnets arranged in an attractive mode on opposite sides of the membrane body or its attached devices in a direction perpendicular to the working surface of the membrane body, so as to form a gradient magnetic field on the outside of the membrane body.

2. The membrane antifouling method based on magnetostrictive tip array electrodes according to claim 1, characterized in that, The needle-like structural unit is a chain-like aggregate formed by magnetically conductive particles stacked in a direction perpendicular to the working surface of the membrane body under the interaction of magnetic dipoles. It is cone-shaped with a large end near the root of the membrane body and a small end away from the membrane body.

3. The membrane antifouling method based on magnetostrictive tip array electrodes according to claim 1, characterized in that, In step S3, the needle array is connected to the circuit as a cathode by directly connecting an external electrode to the bottom of the needle array, or the working surface of the membrane body is modified to make it a conductive film and serve as a conductive substrate for the needle array, so that the needle array can be connected to the circuit as a cathode.

4. A membrane antifouling system for implementing the membrane antifouling method based on magnetostrictive tip array electrodes according to any one of claims 1-3, characterized in that, include: Several magnetic and conductive particles are provided and loaded in particle form on the working surface of the membrane body. The magnetic confinement device is set up by applying an external magnetic field to the membrane body to magnetize the magnetically conductive particles. Based on the magnetic dipole interaction, the magnetically conductive particles are induced to form multiple needle-like structural units that extend in a direction perpendicular to the working surface and have pointed ends away from the working surface. The multiple needle-like structural units are held together under the magnetic confinement and together form a needle array. An electric field application device includes a cathode connection terminal, an anode, and a power source, wherein the cathode connection terminal is electrically connected to the needle array to serve as the cathode as a whole, the anode is disposed outside the membrane body, and the power source is used to apply a working electric field between the cathode and the anode.

5. The membrane antifouling system according to claim 4, characterized in that, An external electrode is directly connected to the bottom of the needle array, and the needle array is used as a cathode connected to the circuit. Alternatively, the working surface of the membrane body can be modified to make the membrane body a conductive membrane, which serves as the conductive substrate of the needle array, so that the needle array can be connected to the circuit as a cathode.

6. The membrane antifouling system according to claim 4, characterized in that, The magnetically conductive particles are designed to be replaceable, so that the radius of curvature of the tip of the needle-shaped structure unit can be adjusted based on the particle size of the magnetically conductive particles, thereby controlling the local enhanced electric field at the tip of the needle-shaped structure unit when a working electric field is applied. And / or, the strength of the external magnetic field is set to be adjustable so that the length of the needle-like structural unit can be adjusted based on the change in the strength of the external magnetic field, thereby modulating the local enhanced electric field at the tip of the needle-like structural unit when a working electric field is applied.

7. A membrane filtration device, characterized in that, It includes a membrane body and a flow channel space formed by the corresponding membrane body, wherein the membrane body has a working surface for separation and filtration; It also includes a membrane antifouling system according to any one of claims 4-6, the membrane antifouling system being associated with the membrane body.

8. The application of a membrane antifouling system according to any one of claims 4-6 in water treatment.

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