Electrically integrated nanofiltration water purification device based on flexible anode functional separation net gasket and water purification method

Abstract

The invention discloses an electric integration nanofiltration water purification device and method based on a flexible anode functional separation net gasket, and belongs to the technical field of sewage advanced treatment and membrane pollution control. The device comprises a raw water tank, a water inlet pump, an electric integrated nanofiltration membrane assembly, a direct-current power supply, a cathode chamber, a water outlet tank and a control system. According to the invention, in a flow channel of a nanofiltration membrane assembly, a flexible anode functional separation net gasket which takes a woven titanium net as a substrate and is loaded with an antimony-doped SnO2-Sb thin film catalyst layer is arranged, and the flexible anode functional separation net gasket and an independent cathode form a loop. When operating under a specific voltage, the separation net simultaneously plays three roles: (1) as a physical separation net, the separation net optimizes the hydraulic conditions of a flow channel and generates turbulent flow; (2) as an anode, generating electrooxidation active species to degrade organic pollutants and electrically stimulate microbial communities to form a loose porous pollution layer; and (3) the gas flow generated by the in-situ electrolyzed water and the separation net have a synergistic effect, so that the turbulence and the wall surface shear force are obviously enhanced, and polysaccharide pollutants are efficiently washed, thereby reducing the membrane pollution.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment and membrane separation technology, and in particular to a nanofiltration membrane fouling control device and method for advanced wastewater treatment and reuse. Specifically, it is a device and method that achieves in-situ enhancement of electrochemical processes by innovatively integrating flexible electrode materials with membrane module mesh, thereby mitigating nanofiltration membrane biofouling through multiple synergistic mechanisms.

[0002] Wastewater reuse is an important way to solve water shortages. Nanofiltration technology is widely used in the field of advanced secondary effluent treatment due to its excellent retention performance of dissolved organic matter and multivalent ions. However, membrane fouling (especially biofouling) leading to decreased flux, increased energy consumption, and shortened membrane life is a key bottleneck restricting its large-scale application. Existing membrane fouling control strategies mainly fall into two categories: one is pretreatment before membrane treatment, such as electrochemical advanced oxidation processes, which degrade pollutants by generating strong oxidizing substances such as hydroxyl radicals, thereby reducing the pollutant load in the influent. However, this strategy usually requires a separate reaction unit, increasing system complexity and construction costs, and traditional rigid electrodes are difficult to integrate with spiral wound membrane modules. The second is optimizing the internal hydraulic conditions of the membrane module, such as placing a spacer in the spiral wound membrane element, which enhances the membrane surface shear force by generating turbulence, reducing concentration polarization and pollutant deposition. However, traditional polymer spacers only have passive antifouling capabilities, and their mesh crossover points easily form flow dead zones, which actually promote the attachment and reproduction of microorganisms, making biofouling inevitable in long-term operation.

[0003] In the prior art, Cheng W, Wang P, Zhang Y, et al. Oxidation resistances of polyamide nanofiltration membranes to hydroxyl and sulfate radicals [J]. Journal of membrane Science, 2023, 666: 121156, etc. disclosed that the oxidative active groups generated during the advanced oxidation process have the function of degrading organic matter. Therefore, during the long-term operation of the advanced oxidation-nanofiltration combined process, there will inevitably be the phenomenon of oxidative active groups attacking the nanofiltration membrane material, directly changing many structural characteristics such as the distribution of nanofiltration membrane components, the distribution of characteristic functional groups, microstructure and surface morphology, weakening the water production capacity and pollutant retention capacity of the nanofiltration membrane. Sim L, Gu J, Coster H, et al. Quantitative determination of the electrical properties of RO membranes during fouling and cleaning processes using electrical impedance spectroscopy [J]. Desalination, 2016, 379: 126-136.

[34] Xu R, Jiang P, WeiC, et al. Depositing sericin on partially degraded polyamide reverse Osmosism membrane for restored salt rejection and simultaneously enhanced resistance to both fouling and chlorine [J]. Journal of Membrane Science, 2018, 545:196-203. This paper discloses experimentally demonstrated that microorganisms deposited on the membrane surface can improve the chlorine resistance of the filter membrane, mainly by acting as a protective layer and sacrificial layer to prevent active chlorine from damaging the polyamide backbone.

