181 results about "Membrane flux" patented technology

The invention discloses a vibrating membrane filtration device which comprises a vibration generation device fixedly connected with a support, a membrane component and a vibration transmission device used for connecting the vibration generation device and the membrane component; the vibration generation device is a motor; the vibration transmission device comprises a bottom plate, a counterweight, an elastic spindle, a transmission shaft and an eccentric block; one end of the elastic spindle is fixedly connected with the center of the bottom plate, and the other end thereof is fixedly connected with the membrane component; the counterweight and the eccentric block are respectively and fixedly connected with both ends of the center of the bottom plate; the rotating shaft of the motor is connected with the eccentric block through the transmission shaft; and the membrane component is provided with a concentrated water pipe, a water inlet pipe and a water outlet pipe, and a filter membrane is arranged in the membrane component. The invention can effectively prevent the filter membrane from being blocked, maintains stable water flux, effectively solves the technical difficult problems of low membrane flux and membrane blockage of wastewater during the filtration process so that a membrane separation technology can be better applied in an industrial wastewater treatment method, thereby not only improving the water treatment efficiency, but also reducing the water treatment cost.

The invention discloses a GO (graphene oxide) and g-C3N4 composite modified membrane material. A preparation method includes steps: activating an original membrane to recover original membrane flux; adding a surfactant into GO and g-C3N4 mixed dispersion liquid to obtain mixed liquid; soaking the activated original membrane into the mixed liquid to realize ultrafiltration adsorption, and soaking the membrane into aniline hydrochloric acid solution; taking out after soaking is finished, and soaking in hydrochloric acid solution of ammonium persulfate immediately to enable interface polymerization reaction; finally, drying the membrane to obtain the composite modified membrane material. By an ultrafiltration adsorption and interface polymerization combined modification method, GO and g-C3N4are combined for surface composite modification of the membrane material, and a visible light responsive catalytic modified membrane is developed. The novel modified membrane is low in preparation cost and recyclable, pollution resistance is remarkably improved, firmness in modifying agent and photocatalyst loading is achieved, the visible catalytic performance and hydrophilic performance are remarkably enhanced, the forbidden bandwidth of a membrane function layer is decreased, the problem of secondary pollution is avoided, and a promising application prospect is achieved.

The invention discloses a charged type chlorine containing polymer nanofiltration membrane and a preparation method thereof. The nanofiltration membrane is composed of a macroporous supporting layer and a dense functional layer. The macroporous supporting layer and the dense functional layer are connected through a C-N bond, the dense functional layer is a positive or charged or zwitterionic crosslinking multivariate amine compound, and the macroporous supporting layer is prepared from chlorine containing polymer. The preparation method of the nanofiltration membrane comprises the steps that a multivariate amine compound is smeared to the surface of a chlorine containing polymer ultrafiltration membrane, thermal treatment is carried out, the chlorine containing polymer ultrafiltration membrane is soaked in a crosslinking agent and charged reagent mixed solution after being washed, and thermal treatment is carried out again. The membrane flux of the prepared polymer nanofiltration membrane can reach 60 L / m<2>.h at the pressure of 0.3 MPa, and the reject rate of micromolecule dyes and high-valent inorganic salt can reach 90%. The chlorine containing polymer nanofiltration membrane comprises a slab ultrafiltration membrane state and a hollow fiber ultrafiltration membrane sate, and good practical prospects are achieved.

The invention relates to a method for hydrolyzing the surface of a polyacrylonitrile ultrafiltration membrane, and belongs to the technical field of membrane separation. The prior soakage method is easy to make the inner surface and the outer surface of the membrane and the insides of membrane pores all perform hydrolysis reaction, so that the mechanical strength and the flux of the membrane are severely reduced. The invention realizes the surface hydrolysis of the polyacrylonitrile ultrafiltration membrane by adopting the following technical proposal: filling a transitional solvent-ethanol into the membrane pores; using a filling solvent-cyclohexane to substitute the ethanol; making a single surface of the membrane contact an alkaline solution for hydrolysis; using the ethanol to substitute the cyclohexane in the membrane pores; and using water to substitute the ethanol in the membrane pores. When the method is adopted to modify the polyacrylonitrile ultrafiltration membrane, the hydrolysis reaction is only performed on the surface of the membrane and not performed in the membrane pores, so that the method improves the pollution resistance and the biocompatibility of the polyacrylonitrile ultrafiltration membrane and simultaneously guarantees the mechanical strength and the flux of the membrane.

