Photocatalysis and multi-dimensional electric field combined composite membrane filtering device

Abstract

The invention provides a photocatalysis and multidimensional electric field composite membrane filtering device, and relates to the technical field of water treatment.The photocatalysis and multidimensional electric field composite membrane filtering device comprises a conductive filter element module which is of a hollow cylinder structure and comprises a hollow porous supporting body and a composite conductive filter membrane wrapping the outer layer of the hollow porous supporting body; the photocatalytic ultrafiltration membrane module is annularly nested on the inner side of the conductive filter element module; the photocatalytic ultrafiltration membrane module is composed of a polyethersulfone base membrane and a TiO2 / rGO composite photocatalytic layer loaded on the surface of the polyethersulfone base membrane; the multi-dimensional electric field electrode system comprises an axial electrode and a radial electrode array; the axial electrode is a hollow carbon fiber tube nested on the inner side of the photocatalytic ultrafiltration membrane module; the radial electrode array is composed of a plurality of arc-shaped graphite electrodes surrounding the periphery of the conductive filter element module. The problems that existing electric field filtration cannot remove neutral / macromolecular pollutants sufficiently, photocatalysis depends on illumination and is low in efficiency, and a film of a traditional electric field device is prone to blockage and short in service life can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and more particularly, to a photocatalytic synergistic multi-dimensional electric field composite membrane filtration device. Background Art

[0002] In existing water treatment technologies, although electric field-driven filtration and photocatalytic technologies each play an important role, they both have obvious limitations, which are as follows: The electric field-driven filtration technology mainly uses the action of electric field force on charged particles to remove pollutants. In an electric field, charged pollutant particles will be attracted by the electric field force and move towards the electrode direction, thereby being intercepted or separated. When treating sewage containing charged particles, this technology can effectively remove charged colloids, microorganisms and other pollutants in water. Although electric field filtration can adsorb charged particles through charge action, its removal effect on neutral or macromolecular organic substances is limited, resulting in the difficulty of reaching higher standards for the treated water quality. In addition, traditional electric field filtration devices mostly have a single-layer or double-layer electric field structure, with a single electric field distribution, which easily leads to the accumulation of impurities on the membrane surface and shortens the membrane life.

[0003] The photocatalytic technology is based on the photo-generated electron-hole pairs generated by photocatalysts under light illumination. These electrons and holes have strong oxidation and reduction capabilities and can react with pollutants in water to decompose them into carbon dioxide, water and other harmless small molecule substances. When treating organic pollutants, this technology does not require the addition of a large amount of chemical reagents and can achieve the mineralization and degradation of pollutants. Although the photocatalytic technology can decompose pollutants only relying on light illumination conditions, the reaction efficiency is limited by the light energy utilization rate and the catalyst activity, and it is difficult to ensure continuous and efficient treatment effects. Summary of the Invention

[0004] The problem solved by the present invention is the insufficient removal of neutral / macromolecular pollutants by existing electric field filtration, the dependence on light illumination and low efficiency of photocatalysis, and the easy blockage and short life of the membrane of traditional electric field devices.

[0005] To solve the above problems, the present invention provides a photocatalytic synergistic multi-dimensional electric field composite membrane filtration device, comprising: A conductive filter element module, which is a hollow cylindrical structure. The conductive filter element module includes a hollow porous support body and a composite conductive filter membrane coated on the outer layer of the hollow porous support body; A photocatalytic ultrafiltration membrane module, which is annularly nested inside the conductive filter element module; the photocatalytic ultrafiltration membrane module is composed of a polyethersulfone-based membrane and a TiO2 / rGO composite photocatalytic layer loaded on the surface of the polyethersulfone-based membrane; A multi-dimensional electric field electrode system, including an axial electrode and a radial electrode array; the axial electrode is a hollow carbon fiber tube nested inside the photocatalytic ultrafiltration membrane module, with micropores on its surface; the radial electrode array is composed of multiple arc-shaped graphite electrodes surrounding the outer periphery of the conductive filter element module, and the spacing between the multiple arc-shaped graphite electrodes is adjustable, with an adjustment range of 10 to 20 cm; and An intelligent control module for measuring the real-time water quality and dynamically adjusting the electric field intensity, electrode polarity and light parameters according to the real-time water quality.