[0004] Chinese patent CN116081785A discloses an adjustable ultrafiltration-electrocatalytic membrane coupled water purification device, including a wastewater treatment tank, two oppositely spaced ultrafiltration membranes and two oppositely spaced electrocatalytic membranes. The two ultrafiltration membranes are located outside the two electrocatalytic membranes, with the selective surface of the ultrafiltration membranes facing outwards. The two electrocatalytic membranes are respectively connected to the positive and negative terminals of an external power supply. The wastewater treatment tank includes an inlet chamber, a membrane filtration clear water chamber, a catalytic degradation chamber, a degradation clear water chamber, and a spare chamber. The inlet chamber is located outside the ultrafiltration membrane at the front end of the water flow channel. The membrane filtration clear water chamber is located between the front ultrafiltration membrane and the front electrocatalytic membrane. The catalytic degradation chamber is located between the two electrocatalytic membranes. The degradation clear water chamber is located between the rear electrocatalytic membrane and the rear ultrafiltration membrane. The spare chamber is located outside the rear ultrafiltration membrane and is used for water purification. However, this method does not consider the problem of membrane fouling.

[0005] If a component combining the fluid disturbance function of a "screen" and the active electrochemical antifouling function of an "electrode" can be developed and integrated in situ into the membrane separation process, it is expected to simultaneously solve the membrane fouling problem existing in current technologies. Although some studies have attempted to attach electrode materials to the membrane surface, these often affect the membrane's own performance or fail to fully utilize the hydraulic synergistic effect. Therefore, developing a flexible anode-functionalized screen that is compatible with commercial nanofiltration membrane modules and can provide multiple antifouling mechanisms (electro-oxidation, electro-stimulation, and electrolytic gas generation flushing) in situ, and constructing an efficient, stable, and low-cost antifouling nanofiltration system, has significant theoretical value and broad engineering application prospects. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to solve the problems of severe membrane biofouling, limited efficiency and low integration of traditional antifouling strategies in the treatment of secondary effluent by existing nanofiltration processes, and to provide an electro-integrated nanofiltration water purification device and method based on flexible anode functionalized mesh gaskets to alleviate nanofiltration membrane fouling.

[0007] In a first aspect, the present invention discloses a flexible anode-functionalized mesh gasket, the flexible anode-functionalized mesh gasket comprising: a substrate, an intermediate layer, and a catalyst layer, the substrate providing support for the flexible anode-functionalized mesh gasket, the intermediate layer connecting the catalyst layer and the substrate to prevent the catalyst layer from detaching and failing, and the catalyst layer electrocatalyzing wastewater under electrocatalysis to affect the replacement cycle of the nanofiltration membrane.

[0008] Preferably, the substrate is a titanium mesh substrate, the intermediate layer is a Sn-Sb intermediate layer, and the catalyst layer is a SnO2-Sb catalyst layer.

[0009] Preferably, the titanium mesh is a woven titanium mesh.

[0010] Preferably, the flexible anodized functionalized mesh gasket is prepared using the following method: Step 1: Obtain a titanium mesh with a wire diameter of 0.3-0.6 mm; Step 2: First, wash with alkali, then etch with acid to obtain the woven titanium mesh obtained in Step 1 to obtain the pretreated woven titanium mesh; Step 3: Based on Step 2, a Sn-Sb layer is loaded using a pulse electrodeposition method; Step 4: After step 3, the SnO2-Sb catalyst layer is formed by air heat treatment at 400-600℃ for 1-12 hours.

[0011] Preferably, the titanium mesh is a woven titanium mesh with a wire diameter of 0.3-0.8 mm, more preferably 0.3-0.5 mm.

