174results about How to "Improve anti-pollution performance" patented technology

The invention discloses a modified hollow fiber membrane which is composed of a separation layer, a supporting layer and a macroporous layer, the pore diameters of the separation layer, the supporting layer and the macroporous layer are sequentially increased, and a preparation method of the modified hollow fiber membrane comprises the following steps: weighing polyether sulfone / polysulfone, a pore-foaming agent, a solvent, an organic macromolecular additive and an inorganic salt additive according to the proportion to prepare a spinning solution; stirring and dissolving at 80-180 DEG C, centrifugally filtering, defoaming at 40-80 DEG C to obtain a spinning solution, carrying out coagulating bath on the spinning solution, molding, cleaning, stretching and drying to obtain the modified hollow fiber membrane. According to the preparation method, micromolecular inorganic salt pore-forming agents with different concentrations are added into a spinning solution and a coagulating bath, and interaction among inorganic salt, a polymer and a solvent is utilized, so that an inner skin layer structure and an outer skin layer structure of the hollow fiber membrane are adjusted, and a unique three-layer structure of a separation layer, a supporting layer and a macroporous layer is formed; the hydrophilic performance is stable, and the clearance on middle molecules is improved.

The invention belongs to the field of separation membranes, and particularly relates to a preparation method of a reverse osmosis membrane. Comprising the following steps: a) coating a water phase solution containing multifunctional amine on the surface of a supporting layer of a base membrane, then coating an oil phase solution containing multifunctional acyl halide, and drying to form a polyamide separation layer on the surface of the supporting layer to obtain a nascent state membrane; b) soaking the nascent state membrane in an alkaline solution with the pH value of 9-12, and then rinsing to obtain a semi-finished membrane; c) coating a post-treatment solution containing polyvinyl alcohol, polydimethylsiloxane and an amino silane coupling agent on the surface of the polyamide separation layer of the semi-finished product membrane, and drying; d, the membrane treated in the step c is soaked in a 3-chloro-2-hydroxypropyl trimethyl ammonium chloride aqueous solution for quaternization reaction and dried, and the reverse osmosis membrane is obtained.The reverse osmosis membrane prepared through the method has good permeability, hydrophilicity, pollution resistance, antibacterial property and washing resistance.

The utility model provides a combined hydraulic valve of a high-lift system. The combined hydraulic valve is composed of an electric connector unit, a shell assembly unit, a pilot control unit and a main valve unit. Wherein an oil filter assembly is arranged at an oil inlet of the pilot control unit; according to the pilot control unit of the combined hydraulic valve, the oil filter assembly is arranged at the oil inlet, foreign matter can be prevented from entering an inner cavity of the pilot valve, and therefore abnormal opening or closing of the pilot valve is avoided; the guide rod and the guide sleeve of the main valve unit are sealed in a sliding ring combination mode, oil leakage is avoided, therefore, the fit clearance of the main valve unit can be properly increased, after the fit clearance is increased, the situation that normal reversing action cannot be achieved due to valve clamping stagnation caused by oil pollution can be avoided, and the anti-pollution capacity of a product is improved.

The invention relates to the technical field of water treatment, and particularly discloses a seawater desalination reverse osmosis membrane and a preparation method thereof. The sea water desalination reverse osmosis membrane comprises a base membrane layer and a separation layer, the base membrane layer comprises a base layer and a porous support layer, and the sea water desalination reverse osmosis membrane is characterized in that the separation layer comprises the following raw materials in parts by weight: 15-20 parts of bis-2-6-N, N-dimethyl formamide, 1-5 parts of sodium hydroxide and 1-5 parts of sodium hydroxide; the environment-friendly anti-corrosion coating is prepared from the following components in parts by weight: 20 to 30 parts of N, N-(2-ethoxyl) diaminotoluene, 10 to 15 parts of triethylamine, 20 to 30 parts of camphorsulfonic acid, 10 to 15 parts of trifluoroacetic anhydride, 0.5 to 1.5 parts of sodium dodecyl sulfate, 10.5 to 20.5 parts of modified microcapsules, 0.5 to 1.5 parts of trimesoyl chloride and 150 to 180 parts of isoparaffin solvent. The reverse osmosis membrane for seawater desalination can be used in the field of seawater desalination, and has the advantages of high chemical stability, large water flux and excellent durability.

