The invention a solvent-resistant polymeric nanofiltration membrane and preparation method thereof. The method includes subjecting a diamine monomer and a dianhydride monomer to cyclization imidization in a first polar organic solvent at 160 to 230° C., to form a polyimide, wherein the diamine monomer includes a diamine monomer with a carboxyl group and a diamine monomer without a carboxyl group; dissolving the polyimide in a second polar organic solvent, to form a membrane-forming solution; performing phase inversion to obtain an intermediate membrane; treating the intermediate membrane with an organic solution of a metal salt, so that the metal ion is coordinated and cross-linked with the carboxyl group in the polyimide, to obtain a solvent-resistant polymeric nanofiltration membrane, wherein the metal salt is a divalent and/or a multi-valent metal salt. The invention also discloses use of the solvent-resistant polymeric nanofiltration membrane in the separation and/or purification of a compound.

The invention relates to the field of industrial wastewater treatment, and particularly discloses a nanofiltration membrane for treating printing and dyeing wastewater and its preparation method. The preparation method comprises the following steps: S1, pouring an aqueous solution containing m-phenylenediamine, camphorsulfonic acid and triethylamine onto the surface of a polysulfone ultrafiltration membrane, setting still for 10 s to 30 s, and then removing the excess aqueous solution from the surface; S2, pouring an organic solution containing trimesoyl chloride and an interface auxiliary polymerization agent onto the surface of the membrane obtained in step S1, reacting for 5 s to 20 s, and then removing the excess solution from the surface; and S3, setting the membrane obtained in step S2 still and then carrying out heat treatment and water rinsing on the membrane in sequence, thus obtaining the nanofiltration membrane.

The present invention relates to the separation and isolation of sialylated human milk oligosaccharides (HMOs) from the reaction mixture in which they are produced.

A water purification filter element is provided. The water purification filter element may include a filter bottle, a filter material, an end cover, and a water self-stopping and passing structure.

The disclosed technology includes a membrane-based device configured to concentrate black liquor, which results from papermaking. Certain embodiments may comprise a nanofiltration membrane configured to remove lignin from black liquor, and the nanofiltration membrane may include a first macroporous polymer substrate and a first graphene oxide membrane covering the first macroporous polymer substrate. Some embodiments may comprise a reverse osmosis membrane, which may include a second macroporous polymer substrate and a second graphene oxide membrane covering the second macroporous polymer substrate.

A method of obtaining a compound may include adding a substrate to a medium in a reactor, and reacting the substrate in the reactor to form the compound. A first stream is separated from the reaction liquid through a first membrane. A second stream is separated from the reaction liquid through a second membrane. The first membrane is a filtration membrane and the second membrane is configured for liquid-gas or liquid-liquid extraction The first membrane and the second membrane are at least partially immersed in the medium and are moved relative to the reactor during the separation steps.

A method and system is provided for treating waste generated from manufacturing operations including at least one of Printed Circuit Boards Fabrication (PCB FAB), General Metal Finishing (GMF), semiconductors manufacturing, chemical milling, and Physical Vapour Deposition (PVD). The method and system are used to create zero liquid discharge recycling.

The present invention relates to a chemical product and process for cleaning nanofiltration and reverse osmosis membranes, based on enzymatic action aiming to remove biofouling and inorganic scale quickly. The product mentioned in present invention also proposes elimination of the neutralization step of the chemical product used, given that the enzymatic action allows an adequate pH for disposal to be maintained, which fact increases the speed and efficiency of the process.

The present invention relates to the separation and isolation of neutral human milk oligosaccharides (HMOs) from the reaction mixture in which they are produced.

An online cleaning system for micro-polluted nanofiltration membranes uses forward osmosis, and a process of the online cleaning system, and relates to the field of water treatment membrane separation technique. The online cleaning system includes a nanofiltration raw water tank, a nanofiltration membrane assembly, a pure water tank, a forward osmosis feed solution tank, a forward osmosis draw solution tank, a first saline water tank, a second saline water tank and a water bath temperature control device. Compared with convention techniques, some embodiments include efficient cleaning of the nanofiltration membranes that is realized by using forward osmosis as a nanofiltration membrane cleaning system, and cyclic regeneration of the nanofiltration membranes can be realized, so that the purposes of removing dissolved organic matters in micro-polluted raw water, reducing hardness of calcium and magnesium and prolonging the service life can be achieved.