[0012] Secondly, this invention discloses an electro-integrated nanofiltration water purification device based on a flexible anode-functionalized mesh gasket. The electro-integrated nanofiltration water purification device includes an electro-integrated nanofiltration membrane assembly, a DC power supply, and a cathode chamber. The electro-integrated nanofiltration membrane assembly has a water-permeable support layer, on which a flexible anode-functionalized mesh gasket and a nanofiltration membrane are sequentially arranged. The flexible anode-functionalized mesh gasket is based on a woven titanium mesh and has an antimony-doped tin dioxide electrocatalytic coating loaded on its surface. A cathode plate is provided in the cathode chamber. The positive terminal of the DC power supply is electrically connected to the flexible anode-functionalized mesh gasket through a wire, and the negative terminal is electrically connected to the cathode plate in the cathode chamber through a wire.

[0013] Preferably, the flexible anode functionalized spacer includes: a titanium mesh substrate, a Sn-Sb intermediate layer, and a SnO2-Sb catalyst layer.

[0014] Preferably, the electro-integrated nanofiltration water purification device further includes a raw water tank, an inlet pump, and an outlet water tank. The raw water tank is connected to the inlet of the electro-integrated nanofiltration membrane module through the inlet pump, and the outlet of the electro-integrated nanofiltration membrane module is connected to the outlet water tank.

[0015] Preferably, the operating voltage of the DC power supply is 3-6V, and more preferably 4-5V.

[0016] Preferably, the water inlet pump is a gear pump.

[0017] Preferably, the electro-integrated nanofiltration membrane module is a flat cross-flow membrane box.

[0018] Preferably, the cathode chamber is located upstream of the electro-integrated nanofiltration membrane assembly.

[0019] Preferably, the flexible anolyl functionalized mesh pad is coated with an electrically insulating protective layer on the side facing the nanofiltration membrane.

[0020] Preferably, the electrically insulating protective layer comprises at least one insulating material selected from the following: metal oxides, metal nitrides, metal carbides, thermosetting resins, thermoplastic resins, and inorganic-organic composite insulating materials; the metal oxides include, but are not limited to, TiO2, Al2O3, SiO2, ZrO2, Y2O3, Ti4O7, and Ti5O9; the metal nitrides / carbides include, but are not limited to, Si3N4, SiON, TiN, and TiC; the thermosetting resins include epoxy resins, polyester resins, polyurethane resins, and silicone resins; and the inorganic-organic composite insulating materials include ceramic particle-filled resins, graphene composite ceramics, and micro-arc oxidation ceramic layer-organic sealing layer composite structures.

[0021] Preferably, the protective layer is a single-layer structure or a multi-layer composite structure; the multi-layer composite structure includes at least two layers selected from a base layer, an intermediate layer, and an insulating surface layer; the base layer is selected from Ti / TiC and Cr / CrN.

[0022] Preferably, the coating method is selected from at least one of micro-arc oxidation, sol-gel, spraying, physical vapor deposition, chemical vapor deposition, electrophoresis, dip coating, brush coating, photocuring, and thermocuring.

[0023] Thirdly, the present invention also discloses a water purification method using the electro-integrated nanofiltration water purification device based on the flexible anode functionalized mesh gasket described in the second aspect; A DC power supply is used as the driving source for the water purification system. The positive output terminal is connected to the flexible anode functionalized mesh pad through an external insulated wire; the negative output terminal is connected to the cathode plate placed in the cathode chamber through an external insulated wire; the operating voltage of the DC power supply is 3-6V. The water to be treated, containing conductive ions, flows through the cathode chamber and the cavity of the electro-integrated nanofiltration membrane assembly under the drive of the inlet pump; Driven by a DC power supply, the gas generated by the in-situ electrolysis of water by the flexible anode functionalized mesh pad forms a microbubble flow. The microbubble flow and the flexible anode functionalized mesh pad work together to strip away surface contaminants from the nanofiltration membrane, forming a porous contaminant layer structure.

[0024] Preferably, the operating voltage of the DC power supply is 4-5V.

