COD separation type composite membrane and preparation method thereof

Abstract

The application relates to the technical field of nanofiltration membrane preparation, and relates to a COD separation type composite membrane and a preparation method thereof.The composite membrane comprises a base film (201), a separation film (202), a catalytic film (203) and a hydrophilic film (204), wherein the base film (201) is located at the bottom layer, the separation film (202) is attached above the base film (201), the catalytic film (203) is attached above the catalytic film (203), and the hydrophilic film (204) is attached above the catalytic film (203); the material of the base film (201) is configured as polysulfone, the material of the separation film (202) is configured as poly (piperazine amide), the material of the catalytic film (203) is configured to comprise Fe3O4 nanoparticles and MXene nanosheets, and the material of the hydrophilic film (204) is configured as polyvinyl alcohol.The application can improve the separation capacity of the nanofiltration membrane for COD and reduce the pollution speed of the nanofiltration membrane.

Description

Technical Field

[0001] This invention relates to the field of nanofiltration membrane preparation technology, and in particular to a COD separation composite membrane and its preparation method. Background Technology

[0002] The main components of COD (Chemical Oxygen Demand) are organic matter (including small molecule organic matter, large molecule organic matter, colloids, etc.). Due to its high cost-effectiveness, including low operating pressure, moderate energy consumption, and high flux, nanofiltration composite membranes have become a commonly used separation tool for COD.

[0003] However, due to the high interception rate of nanofiltration composite membranes, more pollutants will adhere to the surface of the nanofiltration composite membrane, resulting in a faster overall fouling rate of the membrane and requiring frequent cleaning and maintenance. Summary of the Invention

[0004] This invention provides a method for preparing a COD separation composite membrane, the main purpose of which is to improve the COD separation capability of nanofiltration membranes and reduce the fouling rate of nanofiltration membranes.

[0005] To achieve the above objectives, the present invention provides a COD separation composite membrane, comprising a base membrane (201), a separation membrane (202), a catalyst membrane (203), and a hydrophilic membrane (204), wherein the base membrane (201) is located at the bottom layer, the separation membrane (202) is attached above the base membrane (201), the catalyst membrane (203) is attached above the catalyst membrane (203), and the hydrophilic membrane (204) is attached above the catalyst membrane (203). The base membrane (201) is made of polysulfone, the separation membrane (202) is made of polypiperazine amide, the catalyst membrane (203) is made of Fe3O4 nanoparticles and MXene nanosheets, and the hydrophilic membrane (204) is made of polyvinyl alcohol.

[0006] To achieve the above objectives, the present invention also provides a method for preparing a COD separation type composite membrane, comprising: According to the preset base film ratio parameters, a film-forming operation is performed on the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent to obtain the base film; An aqueous solvent and an oil solvent are obtained, and the base film is impregnated with the aqueous solvent and the oil solvent to obtain a polyamide adhesion film. The polyamide film was intercalated using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst intercalation film. According to the preset hydrophilic membrane ratio parameters, the pre-constructed polyvinyl alcohol and pre-constructed graphene oxide are mixed to obtain a hydrophilic membrane raw material. According to the preset dissolution process parameters, the hydrophilic membrane raw material is dissolved in the pre-constructed deionized water to obtain a polyvinyl alcohol solution. The polyvinyl alcohol solution is then diluted to the preset coating solution concentration to obtain a polyvinyl alcohol coating solution. Using the polyvinyl alcohol coating solution, the catalyst embedding membrane is dip-coated for a preset time to obtain a hydrophilic layer film. Using a pre-constructed crosslinking agent and according to preset crosslinking process parameters, the hydrophilic layer membrane is subjected to polyvinyl alcohol molecular crosslinking to obtain the target composite membrane.

[0007] Optionally, the step of performing a film-forming operation on the pre-constructed polysulfone resin, the pre-constructed film-forming solvent, and the pre-constructed pore-forming agent according to preset base film ratio parameters to obtain a base film includes: According to the preset base film ratio parameters, the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent are mixed to obtain the film-forming raw material; The film-forming raw material is stirred at a preset stirring temperature and for a preset stirring time to obtain an initial casting solution. The initial casting solution is then subjected to a settling and degassing operation according to a preset settling time to obtain a final casting solution. According to the preset film thickness parameters, the casting solution is scraped to obtain an initial base film; The initial base film is solidified using pre-constructed deionized water at a preset solidification temperature to obtain the base film.

[0008] Optionally, obtaining the aqueous solvent and the oil solvent includes: According to the preset aqueous solvent ratio parameters, the pre-constructed piperazine, pre-constructed triethylamine, pre-constructed camphor sulfonic acid and pre-constructed sodium chloride are mixed to obtain an aqueous solvent. According to the preset oil phase solvent ratio parameters, the pre-constructed trimesoyl chloride and the pre-constructed n-hexane are mixed to obtain the oil phase solvent.

[0009] Optionally, the impregnation operation of the base film using the aqueous solvent and the oil solvent to obtain the polyamide adhesion film includes: Using the aqueous solvent, the base film is impregnated for a preset aqueous impregnation time to obtain an initial aqueous impregnated base film; According to the preset air knife configuration parameters, the initial aqueous phase impregnated base film is purged to obtain an aqueous phase impregnated base film; Using the oil phase solvent, the aqueous phase impregnation base film is impregnated according to the preset oil phase impregnation time to obtain the initial oil phase impregnation base film; According to the preset heat treatment parameters, the initial oil phase impregnated base film is subjected to heat treatment to obtain a polyamide attached film.

[0010] Optionally, the step of intercalating the polyamide film using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst-intercalated film includes: The pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets were subjected to ultrasonic dispersion for a preset dispersion time to obtain an initial Fe3O4@MXene dispersion. The Fe3O4@MXene initial dispersion was prepared to a preset dispersion concentration to obtain a composite dispersion; Using the composite dispersion, the polyamide membrane is subjected to vacuum filtration according to a preset loading value to obtain a catalyst-embedded membrane.

[0011] Optionally, after obtaining the target composite membrane, the method further includes: Obtain the production record log of the target composite film, and perform sampling inspection on the production record log according to the preset quality inspection frequency to obtain the target composite film to be inspected; Based on the preset product size range, obtain the size of a random rectangle; According to the dimensions of the random rectangle, the target composite film to be tested is randomly cut into regions to obtain the test film; The test membrane was subjected to quality compliance testing, and the test results were obtained.