[0006] Optionally, the intelligent control module includes a water quality sensor, an adjustable power supply and an ultraviolet light source; the water quality sensor is located at the water inlet and outlet, and the ultraviolet light source is evenly distributed around the outer side of the photocatalytic ultrafiltration membrane module.

[0007] Optionally, the axial electrode is connected to the positive pole of the adjustable power supply, the radial electrode array is connected to the variable positive / negative poles of the adjustable power supply in regions, and the photocatalytic ultrafiltration membrane module is connected to the negative pole of the adjustable power supply; the frequency of the adjustable power supply in the pulse output mode is 10 to 100 Hz.

[0008] Optionally, the distance between the ultraviolet light source and the surface of the photocatalytic ultrafiltration membrane module is 3 to 7 cm.

[0009] Optionally, the hollow porous support is a hollow cylinder made of polypropylene, the pore diameter of the holes in the middle of the hollow porous support is 10 to 50 μm, and the porosity is ≥70%.

[0010] Optionally, the thickness of the composite conductive filter membrane is 50 to 100 μm.

[0011] Optionally, the retention molecular weight of the polyethersulfone-based membrane is 10 kDa, and the pore diameter is 0.1 to 0.5 μm.

[0012] Optionally, the pore diameter of the micropores is 5 μm to 15 μm, and the pore density is 90 to 100 pores / cm².

[0013] Optionally, the manufacturing method of the conductive filter element module includes the following steps: Soak the hollow porous support in absolute ethanol and ultrasonically clean it for 20 to 40 minutes; then rinse it with deionized water and vacuum dry it at 50 to 70 °C for 1 to 3 hours for standby to obtain the pretreated hollow porous support; Take a 1 mol / L hydrochloric acid solution, add aniline monomer to make the concentration of aniline monomer 4 to 6 g / mL, and magnetically stir until completely dissolved; Add a 2 mg / mL graphene oxide dispersion solution with 50% volume of the hydrochloric acid solution to the above solution, ultrasonically treat it to uniformly disperse the graphene oxide to form an aniline-graphene oxide mixed solution; immerse the pretreated hollow porous support in the aniline-graphene oxide mixed solution; Under the condition of an ice-water bath at 0 to 5 °C, an ammonium persulfate solution was slowly added dropwise to the aniline-graphene oxide mixed solution to initiate the polymerization reaction of aniline; the reaction was continued for 5 to 7 hours, during which the stirring speed was maintained at 160 to 240 rpm to form a composite conductive layer on the surface of the hollow porous support; The hollow porous support was taken out, rinsed with deionized water, then the hollow porous support was immersed in a 0.1 mol / L NaOH solution for 5 to 15 minutes, and finally dried under vacuum at 50 to 70 °C to obtain a hollow porous support with a graphene / polyaniline composite conductive filter membrane coated on its surface.