[0025] The beneficial effects of this invention include: 1. This invention utilizes a flexible anode functionalized mesh to construct an electro-integrated nanofiltration system, which exhibits excellent synergistic removal and regulation effects on organic pollutants and microbial contamination in the water under appropriate voltage. The device and method of this invention utilize the microbubble flow generated by in-situ electrolysis to synergistically enhance the membrane shear force with the mesh, significantly alleviating membrane fouling, extending membrane lifespan, and reducing cleaning frequency and energy consumption. The device and method of this invention determine the optimal operating voltage, achieving highly efficient synergy of electrocatalytic oxidation, microbial community regulation, and physical flushing mechanisms, resulting in proactive and long-lasting anti-fouling performance. The device and method of this invention integrate the electrode function with the original mesh support, eliminating the need for additional reaction units, and achieving in-situ deep integration of the electrochemical process and membrane separation, resulting in a compact system with low modification and application costs.

[0026] 2. Water electrolysis occurs at the anode and cathode, generating oxygen and hydrogen microbubbles in situ. These microbubble flows synergistically with the diamond-shaped mesh structure of the anode separator, significantly enhancing local turbulence and shear forces on the membrane surface. Computational fluid dynamics simulations confirm that this synergistic effect increases the average shear force of the aqueous phase at the membrane surface by approximately 93% and the shear force of the gas phase by approximately 45%, thus acting like countless "micro-brushes" to efficiently physical flush the membrane surface, especially viscous polysaccharide pollutants. The water, purified through this synergistic process of electrochemical oxidation, biological regulation, and physical flushing, permeates through the nanofiltration membrane under pressure, and the treated water enters the effluent tank, meeting urban reuse standards.

[0027] 3. This invention uses an electrocatalytic anode to treat water. The active species such as hydroxyl radicals generated on the surface of the flexible anode functionalized mesh directly oxidize and degrade organic pollutants in the water, such as sulfamethoxazole. At the same time, the electric field stimulates and changes the structure of the microbial community on the membrane surface, promoting the growth of eukaryotic organisms such as tube feet that have strong mobility and predation capabilities. Their activity helps to build heterogeneous structures and water channels in the subsequently formed fouling layer. Attached Figure Description

[0028] Figure 1 This is a schematic diagram, an internal view and a structural diagram of an electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to the present invention. Figure 2 The following are membrane flux trend graphs: (a) the overall membrane flux curve and (b) the steady-state period (days 30-90) and membrane permeability statistical analysis graph: (c) stage I (interval voltage = 1.2 V), (d) stage II (interval voltage = 2.4 V) and (e) stage III (interval voltage = 4.8 V); where ESNF is an electro-integrated nanofiltration module and DCNF is a conventional nanofiltration module; Figure 3The following is a simulation diagram of the wall shear stress distribution of the nanofiltration crossflow channel of the present invention: (a) simulation without spacers and gas flow; (b) simulation without spacers but with gas flow; (c) simulation with spacers but no gas flow; (d) simulation with spacers and gas flow (1-water phase, 2-gas phase); Figure 4 This is a comparison chart showing the effect of the electro-integrated nanofiltration of the present invention on the removal of pollutants compared with conventional nanofiltration; Figure 5 This is a diagram of the microbial community analysis of the membrane fouling layer according to the present invention; Figure 6 This is a schematic diagram illustrating the working principle of the electro-integrated nanofiltration water purification device based on flexible anode functionalized mesh gaskets of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the embodiments described in this specification are merely for explaining the invention and are not intended to limit the invention. The parameters, proportions, etc., of the embodiments can be selected according to local conditions without substantially affecting the results. Unless otherwise specified, the reagents and methods used in the embodiments are conventional in the art. Example 1

[0030] See the instruction manual appendix Figure 1-5 As shown, an electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket includes a raw water tank (1), an inlet pump (2), an electro-integrated nanofiltration membrane module (3), a DC power supply (4), a cathode chamber (5), and an outlet water tank (6). The electro-integrated nanofiltration membrane module (3) adopts a flat cross-flow membrane box (such as CF042D), and a self-made flexible anode functionalized mesh gasket (301) is placed in close contact with the surface of the nanofiltration membrane (302) (such as NF270) in its inlet flow channel.

