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%.

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 thickener for dewatering fluids having a vessel with a central well extending proximate a top portion of the vessel to a lower cone-shaped portion, a hindered settling zone, and a compressible sediment layer zone within the lower cone-shaped portion. Eductors housed in inlet wells have an inlet nozzle and a mixing tube to receive slurry to be treated and clear fluid to be mixed with the slurry. The fluid from the eductors is directed in counter circular paths via circular chambers situated proximate the inlet wells, such that fluid flowing in each direction collides and forms turbulence within the central well. Resultant fluid is directed into a lamella-type separator circumferentially located about a portion of the central well, having layered fluid paths directed radially outwards from said center longitudinal axis and upwards towards said vessel top portion through a conical, inclined fluid path, plate structure. The eductors are adjustable with a movable iris for limiting the amount of clear fluid exiting the eductor.

A thickener for dewatering fluids having a vessel with a central well extending proximate a top portion of the vessel to a lower cone-shaped portion, a hindered settling zone, and a compressible sediment layer zone within the lower cone-shaped portion. Eductors housed in inlet wells have an inlet nozzle and a mixing tube to receive slurry to be treated and clear fluid to be mixed with the slurry. The fluid from the eductors is directed in counter circular paths via circular chambers situated proximate the inlet wells, such that fluid flowing in each direction collides and forms turbulence within the central well. Resultant fluid is directed into a lamella-type separator circumferentially located about a portion of the central well, having layered fluid paths directed radially outwards from said center longitudinal axis and upwards towards said vessel top portion through a conical, inclined fluid path, plate structure. The eductors are adjustable with a movable iris for limiting the amount of clear fluid exiting the eductor.

A method for producing a semiconducting SWCNT dispersion of the present invention comprises: a step A of preparing a to-be-separated SWCNT dispersion that includes a SWCNT mixture, an aqueous medium, and a polymer including a structural unit A derived from a monomer represented by Formula (1), and a step B of centrifuging the to-be-separated SWCNT dispersion and subsequently collecting a supernatant including the semiconducting SWCNT from the centrifuged to-be-separated SWCNT dispersion. The weight-average molecular weight of the polymer is 1,000 or more and 100,000 or less. ##STR00001##

A method for producing a semiconducting SWCNT dispersion of the present invention comprises: a step A of preparing a to-be-separated SWCNT dispersion that includes a SWCNT mixture, an aqueous medium, and a polymer including a structural unit A derived from a monomer represented by Formula (1), and a step B of centrifuging the to-be-separated SWCNT dispersion and subsequently collecting a supernatant including the semiconducting SWCNT from the centrifuged to-be-separated SWCNT dispersion. The weight-average molecular weight of the polymer is 1,000 or more and 100,000 or less. ##STR00001##

Improved methods for the removal of heavy metals, in particular cadmium, from an aqueous phosphoric acid containing composition, using an organothiophosphorous heavy metal precipitating agent to said composition, wherein the reaction between the heavy metals, in particular cadmium, and the organothiophosphorous precipitating agent is performed at a pH ranging between 1.6 and 2.0 measured after a 13-fold dilution by volume. Advantageously, an ionic polymer, particularly a cationic and/or an anionic poly(meth)acrylamide copolymer may be used to promote heavy metal precipitation and/or to facilitate the removal of the precipitates from the composition. More in particular, the phosphoric acid containing composition is obtained by the acid digestion of phosphate rock, preferably by nitric acid, sulfuric acid, or a combination thereof.

Improved methods for the removal of heavy metals, in particular cadmium, from an aqueous phosphoric acid containing composition, using an organothiophosphorous heavy metal precipitating agent to said composition, wherein the reaction between the heavy metals, in particular cadmium, and the organothiophosphorous precipitating agent is performed at a pH ranging between 1.6 and 2.0 measured after a 13-fold dilution by volume. Advantageously, an ionic polymer, particularly a cationic and/or an anionic poly(meth)acrylamide copolymer may be used to promote heavy metal precipitation and/or to facilitate the removal of the precipitates from the composition. More in particular, the phosphoric acid containing composition is obtained by the acid digestion of phosphate rock, preferably by nitric acid, sulfuric acid, or a combination thereof.

A process for obtaining soluble functional proteins from plant material includes the steps of: mechanically disrupting the cells of the plant material to obtain a mush stream; subjecting the mush stream to a coarse physical separation step, resulting in a permeate and a retentate; subjecting the permeate P.sub.b to mild treatment, resulting in a treated permeate; subjecting the treated permeate to serial centrifugation steps; subjecting centrate to a microfiltration step resulting in a permeate and a retentate; subjecting the permeate to an ultrafiltration step resulting in a permeate and a retentate; subjecting the retentate to hydrophobic column adsorption to provide a column permeate and a retentate; and drying the column permeate to provide a soluble functional protein isolate.

A process for obtaining soluble functional proteins from plant material includes the steps of: mechanically disrupting the cells of the plant material to obtain a mush stream; subjecting the mush stream to a coarse physical separation step, resulting in a permeate and a retentate; subjecting the permeate P.sub.b to mild treatment, resulting in a treated permeate; subjecting the treated permeate to serial centrifugation steps; subjecting centrate to a microfiltration step resulting in a permeate and a retentate; subjecting the permeate to an ultrafiltration step resulting in a permeate and a retentate; subjecting the retentate to hydrophobic column adsorption to provide a column permeate and a retentate; and drying the column permeate to provide a soluble functional protein isolate.