[0014] Optionally, the manufacturing method of the photocatalytic ultrafiltration membrane module includes the following steps: The polyethersulfone base membrane was immersed in deionized water and ultrasonically cleaned; rinsed with absolute ethanol and dried under vacuum at 30 to 50 °C for standby to obtain a pretreated polyethersulfone base membrane; Tetrabutyl titanate was added dropwise to absolute ethanol so that the volume fraction of tetrabutyl titanate was 20 to 30%, and magnetically stirred for 20 - 30 minutes; then acetic acid with a volume of 50% of the tetrabutyl titanate was added and stirred continuously until the solution became clear; then deionized water was added dropwise until a transparent TiO2 sol was formed; Take a graphene oxide dispersion with a volume twice that of tetrabutyl titanate and add it to the TiO2 sol; ultrasonically treat for 1 to 3 hours, add cetyltrimethylammonium bromide to make its concentration 1 to 2 g / L, and stir for 1 to 3 hours to form a TiO2 / rGO composite sol; The pretreated polyethersulfone base membrane was fixed on the dip coater bracket, and the polyethersulfone base membrane was immersed in the TiO2 / rGO composite sol at a speed of 0.3 to 0.7 cm / s, stayed for 8 to 12 seconds and then pulled up evenly to form a uniform coating; dip coating was repeated multiple times, and dried at room temperature after each layer was coated to obtain a coated polyethersulfone base membrane; The coated polyethersulfone base membrane was placed in an ultraviolet curing box and irradiated with ultraviolet light at 365 nm for 20 to 40 minutes; the cured polyethersulfone base membrane was immersed in a 0.1 mol / L NaOH solution for 8 to 12 minutes; rinsed with deionized water and dried under vacuum at 30 to 50 °C to obtain a polyethersulfone base membrane loaded with a TiO2 / rGO composite photocatalytic layer.

[0015] The beneficial effects of a photocatalytic synergistic multi-dimensional electric field composite membrane filtration device of the present invention are as follows: It organically combines electric field adsorption, photocatalytic degradation, and membrane separation technologies, and realizes efficient removal of pollutants and long-term operation of the system through modular innovative design. The conductive filter element cooperates with the multi-dimensional electrode system to form a dynamic cross electric field, which can effectively remove charged and neutral pollutants; the photocatalytic ultrafiltration membrane module decomposes macromolecular organic matter through the composite photocatalytic layer and realizes the self-cleaning function of the membrane, reducing the need for chemical cleaning. The intelligent control module can adjust the electric field intensity, electrode polarity, and light parameters in real time according to the water quality to ensure that the system is always in an efficient operating state. The structures of the components of the device are optimized, effectively reducing membrane fouling, improving the uniformity of water flow distribution, significantly reducing energy consumption and maintenance costs, and can be widely applied to scenarios such as industrial wastewater treatment and drinking water purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of a photocatalytic synergistic multi-dimensional electric field composite membrane filtration device.

[0017] Description of the reference numerals in the drawings: 1. Conductive filter element module; 1a. Composite conductive filter membrane; 1b. Hollow porous support; 2. Photocatalytic ultrafiltration membrane module; 2a. Polyethersulfone-based membrane; 2b. TiO2 / rGO composite photocatalytic layer; 3. Axial electrode; 3a. Micropores; 4. Radial electrode array; 5. Intelligent control module; 6. Water inlet; 7. Water outlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is provided in conjunction with the drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.

[0019] The term "including" and its variations used herein are open-ended, that is, "including but not limited to"; the term "based on" is "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules, or units, and are not used to limit the order or interdependence relationship of the functions performed by these devices, modules, or units.

[0020] It should be noted that the modification of "one" and "multiple" mentioned in the present invention is illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly specified in the context, it should be understood as "one or more".

[0021] As Figure 1 shown, this embodiment provides a photocatalytic synergistic multi-dimensional electric field composite membrane filtration device, which includes a cylindrical housing and the following components arranged in the housing: The conductive filter element module 1 has a hollow cylindrical structure and includes a hollow porous support 1b and a composite conductive filter membrane 1a coated on the outer layer of the hollow porous support 1b; The photocatalytic ultrafiltration membrane module 2 is annularly nested inside the conductive filter element module 1 and is composed of a polyethersulfone base membrane 2a and a TiO2 / rGO composite photocatalytic layer 2b loaded on the surface of the polyethersulfone base membrane 2a; The multi-dimensional electric field electrode system includes an axial electrode 3 and a radial electrode array. The axial electrode 3 is a hollow carbon fiber tube nested inside the photocatalytic ultrafiltration membrane module 2 and has micropores 3a on its surface; the radial electrode array 4 is composed of a plurality of arc-shaped graphite electrodes surrounding the outer periphery of the conductive filter element module 1, and the spacing between the plurality of arc-shaped graphite electrodes can be adjusted, and the adjustment range is 10 to 20 cm; The intelligent control module 5 is used to measure the real-time water quality and dynamically adjust the electric field intensity, electrode polarity and light parameters according to the real-time water quality; Among them, a water inlet 6 is arranged at the middle position on the side surface of the housing, and a water outlet 7 is arranged at the bottom. There can be multiple water inlets 6, which are evenly arranged on the outer side of the housing. The axis of the photocatalytic ultrafiltration membrane module 2 coincides with the axis of the hollow porous support 1b.