[0012] Optionally, the step of performing quality compliance testing on the test membrane to obtain the test results includes: According to a preset flux formula, the pure water flux of the test membrane is measured to obtain the pure water flux value, wherein the flux formula is expressed as: ; In the formula, This represents the pure water flux value. Indicates the volume of pure water passing through. This indicates the effective area of ​​the test membrane. Indicates the time taken to purify the water. Indicates the operating pressure through pure water; When the pure water flux value is greater than the preset flux threshold, the COD rejection rate of the test membrane is detected using pre-constructed standard COD simulated wastewater to obtain a rejection rate score, wherein the rejection rate score is expressed as: ; In the formula, This represents the retention rate fraction. This indicates the COD concentration of the permeate after the standard COD simulated wastewater has been filtered through the test membrane. This indicates the preset initial COD concentration in the standard COD simulated wastewater; When the rejection rate fraction is greater than the preset rejection threshold, the test membrane is continuously filtered using the standard COD simulated wastewater to obtain a real-time water flux curve. If the real-time water flux curve decreases to a preset cleaning threshold, the runtime and fouling composite membrane are obtained; When the running time exceeds the preset running threshold, the contaminated composite membrane is cleaned to obtain a cleaned composite membrane. The water flux of the cleaning composite membrane was verified using the standard COD simulated wastewater to obtain the updated water flux. Obtain the initial water flux from the real-time water flux curve, and calculate the flux decay rate based on the initial water flux and the updated water flux, wherein the flux decay rate is expressed as: ; In the formula, This represents the flux attenuation rate. This refers to the updated water flux. This represents the initial water flux; When the flux attenuation rate is greater than the preset attenuation threshold, the test result indicating that the test membrane is qualified is output.

[0013] To achieve the above objectives, the present invention also provides a system for preparing a COD separation type composite membrane, comprising: The base film preparation module is used to perform a film-forming operation on a pre-constructed polysulfone resin, a pre-constructed film-forming solvent, and a pre-constructed pore-forming agent according to preset base film ratio parameters to obtain a base film. A separation membrane configuration module is used to obtain an aqueous solvent and an oil solvent, and to impregnate the base membrane with the aqueous solvent and the oil solvent to obtain a polyamide attached membrane; A catalyst membrane configuration module is used to embed the polyamide attached membrane using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst embedded membrane. The hydrophilic membrane configuration module is used to prepare a hydrophilic membrane raw material by mixing pre-constructed polyvinyl alcohol and pre-constructed graphene oxide according to preset hydrophilic membrane mixing parameters, dissolving the hydrophilic membrane raw material in pre-constructed deionized water according to preset dissolution process parameters to obtain a polyvinyl alcohol solution, diluting the polyvinyl alcohol solution to a preset coating solution concentration to obtain a polyvinyl alcohol coating solution, and using the polyvinyl alcohol coating solution to perform a preset dip coating operation on the catalyst embedded membrane to obtain a hydrophilic layer attached membrane, and using a pre-constructed crosslinking agent according to preset crosslinking process parameters to perform a polyvinyl alcohol molecular crosslinking operation on the hydrophilic layer attached membrane to obtain a target composite membrane.

[0014] Optionally, the system includes a base film preparation device, an interface polymerization device, a catalyst layer embedding device, and a hydrophilic modification device; The base film preparation equipment includes a stirred reaction vessel, a vacuum degassing box, an automatic film scraper, a coagulation bath, a winding machine, and a washing tank. The interface polymerization equipment includes an aqueous phase impregnation tank, an air knife purging device, an oil phase impregnation tank, and a heat treatment oven. The catalyst layer embedding device includes an ultrasonic disperser and a vacuum filtration device; The hydrophilic modification equipment includes a heating stirrer, an immersion coating tank, a crosslinking reaction tank, and a deionized water cleaning tank.

[0015] To address the above problems, the present invention also provides an electronic device, the electronic device comprising: Memory, storing at least one instruction; The processor executes the instructions stored in the memory to implement the above-described method for preparing the COD separation composite membrane.

[0016] To address the aforementioned problems, the present invention also provides a computer-readable storage medium storing at least one instruction, which is executed by a processor in an electronic device to implement the above-described method for preparing a COD separation composite membrane.

[0017] To address the problems described in the background section, this invention first utilizes polysulfone resin to produce a base membrane, providing mechanical support for the composite membrane. Then, using pre-constructed aqueous and oil phase solvents, a polyamide adhesion membrane is constructed to achieve COD separation. Specifically, sodium chloride is incorporated into the aqueous solvent ratio to regulate interfacial tension and create suitable channels for organic matter passage. Furthermore, precise air purging improves the accuracy of the finished polyamide adhesion membrane. The invention employs Fe3O4 nanoparticles with Fenton-like catalytic activity, which can improve COD decomposition capacity at a lower cost, reduce membrane fouling rate, and extend product life. Considering subsequent hydrophilic arrangement, hydrophilic MXene nanosheets are used, providing uniformly dispersed attachment points for the Fe3O4 nanoparticles, preventing aggregation, and increasing membrane flux through hydrophilicity. Finally, hydrophilic layer modification makes it easier to clean accumulated contaminants from the membrane, improving the reusability of the composite membrane. Therefore, this invention improves the COD separation capacity of nanofiltration membranes and reduces their fouling rate. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart illustrating a method for preparing a COD separation composite membrane according to an embodiment of the present invention. Figure 2 A functional block diagram of a COD separation composite membrane preparation system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electronic device for implementing the method for preparing the COD separation composite membrane according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the COD separation composite membrane provided in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Electronic device; 10. Processor; 11. Memory; 12. Bus; 2. COD separation type composite membrane; 201, base membrane; 202, separation membrane; 203, catalytic membrane; 204, hydrophilic membrane.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] This application provides a method for preparing a COD separation composite membrane. The execution entity of the COD separation composite membrane preparation method includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the COD separation composite membrane preparation method can be executed by software or hardware installed on a terminal device or a server device, and the software can be a blockchain platform. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0023] Reference Figure 1 The diagram shown is a schematic flow chart of a method for preparing a COD separation composite membrane according to an embodiment of the present invention. In this embodiment, the method for preparing the COD separation composite membrane includes: S1. According to the preset base film ratio parameters, perform a film-forming operation on the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent to obtain the base film.

[0024] The base film formulation parameters are configured as follows: 18 wt% polysulfone resin, 5 wt% film-forming solvent, and 77 wt% pore-forming agent.

[0025] The polysulfone resin (PSF) refers to a thermoplastic polymer whose main chain contains sulfone groups (-SO2-) and aromatic ring structures. In this invention, it is used to improve mechanical strength and chemical stability, and can form a porous support structure through phase inversion.

[0026] The film-forming solvent refers to an aprotic polar solvent. In this invention, dimethylacetamide (DMAC) is used, which is mainly used in the phase transformation process. DMAC can quickly diffuse into the coagulation bath (water) to precipitate and solidify polysulfone resin into a film.

[0027] The pore-forming agent refers to a water-soluble polymer. Specifically, the present invention uses polyvinylpyrrolidone (PVP) as a pore-forming agent. PVP can improve the porosity and flux of the base film. In addition, PVP will be washed out during the water washing process after film formation.

[0028] The membrane-forming operation refers to the process of dissolving polysulfone resin, membrane-forming solvent, and pore-forming agent, allowing them to stand, scraping them to a predetermined thickness using a membrane-scraping device, and then subjecting them to phase inversion with deionized water to obtain a polysulfone ultrafiltration membrane. Phase inversion refers to the process of a change in the state of a substance, such as the transformation of polysulfone resin from a liquid to a solid state, which will not be elaborated upon here.

[0029] The base membrane is made of polysulfone resin and has the functions of mechanical support and reducing mass transfer resistance.