[0031] In this embodiment, the flexible anode functionalized separator uses a rhombic woven titanium mesh (0.45 mm wire diameter) as the substrate. After alkaline washing and acid etching pretreatment, a Sn-Sb layer is loaded using pulse electrodeposition, and then a stable SnO2-Sb catalyst layer is formed by air heat treatment at 500℃ for 1 hour. The cathode chamber (5) is located upstream of the membrane module inlet. The DC power supply (4) (HSPY-120-01) is connected to the anode and cathode.

[0032] Simulated secondary effluent is stored in the raw water tank (1) and pumped into the electro-integrated nanofiltration membrane module (3) at a constant flow rate by the inlet pump (2). The operating pressure is 0.4 MPa and the crossflow velocity is 0.1 m / s.

[0033] Turn on the DC power supply (4) and set the anode grid voltage to 4.8 V. The system runs continuously for 90 days.

[0034] In Example 1, the DC power supply (4) serves as the driving source of the system. Its positive output terminal is connected to the flexible anode functionalized mesh pad (301) via an external insulated wire, making the flexible anode functionalized mesh pad the anode. Its negative output terminal is connected to the cathode plate placed in the cathode chamber (5) via an external insulated wire. The secondary effluent to be treated contains Cl. - HCO3 - Na + The water, carrying conductive ions, flows sequentially through the cathode chamber (5) and the cavity of the electro-integrated nanofiltration membrane assembly (3) under the drive of the high-pressure gear pump (2), and serves as the electrolyte for the entire circuit, providing an ion migration channel for charge transfer between the anode and cathode. Thus, the current loop travels from the positive terminal of the power supply through the wire to the anode, through the electrolyte (water flow) to the cathode, and then back to the negative terminal of the power supply through the wire, forming a complete closed loop.

[0035] When the voltage is 4.8 V, it can effectively activate electrocatalytic oxidation, microbial stimulation and water electrolysis gas generation mechanism at the same time, and the membrane flux improvement effect is the best. Compared with the control group without electrical functional grid, the flux can be increased by about 10%.

[0036] Operating at 4.8 V in Example 1, the gas generated by the in-situ electrolysis of water by the flexible anode functionalized separator (301) (hydrogen production at the cathode and oxygen production at the anode) forms a microbubble flow. Computational fluid dynamics simulations confirm that the flexible anode functionalized separator, in synergy with this in-situ generated bubble flow, can increase the average shear force on the membrane surface by 45% to 93%, effectively stripping polysaccharide contaminants from the membrane surface and forming a loose and porous contaminant layer structure.

[0037] The method described above can effectively treat secondary effluent from urban wastewater treatment plants, and has a enhanced removal effect on COD, TOC, and especially trace organic pollutants such as sulfamethoxazole (SMZ). After long-term operation (e.g., 90 days), the quality of the produced water can stably meet the standards of "Water Quality Standard for Urban Wastewater Reuse for Miscellaneous Use" (GB / T18920) and "Water Quality Standard for Urban Wastewater Reuse for Industrial Use" (GB / T19923).

[0038] The electrochemical action of the flexible anodic functionalized mesh gasket (301) alters the structure of the membrane surface microbial community, enriching eukaryotes with strong motility and predation capabilities (such as Elardia, with a relative abundance of up to 66%). Their activity helps to form heterogeneous structures and water channels in the fouling layer, further improving membrane permeability. See the appendix of the instruction manual. Figure 5 . Example 2

[0039] This embodiment discloses a method for preparing a flexible anodized functionalized mesh gasket: Step 1: Selection of titanium mesh to obtain a woven titanium mesh; the woven titanium mesh is made of titanium wire, the weaving method is plain weave, the wire diameter is selected as 0.45mm, the mesh size of the titanium mesh is 1.0mm×1.0mm, the width of the titanium mesh is 50mm and the length is 100mm.

[0040] Step 2: Pretreatment of titanium mesh (alkali washing + acid etching); First, the woven titanium mesh selected in step 1 is subjected to alkaline washing to remove oil, organic impurities, and some loose oxide layer from its surface. The alkaline washing reagent is a 10% sodium hydroxide solution at a temperature of 60℃. The titanium mesh is immersed in the sodium hydroxide solution for 30 minutes, stirring every 5 minutes to ensure that all parts of the mesh surface are fully in contact with the alkaline solution. After alkaline washing, the titanium mesh is removed and rinsed repeatedly with deionized water until no alkaline residue remains on the surface. The surface is then dried.

