The disclosure relates to a method for separation and purification of N-acetyl-glucosamine, and belongs to the technical field of biological engineering. In the disclosure, a raw material solution containing N-acetyl-glucosamine is obtained by microbial fermentation or by hydrolyzing the chitin. The raw material solution is subjected to flocculation pretreatment, and continuous centrifugation or pressure filtration is performed to remove suspended solids such as microorganisms, proteins and polysaccharides to obtain clear liquid. Double-stage ion exchange chromatography is performed to remove impurities such as charged organic molecules and inorganic salts. Membrane concentration is performed to efficiently remove water to improve the concentration of the target product. Spray drying or further evaporation concentration and crystallization are performed. Finally drying is performed to obtain an N-acetyl-glucosamine crystal of which the purity is more than 99%.

A submerged water purification system including a plurality of spiral wound hyperfiltration membrane modules each connected in a parallel flow arrangement to a common feed manifold and a common permeate manifold; wherein each module includes at least one feed spacer sheet and one membrane envelop wound about a permeate collection tube having a plurality of openings along its length that are in fluid communication with the membrane envelop, and further including an end cap secured to an end of the module with a manifold junction reversibly connected to the end cap of each module, wherein the manifold junction provides a sealed fluid communication between the feed spacer sheets and permeate collection tubes of each module to the feed manifold and permeate manifold, respectively.

A submerged water purification system including a plurality of spiral wound hyperfiltration membrane modules each connected in a parallel flow arrangement to a common feed manifold and a common permeate manifold; wherein each module includes at least one feed spacer sheet and one membrane envelop wound about a permeate collection tube having a plurality of openings along its length that are in fluid communication with the membrane envelop, and further including an end cap secured to an end of the module with a manifold junction reversibly connected to the end cap of each module, wherein the manifold junction provides a sealed fluid communication between the feed spacer sheets and permeate collection tubes of each module to the feed manifold and permeate manifold, respectively.

A water desalination system includes a first set of ultrafiltration membranes, a second set of ultrafiltration membranes, a first backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with brine generated by a reverse osmosis process, and a second backwashing system configured to treat at least one of the first set of ultrafiltration membranes or the second set of ultrafiltration membranes with one or more chemicals and reverse osmosis permeate water.

A method of removing contaminants from an aqueous material, the method comprising the steps of: providing an aqueous material comprising one or more non-particulate contaminants; and filtering the aqueous material to remove at least part of the one or more non-particulate contaminants to form a recovered portion of the aqueous material in which the amount of contaminant is reduced to an amount allowing re-use of the recovered portion of the aqueous material, wherein filtering the aqueous material includes passing the aqueous material across a partially permeable membrane at a temperature higher than 50° C.

A device for obtaining protein-enriched fractions from human or animal milk comprises a delipidating unit for reducing a lipid content in the human or animal milk to obtain delipidated milk and a filtering unit for increasing a protein concentration of the delipidated milk to obtain the protein-enriched fraction, comprising a replaceable filter having a nominal molecular weight limit of 2 kDa or more, in particular of 5 kDa or more.

A filter medium of the present invention includes a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a volume of fine pores by a BJH method of 0.3 cm.sup.3/g or more, and a particle size of 75 μm or more, alternatively, a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a total of volumes of fine pores having a diameter of from 1×10.sup.−9 m to 5×10.sup.−7 m, obtained by a non-localized density functional theory method, of 1.0 cm.sup.3/g or more, and a particle size of 75 μm or more.

A filter medium of the present invention includes a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a volume of fine pores by a BJH method of 0.3 cm.sup.3/g or more, and a particle size of 75 μm or more, alternatively, a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a total of volumes of fine pores having a diameter of from 1×10.sup.−9 m to 5×10.sup.−7 m, obtained by a non-localized density functional theory method, of 1.0 cm.sup.3/g or more, and a particle size of 75 μm or more.

The invention is about a stabilized electromagnetic base liquid, as well as its preparation method and its application in the high-salt wastewater treatment. The raw material components of the electromagnetic base fluid include: 20-30 parts of alkali metal hydroxides(e.g., as sodium hydroxide); 20-30 parts of non-alkali metal (e.g., as silicon or phosphorus); 2-6 parts of ammonia; 31-140 parts of water; after treatment with a direct electrical current the parameters of the stabilized electromagnetic base liquid are: pH value: 12 to 14; oxidation reduction potential value: −1.0 to −1.8 v; with no corrosivity, confirming the presence of stabilized hydrated electrons (e.sub.aq−−). With the stabilized electromagnetic base liquid, the storage problem of the electromagnetic base liquid is solved, and the large-scale application in the industrial field can be realized, thereby achieving a large-scale high-salt wastewater treatment process with low cost, high recovery rate.

A ultrapure water supply system 10 includes a pure water tank 16 provided vertically below a use point 30, a return pipe 32 through which ultrapure water is returned from the use point 30 to the pure water tank 16, a first pressure regulating valve 40 that is provided at a first position H1 of the return pipe 32 and adjusts a first pressure upstream of the first position H1 and a second pressure regulating valve 42 that is provided at a second position H2 downstream of the first position H1 and vertically below the first position H1 of the return pipe 32 and adjusts a second pressure downstream of the first position H1 and upstream of the second position H2.