[0030] In detail, in this embodiment of the invention, the step of performing a film-forming operation on a pre-constructed polysulfone resin, a pre-constructed film-forming solvent, and a pre-constructed pore-forming agent according to preset base film ratio parameters to obtain a base film includes: According to the preset base film ratio parameters, the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent are mixed to obtain the film-forming raw material; The film-forming raw material is stirred at a preset stirring temperature and for a preset stirring time to obtain an initial casting solution. The initial casting solution is then subjected to a settling and degassing operation according to a preset settling time to obtain a final casting solution. According to the preset film thickness parameters, the casting solution is scraped to obtain an initial base film; The initial base film is solidified using pre-constructed deionized water at a preset solidification temperature to obtain the base film.

[0031] The film-forming raw materials refer to a mixture of polysulfone resin, film-forming solvent, and pore-forming agent under the base film ratio parameters.

[0032] The preset stirring temperature is set to 60℃. The preset stirring time is set to 6 hours.

[0033] The stirring operation refers to the process of thoroughly mixing the film-forming raw materials using a pre-constructed stirred reactor according to the parameters preset by the company. The initial casting solution refers to the result of the stirring operation on the film-forming raw materials.

[0034] The settling time is configured to be 24 hours.

[0035] The aforementioned static degassing operation refers to the process of allowing the initial casting solution to stand, thereby gradually eliminating internal air bubbles. The casting solution refers to the initial casting solution that has undergone the static degassing operation.

[0036] The membrane thickness parameters are configured as a spacing of 150 μm and a speed of 3 m / min.

[0037] The coating operation refers to the process of spreading the casting solution to a uniform thickness of 150 μm using a pre-built automatic coating machine. The initial base film refers to the result of the casting solution after the coating operation.

[0038] Deionized water refers to water in which cations (such as Ca) have been removed through ion exchange resin. 2+ Na + K + (etc.) and anions (such as Cl) - SO4 2-The high-purity water obtained after (etc.) is used multiple times in this invention and will not be described in detail hereafter.

[0039] The solidification temperature is set to 25°C.

[0040] The solidification operation refers to the process of gradually cooling and solidifying the initial base film by using a low temperature of 25°C.

[0041] Specifically, in this embodiment of the invention, the film-forming raw materials are first mixed with polysulfone resin at a ratio of 18 wt%, film-forming solvent at 5 wt%, and pore-forming agent at 77 wt%. Then, the raw materials are stirred at 60°C for 6 hours to ensure uniform distribution and obtain an initial casting solution. Subsequently, the air bubbles in the initial casting solution are removed by a 24-hour settling and degassing process to obtain the final casting solution.

[0042] This invention employs an automatic film scraping machine to scrape the casting solution according to a preset film thickness of 150 μm and a film scraping speed of 3 m / min to obtain an initial base film. Then, the initial base film is solidified using deionized water at 25°C to obtain the base film.

[0043] S2. Obtain an aqueous solvent and an oil solvent, and use the aqueous solvent and oil solvent to impregnate the base film to obtain a polyamide film.

[0044] The aqueous solvent refers to a mixed aqueous solution containing piperazine (PIP), triethylamine (TEA), camphor sulfonic acid (CSA), and sodium chloride (NaCl) dissolved in deionized water. This solution is used to impregnate the base film before interfacial polymerization, providing amine monomers for the formation of the separation layer.

[0045] The piperazine (PIP) is an aqueous monomer that provides an amino group (-NH-) to undergo a polycondensation reaction with trimesoyl chloride (TMC) in the oil phase to generate a polypiperazine amide separation layer.

[0046] The triethylamine (TEA) is an acid-binding agent used to neutralize the HCl generated in the reaction, allowing the reaction to proceed in the forward direction.

[0047] Camphor sulfonic acid (CSA) is a reaction regulator used to adjust pH, slow down the reaction rate, and make the separation layer more uniform.

[0048] In this invention, sodium chloride (NaCl) is used as a pore-regulating agent to adjust interfacial tension and form nanopores suitable for the passage of organic matter.

[0049] The oil phase solvent refers to an organic solution containing trimethylbenzene chloride (TMC) dissolved in hexane, which is used to contact the base film adsorbed with aqueous monomers, and a polycondensation reaction occurs at the oil / water interface to generate a polyamide separation layer.

[0050] Wherein, n-hexane refers to C6H 14 It is used as a solvent in this invention and is incompatible with water.

[0051] The pyromellitic trimethylolpropionate chloride (TMC) is an oil-phase monomer that provides an acyl chloride group (-COCl), which can undergo a polycondensation reaction with piperazine.

[0052] The soaking operation refers to the process of immersing the item in a solution for a certain period of time.

[0053] The polyamide coating film refers to the base film after being impregnated with aqueous and oil solvents.

[0054] In detail, in this embodiment of the invention, obtaining the aqueous solvent and the oil solvent includes: According to the preset aqueous solvent ratio parameters, the pre-constructed piperazine, pre-constructed triethylamine, pre-constructed camphor sulfonic acid and pre-constructed sodium chloride are mixed to obtain an aqueous solvent. According to the preset oil phase solvent ratio parameters, the pre-constructed trimesoyl chloride and the pre-constructed n-hexane are mixed to obtain the oil phase solvent.

[0055] The aqueous solvent ratio is configured as follows: piperazine 0.5 wt% : triethylamine 0.5 wt% : camphor sulfonic acid 0.3 wt% : sodium chloride 5~15 wt% (to regulate interfacial tension and form suitable channels for organic matter to pass through).

[0056] The mixing process refers to the process of uniformly distributing the various substances.

[0057] The oil phase solvent ratio is configured as follows: 0.15 wt% pyromellitic acid chloride and 99.85 wt% n-hexane.

[0058] Specifically, in this embodiment of the invention, piperazine, triethylamine, camphor sulfonic acid, and sodium chloride are mixed according to the aqueous phase solvent ratio parameters to obtain an aqueous phase solvent. Then, according to the oil phase solvent ratio parameters, pyromellitic trimethylol chloride and n-hexane are mixed to obtain an oil phase solvent.

[0059] In detail, in this embodiment of the invention, the impregnation operation of the base film using the aqueous solvent and the oil solvent to obtain the polyamide adhesion film includes: Using the aqueous solvent, the base film is impregnated for a preset aqueous impregnation time to obtain an initial aqueous impregnated base film; According to the preset air knife configuration parameters, the initial aqueous phase impregnated base film is purged to obtain an aqueous phase impregnated base film; Using the oil phase solvent, the aqueous phase impregnation base film is impregnated according to the preset oil phase impregnation time to obtain the initial oil phase impregnation base film; According to the preset heat treatment parameters, the initial oil phase impregnated base film is subjected to heat treatment to obtain a polyamide attached film.

[0060] The aqueous immersion time is configured to be 3 minutes.

[0061] The impregnation operation refers to the process of immersing the item, which in this case means immersing the base film in an aqueous solvent. The subsequent process is to immerse the obtained initial aqueous impregnation base film in an oil solvent.

[0062] The initial aqueous impregnated base film refers to the base film after being impregnated with an aqueous solvent.

[0063] The air knife is configured with the following parameters: pressure 200 kPa, distance 10 mm, and angle 45°.