[0022] In this embodiment, significant performance breakthroughs are achieved through the collaborative design of multiple components: the composite conductive filter membrane cooperates with the multi-dimensional electric field electrode system, uses the axial main electric field and the radial dynamic cross electric field, and combines the dielectrophoresis effect to efficiently remove charged and neutral pollutants. At the same time, the TiO2 / rGO composite photocatalytic layer in the photocatalytic ultrafiltration membrane module decomposes macromolecular organic substances; the adjustable characteristic of the radial electrode array avoids local accumulation of pollutants on the membrane surface, and the self-cleaning function of the photocatalytic layer further reduces membrane fouling and extends the service life of the membrane; the intelligent control module monitors the water quality in real time and dynamically adjusts the electric field intensity, electrode polarity and light parameters to ensure that the device can operate efficiently under different water quality and light conditions; in addition, the structural design such as the hollow porous support and the spiral diversion groove optimizes the mass transfer efficiency, and the durable materials ensure long-term stable operation, making it widely applicable to various complex water quality treatment scenarios.

[0023] The device of the present invention realizes the efficient removal of pollutants and the optimization of membrane performance through the synergistic effect of multi-dimensional electric fields and photocatalysis: the removal rate of DOC (Dissolved Organic Carbon) exceeds 90%, the COD (Chemical Oxygen Demand) is reduced to less than 15 mg / L, the microbial retention rate reaches over 99.9%, significantly improving the water purification effect; the fluctuation of the membrane operating pressure is reduced by 40%, and the cleaning cycle is extended to twice that of traditional devices, effectively reducing membrane fouling and maintenance costs; the comprehensive energy consumption is reduced by 30%, and it is applicable to the deep treatment scenarios of highly polluted industrial wastewater and drinking water, combining high efficiency, economy and wide applicability.

[0024] Specifically, the intelligent control module 5 includes a water quality sensor, an adjustable power supply and an LED ultraviolet light source; the water quality sensors are located at the inlet and outlet. The water quality sensor at the inlet is located at the front end of the inlet pipe and is used to monitor the raw water quality parameters (such as COD, TOC, turbidity, pH value, conductivity, etc.) in real time. The water quality sensor at the outlet is located at the purified water outlet and is used for the final verification of water quality compliance.

[0025] Specifically, the axial electrode 3 is connected to the positive electrode, the radial electrode array 4 is connected to the variable positive / negative electrode in regions, and the photocatalytic ultrafiltration membrane module 2 is connected to the negative electrode.

[0026] Specifically, the ultraviolet light sources are evenly distributed around the outside of the photocatalytic ultrafiltration membrane module 2; the frequency of the adjustable power supply in the pulse output mode is 10 to 100 Hz.

[0027] Specifically, the distance between the ultraviolet light source and the surface of the photocatalytic ultrafiltration membrane module 2 is 3 to 7 cm.

[0028] The water quality parameters mainly detected by the water quality sensor are COD, TOC, turbidity, pH value, conductivity, etc. The process of the intelligent control module 5 dynamically adjusting the electric field strength, electrode polarity and light intensity parameters according to the real-time water quality is as follows: when the COD increases by 20 mg / L each time, the axial electric field strength is increased by 1 V / cm; when TOC > 10 mg / L, the ultraviolet light intensity is increased from 30 mW / cm² to 50 mW / cm². If TOC < 5 mg / L and turbidity < 1 NTU, the ultraviolet lamp is turned off; when the conductivity > 3 mS / cm, the pulse mode (10 to 100 Hz) is started, and the positive and negative electrodes are switched every 5 minutes; when the pH value < 4 or > 10, the ultraviolet light source switch is turned off.