[0041] The alkaline-washed titanium mesh was then subjected to acid etching to further remove the dense oxide film on the surface, roughen the surface, and improve the adhesion of the subsequent Sn-Sb layer. The acid etching reagent was a mixed acid solution of hydrofluoric acid, nitric acid, and deionized water in a volume ratio of 1:1:2. The etching temperature was room temperature (25℃). The dried titanium mesh was immersed in the mixed acid solution for 2 minutes, and the surface was observed during etching until a uniform light gray rough surface appeared. After etching, the titanium mesh was removed, quickly rinsed with deionized water to remove residual acid, and then placed in a vacuum drying oven at 80℃ for 2 hours to obtain the pretreated woven titanium mesh.

[0042] Step 3: Pulse electrodeposition of Sn-Sb loaded layer Using the pretreated woven titanium mesh obtained in step 2 as the working electrode, a pure platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode, a three-electrode electrode deposition system was constructed. Preparation of the electrodeposition electrolyte: Deionized water was used as the solvent, and stannous chloride (SnCl2·2H2O) and antimony trichloride (SbCl3) were added as solutes. An appropriate amount of hydrochloric acid was added to adjust the pH of the electrolyte to 1.0, where the concentration of stannous chloride was 0.1 mol / L and the concentration of antimony trichloride was 0.01 mol / L. After stirring evenly, the solution was allowed to stand for 10 min to remove air bubbles.

[0043] The Sn-Sb layer was loaded using pulsed electrodeposition. The electrodeposition equipment was a pulsed power supply, and the electrodeposition parameters were set as follows: pulse frequency of 100Hz, duty cycle of 50%, deposition potential of -0.8V (relative to a saturated calomel electrode), deposition temperature of 30℃, and deposition time of 60min. The electrolyte was continuously stirred during deposition to ensure uniform electrolyte concentration, allowing the Sn layer to be deposited. 2+ and Sb 3+ Uniform deposition was performed on the surface of the titanium mesh. After deposition, the titanium mesh was removed, rinsed with deionized water to remove residual electrolyte, and then placed in a vacuum drying oven and dried at 80°C for 1 hour to obtain a titanium mesh loaded with a Sn-Sb layer.

[0044] Step 4: High-temperature air heat treatment to form the SnO2-Sb catalyst layer; The titanium mesh with the Sn-Sb layer obtained in step 3 was placed in a box-type resistance furnace for heat treatment in an air atmosphere. The heat treatment temperature was set to 400℃, the heating rate was 5℃ / min, and after reaching the set temperature of 500℃, the holding time was 12h. During the heat treatment, air circulation was maintained in the furnace to ensure that the Sn-Sb layer was fully oxidized. After the heat treatment was completed, the power was turned off, and the titanium mesh was allowed to cool to room temperature with the furnace. The Sn-Sb layer was transformed into a SnO2-Sb catalyst layer through an oxidation reaction, and finally, a flexible anode functionalized spacer was obtained.

[0045] Comparative Example 1 The apparatus of Comparative Example 1 is the same as that of Example 1, except that the voltage applied to the anode grid by the DC power supply (4) is different. Comparative Example 1 is set to 1.2V. Comparative Example 2

[0046] The apparatus of Comparative Example 2 is the same as that of Example 1, except that the voltage applied to the anode grid by the DC power supply (4) is different. Comparative Example 1 is set to 2.4V.

[0047] At 1.2 V, the effect of the electrofunctionalized membrane on membrane flux and pollutant removal was not significantly different from that of the non-functionalized membrane group (DCNF), indicating that the electrochemical effect was not fully activated at this voltage. At 2.4 V, the system showed enhanced degradation of SMZ, but the membrane flux was slightly lower than that of the DCNF group. Analysis suggests that at this voltage, electrical stimulation promoted microbial metabolic activity, but the small molecule metabolites produced may enter the membrane pores and cause blockage. Simultaneously, the electrolytic gas generation effect was weak and insufficient to offset the negative impact of biomass proliferation. This comparison further highlights the importance of optimizing the operating voltage to 4.8 V (close to the oxygen evolution potential of the SnO2-Sb coating to activate gas generation) for synergistic activation of multiple antifouling mechanisms and achieving improved net flux.