[0064] The purging operation refers to the process of uniformly distributing the aqueous solvent adhering to the aqueous impregnated base membrane using a pre-constructed air knife purging device. The aqueous impregnated base membrane refers to the aqueous impregnated base membrane that has undergone the purging operation.

[0065] The oil phase immersion time is configured to be 30 seconds.

[0066] The initial oil-phase impregnated base film refers to the aqueous-phase impregnated base film that has undergone an oil-phase solvent impregnation operation.

[0067] The heat treatment parameters are configured as follows: temperature 70℃, duration 10 min, and pressure -0.01MPa.

[0068] The heat treatment operation refers to the process of evaporating hexane, water, and other substances remaining in the initial oil phase impregnation base film by heating, which also helps to rearrange the polyamide molecular chains and eliminate internal stress.

[0069] Specifically, in this embodiment of the invention, the base film is first soaked in an aqueous solvent for 3 minutes to obtain an aqueous impregnated base film. Then, an air knife purging device is used to purge the aqueous impregnated base film according to preset air knife configuration parameters of 200 kPa, 10 mm distance, and 45° angle to obtain the aqueous impregnated base film.

[0070] Then, the aqueous phase impregnation base film is immersed in the oil phase solvent for 30 seconds to obtain the initial oil phase impregnation base film. Finally, the initial oil phase impregnation base film is subjected to heat treatment according to the preset heat treatment parameters (temperature 70℃, duration 10 min, and pressure -0.01MPa) to obtain the polyamide adhesion film.

[0071] S3. Using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets, the polyamide film is embedded to obtain a catalyst-embedded film.

[0072] The Fe3O4 nanoparticles are a mixed-valence iron oxide, and the particle size of the Fe3O4 nanoparticles configured in this invention is 20 nm.

[0073] The MXene nanosheets are configured as a two-dimensional transition metal carbide, and the MXene nanosheets configured in this invention are of the type Ti3C2T. x It consists of 3 layers of titanium atoms, 2 layers of carbon atoms (interspersed between the titanium atom layers), and an uncertain number of surface functional groups (-OH, -O, -F, etc.).

[0074] The embedding operation refers to the process of uniformly attaching Fe3O4 nanoparticles onto MXene nanosheets, then uniformly distributing the MXene nanosheets to form a catalytic functional layer, and then attaching the catalytic functional layer to the surface of the polyamide film. Preferably, the mass distribution of Fe3O4 nanoparticles to MXene nanosheets is 3:1.

[0075] The catalyst-embedded membrane refers to a polyamide-attached membrane that has undergone an embedding operation.

[0076] In detail, in this embodiment of the invention, the step of using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to embed the polyamide film to obtain a catalyst-embedded film includes: The pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets were subjected to ultrasonic dispersion for a preset dispersion time to obtain an initial Fe3O4@MXene dispersion. The Fe3O4@MXene initial dispersion was prepared to a preset dispersion concentration to obtain a composite dispersion; Using the composite dispersion, the polyamide membrane is subjected to vacuum filtration according to a preset loading value to obtain a catalyst-embedded membrane.

[0077] The ultrasonic dispersion operation refers to the process of uniformly distributing MXene nanosheets in deionized water to form a dispersion using a pre-constructed ultrasonic disperser, and then uniformly distributing most of the Fe3O4 nanoparticles on each MXene nanosheet.

[0078] The Fe3O4@MXene initial dispersion refers to the result of ultrasonic dispersion of Fe3O4 nanoparticles and MXene nanosheets.

[0079] The concentration of the dispersion is set at 0.5 mg / ml. The composite dispersion refers to the initial Fe3O4@MXene dispersion with a concentration of 0.5 mg / ml.

[0080] The load value is configured to be 0.1~0.5 mg / cm².

[0081] The vacuum filtration operation refers to the process of allowing the composite dispersion to pass through the polyamide adhesion membrane under a certain negative pressure, which can be achieved using a pre-constructed vacuum filtration device.

[0082] Specifically, in this embodiment of the invention, Fe3O4 nanoparticles and MXene nanosheets at a mass ratio of 3:1 are first obtained. Then, using an ultrasonic disperser, the Fe3O4 nanoparticles and MXene nanosheets are uniformly distributed in deionized water to form a dispersion. Most of the Fe3O4 nanoparticles adhere to the MXene nanosheets, thus forming an initial Fe3O4@MXene dispersion. Preferably, this invention selects an initial Fe3O4@MXene dispersion with a concentration of 0.5 mg / ml as the composite dispersion.

[0083] Specifically, in this embodiment of the invention, a polyamide film is laid flat at the bottom of a funnel in a vacuum filtration device, and then the composite dispersion is poured onto it. A vacuum pump is connected below the funnel to evacuate the air. When the composite dispersion passes through the polyamide film, the water is removed, but the solid (Fe3O4@MXene) is blocked by the surface of the polyamide film and evenly spread on the surface of the polyamide film, thereby obtaining a catalyst-embedded membrane.

[0084] S4. According to the preset hydrophilic membrane ratio parameters, the pre-constructed polyvinyl alcohol and the pre-constructed graphene oxide are mixed to obtain a hydrophilic membrane raw material. According to the preset dissolution process parameters, the hydrophilic membrane raw material is dissolved in the pre-constructed deionized water to obtain a polyvinyl alcohol solution. The polyvinyl alcohol solution is then diluted to the preset coating solution concentration to obtain a polyvinyl alcohol coating solution.

[0085] The hydrophilic membrane ratio is as follows: the mass distribution of polyvinyl alcohol to graphene oxide is 10:1.

[0086] Polyvinyl alcohol refers to a hydrophilic polymer material that can form a film like glue.

[0087] The graphene oxide mentioned refers to an oxide of graphene with many oxygen-containing groups (-OH, -COOH) on its surface, exhibiting good hydrophilicity.

[0088] The hydrophilic membrane material refers to a mixture of polyvinyl alcohol and graphene oxide.

[0089] The dissolution process parameters are configured as follows: temperature 90℃ and duration 2h.

[0090] The polyvinyl alcohol solution refers to a solution composed of deionized water, polyvinyl alcohol, and graphene oxide.

[0091] The coating solution concentration is configured such that the total solid concentration of polyvinyl alcohol and graphene oxide is 0.5 wt%.

[0092] The polyvinyl alcohol coating solution is a polyvinyl alcohol solution with a mass fraction of 0.5 wt%.

[0093] Specifically, in this embodiment of the invention, polyvinyl alcohol and pre-constructed graphene oxide are first proportioned according to the hydrophilic membrane ratio parameters to obtain a hydrophilic membrane raw material. Then, according to the dissolution process parameters of 90°C and 2h, the hydrophilic membrane raw material is dissolved in deionized water to obtain a polyvinyl alcohol solution. Finally, the polyvinyl alcohol solution is diluted to a coating solution concentration of 0.5wt% to obtain a polyvinyl alcohol coating solution.

[0094] S5. Using the polyvinyl alcohol coating solution, perform a pre-set immersion coating operation on the catalyst embedding membrane to obtain a hydrophilic layer attached membrane.