According to the preparation method of the anti-pollution nanofiltration membrane, the surface of a nascent state membrane generated after an interface is coated with glycine-N-carboxyl-cycloendoic acid, the glycine-N-carboxyl-cycloendoic acid reacts with part of acyl chloride groups in trimesoyl chloride, then the glycine-N-carboxyl-cycloendoic acid is grafted to the surface of the membrane, and the glycine-N-carboxyl-cycloendoic acid grafted to the surface of the membrane contains hydrophilic molecules and also contains hydrophilic groups; the glycine-N-carboxyl-cyclic acid can adsorb a layer of water molecules and effectively prevent organic matters from polluting the surface of the membrane, and in the use process, the glycine-N-carboxyl-cyclic acid is gradually hydrolyzed into hydrophilic molecules, the hydrophilicity cannot be weakened along with the change of the use time, and the anti-pollution nanofiltration membrane prepared by the method can be applied to industrial water treatment and industrial wastewater treatment. Wide application prospects are realized in the fields of dairy product concentration and the like.

The invention discloses a chlorine-resistant polyamide composite nanofiltration membrane and a preparation method thereof. The composite nanofiltration membrane is composed of a polysulfone-based membrane, and a catechol intermediate layer and a polyamide desalination layer which are sequentially arranged on the polysulfone-based membrane, wherein the catechol middle layer comprises a plurality of catechol self-polymerization layers, and catechol is subjected to oxidation self-polymerization and then is constructed on the polysulfone base membrane layer by layer to obtain the catechol self-polymerization layers; and the polyamide desalination layer is constructed on the catechol intermediate layer through an interfacial polymerization reaction. The chlorine-resistant polyamide composite nanofiltration membrane comprises a polysulfone base membrane, a catechol middle layer and a polyamide desalination layer, the catechol self-polymerization middle layer is formed through a layer-by-layer construction technology, certain chlorine resistance is provided, meanwhile, the possibility that the middle layer falls off is reduced, and the stability of the composite nanofiltration membrane is enhanced; the tannic acid is added into a water-phase solution, so that the performance of the polyamide composite nanofiltration membrane is adjusted, and the polyamide composite nanofiltration membrane is endowed with relatively high chlorine resistance.

The present invention relates to a method for preparing a reverse osmosis membrane and a reverse osmosis membrane prepared thereby. The method comprises the following steps: preparing a polymer solution as a membrane casting solution, and coating a reinforcing material with the membrane casting solution to form a polymer supporting layer; a desalination layer is formed by contacting a polymer support layer with an aqueous phase solution containing an amine compound and an oil phase solution containing an acyl chloride compound in a slit coating manner, in which N slit coating heads are respectively provided in the lateral direction during contact with the oil phase solution so as to respectively form N coating regions, and from the second coating region, N is a positive integer greater than or equal to 1, and N is a negative integer greater than or equal to 2. The coating flow of each coating area is gradually increased relative to the coating flow of the previous coating area; and performing post-treatment to obtain the reverse osmosis membrane. The reverse osmosis membrane prepared by the method provided by the invention has gradual change performance (including gradual change of water flux and gradual change of desalination rate), effectively reduces the flux attenuation of the membrane element in the operation process, and improves the anti-pollution performance.

The invention discloses a hollow fiber membrane module with an anti-pollution function, the anti-pollution hollow fiber membrane module comprises a lower fixed end and an aeration pipe with specific structures, and particularly comprises a sealant layer with an upper surface in a specific shape and a sub-aeration pipe with an upper opening (also called as an aeration hole) in a specific shape; the upper surface of the sealing glue layer is high in the middle and low in the two sides in the extending direction of the sealing glue layer, the upper opening of each sub-aeration pipe is provided with the two ends with different heights, and the outer side of each sub-aeration pipe is lower, so that pollutants are not prone to accumulation on the upper surface of the lower fixing end and the hollow fiber membrane filaments through cooperation of the two ends, and the pollutants fall off outwards more easily; therefore, the pollution resistance of the membrane component is improved.