[0048] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. An electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket, characterized in that: The electro-integrated nanofiltration water purification device includes an electro-integrated nanofiltration membrane assembly (3), a DC power supply (4), and a cathode chamber (5). The electro-integrated nanofiltration membrane assembly (3) is provided with a water-permeable support layer (303). A flexible anode-functionalized mesh pad (301) and a nanofiltration membrane (302) are sequentially provided on the water-permeable support layer (303). The flexible anode-functionalized mesh pad (301) is based on a woven titanium mesh and has an antimony-doped tin dioxide electrocatalytic coating loaded on its surface. A cathode plate is provided in the cathode chamber (5). The positive electrode of the DC power supply (4) is electrically connected to the flexible anode-functionalized mesh pad (301) through a wire, and the negative electrode is electrically connected to the cathode plate in the cathode chamber (5) through a wire.

2. The electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to claim 1, characterized in that: The flexible anode functionalized mesh gasket (301) includes: a titanium mesh substrate, a Sn-Sb intermediate layer, and a SnO2-Sb catalyst layer. Preferably, the flexible anode functionalized mesh gasket is coated with an electrically insulating protective layer on the side facing the nanofiltration membrane.

3. The electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to claim 1, characterized in that: The electro-integrated nanofiltration water purification device also includes a raw water tank (1), an inlet pump (2), and an outlet water tank (6). The raw water tank (1) is connected to the inlet of the electro-integrated nanofiltration membrane module (3) through the inlet pump (2), and the outlet of the electro-integrated nanofiltration membrane module (3) is connected to the outlet water tank (6).

4. An electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to any one of claims 1-3, characterized in that: The operating voltage of the DC power supply (4) is 3-6V, preferably 4-5V.

5. An electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to any one of claims 1-3, characterized in that: The water inlet pump (2) is a gear pump.

6. An electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to any one of claims 1-3, characterized in that: The electro-integrated nanofiltration membrane module (3) is a flat cross-flow membrane box.

7. An electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to any one of claims 1-3, characterized in that: The flexible anodized functionalized spacer pad (301) is prepared by the following method: Step 1: Obtain a woven titanium mesh with a wire diameter of 0.3-0.8 mm; Step 2: First, wash with alkali, then etch with acid to obtain the woven titanium mesh obtained in Step 1 to obtain the pretreated woven titanium mesh; Step 3: Based on Step 2, a Sn-Sb layer is loaded using pulse electrodeposition. Step 4: After step 3, the SnO2-Sb catalyst layer is formed by air heat treatment at 400-600℃ for 1-12 hours.

8. An electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket according to any one of claims 1-3, characterized in that: The cathode chamber (5) is located upstream of the electro-integrated nanofiltration membrane assembly (3).

9. A water purification method using an electro-integrated nanofiltration water purification device based on a flexible anode functionalized mesh gasket as described in any one of claims 1-7, characterized in that: A DC power supply (4) is used as the driving source for the water purification system. The positive output terminal is connected to the flexible anode functionalized mesh pad (301) through an external insulated wire; the negative output terminal is connected to the cathode plate placed in the cathode chamber (5) through an external insulated wire; the working voltage of the DC power supply is 3-6V. The water to be treated, containing conductive ions, flows through the cathode chamber (5) and the cavity of the electro-integrated nanofiltration membrane assembly (3) under the drive of the inlet pump (2); Driven by a DC power supply (4), the gas generated by the in-situ electrolysis of water by the flexible anode functionalized mesh pad (301) forms a microbubble flow. The microbubble flow and the flexible anode functionalized mesh pad (301) work together to peel off surface pollutants from the nanofiltration membrane (302) to form a porous pollutant layer structure.

10. The water purification method according to claim 9, characterized in that: The operating voltage of the DC power supply is 4-5V.

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