[0095] The preset immersion coating time is configured to be 5 minutes.

[0096] The dip-coating operation refers to the process of immersing the catalyst embedded in the membrane in a polyvinyl alcohol coating solution.

[0097] The hydrophilic layer coating film refers to a catalyst-embedded film that has undergone a dip-coating process.

[0098] Specifically, in this embodiment of the invention, a polyvinyl alcohol coating liquid is used to dip-coat the catalyst-embedded membrane for 5 minutes, allowing the liquid to fully contact the membrane surface and obtain a hydrophilic layer attached membrane.

[0099] S6. Using a pre-constructed crosslinking agent, and according to preset crosslinking process parameters, perform polyvinyl alcohol molecular crosslinking on the hydrophilic layer attachment membrane to obtain the target composite membrane.

[0100] The crosslinking agent refers to a substance used to link the individual molecules of polyvinyl alcohol together. In this invention, the crosslinking agent is glutaraldehyde, with each glutaraldehyde molecule having an aldehyde group (-CHO) at both ends.

[0101] The crosslinking process parameters are configured as follows: 0.5 wt% glutaraldehyde, temperature 40°C, and duration 30 min.

[0102] The polyvinyl alcohol molecular crosslinking operation refers to the process of linking the individual molecules of polyvinyl alcohol together.

[0103] The target composite membrane refers to a hydrophilic layer membrane that has undergone polyvinyl alcohol molecular crosslinking.

[0104] Specifically, in this embodiment of the invention, the polyvinyl alcohol molecules on the hydrophilic layer of the film are only physically adsorbed on the surface of the catalyst embedded in the film, and will be washed away when soaked in water. Therefore, this invention uses glutaraldehyde as a crosslinking agent to connect the polyvinyl alcohol molecular chains with chemical bonds to form a stable network structure, which makes it water-resistant.

[0105] Specifically, in this embodiment of the invention, since the crosslinking agent has a certain degree of toxicity, the target composite membrane needs to be further cleaned with deionized water after it is obtained.

[0106] In detail, in this embodiment of the invention, after obtaining the target composite film, the method further includes: Obtain the production record log of the target composite film, and perform sampling inspection on the production record log according to the preset quality inspection frequency to obtain the target composite film to be inspected; Based on the preset product size range, obtain the size of a random rectangle; According to the dimensions of the random rectangle, the target composite film to be tested is randomly cut into regions to obtain the test film; The test membrane was subjected to quality compliance testing, and the test results were obtained.

[0107] The production log refers to a file that records the production time, serial number, and production line information of the target composite film.

[0108] The quality inspection frequency is configured as 1%.

[0109] The sampling inspection refers to the process of randomly selecting one target composite membrane from every 100 target composite membranes for inspection.

[0110] The target composite membrane to be tested refers to the target composite membrane selected through sampling and testing.

[0111] The product size range is configured to be 0.1m. 2 ~1m 2 .

[0112] The random rectangle size refers to 0.1m. 2 ~1m 2 The range of arbitrary rectangle sizes.

[0113] The random region cutting refers to the process of randomly selecting a region of random rectangular size within the composite film to be tested.

[0114] The test membrane refers to the result of randomly cutting a region of the target composite membrane under random rectangular dimensions.

[0115] The quality compliance test refers to the test results based on four aspects: throughput, rejection rate, runtime, and throughput decay rate.

[0116] The test results refer to the results of quality compliance testing. The product is considered qualified only if all four aspects—flux, rejection rate, running time, and flux attenuation rate—are qualified. If any one aspect is unqualified, the target composite membrane product is considered unqualified.

[0117] Specifically, in this embodiment of the invention, the detection range is first determined based on the production log. Then, based on the quality inspection frequency, a target composite film is selected from the detection range as the target composite film to be tested. Next, a random rectangle size and area are randomly determined, and the random area is cut to obtain the test film. Finally, the quality compliance is tested through specific experiments to obtain the test results.

[0118] In detail, in this embodiment of the invention, the quality compliance test of the test membrane to obtain the test result includes: According to a preset flux formula, the pure water flux of the test membrane is measured to obtain the pure water flux value, wherein the flux formula is expressed as: ; In the formula, This represents the pure water flux value. Indicates the volume of pure water passing through. This indicates the effective area of ​​the test membrane. Indicates the time taken to purify the water. Indicates the operating pressure through pure water; When the pure water flux value is greater than the preset flux threshold, the COD rejection rate of the test membrane is detected using pre-constructed standard COD simulated wastewater to obtain a rejection rate score, wherein the rejection rate score is expressed as: ; In the formula, This represents the retention rate fraction. This indicates the COD concentration of the permeate after the standard COD simulated wastewater has been filtered through the test membrane. This indicates the preset initial COD concentration in the standard COD simulated wastewater; When the rejection rate fraction is greater than the preset rejection threshold, the test membrane is continuously filtered using the standard COD simulated wastewater to obtain a real-time water flux curve. If the real-time water flux curve decreases to a preset cleaning threshold, the runtime and fouling composite membrane are obtained; When the running time exceeds the preset running threshold, the contaminated composite membrane is cleaned to obtain a cleaned composite membrane. The water flux of the cleaning composite membrane was verified using the standard COD simulated wastewater to obtain the updated water flux. Obtain the initial water flux from the real-time water flux curve, and calculate the flux decay rate based on the initial water flux and the updated water flux, wherein the flux decay rate is expressed as: ; In the formula, This represents the flux attenuation rate. This refers to the updated water flux. This represents the initial water flux; When the flux attenuation rate is greater than the preset attenuation threshold, the test result indicating that the test membrane is qualified is output.

[0119] The flux formula refers to the formula that records the relationship between the pure water flux value and the volume of pure water permeated, the effective area of ​​the target composite membrane involved in the detection, the time taken for pure water permeation, and the operating pressure of pure water permeation.

[0120] The pure water flux detection refers to the process of measuring data experimentally and then substituting that data into the specific value of the flux formula. The pure water flux value refers to the experimental result of the pure water flux detection.

[0121] The throughput threshold is configured to be 10.

[0122] The standard COD simulated wastewater is prepared as a mixed solution of glucose (small molecule COD), PEG-1000 (medium molecule COD), and bovine serum albumin (large molecule COD) at a concentration of 500 mg / L.

[0123] The COD retention rate detection refers to the process of filtering standard COD simulated wastewater using a target composite membrane, thereby comparing the changes in COD in the wastewater before and after filtration. The retention rate score is the experimental COD retention rate detection result.

[0124] The threshold for interception is configured as 95%.

[0125] The continuous filtration refers to the filtration process in which the standard COD simulated wastewater is passed through the test membrane multiple times via a circulation device.

[0126] The real-time water flux curve refers to the curve showing the change in the real-time pure water flux value during the continuous filtration process.

[0127] The cleanup threshold is configured to be 7.

[0128] The runtime refers to the length of time from the start to the end of the continuous filtering operation.

[0129] The fouling composite membrane refers to the test membrane when the real-time water flux curve drops to 7.

[0130] The operating threshold is configured to be 15 days (which can be adaptively configured according to the specific scenarios in the company's work).