The invention discloses a nano-sized high-flux PVDF (polyvinylidene fluoride) plate ultrafiltration membrane as well as a screening method and a preparation method thereof, and belongs to the technical field of PVDF plate ultrafiltration membranes. The PVDF plate ultrafiltration membrane with high membrane flux is characterized by being prepared from raw materials in parts by weight as follows: 10-25 parts of PVDF, 70-85 parts of a solvent, 5-15 parts of a pore forming agent and 0.5-5 parts of a nanomaterial. According to the plate ultrafiltration membrane with high-flux PVDF membrane flux as well as the screening method and the preparation method thereof, the membrane formula screen method is optimized scientifically, so that the material ratio is optimized, the consumption quantity accuracy of the materials is improved, and a membrane product with high flux, low cost and long service life is prepared.

The invention discloses a method for modifying a membrane material in a membrane bioreactor in the field of sewage treatment, which comprises the following steps: preparing membrane liquid by using polyvinylidene fluoride as the membrane material, using polyvinylpyrrolidone as a porogen, using N-Methyl-2-pyrrolidinone as an organic solvent, using sodium hexametaphosphate as a dispersing agent and using deionized water with the temperature of 25 DEG C as coagulating bath, heating the membrane liquid to the temperature of 50 DEG C and carrying out deaeration for 30 minutes under the vacuum condition of minus 50kPa after stirring so as to form uniform cast membrane liquid; uniformly adding nano TiO2 particles into the cast membrane liquid to prepare an organic-inorganic hybrid membrane by a blending method through adopting an L-S phase conversion method, wherein the added nano TiO2 particles account for 3 to 5 percent by weight of the polyvinylidene fluoride; and preparing the organic-inorganic hybrid membrane into a flat membrane or a hollow fiber membrane. The modified membrane shows obvious hydrophilcity, has excellent membrane flux and membrane separation performance and can effectively improve the problem of membrane pollution in the membrane bioreactor.

The invention discloses a method for cleaning a heavy oil sludge-polluted membrane module, which realizes the cleaning for the heavy oil sludge-polluted membrane module by stepwise combination of online backwash with clean water, acidic hydrogen peroxide solution with the concentration of 300ppm to 500ppm and sodium hypochlorite solution with the concentration of 300ppm to 500ppm, and high strength aeration. After the membrane module is cleaned, the water flux of the membrane reaches 130m3 / h under negative pressure of -0.02mPa according to one-week real-time monitoring, thus the water flux restores to the level as much as 92.86% of initial flux so as to meet the demand of the design flux of 125m3 / h required by normal operation of system. The method for cleaning heavy oil sludge-polluted curtain membrane restores membrane flux effectively and simultaneously saves a great amount of manpower and resources, besides, the online cleaning in the method of the invention is characterized by directly adding agents to the heavily-polluted area of the membrane, so the agents are strongly targeted and high in utilization rate, and compared with offline cleaning in the manner of immersing the membrane module in a cleaning pool, the method saves plenty of agents, is more remarkable in effect and has superior market prospect.

The invention discloses an immersed flat sheet membrane bioreactor with micro-channel turbulence-flow promoters. The micro-channel turbulence-flow promoters are arranged in the immersed flat sheet membrane bioreactor at certain intervals in a certain arrangement manner, so that the micro-channel turbulence-flow promoters can generate a sluggish flow since gas generated in an aerator and liquid carried in the micro-channel turbulence-flow promoters are combined to form a mixed fluid which is lifted in a channel between a membrane and the micro-channel turbulence-flow promoters. The micro-channel turbulence-flow promoters can increase the turbulent degree on the surface of the membrane and further generate a shear force on the surface of the membrane, thereby reducing the thickness of a boundary layer and slowly-reducing concentration polarization. When sewage passes through the micro-channel turbulence-flow promoters, sludge particles are blocked in the micro-channels due to adsorption and bridging and such effects so that pores in the membrane is not liable to be blocked. A plurality of micro-pores are distributed on the micro-channel turbulence-flow promoters so that when suspension particles are deposited on the surface of the membrane, a filter cake layer which is better in compression resistance and is higher in porosity is formed, so that the filter cake layer deposited on the surface of the membrane is promoted to fall, thereby reducing the accumulation speed of the filter cake layer, improving membrane flux and correspondingly slowly-reducing membrane pollution.