The utility model relates to a vibrating MBR membrane device and a vibrating MBR membrane sewage treatment system, which are characterized in that the vibrating MBR membrane sewage treatment system comprises an anaerobic tank, an anoxic tank, an aerobic tank, an MBR membrane tank and a clear water tank which are sequentially arranged according to a water flow sequence, the anaerobic tank is provided with a water inlet, the clear water tank is provided with a clear water discharge pipe, and the anoxic tank is provided with a water outlet. A vibrating MBR membrane device is arranged in the MBR membrane tank and comprises a rack, a moving frame which is erected at the top of the rack and slides along the rack, an MBR membrane assembly arranged on the moving frame and a crankshaft driving mechanism for driving the moving frame to do reciprocating linear motion. And the MBR membrane tank is also communicated with the anoxic tank through a steam stripping return pipe, and the anoxic tank is communicated with the anaerobic tank through a steam stripping return pipe. According to the utility model, not only is the sewage treatment effect greatly improved, but also the service life of the MBR membrane is prolonged, and the energy consumption is saved.

The invention discloses a preparation method of a hollow fiber membrane based on reaction surface segregation, which comprises the following steps: by taking polyvinylidene fluoride powder as a main polymer and a block copolymer pluronic F127 as a segregation agent, mixing the polyvinylidene fluoride powder, the block copolymer pluronic F127 and an organic solvent, heating, stirring, standing and defoaming to form a membrane casting solution; the membrane casting solution is spun and guided into a coagulating bath composed of an aqueous solution of a polyphenol hydroxyl polymer and a metal ion precursor to be cured, a formed hollow fiber membrane is obtained, the mass percent of the polyphenol hydroxyl polymer in the coagulating bath is 0.1%-0.5%, and the molar ratio of the metal ion precursor to the polyphenol hydroxyl polymer is 1: 1; and soaking the formed hollow fiber membrane in an aqueous solution. The preparation method is an in-situ anti-pollution membrane preparation method, preparation and modification of the membrane are carried out at the same time, the flux and anti-pollution performance of the hollow fiber membrane can be synchronously improved, the process is simple, and the method has great industrial application prospects.

The invention relates to a polyamide composite membrane containing a middle layer and a preparation method of the polyamide composite membrane. The polyamide composite membrane comprises a polyborosiloxane-based porous polymer substrate, a modified polyimide middle layer and a polyamide separation layer, a modified polyimide intermediate layer is loaded on the surface of the porous polymer substrate, and a polyamide separation layer is loaded on the surface of the modified polyimide intermediate layer. The polyborosiloxane-based porous polymer substrate and the modified polyimide intermediate layer have better compatibility, interface defects can be reduced, the overall performance of the membrane can be improved, moreover, the polyborosiloxane-based porous polymer substrate also has a self-healing characteristic, and after the polyborosiloxane-based porous polymer substrate is damaged, the self-healing property of the polyborosiloxane-based porous polymer substrate is improved. Fractured connection can be repaired without external stimulation (such as light and heat), and self-repairing of the substrate is achieved.

The invention discloses an anti-pollution composite membrane, a preparation method thereof and a reverse osmosis membrane, and relates to the technical field of water treatment separation membranes, the anti-pollution composite membrane comprises a support membrane and a separation function layer formed on the support membrane; wherein the separation function layer comprises a polyamide crosslinking layer containing an acyl halide group and a compound containing an aminophosphonic acid group, and an amino group in the compound containing the aminophosphonic acid group and the acyl halide group in the polyamide crosslinking layer are bonded with each other through an amido bond. According to the anti-pollution composite membrane provided by the invention, the polyamide crosslinking layer containing the acyl halide group and the compound containing the amino phosphonic acid group are bonded through the amido bond, so that the phosphonic acid group is grafted on the polyamide crosslinking layer, the hydrophilicity of the polyamide crosslinking layer is improved, and the membrane is easy to form a hydration layer when being subjected to separation treatment; therefore, pollutants are prevented from being adsorbed or deposited on the surface of the membrane, the anti-pollution capacity of the membrane is improved, and the service life of the membrane is prolonged.