[0131] The cleaning operation refers to the process of closing the permeate valve, opening the concentrate discharge valve, and then rinsing the membrane surface with deionized water at 2-3 times the normal flow rate. The cleaned composite membrane refers to the test membrane that has undergone the cleaning operation.

[0132] The water flux verification process is equivalent to the pure water flux detection process described above, except that it uses standard COD simulated wastewater to pass through the cleaning composite membrane. The updated water flux refers to the water flux verification result of standard COD simulated wastewater passing through the cleaning composite membrane.

[0133] The process of calculating the flux decay rate refers to the process of calculating the percentage relationship between the renewed water flux and the initial water flux. The flux decay rate refers to the percentage relationship between the renewed water flux and the initial water flux.

[0134] The attenuation threshold is configured to be 70%.

[0135] Specifically, the basic water output rate of the test membrane under clean water conditions is used as a performance benchmark. Therefore, pure water flux testing is required to obtain the pure water flux value. When the pure water flux value is greater than 10, it indicates that the pure water flux is qualified and can be used for wastewater filtration.

[0136] In this embodiment of the invention, standard COD simulated wastewater is used to test the COD rejection rate of the test membrane and obtain a rejection rate score. When the rejection rate score is greater than the rejection threshold of 95%, it indicates that the separation ability is good and the durability test can be performed.

[0137] In this embodiment of the invention, the test membrane is continuously filtered using standard COD simulated wastewater to obtain a real-time water flux curve. This real-time water flux curve allows for control over the usability of the test membrane. When the real-time water flux curve drops to a cleaning threshold of 7, it indicates that the water flow capacity has decreased to the point of being unusable. Therefore, the operating time and fouling composite membrane are determined. The traditional membrane without a catalyst layer has a service life of approximately 6 days, while this solution offers 2-3 times the service life. When the operating time exceeds the preset 15 days, it indicates that the product is qualified and its cleaning capacity can be measured.

[0138] Specifically, in this embodiment of the invention, the contaminated composite membrane is cleaned to obtain a cleaned composite membrane. Then, the water flux of the cleaned composite membrane is verified using standard COD simulated wastewater to obtain the refresh water flux. The percentage relationship between the refresh water flux and the initial water flux is then calculated to obtain the flux decay rate. When the flux decay rate is greater than a preset 90%, it indicates that the cleaning process can effectively remove most of the contaminants, resulting in a high reuse rate.

[0139] Once all the above tests are completed, a test result indicating that the test membrane is qualified can be output.

[0140] To address the problems described in the background section, this invention first utilizes polysulfone resin to produce a base membrane, providing mechanical support for the composite membrane. Then, using pre-constructed aqueous and oil phase solvents, a polyamide adhesion membrane is constructed to achieve COD separation. Specifically, sodium chloride is incorporated into the aqueous solvent ratio to regulate interfacial tension and create suitable channels for organic matter passage. Furthermore, precise air purging improves the accuracy of the finished polyamide adhesion membrane. The invention employs Fe3O4 nanoparticles with Fenton-like catalytic activity, which can improve COD decomposition capacity at a lower cost, reduce membrane fouling rate, and extend product life. Considering subsequent hydrophilic arrangement, hydrophilic MXene nanosheets are used, providing uniformly dispersed attachment points for the Fe3O4 nanoparticles, preventing aggregation, and increasing membrane flux through hydrophilicity. Finally, hydrophilic layer modification makes it easier to clean accumulated contaminants from the membrane, improving the reusability of the composite membrane. Therefore, this invention improves the COD separation capacity of nanofiltration membranes and reduces their fouling rate.

[0141] like Figure 2 The diagram shown is a functional block diagram of a COD separation type composite membrane preparation system provided in an embodiment of the present invention.

[0142] The COD separation composite membrane preparation system 100 of the present invention can be installed in an electronic device. Depending on the functions to be implemented, the COD separation composite membrane preparation system 100 may include a base membrane configuration module 101, a separation membrane configuration module 102, a catalytic membrane configuration module 103, and a hydrophilic membrane configuration module 104. The module described in this invention can also be referred to as a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and are stored in the memory of the electronic device.

[0143] The base film preparation module 101 is used to perform a film-forming operation on a pre-constructed polysulfone resin, a pre-constructed film-forming solvent, and a pre-constructed pore-forming agent according to preset base film ratio parameters to obtain a base film. The separation membrane configuration module 102 is used to obtain an aqueous solvent and an oil solvent, and to use the aqueous solvent and the oil solvent to impregnate the base membrane to obtain a polyamide adhesion membrane. The catalyst membrane configuration module 103 is used to embed the polyamide attachment membrane with pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst embedded membrane. The hydrophilic membrane configuration module 104 is used to prepare a hydrophilic membrane raw material by mixing pre-constructed polyvinyl alcohol and pre-constructed graphene oxide according to preset hydrophilic membrane ratio parameters, dissolving the hydrophilic membrane raw material in pre-constructed deionized water according to preset dissolution process parameters to obtain a polyvinyl alcohol solution, diluting the polyvinyl alcohol solution to a preset coating solution concentration to obtain a polyvinyl alcohol coating solution, and using the polyvinyl alcohol coating solution to perform a preset immersion coating operation on the catalyst embedding membrane to obtain a hydrophilic layer attachment membrane, and using a pre-constructed crosslinking agent according to preset crosslinking process parameters to perform a polyvinyl alcohol molecular crosslinking operation on the hydrophilic layer attachment membrane to obtain a target composite membrane.

[0144] In detail, the modules in the COD separation composite membrane preparation system 100 described in this embodiment of the invention employ the same methods as described above during use. Figure 1 The preparation method of the COD separation composite membrane described herein uses the same technical means and can produce the same technical effect, so it will not be repeated here.

[0145] like Figure 3 The diagram shown is a schematic diagram of an electronic device for implementing a method for preparing a COD separation type composite membrane according to an embodiment of the present invention.

[0146] The electronic device 1 may include a processor 10, a memory 11 and a bus 12, and may also include a computer program stored in the memory 11 and executable on the processor 10, such as a method program for preparing a COD separation type composite membrane.

[0147] The memory 11 includes at least one type of readable storage medium, such as flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, disk, optical disk, etc. In some embodiments, the memory 11 can be an internal storage unit of the electronic device 1, such as a portable hard drive. In other embodiments, the memory 11 can be an external storage device of the electronic device 1, such as a plug-in portable hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 1. Furthermore, the memory 11 includes both internal storage units and external storage devices of the electronic device 1. The memory 11 can be used not only to store application software and various types of data installed on the electronic device 1, such as the code of the COD separation composite membrane preparation method program, but also to temporarily store data that has been output or will be output.

[0148] In some embodiments, the processor 10 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The processor 10 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the memory 11 (e.g., a method for preparing a COD separation composite membrane) and calls data stored in the memory 11 to perform various functions of the electronic device 1 and process data.

[0149] The bus 12 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 12 can be divided into an address bus, a data bus, a control bus, etc. The bus 12 is configured to realize the connection and communication between the memory 11 and at least one processor 10, etc.