[0029] In this embodiment, the intelligent control module 5 sets water quality sensors at the water inlet and outlet respectively to monitor key parameters of raw water and purified water in real time, such as COD, TOC, turbidity, pH value, conductivity, etc., and dynamically adjusts the electric field strength, electrode polarity and light parameters in combination with preset rules. This intelligent regulation mechanism with multi-parameter linkage not only realizes the adaptive treatment of complex water quality, avoids energy waste, but also significantly improves the pollutant removal efficiency and extends the service life of the membrane module by precisely matching the electric field and photocatalysis conditions, ensuring that the device can operate stably and efficiently under different working conditions.

[0030] The present invention adsorbs charged pollutants through a stable main electric field, captures neutral pollutants through a dynamic cross electric field dielectrophoresis, and utilizes the synergistic effect of the electric field and photocatalysis to optimize the pollutant distribution on the membrane surface and achieve self-cleaning, thereby significantly improving the removal efficiency of the device for all types of pollutants and the long-term stability of the membrane performance.

[0031] Specifically, the hollow porous support 1b is a hollow cylinder made of polypropylene, the aperture of the hole in the middle of the hollow porous support (1b) is 10 to 50 μm, and the porosity ≥ 70%.

[0032] Specifically, the thickness of the composite conductive filter membrane 1a is 50 to 100 μm.

[0033] Specifically, the cut-off molecular weight of the polyethersulfone-based membrane 2a is 10 kDa, and the aperture is 0.1 to 0.5 μm.

[0034] Specifically, the aperture of the micropores 3a is 5 μm to 15 μm, and the pore density is 90 to 100 pores / cm².

[0035] In this embodiment, the thickness of the composite conductive filter membrane can maintain a high ion conduction efficiency while ensuring mechanical strength, avoiding an increase in resistance caused by being too thick or a risk of breakage caused by being too thin; the polyethersulfone-based membrane can not only accurately intercept macromolecular pollutants with a molecular weight greater than 10 kDa (such as proteins and colloids), but also reduce the membrane filtration resistance through a larger aperture and improve the water flux; the axial electrode micropores can ensure uniform water flow while providing sufficient migration channels for charged pollutants, enhancing the electric field adsorption effect, and the dense and uniform micropore distribution can optimize the electric field distribution, reduce local eddy currents, and improve the overall filtration efficiency and stability.

[0036] Optionally, the manufacturing method of the conductive filter element module 1 includes the following steps: Immerse the hollow porous support 1b in absolute ethanol and ultrasonically clean it for 30 minutes to remove surface impurities; then rinse it 3 times with deionized water and vacuum dry it at 60 °C for 2 hours for standby; Take 100 mL of 1 mol / L hydrochloric acid solution, add 5 g of aniline monomer, and magnetically stir until completely dissolved; Add 50 mL of 2 mg / mL graphene oxide dispersion to the above solution, and ultrasonically treat for 2 hours to uniformly disperse GO, forming an aniline-GO mixed solution; Immerse the pretreated hollow porous support 1b into the aniline-GO mixed solution to ensure complete immersion; Under the condition of an ice-water bath at 0 to 5 °C, slowly dropwise add ammonium persulfate solution (APS: aniline molar ratio = 1:1) to initiate the aniline polymerization reaction; Continuously react for 6 hours, maintaining a stirring speed of 200 rpm during this period, so that polyaniline (PANI) and GO copolymerize on the surface of the support to form a composite conductive layer; Take out the hollow porous support 1b, rinse it 3 times with deionized water to remove unreacted monomers and impurities, then soak the sample in 0.1 mol / L NaOH solution for 10 minutes to neutralize the residual hydrochloric acid, and finally dry it under vacuum at 60 °C for 4 hours to obtain the hollow porous support 1b with a graphene / polyaniline composite conductive filter membrane 1a coated on its surface. The thickness of the graphene / polyaniline composite conductive filter membrane 1a is 50 μm to 100 μm.