The invention relates to a dirt cleaning agent for a reverse osmosis membrane. The dirt cleaning agent for the reverse osmosis membrane comprises the following components in percentage by weight: 43 to 50 percent of an anionic surfactant, 0.8 to 1 percent of a metal complexing agent, 3.8 to 4.5 percent of an anti-deposition agent, 17.6 to 20.2 percent of lauryl diethanolamine, 8 to 8.5 percent ofsodium xylene sulfonate, 3.5 to 4.0 percent of sodium chloride, 0.4 to 0.6 percent of sodium sulfate, 0.8 to 1.0 percent of a sterilizing agent and the balance of deionized water. According to the dirt cleaning agent for the reverse osmosis membrane, which is provided by the invention, the anionic and nonionic surfactant is added in the cleaning agent, so the cleaning efficiency of the cleaning agent is greatly improved; the membrane flux can be maintained and the life of the membrane can be prolonged; the surfactant which the cleaning agent contains can permeate rapidly, so dirt can be removed effectively; the sterilizing agent DBNPA is added, so that microorganisms are killed and cleaning is realized; and due to the excellent bacteriostatic function of the sterilizing agent, the microorganisms are not liable to grow continuously and damage to the membrane caused by multi-time cleaning is avoided.

The invention discloses an online monitoring method and system for MBR membrane pollution, and the method comprises the steps: obtaining MBR membrane pollution influence parameters in incoming water at a current moment, inputting the MBR membrane pollution influence parameters at the current moment into a current optimal LSTM recurrent neural network model, obtaining a membrane flux prediction result at the current moment, and judging the pollution and blockage conditions of an MBR; wherein the LSTM recurrent neural network model is mainly established on the basis of a training data set formedby MBR membrane pollution influence factors and historical data of membrane flux according to principal component analysis and an LSTM recurrent neural network algorithm. According to the method, theredundancy in the MBR membrane flux judgment process is reduced through a principal component analysis algorithm, the dimensionality of a training sample is reduced, and the calculation speed is increased; aiming at the time characteristic of MBR membrane pollution, the LSTM recurrent neural network solves the problem of time serialization. According to the method, a nonlinear relationship between membrane pollution factors and membrane flux representing the membrane pollution degree is well established, and the pollution and blockage conditions of the membrane are predicted in advance.

The invention discloses a preparation method of a self-assembly nanofiltration separation membrane for high salinity and high ammonia nitrogen wastewater, and the nanofiltration separation membrane is used for the treatment of high ammonia nitrogen and high salinity wastewater. Polysulfone ultrafiltration membrane is used as a basic membrane; static layer-by-layer self-assembly technique is employed; and a PST surface modifier of nanofiltration membrane material aiming at desalination of high salinity and high ammonia nitrogen wastewater and recycling of ammonia nitrogen components is developed; and poly diallyl dimethyl ammonium chloride (PDADMAC) / sodium polystyrene sulfonate (PSS) multilayer polyelectrolyte nanofiltration membrane is prepared. Aiming at the influences of species, concentration and self-assembly layer of ions on separation performance, charge property and hydrophilicity of the membrane, the surface properties of nanofiltration membrane are adjusted; and according to the retention rate of nanofiltration membrane on different ions in waste water under different operation conditions and change of membrane flux and recovery rate, targeted membrane material and technology for desalination of high salinity alkali wastewater and separation of ammonia nitrogen are developed.

The invention provides a gas drive membrane separation method. When a membrane works, continuous bubbles are introduced into one side or two sides of the membrane so that the membrane is vibrated within a definite frequency spectrum range. The invention also provides a membrane separation device. When the method and the device are applied, the prior process flow and the prior operating devices are not needed to be improved greatly, and a membrane device can be subjected to dirt removing operation during the running of the membrane only by increasing a bubble generating and controlling device so as to reduce membrane pollution, reduce plugging ratio, increase membrane flux, keep long-time continuous and stable operation during membrane separation, prolong the service life of the membrane, and improve the water yield of the membrane.