[0150] Figure 3 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 3The structure shown does not constitute a limitation on the electronic device 1, and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0151] For example, although not shown, the electronic device 1 may also include a power supply (such as a battery) to power the various components. Preferably, the power supply can be logically connected to the at least one processor 10 through a power management device, thereby enabling functions such as charging management, discharging management, and power consumption management. The power supply may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device 1 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0152] Furthermore, the electronic device 1 may also include a network interface. Optionally, the network interface may include a wired interface and / or a wireless interface (such as a Wi-Fi interface, a Bluetooth interface, etc.), which is typically used to establish communication connections between the electronic device 1 and other electronic devices.

[0153] Optionally, the electronic device 1 may further include a user interface, which may be a display, an input unit (such as a keyboard), or a standard wired or wireless interface. Optionally, in some embodiments, the display may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen, etc. The display may also be appropriately referred to as a screen or display unit, used to display information processed in the electronic device 1 and to display a visual user interface.

[0154] The COD separation composite membrane preparation method program stored in the memory 11 of the electronic device 1 is a combination of multiple instructions. When run in the processor 10, it can achieve the following: According to the preset base film ratio parameters, a film-forming operation is performed on the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent to obtain the base film; An aqueous solvent and an oil solvent are obtained, and the base film is impregnated with the aqueous solvent and the oil solvent to obtain a polyamide adhesion film. The polyamide film was intercalated using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst intercalation film. According to the preset hydrophilic membrane ratio parameters, the pre-constructed polyvinyl alcohol and pre-constructed graphene oxide are mixed to obtain a hydrophilic membrane raw material. According to the preset dissolution process parameters, the hydrophilic membrane raw material is dissolved in the pre-constructed deionized water to obtain a polyvinyl alcohol solution. The polyvinyl alcohol solution is then diluted to the preset coating solution concentration to obtain a polyvinyl alcohol coating solution. Using the polyvinyl alcohol coating solution, the catalyst embedding membrane is dip-coated for a preset time to obtain a hydrophilic layer film. Using a pre-constructed crosslinking agent and according to preset crosslinking process parameters, the hydrophilic layer membrane is subjected to polyvinyl alcohol molecular crosslinking to obtain the target composite membrane.

[0155] Specifically, the processor 10's implementation method for the above instructions can be found in [reference needed]. Figures 1 to 3 The descriptions of the relevant steps in the corresponding embodiments are not repeated here.

[0156] Furthermore, if the modules / units integrated in the electronic device 1 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. The computer-readable storage medium can be volatile or non-volatile. For example, the computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, or a read-only memory (ROM).

[0157] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor of an electronic device, can perform the following: According to the preset base film ratio parameters, a film-forming operation is performed on the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent to obtain the base film; An aqueous solvent and an oil solvent are obtained, and the base film is impregnated with the aqueous solvent and the oil solvent to obtain a polyamide adhesion film. The polyamide film was intercalated using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst intercalation film. According to the preset hydrophilic membrane ratio parameters, the pre-constructed polyvinyl alcohol and pre-constructed graphene oxide are mixed to obtain a hydrophilic membrane raw material. According to the preset dissolution process parameters, the hydrophilic membrane raw material is dissolved in the pre-constructed deionized water to obtain a polyvinyl alcohol solution. The polyvinyl alcohol solution is then diluted to the preset coating solution concentration to obtain a polyvinyl alcohol coating solution. Using the polyvinyl alcohol coating solution, the catalyst embedding membrane is dip-coated for a preset time to obtain a hydrophilic layer film. Using a pre-constructed crosslinking agent and according to preset crosslinking process parameters, the hydrophilic layer membrane is subjected to polyvinyl alcohol molecular crosslinking to obtain the target composite membrane.

[0158] In the embodiments provided by this invention, it should be understood that the disclosed devices, systems, and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative, and actual implementations may have other classification methods.

[0159] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0160] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional modules.

[0161] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0162] 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.

[0163] refer to Figure 4 The diagram shown is a schematic representation of the COD separation composite membrane of the present invention.

[0164] The present invention discloses a COD separation composite membrane, the composite membrane comprising a base membrane (201), a separation membrane (202), a catalyst membrane (203), and a hydrophilic membrane (204), wherein the base membrane (201) is located at the bottom layer, the separation membrane (202) is attached above the base membrane (201), the catalyst membrane (203) is attached above the catalyst membrane (203), and the hydrophilic membrane (204) is attached above the catalyst membrane (203). The base membrane (201) is made of polysulfone, the separation membrane (202) is made of polypiperazine amide, the catalyst membrane (203) is made of Fe3O4 nanoparticles and MXene nanosheets, and the hydrophilic membrane (204) is made of polyvinyl alcohol.

[0165] Among them, the base membrane (201) is used for mechanical support.

[0166] The separation membrane (202) is used to physically retain dissolved COD.

[0167] The catalytic membrane (203) is used to degrade COD via Fenton-like catalysis.

[0168] The hydrophilic membrane (204) is used to resist pollution, prevent biofouling, and facilitate cleaning.

[0169] Specifically, the present invention attaches a separation membrane to a base membrane, then attaches a catalytic membrane, and finally attaches a hydrophilic membrane, thereby achieving a three-in-one COD separation composite membrane with interfacial polymerization to prepare a dense separation layer, an embedded catalytic functional layer, and anti-fouling surface modification.

Claims

1. A COD separation type composite membrane, characterized in that, The composite membrane includes a base membrane (201), a separation membrane (202), a catalytic membrane (203), and a hydrophilic membrane (204), wherein the base membrane (201) is located at the bottom layer, the separation membrane (202) is attached above the base membrane (201), the catalytic membrane (203) is attached above the catalytic membrane (203), and the hydrophilic membrane (204) is attached above the catalytic membrane (203). The base membrane (201) is made of polysulfone, the separation membrane (202) is made of polypiperazine amide, the catalyst membrane (203) is made of Fe3O4 nanoparticles and MXene nanosheets, and the hydrophilic membrane (204) is made of polyvinyl alcohol.

2. The method for preparing the COD separation composite membrane as described in claim 1, characterized in that, The method includes: According to the preset base film ratio parameters, a film-forming operation is performed on the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent to obtain the base film; An aqueous solvent and an oil solvent are obtained, and the base film is impregnated with the aqueous solvent and the oil solvent to obtain a polyamide adhesion film. The polyamide film was intercalated using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst intercalation film. According to the preset hydrophilic membrane ratio parameters, the pre-constructed polyvinyl alcohol and pre-constructed graphene oxide are mixed to obtain a hydrophilic membrane raw material. According to the preset dissolution process parameters, the hydrophilic membrane raw material is dissolved in the pre-constructed deionized water to obtain a polyvinyl alcohol solution. The polyvinyl alcohol solution is then diluted to the preset coating solution concentration to obtain a polyvinyl alcohol coating solution. Using the polyvinyl alcohol coating solution, the catalyst embedding membrane is dip-coated for a preset time to obtain a hydrophilic layer film. Using a pre-constructed crosslinking agent and according to preset crosslinking process parameters, the hydrophilic layer membrane is subjected to polyvinyl alcohol molecular crosslinking to obtain the target composite membrane.