[0037] In this embodiment, the manufacturing method of the conductive filter element module realizes performance optimization through a multi-step process. Through precise control of process parameters, a firm combination of the composite conductive filter membrane and the support is achieved, and a balance between conductive performance and mechanical strength is realized, providing a basis for efficient and stable electric field conduction for the device.

[0038] Optionally, the manufacturing method of the photocatalytic ultrafiltration membrane module 2 includes the following steps: Immerse the polyethersulfone base membrane 2a in deionized water and ultrasonically clean for 20 minutes to remove surface impurities; Rinse it 3 - 5 times with absolute ethanol and dry it under vacuum at 40 °C for 1 hour for standby; Slowly drop 10 mL of tetrabutyl titanate (TBOT) into 40 mL of absolute ethanol and magnetically stir for 20 - 30 minutes; Then add 5 mL of glacial acetic acid as a stabilizer and continue stirring until the solution becomes clear; Then gradually dropwise add 10 mL of deionized water (controlling the dropping speed at 1 mL / min) to form a transparent TiO2 sol; Take 20 mL of graphene oxide dispersion (GO concentration 2 mg / mL) and add it to the TiO2 sol; Ultrasonically treat for 2 hours to uniformly disperse GO and combine it with TiO2 nanoparticles; Add 0.1 g of cetyltrimethylammonium bromide (CTAB) as a surfactant and stir for 2 hours to form a TiO2 / rGO composite sol; Fix the pretreated polyethersulfone base membrane 2a on the dip coater bracket, immerse the polyethersulfone base membrane (2a) into the composite sol at a speed of 0.5 cm / s, stay for 10 seconds and then uniformly lift it to form a uniform coating; Repeat dip coating 3 times, and dry at room temperature for 10 minutes after each coating; The coated polyethersulfone-based membrane (2a) was placed in an ultraviolet curing box and irradiated with ultraviolet light at 365 nm for 30 minutes (light intensity 30 W / cm²); the cured polyethersulfone-based membrane (2a) was immersed in a 0.1 mol / L NaOH solution for 10 minutes to remove residual surfactants; rinsed 3 times with deionized water and vacuum dried at 40 °C for 2 hours to obtain the polyethersulfone-based membrane (2a) loaded with the TiO2 / rGO composite photocatalytic layer (2b).

[0039] In this embodiment, the manufacturing method of the photocatalytic ultrafiltration membrane module 2 realizes performance optimization through a multi-step process. Through precise control of process parameters, a firm bonding between the TiO2 / rGO composite photocatalytic layer and the polyethersulfone-based membrane is achieved, optimizing the synergistic effect of photocatalytic activity and membrane separation performance, and providing the device with efficient and stable pollutant degradation and separation capabilities.

[0040] Optionally, the manufacturing method of the axial electrode 3 includes the following steps: The hollow carbon fiber tube was soaked in acetone and ultrasonically cleaned for 30 minutes to remove surface contaminants. After rinsing with deionized water, it was vacuum dried at 80 °C for 2 hours. Using an ultraviolet laser drilling machine (wavelength 355 nm, power 30 W), holes with a diameter of 5 to 15 μm and a pore density of 100 holes / cm² were evenly drilled on the surface of the carbon fiber tube. After drilling, it was ultrasonically cleaned again to remove residual carbon chips. Conductive silver paste was coated on the inner walls at both ends of the carbon fiber tube, and copper wires (diameter 2 mm) were connected. After curing, the resistance ≤ 0.1 Ω. The hollow carbon fiber tube was nested inside the photocatalytic ultrafiltration membrane module and fixed by a sealing ring to avoid water leakage.