The present invention relates to the technical field of hollow fiber membranes, and to a PVDF hollow fiber membrane and a preparation method and use thereof. In the present invention, a nascent hollow fiber membrane having a hydrophilic photoinitiator molecular chain is subjected to ultraviolet irradiation to cause a cross-linking reaction to form a semi-interpenetrating structure, and a hydroxyl hydrophilic group is generated at the same time, so that the hydrophilicity and mechanical properties of the membrane are improved, the reaction degree is easy to control, and continuous operation can be achieved.

The invention discloses an anti-pollution ultrafiltration membrane and a preparation method thereof, and relates to the technical field of organic polymer materials. The anti-pollution ultrafiltration membrane is prepared from the following raw materials by weight: 80 parts of hydrophilic modified polyethersulfone, 2-4 parts of coupling agent, 3-5 parts of Al-Nb-Sc-O-Te, 15-25 parts of additive, 5-8 parts of polyethylene glycol diacrylate, 2-4 parts of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and 3-5 parts of 1-allyl-3-vinyl imidazole chloride; the hydrophilic modified polyethersulfone is trishydroxymethylaminomethanesulfonic acid modified polyethersulfone. The anti-pollution ultrafiltration membrane has good anti-pollution performance, sufficient pure water flux, and high BSA retention rate.

The invention relates to a super-hydrophobic nanofiber composite membrane with a gradient structure and a preparation method and application of the super-hydrophobic nanofiber composite membrane, the super-hydrophobic nanofiber composite membrane comprises a supporting layer and a gradient hydrophobic layer, and the gradient hydrophobic layer is made of zinc oxide nanowires. The nanofiber composite membrane has pollution resistance and high permeability, and has excellent cycle stability in practical application.

The invention discloses a reverse osmosis membrane assembly which comprises a reverse osmosis core and sealing covers mounted at two ends of the reverse osmosis core in a sealing manner, the reverse osmosis core comprises a middle inner membrane supporting layer as well as two groups of micro-filtration membranes and two groups of ultra-filtration membranes which wrap the outer side of the inner membrane supporting layer, a laminated pre-filtration layer is arranged between the micro-filtration membranes and the ultra-filtration membranes wrapping the inner membrane supporting layer, a PA reverse osmosis membrane wraps the rear parts of the micro-filtration membranes and the ultra-filtration membranes, and a separation net is arranged behind the PA reverse osmosis membrane; due to the synergistic effect of the multiple layers of membranes, the system can treat a more complex and worse seawater environment, and the stability and reliability of the effluent quality are ensured; due to the design of the laminated pre-filtering layer and the separation net, pollutants are effectively prevented from being in direct contact with the membrane holes and blocking the membrane holes, and the stability of the membrane assembly is further enhanced. Due to the introduction of the automatic backwashing device, the automatic backwashing device can be automatically started at regular intervals or according to a water quality monitoring result, the pre-filter is subjected to backwashing, the service life of the pre-filter is prolonged, and the maintenance cost is reduced.