The invention discloses a method and a device for cleaning a high-efficiency water-saving medicine-saving membrane unit. The method comprises the following steps: allowing reclaimed water subjected to MBR treatment to pass through three bubble pools, a clean-water reservoir and two dosing pools, adding 1000kg of 13 mass percent of sodium hypochlorite solution and 25+ / -0.1kg of industrial sodium hydroxide, and stirring until the sodium hydroxide is completely dissolved; moving the membrane unit into the clean-water reservoir, mixing the reclaimed water and gas to perform continuous and effective air scrubbing and water scrubbing on membranes which are difficultly cleaned in a membrane box, and cleaning organic matters such as activated sludge attached to the membranes on the surface of the membrane box and in the membrane unit; transferring the membrane unit into the dosing pools, performing bottom aeration, jittering to blow out the sludge on the membranes in the membrane unit, and effectively cleaning the membranes through air bubbles generated by air aeration. According to the method and device, the waste of dose is effectively reduced, the membrane flux is improved, and the effluent amount and water quality stability of the MBR process are guaranteed.

The inventiondiscloses a spray pipe, a membrane spray device and a membrane spray systemfor preparing a tubular nanofiltration membrane. One end of the spray pipe is closed, and the other end is open;the spray pipe is internally and radially divided into a water phase area, an oil phase area and a hot air area which are not connectedcommunicated; micropores axially penetrates in the pipe wall ofthe spray pipe in each area. The membrane spray device for preparing the tubular nanofiltration membrane comprises the spray pipe, a power mechanism for driving the spray pipe to rotate, and a slidingsupport mechanism. The system for preparing the tubular nanofiltration membrane comprises a membrane fixing device, a membrane spray device, a feed device and a hot air device; a water phase medium and an oil phase medium are sprayed in turn to the inner wall of a tubular membrane for interfacial polymerization, through the feed device and the spray device; heat treatment is performed through thehot air device, so as to finish preparation of the tubular nanofiltration membrane. According to the spray pipe, the membrane spray device and the membrane spray system disclosed by the invention, the technical defect of traditional methods that interfacial polymerization easily occurs on the inner and outer walls of the tubular membrane at the same time during soaking is resolved; the dosage oftraditional Chinese medicine agents and the waste liquid amount are reduced in the interfacial polymerization process; meanwhile, the formed dense separation layer is thinner, and the membrane flux isincreased.

The invention discloses pectin and an extraction method and a preparation method thereof. The extraction method comprises the steps: adding organic weak acid salt into an acidic pectin extracting solution, uniformly mixing, carrying out membrane filtration on the extracting solution treated by the organic weak acid salt, carrying out alcohol precipitation or salting-out on the extracting solution,and separating to obtain the pectin, wherein the addition amount of the organic weak acid salt in the mixed solution is 0.2-1 mg / mL. Due to the fact that a proper amount of organic weak acid salt isadded before membrane filtration, pectin colloid is further stabilized, pectin is not prone to precipitation on the surface of a membrane during membrane concentration, meanwhile, pigments, saccharides, calcium, magnesium and other salts in the pectin can be removed, the membrane flux can be increased, and membrane pollution is effectively relieved. Besides, in the salting-out process, low-valencesalt can be used as a precipitating agent, complexing of high-valence cations in a salt solution and the pectin is avoided, pectin desalination is easy to carry out, and thus the problems that pectinis low in extraction rate, heavy in color and low in purity are solved, and the ash content of the pectin is not high.

A method for or producing an organic-inorganic hybrid membrane by enzyme induction belongs to the technical field of membrane separation and comprises steps: firstly, assembling a plurality of layers of cationic polyelectrolyte and anionic polyelectrolyte alternately on the surface of a treated membrane to obtain a membrane 1; secondly assembling a plurality of layers of cationic polyelectrolyte, calcium salt and anionic polyelectrolyte and urease alternately on the surface of the membrane 1 to obtain a membrane 2; and finally soaking the membrane 2 in a urea solution, catalyzing urea in the urea solution by the urease in the membrane 2 to generate carbon dioxide, and then reacting with calcium salt on the surface of the membrane 2 to obtain calcium carbonate particles. The obtained calcium carbonate particles can effectively enhance the hydrophilic performance of the surface of the membrane, so that the membrane flux is increased.