3. The method for preparing the COD separation composite membrane as described in claim 2, characterized in that, The step involves performing a film-forming operation on a pre-constructed polysulfone resin, a pre-constructed film-forming solvent, and a pre-constructed pore-forming agent according to preset base film ratio parameters to obtain a base film, including: According to the preset base film ratio parameters, the pre-constructed polysulfone resin, the pre-constructed film-forming solvent and the pre-constructed pore-forming agent are mixed to obtain the film-forming raw material; The film-forming raw material is stirred at a preset stirring temperature and for a preset stirring time to obtain an initial casting solution. The initial casting solution is then subjected to a settling and degassing operation according to a preset settling time to obtain a final casting solution. According to the preset film thickness parameters, the casting solution is scraped to obtain an initial base film; The initial base film is solidified using pre-constructed deionized water at a preset solidification temperature to obtain the base film.

4. The method for preparing the COD separation composite membrane as described in claim 3, characterized in that, The process of obtaining the aqueous phase solvent and the oil phase solvent includes: According to the preset aqueous solvent ratio parameters, the pre-constructed piperazine, pre-constructed triethylamine, pre-constructed camphor sulfonic acid and pre-constructed sodium chloride are mixed to obtain an aqueous solvent. According to the preset oil phase solvent ratio parameters, the pre-constructed trimesoyl chloride and the pre-constructed n-hexane are mixed to obtain the oil phase solvent.

5. The method for preparing the COD separation composite membrane as described in claim 4, characterized in that, The process of impregnating the base film with the aqueous solvent and the oil solvent to obtain a polyamide-coated film includes: Using the aqueous solvent, the base film is impregnated for a preset aqueous impregnation time to obtain an initial aqueous impregnated base film; According to the preset air knife configuration parameters, the initial aqueous phase impregnated base film is purged to obtain an aqueous phase impregnated base film; Using the oil phase solvent, the aqueous phase impregnation base film is impregnated according to the preset oil phase impregnation time to obtain the initial oil phase impregnation base film; According to the preset heat treatment parameters, the initial oil phase impregnated base film is subjected to heat treatment to obtain a polyamide attached film.

6. The method for preparing the COD separation composite membrane as described in claim 5, characterized in that, The process of embedding the polyamide film using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst-embedded film includes: The pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets were subjected to ultrasonic dispersion for a preset dispersion time to obtain an initial Fe3O4@MXene dispersion. The Fe3O4@MXene initial dispersion was prepared to a preset dispersion concentration to obtain a composite dispersion; Using the composite dispersion, the polyamide membrane is subjected to vacuum filtration according to a preset loading value to obtain a catalyst-embedded membrane.

7. The method for preparing the COD separation composite membrane as described in claim 6, characterized in that, After obtaining the target composite membrane, the method further includes: Obtain the production record log of the target composite film, and perform sampling inspection on the production record log according to the preset quality inspection frequency to obtain the target composite film to be inspected; Based on the preset product size range, obtain the size of a random rectangle; According to the dimensions of the random rectangle, the target composite film to be tested is randomly cut into regions to obtain the test film; The test membrane was subjected to quality compliance testing, and the test results were obtained.

8. The method for preparing the COD separation composite membrane as described in claim 7, characterized in that, The quality compliance test of the test membrane, and the resulting test results, include: According to a preset flux formula, the pure water flux of the test membrane is measured to obtain the pure water flux value, wherein the flux formula is expressed as: ； In the formula, This represents the pure water flux value. Indicates the volume of pure water passing through. This indicates the effective area of ​​the test membrane. Indicates the time taken to purify the water. Indicates the operating pressure through pure water; When the pure water flux value is greater than the preset flux threshold, the COD rejection rate of the test membrane is detected using pre-constructed standard COD simulated wastewater to obtain a rejection rate score, wherein the rejection rate score is expressed as: ； In the formula, This represents the retention rate fraction. This indicates the COD concentration of the permeate after the standard COD simulated wastewater has been filtered through the test membrane. This indicates the preset initial COD concentration in the standard COD simulated wastewater; When the rejection rate fraction is greater than the preset rejection threshold, the test membrane is continuously filtered using the standard COD simulated wastewater to obtain a real-time water flux curve. If the real-time water flux curve decreases to a preset cleaning threshold, the runtime and fouling composite membrane are obtained; When the running time exceeds the preset running threshold, the contaminated composite membrane is cleaned to obtain a cleaned composite membrane. The water flux of the cleaning composite membrane was verified using the standard COD simulated wastewater to obtain the updated water flux. Obtain the initial water flux from the real-time water flux curve, and calculate the flux decay rate based on the initial water flux and the updated water flux, wherein the flux decay rate is expressed as: ； In the formula, This represents the flux attenuation rate. This refers to the updated water flux. This represents the initial water flux; When the flux attenuation rate is greater than the preset attenuation threshold, the test result indicating that the test membrane is qualified is output.

9. A system for preparing a COD separation type composite membrane, characterized in that, The system includes: The base film preparation module is used to perform a film-forming operation on a pre-constructed polysulfone resin, a pre-constructed film-forming solvent, and a pre-constructed pore-forming agent according to preset base film ratio parameters to obtain a base film. A separation membrane configuration module is used to obtain an aqueous solvent and an oil solvent, and to impregnate the base membrane with the aqueous solvent and the oil solvent to obtain a polyamide attached membrane; A catalyst membrane configuration module is used to embed the polyamide attached membrane using pre-constructed Fe3O4 nanoparticles and pre-constructed MXene nanosheets to obtain a catalyst embedded membrane. The hydrophilic membrane configuration module is used to prepare a hydrophilic membrane raw material by mixing pre-constructed polyvinyl alcohol and pre-constructed graphene oxide according to preset hydrophilic membrane mixing parameters, dissolving the hydrophilic membrane raw material in pre-constructed deionized water according to preset dissolution process parameters to obtain a polyvinyl alcohol solution, diluting the polyvinyl alcohol solution to a preset coating solution concentration to obtain a polyvinyl alcohol coating solution, and using the polyvinyl alcohol coating solution to perform a preset dip coating operation on the catalyst embedded membrane to obtain a hydrophilic layer attached membrane, and using a pre-constructed crosslinking agent according to preset crosslinking process parameters to perform a polyvinyl alcohol molecular crosslinking operation on the hydrophilic layer attached membrane to obtain a target composite membrane.

10. The preparation system for the COD separation type composite membrane as described in claim 9, characterized in that, The system includes a base film preparation device, an interface polymerization device, a catalyst layer embedding device, and a hydrophilic modification device; The base film preparation equipment includes a stirred reaction vessel, a vacuum degassing box, an automatic film scraper, a coagulation bath, a winding machine, and a washing tank. The interface polymerization equipment includes an aqueous phase impregnation tank, an air knife purging device, an oil phase impregnation tank, and a heat treatment oven. The catalyst layer embedding device includes an ultrasonic disperser and a vacuum filtration device; The hydrophilic modification equipment includes a heating stirrer, an immersion coating tank, a crosslinking reaction tank, and a deionized water cleaning tank.

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