The invention discloses a preparation method of an anti-pollution membrane based on amphoteric dynamic supramolecules, and belongs to the technical field of preparation of water treatment membranes. The method comprises the following steps: preparing a high-flux base membrane by a non-solvent induced phase separation method; the preparation method comprises the following steps: preparing an amphoteric supramolecule with a line-through-ring quasi-polyrotaxane structure through a solvent-induced self-assembly method; based on free radical polymerization reaction, amphoteric dynamic supramolecules are grafted to the surface of the base membrane to form an anti-pollution layer. A supramolecular structure formed by cyclodextrin and polydimethylsiloxane is combined with a hydrophilic and low-surface-energy micro-area synergistic anti-pollution mechanism, so that the anti-pollution performance and the water flux of the membrane are improved. The dynamic supramolecular structure has good anti-pollution performance, adapts to different flow velocity and temperature conditions, is high in flux and low in attenuation rate, and is suitable for various water treatment processes. The preparation process is simple, raw materials are easy to obtain, and the cost is low; the membrane flux is obviously improved, the anti-pollution capacity is enhanced, and the performance is easy to recover through simple cleaning; good adaptability is realized in a wide temperature range and a wide pH (Potential of Hydrogen) range.

The utility model relates to the technical field of water purification equipment, in particular to a pretreatment filter element and a water purification system. The pretreatment filter element comprises a filter bottle, a filter layer, a lifting mechanism and a driving part, wherein the filter layer is arranged in the filter bottle; the lifting mechanism is arranged in the filter bottle and is connected with the filter layer; the driving part is arranged outside the filter bottle and is used for driving the lifting mechanism to lift. During self-cleaning, the filter layer is driven by the lifting mechanism to be switched back and forth between the bending state and the stretching state, pollutants attached and deposited on the surface of the filter layer can be removed, self-cleaning is more thorough, the anti-pollution performance of the pretreatment filter element is improved, the element replacement time of the pretreatment filter element is delayed, and the use cost of a user is reduced; and raw material resources for pretreating the filter element are saved.

The invention relates to a processing method of a tubular polycrystalline film, the obtained film and application of the film. The present invention relates to a method for treating a tubular polycrystalline film supported by a carrier, the method comprising a step of applying a solution to the inner surface of the tubular polycrystalline film by a perfusion method, the solution comprising a prepolymer and a cross-linking agent, and a step of roll-coating the coated tubular polycrystalline film, in the roll-coating process, the pre-polymer and the cross-linking agent are added to the inner surface of the tubular polycrystalline film, and the cross-linking agent is added to the pre-polymer and the cross-linking agent. The prepolymer and the cross-linking agent are subjected to an in-situ cross-linking reaction, and the in-situ cross-linking temperature is 25-60 DEG C. According to the treatment method, a uniformly covered polymer coating can be obtained on the surface of the tubular polycrystalline film, so that the purpose of remarkably repairing defects of the tubular polycrystalline film is achieved, and the gas separation selectivity of the tubular polycrystalline film is improved.

The invention belongs to the technical field of membrane separation, and relates to a preparation method of an efficient antibacterial microfiltration membrane for a biopharmaceutical process, a composite additive system is introduced into a membrane casting solution, a modifier is added, the modifier comprises a composite alcohol pore-foaming agent and an antibacterial agent, the membrane casting solution is coupled, and a high-throughput antibacterial membrane is obtained through cooperation of membrane preparation processes. The antibacterial agent can enhance the effect of the composite alcohol pore-foaming agent, assists in membrane pore size regulation and control and fixes the membrane structure, and through the synergistic effect of the composite alcohol pore-foaming agent and the antibacterial agent, the selective permeability is improved while the microfiltration membrane maintains high antibacterial performance, and selective separation of microorganisms of different sizes is achieved. The membrane is expected to be a potential candidate in a biopharmaceutical sterile filtration process.

The invention relates to the technical field of oil-water separation membrane preparation, in particular to a heterogeneous carbon nanotube and an oil-water separation membrane prepared from the same. The heterogeneous carbon nanotubes are obtained by grafting a titanium dioxide / carbon nanotube composite material and a hydrophilic oleophobic modifier; the oil-water separation membrane is prepared from the following components in percentage by mass: 5%-15% of heterogeneous carbon nanotubes, 60%-70% of N, N-dimethylacetamide, 15%-25% of polyacrylonitrile, 2%-8% of polyvinylpyrrolidone and 2%-4% of a defoaming agent. According to the invention, the oil-water separation membrane with excellent hydrophilic and oleophobic performance is prepared by carrying out hydrophilic and oleophobic modification on the carbon nano tube, can well realize oil-water separation, also has certain anti-pollution capacity, and can keep good separation efficiency.