[0041] The manufacturing method of the radial electrode array 4 includes the following steps: The radius of the arc-shaped graphite electrode matches the outer diameter of the conductive filter element. A copper conducting sheet is welded to the back of each electrode to support independent pressure control for each zone. The electrode sheets are wound around the conductive filter element module with a spacing of 10 to 20 cm and connected to a power supply through a waterproof junction box.

[0042] In this embodiment, through precise control of process parameters, the axial electrode achieves a clean surface, uniform pores, and excellent electrical conductivity, and the nested fixed design ensures the sealing performance; through precise control of process parameters, the radial electrode realizes dynamic adjustment of the electric field direction and stable power supply. Both processes improve the uniformity of the electric field distribution, the electrical conductivity of the electrodes, and the overall reliability of the device through material treatment and structural optimization, providing an efficient and stable electric field basis for multi-dimensional electric field synergistic photocatalysis.

[0043] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A photocatalytic synergistic multi-dimensional electric field composite membrane filtration device, characterized in that Comprising: A conductive filter element module (1), which is a hollow cylindrical structure. The conductive filter element module (1) includes a hollow porous support (1b) and a composite conductive filter membrane (1a) coated on the outer layer of the hollow porous support (1b); A photocatalytic ultrafiltration membrane module (2), which is annularly nested inside the conductive filter element module (1); the photocatalytic ultrafiltration membrane module (2) is composed of a polyethersulfone-based membrane (2a) and a TiO2 / rGO composite photocatalytic layer (2b) loaded on the surface of the polyethersulfone-based membrane (2a); A multi-dimensional electric field electrode system, including an axial electrode (3) and a radial electrode array (4); the axial electrode (3) is a hollow carbon fiber tube nested inside the photocatalytic ultrafiltration membrane module (2), and has micropores (3a) on the surface; the radial electrode array (4) is composed of a plurality of arc-shaped graphite electrodes surrounding the outer periphery of the conductive filter element module (1), and the spacing of the plurality of arc-shaped graphite electrodes is adjustable, and the adjustment range is 10 to 20 cm; And An intelligent control module (5), which is used to measure the real-time water quality and dynamically adjust the electric field intensity, electrode polarity and light parameters according to the real-time water quality.

2. The photocatalytic synergistic multi-dimensional electric field composite membrane filtration device according to claim 1, wherein The intelligent control module (5) includes a water quality sensor, an adjustable power supply and an ultraviolet light source; the water quality sensor is located at the water inlet and the water outlet, and the ultraviolet light sources are evenly distributed around the outer side of the photocatalytic ultrafiltration membrane module (2).

3. The photocatalytic synergy multi-dimensional electric field composite membrane filtration device according to claim 2, wherein The axial electrode (3) is connected to the positive pole of the adjustable power supply, the radial electrode array (4) is connected to the variable positive / negative pole of the adjustable power supply in regions, and the photocatalytic ultrafiltration membrane module (2) is connected to the negative pole of the adjustable power supply; the frequency of the adjustable power supply in the pulse output mode is 10 to 100 Hz.

4. The photocatalytic synergy multi-dimensional electric field composite membrane filtration device according to claim 2, characterized in that, The distance between the ultraviolet light source and the surface of the photocatalytic ultrafiltration membrane module (2) is 3 to 7 cm.

5. The photocatalytic synergistic multi-dimensional electric field composite membrane filtration device according to claim 1, wherein The hollow porous support (1b) is a hollow cylinder made of polypropylene, and the aperture of the hole in the middle of the hollow porous support (1b) is 10 to 50 μm, and the porosity ≥ 70%.

6. The photocatalytic synergistic multi-dimensional electric field composite membrane filtration device according to claim 1, wherein The thickness of the composite conductive filter membrane (1a) is 50 to 100 μm.

7. The photocatalytic synergy multi-dimensional electric field composite membrane filtration device according to claim 1, wherein The cut-off molecular weight of the polyethersulfone-based membrane (2a) is 10 kDa, and the aperture is 0.1 to 0.5 μm.

