Improved integrally skinned asymmetric membranes for organic solvent nanofiltration, and their methods of preparation and use are disclosed. Membranes are formed from polybenzimidazoles by phase inversion and are then crosslinked by addition of crosslinking agents. These stabilise the membranes and allow solvent nanofiltration to be maintained even in the solvents from which the membranes were formed by phase inversion, and in strongly acidic and strongly basic solvents.

The present invention relates to porous hollow fiber membranes suitable for hemodialysis, hemodiafiltration or hemofiltration of blood and processes for their production involving UV irradiation of the membrane.

A membrane supported biofilm apparatus has a plurality of hollow fiber gas permeable membranes in a tank containing water to be treated. A biofilm supported on the membranes occupies between about 40% and 80% of the volume of water to be treated in a reactor. Wastewater treatment processes are described. A process to denitrify water or treat oxidized contaminants comprises introducing hydrogen into an inner volume of the membranes to grow autotrophic organisms in the biofilm near the membrane and heterotrophic organism near the water. Another process is operated as a biomass concentration of at least 10 g/L and up to about 40 g/L to maintain a biofilm having a surface area of over 1000 square meters per cubic meter of tank volume. A hybrid process has suspended biomass and a membrane supported biofilm.

A thin film composite membrane including a thin film polyamide layer positioned between a porous support and an outer coating, and a humectant; wherein the membrane has an A-value of at least 8 l/m.sup.2 hr/bar when tested at 25 l/m.sup.2 hr with pure water at 25 C. for one hour, and wherein the outer coating comprises a dissolvable cellulose polymer provided at coverage of at least 10 mg/m.sup.2 that substantially dissolves from the membrane after one hour of continuous cross-flow of water at 25 l/m.sup.2 hr and 25 C.

Disclosed in the present disclosure is a preparation method for a chelating membrane for purifying wet electronic chemicals, including the following steps: performing hydrophilic treatment on a porous PTFE membrane to obtain a hydrophilic base membrane; sequentially cleaning a chelating resin with a hydrochloric acid solution, a sodium hydroxide solution and deionized water, and then drying; grinding and sieving the cleaned and dried chelating resin to obtain a powder; mixing the powder with polyisobutylene and a polyhexafluoroethylene emulsion, and performing vacuum defoaming to form a membrane coating solution; coating the hydrophilic base membrane with the membrane coating solution to prepare a chelating membrane; and sequentially washing the chelating membrane with a hydrochloric acid solution, a sodium hydroxide solution and pure water until the chelating membrane is neutral, and then drying and storing the chelating membrane.

Disclosed in the present disclosure is a preparation method for a chelating membrane for purifying wet electronic chemicals, including the following steps: performing hydrophilic treatment on a porous PTFE membrane to obtain a hydrophilic base membrane; sequentially cleaning a chelating resin with a hydrochloric acid solution, a sodium hydroxide solution and deionized water, and then drying; grinding and sieving the cleaned and dried chelating resin to obtain a powder; mixing the powder with polyisobutylene and a polyhexafluoroethylene emulsion, and performing vacuum defoaming to form a membrane coating solution; coating the hydrophilic base membrane with the membrane coating solution to prepare a chelating membrane; and sequentially washing the chelating membrane with a hydrochloric acid solution, a sodium hydroxide solution and pure water until the chelating membrane is neutral, and then drying and storing the chelating membrane.

The disclosure provides a solvent resistant polyimide/polyethyleneimine@titanium dioxide nanohybrid ultrafiltration membrane with high solvent permeability and a preparation method thereof. The preparation method comprises the following steps: dissolving a titanium dioxide precursor Ti-BALDH and polyimide into N-methylpyrrolidone to prepare a casting solution, then coating on the non-woven fabric, and preparing the solvent resistant nanohybrid polyimide membrane in one step through a non-solvent induced phase separation-interface crosslinking-in-situ biomimetic mineralization coupling method. According to the disclosure, a solvent resistant polyimide/polyethyleneimine@TiO.sub.2 nanohybrid ultrafiltration membrane (PEIPI@TiO.sub.2) with high solvent permeability prepared through a simple non-solvent induced phase separation-interface chemical crosslinking-in-situ bionic mineralization coupling method.

The invention provides a preparation method for a reverse osmosis membrane resistant to a high-temperature water environment, comprising: synthesizing an -cyclodextrin@polyethylene glycol supramolecular inclusion complex by a saturated aqueous solution coprecipitation method; preparing an aqueous phase solution containing m-phenylenediamine, D(+) camphorsulfonic acid and triethylamine; preparing an oil phase solution containing trimesoyl chloride; preparing a secondary aqueous solution containing -cyclodextrin@polyethylene glycol powder and triethylamine; forming an ultrathin polyamide separation layer on a base membrane by interfacial polymerization; and performing secondary interfacial polymerization to form an -CD@PEG polyester protection layer, and storing a prepared reverse osmosis membrane in ultrapure water.

The present invention is related to an osmosis membrane, specifically to a modified forward osmosis membrane and the method of preparing same. The inventive forward osmosis membrane has a modified membrane structure including a hydrophilic support mesh and a hydrophilic polymer membrane layer mixed antioxidant. The hydrophilic polymer membrane layer with antioxidant not only has high salt rejection, but also ensures high oxidation resistance under a strong oxidation environment, and can be used safely and stably. The inventive oxidation resistant forward osmosis membrane has the advantages of improving the efficiency of purifying and separating water, extending the service life, significantly reducing the operation cost of the forward osmosis membrane system. The inventive forward osmosis membrane can be applied in the industries of treatment of strong oxidation waste water, water purifying, filtration and purification of food and medicine filtering and so on.

A method of preparing a polyamide membrane with multi-level pore structure mediated by protein fiber network includes the steps of: preparing protein fiber; quenching and carrying out dialysis; loading protein fiber network on ultrafiltration membrane; preparing aqueous and organic phase solutions; and carrying out interfacial polymerization, which can solve the problems of the integrity and separation performance of the polyamide layer being affected by low porosity of the base membrane and uneven distribution of amine monomers. The polyamide membrane prepared by the method of the present invention greatly improves the water flux while ensuring a high salt rejection rate. At the same time, the introduction of the protein fiber network also enhances the mechanical strength and anti-pollution ability of the membrane.