The invention discloses a high organic matter removal anti-pollution polyamide reverse osmosis membrane and a preparation method and application thereof, the polyamide reverse osmosis membrane sequentially comprises a polyester non-woven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer and a hydrophilic polymer anti-pollution layer; the polyamide separation bottom membrane layer is a cross-linked polymer formed by an interfacial polycondensation reaction of polyamine and polyacyl chloride; the hydrophilic polymer anti-pollution layer is a polymer formed by carrying out a cross-linking reaction on a diblock hydrophilic polymer containing a pyrrolidone chain segment and an amino chain segment and a small molecular compound containing an epoxy group and / or an allyl group. The polyamide reverse osmosis membrane has good application prospects in the fields of removal of organic matters in pure water in the electronic industry, removal of trace organic matters in domestic drinking water and the like.

The invention discloses a protein pollution resistant polyacrylonitrile hydrolysis modified ultrafiltration membrane, which is prepared by mixing hydrolyzed polyacrylonitrile (H-PAN) and graphene oxide (GO), and the content of the GO is 0.005-0.04 wt% of the weight of a membrane casting solution. The preparation method has the advantages that the hydrolyzed polyacrylonitrile is used as a base membrane material, and the two-dimensional nano material graphene oxide rich in carboxyl and hydroxyl is introduced and has a synergistic effect with the base membrane material to improve the anti-pollution performance of the ultrafiltration membrane. The core of the invention is that hydrolyzed polyacrylonitrile H-PAN and graphene oxide GO are ingeniously combined to form a novel H-PAN / GO mixed matrix ultrafiltration membrane.

The application discloses an ultrafiltration membrane for sewage treatment and a preparation method thereof, and relates to the field of membrane separation technology. The method comprises the following steps: firstly, ZnO@PHEMA-Ag nanoparticles are prepared, and the nanoparticles are pretreated, modified, grafted and loaded with silver nanoclusters; then, maleic anhydride grafted PVDF and modified MXene are prepared; then, a composite casting solution is prepared, and the solution is cast into a film and then immersed into a polyvinyl alcohol coagulation bath containing dimethylformamide to form a film; finally, the finished ultrafiltration membrane is obtained through ultraviolet crosslinking post-processing. The ultrafiltration membrane has excellent anti-pollution performance through functional nanoparticles, substrate modification and process optimization.

The invention belongs to the technical field of silicon carbide flat membranes, and particularly provides a high-electronegativity silicon carbide flat membrane material and a preparation method thereof. The invention relates to a preparation method of a high-electronegativity silicon carbide flat sheet membrane material, which comprises the following steps: mixing phytic acid and an organic solvent to prepare a precursor solution, impregnating a silicon carbide flat sheet membrane substrate with the precursor solution, carrying out a reaction, and carrying out stage heat treatment. The high-electronegativity silicon carbide flat sheet membrane material prepared by the method has high electronegativity in a wide pH range, the water permeation flux is high, and after multiple humic acid pollution-cleaning cycles, the flux attenuation is less, and the anti-pollution performance is good. When silica sol is added into the precursor solution, the electronegativity of the silicon carbide flat sheet membrane material can be further improved, so that the anti-pollution performance of the high-electronegativity silicon carbide flat sheet membrane material is further improved.

The application discloses a preparation method of a high-peeling-strength inner support polyvinylidene fluoride hollow fiber membrane, and comprises the following steps: (1) mixing polyvinylidene fluoride, a hydrophilic pore-forming agent and an organic solvent to obtain a casting solution; (2) coating the casting solution on a modified support tube through a spinning nozzle, then walking vertically downward in the air, and then entering a coagulation bath to be coagulated and formed into a formed piece; and (3) soaking the formed piece obtained in the step (2) in pure water, then placing the formed piece in a mixed liquid of water and glycerol, and then drying to obtain the high-peeling-strength inner support polyvinylidene fluoride hollow fiber membrane. The anti-hook type support tube prepared by using the anti-hook technology has an increased roughness of the surface of the support tube, the casting solution and the support tube can have more contact areas, the adhesion between the membrane layer and the support tube is greatly improved, and the peeling and peeling-off of the membrane layer caused by washing during the operation of a membrane module can be effectively reduced.