8. The photocatalytic synergistic multi-dimensional electric field composite membrane filtration device according to claim 1, characterized in that, The aperture of the micropores (3a) is 5 μm to 15 μm, and the pore density is 90 to 100 pores / cm².

9. The photocatalytic synergistic multi-dimensional electric field composite membrane filtration device according to claim 1, wherein, The manufacturing method of the conductive filter element module (1) includes the following steps: Immerse the hollow porous support (1b) in absolute ethanol and ultrasonically clean for 20 to 40 minutes; then rinse with deionized water and vacuum dry at 50 to 70 °C for 1 to 3 hours for standby to obtain the pretreated hollow porous support (1b); Take 1 mol / L hydrochloric acid solution, add aniline monomer to make the concentration of aniline monomer 4 to 6 g / mL, and magnetically stir until completely dissolved; Add a 2 mg / mL graphene oxide dispersion liquid with 50% volume of the hydrochloric acid solution to the above solution, and ultrasonically treat to uniformly disperse the graphene oxide to form an aniline-graphene oxide mixed solution; immerse the pretreated hollow porous support (1b) into the aniline-graphene oxide mixed solution; Under the condition of an ice-water bath at 0 to 5 °C, slowly add ammonium persulfate solution to the aniline-graphene oxide mixed solution to initiate the polymerization reaction of aniline; continue the reaction for 5 to 7 hours, maintaining the stirring speed at 160 to 240 rpm during this period, and form a composite conductive layer on the surface of the hollow porous support (1b). Take out the hollow porous support (1b), rinse it with deionized water, then soak the hollow porous support (1b) in 0.1 mol / L NaOH solution for 5 to 15 minutes, and finally dry it under vacuum at 50 to 70 °C to obtain a hollow porous support (1b) with a graphene / polyaniline composite conductive filter membrane (1a) coated on its surface.

10. The photocatalytic synergistic multi-dimensional electric field composite membrane filtration device according to claim 1, characterized in that, The manufacturing method of the photocatalytic ultrafiltration membrane module (2) includes the following steps: Soak the polyethersulfone substrate membrane (2a) in deionized water and ultrasonically clean it; rinse it with absolute ethanol and dry it under vacuum at 30 to 50 °C for standby to obtain a pretreated polyethersulfone substrate membrane (2a). Add tetrabutyl titanate dropwise to absolute ethanol to make the volume fraction of tetrabutyl titanate 20 to 30%, and stir magnetically for 20 - 30 minutes; then add acetic acid with a volume of 50% of the tetrabutyl titanate volume and continue stirring until the solution becomes clear; then gradually add deionized water dropwise until a transparent TiO2 sol is formed. Take a graphene oxide dispersion with a volume twice that of the tetrabutyl titanate and add it to the TiO2 sol; ultrasonically treat it for 1 to 3 hours, add cetyltrimethylammonium bromide to make its concentration 1 to 2 g / L, and stir for 1 to 3 hours to form a TiO2 / rGO composite sol. Fix the pretreated polyethersulfone substrate membrane (2a) on the dip coater bracket, immerse the polyethersulfone substrate membrane (2a) into the TiO2 / rGO composite sol at a speed of 0.3 to 0.7 cm / s, stay for 8 to 12 seconds and then pull it up evenly to form a uniform coating; repeat dip coating multiple times, and dry it at room temperature after each coating to obtain a coated polyethersulfone substrate membrane (2a). Place the coated polyethersulfone substrate membrane (2a) in an ultraviolet curing box and irradiate it with ultraviolet light at 365 nm for 20 to 40 minutes; soak the cured polyethersulfone substrate membrane (2a) in 0.1 mol / L NaOH solution for 8 to 12 minutes; rinse it with deionized water and dry it under vacuum at 30 to 50 °C to obtain a polyethersulfone substrate membrane (2a) loaded with a TiO2 / rGO composite photocatalytic layer (2b).

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