The invention discloses a high-stability and high-flux polydopamine nanoparticle modified membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out vacuum filtration on a mixed solution of polydopamine / polyethyleneimine nanoparticles and polyethyleneimine macromolecules, loading the nanoparticles in a polydopamine / polyethyleneimine co-deposited film, and further reacting to prepare the polydopamine / polyethyleneimine co-deposited film. In the vacuum filtration process, the nano-particles with covalent bonds formed inside are selectively adhered to dead corner areas in membrane holes, so that fluid in the nano-particles in the membrane is prevented from being washed away, and macromolecules on the surfaces of the nano-particles are prevented from being eroded by the fluid. In addition, the nano-particles cannot block through pore channels in the membrane, and the hydrophilicity of the membrane is enhanced after the particles are loaded, so that the membrane flux is further increased, and the membrane has better anti-pollution performance.

The invention relates to a membrane casting solution for preparing an anti-pollution and high-flux ultrafiltration membrane. The membrane casting solution is prepared from the following components by weight: 16-30% of polyether sulfone, 1-6% of a mutual matching pore forming agent, 0.5-5% of an organic acid additive and 60-80% of a solvent. The invention also relates to the anti-pollution and high-flux ultrafiltration membrane and a preparation method thereof. The tubular or flat ultrafiltration membrane prepared from the membrane casting solution has the characteristics of uniform pore size distribution, high membrane flux, good stability, strong pollution resistance, high flux recovery rate after backwashing, wide range of application, good mechanical strength and chemical resistance, and is applicable to high viscosity and high solid content system. Compared with other preparation method, the preparation method has the characteristics of simple process, controllable membrane pore size, low cost and convenience for industrialized production.

The invention relates to a method used for improving an organic nanofiltration membrane separating property, and belongs to the technical field of membrane separation. Aiming at the limitation in a membrane separating technology, the invention provides a method for improving organic nanofiltration membrane separating property by utilizing the photo-thermal effect of a metal nano particle. According to the method, laser is used for irradiating the upper surface of a nanometer inorganic-inorganic compound nanofiltration membrane during filtering, and the part of a filter unit between a laser transmitting terminal and the nanometer inorganic-inorganic compound nanofiltration membrane is made of transparent material, so that laser can pass through the filter unit to irradiate the upper surface of the nanometer inorganic-inorganic compound nanofiltration membrane. According to the invention, the improvement of the separating property of the membrane is caused by temperature increment of the membrane and does not derive from the modification of any membrane or the formation of membrane holes, so that the membrane flux of the organic nano filter membrane can be greatly improved under the condition that the retention rate is not obviously changed, and an 'inverse effect' of the membrane flux and the retention rate is overcome.

The invention relates to a method for synchronously improving the flux and the anti-pollution performance of a polyamide reverse osmosis composite membrane. The method comprises the steps that first,1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is used for activating carboxyl group on the surface of the polyamide reverse osmosis composite membrane to react with primary amine, secondary amine or hydroxyl group to introduce a tertiary amine group; then the tertiary amine group reacts with sultone on the surface of the membrane to achieve the purpose of introducing amphoteric molecules in the form of chemical bonds; on the other hand, due to the protection of a water molecular layer, the condition that membrane fouling is caused due to the fact pollutants in feed liquid are deposited on the membrane surface is avoided; and in addition, the method is post-processing and does not affect the overall consistency of a polyamide separation layer so as to simultaneously improve the permeability and the anti-pollution performance of a commercial polyamide reverse osmosis composite membrane without sacrificing the retention performance of the polyamide reverse osmosis compositemembrane, and good application prospects are achieved.

The invention relates to an immersed MBR membrane tank device, and a method for treating sewage by using the same. The immersed MBR membrane tank device comprises a PLC, a total liquid level sensor, a raw water pump, a sewage treatment tank, an MBR membrane filtration assembly, an aeration washing assembly, a backwashing assembly, a water production assembly and a sludge discharge pump, and the MBR membrane filtration assembly comprises at least two MBR membrane filtration units. According to the invention, the defects of large occupied area, high manufacturing cost, low activated sludge concentration, low sewage treatment efficiency, low membrane flux recovery degree after MBR membrane cleaning and the like of the existing sewage treatment device are overcome; the MBR membrane filtration assembly is arranged in the sewage treatment tank, and the aeration washing assembly, the backwashing assembly, the water production assembly and the sludge discharge pump are connected into the sewage treatment tank and are controlled by the PLC, so that aeration, filtration, water production and backwashing are performed in the same sewage treatment tank; and the device has the advantages of standard water quality after treatment, small occupied area, low manufacturing cost, high activated sludge concentration, high sewage treatment efficiency, high membrane flux recovery degree after membrane cleaning and the like.