The utility model discloses a water treatment system in the field of water treatment, aims at solving the technical problem of reverse osmosis membrane scale, block, system cannot stable operation. The system includes: primary pretreatment unit, primary ultrafiltration device, primary reverse osmosis device, secondary pretreatment unit, secondary ultrafiltration device, secondary reverse osmosis device and tertiary reverse osmosis device, the primary pretreatment unit water connection primary ultrafiltration device water intake, primary ultrafiltration device water access primary reverse osmosis device, primary reverse osmosis device concentrated water end connects secondary pretreatment unit, and the secondary pretreatment unit water is through secondary ultrafiltration device, and the secondary ultrafiltration water end access secondary reverse osmosis device, and its concentrated water finally enters tertiary reverse osmosis device. The utility model can combine and handle the circulating water drainage and the sewage collected in factory area, to realize water resource recovery and minimum wastewater discharge.

This invention relates to a method for preparing electronic-grade hydrofluoric acid. The invention utilizes a microchannel reactor for the fluorine oxidation reaction, significantly reducing fluorine consumption and safety hazards during production. Furthermore, the microchannel reactor enhances the gas-liquid two-phase mass transfer during the oxidation reaction, further improving impurity removal and product quality. The addition of multi-effect distillation to the distillation process not only enables secondary heat utilization but also saves on the use of high-temperature heating media at the bottom of the column, effectively reducing energy consumption. In the modified liquid, DMF serves as the solvent, cobalt nitrate provides cobalt ions, and vinylguanidine provides guanidine functional groups and amino groups. Ammonia and propanethiol are used as plasma gases to introduce amino and thiol groups onto the membrane surface. These groups help improve membrane selectivity, effectively separating metal and non-metal ions, as well as acidic impurities in the raw materials.

The application discloses a method for preparing an antibacterial nanofiltration membrane by using amikacin as a water-phase monomer, and belongs to the technical field of composite nanofiltration membrane preparation. The method uses amikacin as a water-phase monomer and adopts an interfacial polymerization method to prepare an antibacterial nanofiltration membrane (polyamide nanofiltration membrane). The method has the advantages of simple operation, mild reaction conditions and relatively low raw material cost. In addition, the prepared polyamide composite nanofiltration membrane has higher selective permeation performance and good antibacterial performance. The nanofiltration membrane flux can be as high as 20 L / (m 2 ·h·bar), and the tetracycline rejection rate can be as high as 99.3%. In addition, the application can also provide a reference for the preparation of other antibacterial interfacial polymerization separation membranes.

The invention provides a composite nanofiltration membrane, a preparation method and application of the composite nanofiltration membrane in interception and filtration of emerging micropollutants. The composite nanofiltration membrane comprises a porous base membrane supporting layer, a hydrophobic middle layer and a filtering skin layer, the hydrophobic middle layer is made of hydrophobic organic materials, and the porous base membrane supporting layer and the filtering skin layer are both made of hydrophilic organic materials; the thickness of the hydrophobic middle layer is smaller than that of the porous base membrane supporting layer. The preparation method comprises the following steps: S1, obtaining the hydrophilic porous basement membrane supporting layer; s2, preparing a hydrophobic middle layer on the porous base membrane supporting layer; s3, performing interfacial polymerization reaction on the hydrophobic middle layer to form a hydrophilic filtering skin layer. By adopting the composite nanofiltration membrane, the problem of collapse of a filtering cortex layer is effectively prevented, the composite nanofiltration membrane has excellent water flux and pollutant interception performance, and the interception effect on emerging micropollutants has remarkable stability and anti-pollution performance.