The invention provides a preparation process of a nanofiltration composite membrane, wherein the preparation process comprises the steps: firstly, compounding an aqueous phase solution on a non-woven fabric composite bottom membrane, and then compounding an oil phase solution to obtain a semi-finished product; performing heat treatment on the semi-finished product obtained in the step 1 through a drying oven, and controlling the membrane surface temperature of an outlet of the drying oven after heat treatment by adjusting the air speed and temperature of the drying oven to obtain the nanofiltration composite membrane, wherein the temperature of the membrane surface at the outlet of the drying oven is 20-30 DEG C. According to the preparation process, the membrane flux can be remarkably improved under the condition that the desalination rate of the composite nanofiltration membrane is not greatly reduced, and the problems that the water flux is generally low and the separation efficiency cannot be effectively improved in an existing NF membrane are effectively solved. Meanwhile, according to the preparation process provided by the invention, a reaction system is not greatly changed as much as possible, the variation of related matching parameters is small, the debugging period is short, the process application prospect is good, and the preparation process is more suitable for industrial production and application.

The invention belongs to the technical field of reverse osmosis membrane preparation, and particularly relates to an anti-pollution polyamide reverse osmosis membrane preparation method, which comprises: 1) taking a base membrane material, placing into a membrane casting solution solvent to prepare a membrane casting solution, adding an amine monomer during the preparation process, slowly adding an initiator and an additive, standing and defoaming at room temperature after complete dissolution, and preparing a base membrane through any one of slits and blade coating after coagulating bath; and2) soaking the base membrane in a polyamine solution, drying the surface of the membrane after soaking is finished, soaking the membrane in an organic solution containing trimesoyl chloride, taking out the membrane after reaction is finished, rinsing the membrane with pure water, and drying the membrane at the drying temperature of 40-100 DEG C to obtain the anti-pollution polyamide reverse osmosis membrane. The method is simple and easy to implement, the prepared reverse osmosis membrane has long-term stable pollution resistance, meanwhile, the structure of the polyamide membrane is optimized, the membrane flux is increased, the attenuation rate of the membrane flux is reduced, and the desalination effect is guaranteed.

The invention discloses a method for preparing a catechol-based hydrophilic modified organic tubular membrane, which comprises the following steps: soaking a membrane tube in pure water to obtain a completely infiltrated membrane tube; adding a catechol group-containing hydrophilic modifier and a silane coupling agent into a pH buffer solution to prepare a solution; and completely immersing the infiltrated membrane tube in the hydrophilic modifier solution, carrying out aeration treatment at the bottom of a hydrophilic modifier solution container to enable the hydrophilic modifier to be subjected to a full oxidation reaction, then conducting immersing in pure water to remove residues on the surface of the membrane tube, and conducting packaging to obtain a tubular membrane product. According to the method for hydrophilically modifying the organic tubular membrane through the catechol groups, the catechol group-containing hydrophilic modifier such as dopamine and tannic acid and the silane coupling agent are subjected to composite deposition on the surface of the membrane, so that the hydrophilicity of the membrane is improved, and the organic tubular membrane which is large in membrane flux, good in hydrophilicity and easy to clean is prepared. The method is simple to operate and easy for industrial production, improves the oil-water separation performance of partial material membranes, and expands the application range.

The invention relates to a preparation method of a high molecular ultra-filtration membrane. The preparation method specifically comprises the steps of adding a fusiform solid pore-forming agent into a high molecular basement membrane material solution for ultrasonic oscillation and dispersion; carrying out vacuum defoamation treatment to form a casting solution; consolidation-forming the casting solution to prepare a membrane; dissolving the pore-forming agent in the prepared membrane; and forming fusiform pores to obtain the high molecular ultra-filtration membrane with a fusiform micropore structure. When the liquid is separated and filtered, the flow resistance of the liquid in the micropores of the high molecular ultra-filtration membrane is small, the pressure loss is less, the membrane flux is high. The ultra-filtration membrane is especially suitable for treating thick liquid and has wide application value.

The invention discloses preparation of a carbon nanotube / polyaniline / polysulfone conductive ultrafiltration membrane and a membrane pollution online monitoring technology. With polysulfone as a film-forming material, and carbon nanotubes and polyaniline nanofibers as fillers, the carbon nanotube / polyaniline / polysulfone conductive ultrafiltration membrane is prepared by a blending method and immersion phase transformation. A polysulfone membrane itself is non-conductive, so with the addition of conductive material carbon nanotubes and polyaniline, not only are the flux, hydrophilicity, mechanical strength and other properties of the membrane improved, but also the electrical conductivity of the membrane is improved. The change of the membrane flux is reflected through the change of the membrane resistance, and a membrane pollution condition can be monitored in real time. The preparation method and process flow of the conductive ultrafiltration membrane are simple and easy to operate andlow in cost; the prepared membrane has excellent performance, the real-time monitoring method of the membrane pollution is sensitive and simple, the service life of the membrane is prolonged, and themembrane can be used in the industrial fields such as sewage treatment, protein separation and the like.

The invention belongs to the technical field of chemical engineering, and particularly relates to an ultrafiltration membrane cleaning agent and a cleaning method thereof. The invention provides an ultrafiltration membrane cleaning agent and a cleaning method thereof in order to effectively remove ultrafiltration membrane pollution retentate, recover membrane flux, reduce operation resistance andremarkably improve the cleaning effect. The cleaning agent comprises a component A and a component B, wherein the component A is an aqueous solution of sodium hydroxide and sodium hypochlorite, and the component B is an aqueous solution of citric acid. The cleaning method comprises the following steps of feeding the component A into an ultrafiltration membrane, carrying out circulating alkali washing, and then washing with water, and feeding the component B into an ultrafiltration membrane, carrying out cyclic acid washing, and washing with water again. The pressure at the operation inlet endof the ultrafiltration membrane device can be reduced to the maximum extent, the membrane flux is recovered, the cleaning period is prolonged, and a good cleaning effect is achieved.

The invention relates to a method for preparing a composite ultrafiltration membrane, and belongs to the technical field of water treatment. The composite ultrafiltration membrane is prepared by a sol-gel method. Silica and titanium dioxide are added to a casting solution, and the phase splitting process in the film formation process is controlled by means of the unique chain structure of the silica and the hydroxyl group on the surface thereof. The blending of nano titanium dioxide and a membrane material can enhance the hydrophilicity of the membrane, increase the membrane flux, improve theroughness of the membrane surface, delay membrane fouling, prolong the service life of the membrane, and reduce the operating cost of the membrane device. The porosity of the composite ultrafiltrationmembrane is gradually increased, and the water flux is gradually increased. A hydrogen bond may also be formed between polyvinylidene fluoride and cellulose micro / nano crystal, which enables the cellulose micro / nano crystal to be uniformly dispersed in a polyvinylidene fluoride solution, and have good interface bonding with the polyvinylidene fluoride, so that the composite membrane has certain strength and toughness, and thus the composite membrane exhibits good mechanical properties.

The invention relates to a preparation method of a pollution-resistant modified porous membrane, which utilizes C-Cl bonds in a vinylidene fluoride-chlorotrifluoroethylene copolymer and polyvinyl chloride polymer molecules to react with micromolecular monoamino hydrophilic compounds to realize functionalization of a membrane material so as to improve the pollution resistance and blood compatibility of the porous membrane. The method is simple in grafting reaction process, mild in reaction condition and easy to implement. Chemical grafting modification is adopted, the formed modified material cannot fall off from the membrane material, meanwhile, the problem that membrane holes are blocked due to conventional grafted macromolecules can be avoided, the membrane flux is not reduced, and the negatively charged or electrically neutral anti-pollution and high-blood-compatibility porous membrane can be obtained.

The invention provides a magnetic response oil-water separation membrane, a preparation method and a self-cleaning method thereof. The magnetic response oil-water separation membrane comprises a basemembrane and magnetic composite nanoparticles chemically grafted on the surface of the base membrane. The oil-water separation membrane provided by the invention can realize self-cleaning of the membrane surface by utilizing periodic transformation of an external magnetic field; meanwhile, the oil-water separation membrane provided by the invention can well prevent oil macromolecules from being incontact with a membrane contact channel to pollute pore channels, so that the oil-water separation membrane can keep a certain membrane flux and stable separation efficiency, and has a good application prospect.