Lactic acid is obtained by a method including (A) a step of continuous fermentation wherein a fermentation culture medium of a microorganism having an ability of lactic acid fermentation is filtered through a porous membrane having an average pore size of not less than 0.01 μm and less than 1 μm with a transmembrane pressure difference within the range of 0.1 to 20 kPa, and the permeate is collected, while retaining the non-permeated liquid in or returning the non-permeated liquid to the culture, and adding a fermentation feedstock to the culture; (B) a step of filtering the permeate obtained in Step (A) through a nanofiltration membrane; and (C) a step of distilling the permeate obtained in Step (B) under a pressure of not less than 1 Pa and not more than atmospheric pressure, at 25° C. to 200° C. to recover lactic acid.

A thin film composite gas separation membrane comprising a polyether block amide copolymer coating layer and a nanoporous asymmetric support membrane with nanopores on the skin layer surface of the support membrane and gelatin polymers inside the nanopores on the skin layer surface of the support membrane. A method for making the thin film composite gas separation membrane is provided as well as the use of the membrane for a variety of separations such as separations of hydrogen sulfide and carbon dioxide from natural gas, carbon dioxide removal from flue gas, fuel gas conditioning, hydrogen/methane, polar molecules, and ammonia mixtures with methane, nitrogen or hydrogen and other light gases separations, but also for natural gas liquids recovery and hydrogen sulfide and carbon dioxide removal from natural gas in a single step.

A thin film composite gas separation membrane comprising a polyether block amide copolymer coating layer and a nanoporous asymmetric support membrane with nanopores on the skin layer surface of the support membrane and gelatin polymers inside the nanopores on the skin layer surface of the support membrane. A method for making the thin film composite gas separation membrane is provided as well as the use of the membrane for a variety of separations such as separations of hydrogen sulfide and carbon dioxide from natural gas, carbon dioxide removal from flue gas, fuel gas conditioning, hydrogen/methane, polar molecules, and ammonia mixtures with methane, nitrogen or hydrogen and other light gases separations, but also for natural gas liquids recovery and hydrogen sulfide and carbon dioxide removal from natural gas in a single step.

A porous electrospun polymeric nanofiber liquid filtration medium, such as an electrospun mats, used for the removal of viral particles (e.g., parvovirus) and other particles in the 18 nm to 30 nm size range from fluid streams, having a mean flow bubble point measured with perfluorohexane above 100 psi. The electrospun medium includes nanofibers having an average fiber diameter of about 6 nm to about 13 nm, and the nanofiber liquid filtration medium has a mean pore size ranging from about 0.01 μm to about 0.03 μm, a porosity ranging from about 80% to about 95%, a thickness ranging from about 1 μm to about 100 μm, and a liquid permeability greater than about 10 LMH/psi. The high porosity of the electrospun mats enable much higher water fluxes, thus reducing the time required to complete virus filtration steps on a fluid stream.

A porous electrospun polymeric nanofiber liquid filtration medium, such as an electrospun mats, used for the removal of viral particles (e.g., parvovirus) and other particles in the 18 nm to 30 nm size range from fluid streams, having a mean flow bubble point measured with perfluorohexane above 100 psi. The electrospun medium includes nanofibers having an average fiber diameter of about 6 nm to about 13 nm, and the nanofiber liquid filtration medium has a mean pore size ranging from about 0.01 μm to about 0.03 μm, a porosity ranging from about 80% to about 95%, a thickness ranging from about 1 μm to about 100 μm, and a liquid permeability greater than about 10 LMH/psi. The high porosity of the electrospun mats enable much higher water fluxes, thus reducing the time required to complete virus filtration steps on a fluid stream.

Described herein are mixed matrix filtration membranes and related, dendrimers, dendrimer particles, compositions, methods and systems and in particular mixed matrix filtration membranes with an embedded dendrimer particles and related compositions, methods, and systems wherein each dendrimer particle comprises at least two dendrimers each having at least two core chemical moieties having a core multiplicity Nc; branch cell units attached to the core chemical moiety or one to another, with the branch cell units attached one to another having a branch cells multiplicity Nb; and a number of surface functional groups Z presented on terminal branch cell units, wherein NcNb.sup.G with G≤3.

The present invention relates to an anti-fouling, semi-permeable membrane comprising a porous support layer, a thin film composite (TFC) layer formed on a surface of the support layer, and a cross-linked polyvinyl alcohol (PVA) layer formed on top of the TFC layer, wherein the cross-linked PVA layer is the reaction product of PVA and a cross-linking agent, said cross-linking agent being a polybasic acid comprising three or more acid groups or precursors thereof. The obtained membrane shows a high water flux and a low roughness suitable for an effective membrane notable for feed solution having a tendency of fouling the membrane.

The present invention relates to an anti-fouling, semi-permeable membrane comprising a porous support layer, a thin film composite (TFC) layer formed on a surface of the support layer, and a cross-linked polyvinyl alcohol (PVA) layer formed on top of the TFC layer, wherein the cross-linked PVA layer is the reaction product of PVA and a cross-linking agent, said cross-linking agent being a polybasic acid comprising three or more acid groups or precursors thereof. The obtained membrane shows a high water flux and a low roughness suitable for an effective membrane notable for feed solution having a tendency of fouling the membrane.

Zero liquid discharge systems, processes, and techniques for treating a saltwater without evaporative crystallization. The saltwater is treated by a fluidic circuit comprising a high-pressure reverse osmosis (“HPRO”) unit configured to operate at a hydraulic pressure of at least 1,500 psi, a cooling crystallizer, and a solids-liquid separator. The saltwater is first concentrated by the HPRO unit to produce an HPRO brine, which is subsequently cooled to a designated crystallization temperature by the cooling crystallizer. The cooling crystallizer crystallizes salt crystals from the cooled HPRO brine and produces a salt-diminished brine. The solids-liquid separator separates the salt-diminished brine from the salt crystals. The salt-diminished brine from the solids-liquid separator is returned to the HPRO unit for further treatment, which allows additional salts to be crystallized from the returned salt-diminished brine.

A polyamide (PA) nanofiltration (NF) membrane and a preparation method thereof by regeneration from a scrapped microfiltration (MF) membrane are provided. The method adopts a cleaning-repairing-interfacial polymerization upgrading strategy, where, sodium hypochlorite and oxalic acid are used for deeply cleaning a scrapped MF membrane. PDA is used as a repairing agent to construct a reaction platform on the membrane surface, and finally a reaction system of piperazine and trimesoyl chloride (TMC) are used to form a PA NF membrane with a PA active layer. The repairing can construct a coating with a given thickness and prominent hydrophilicity on the membrane surface, which provides favorable base membrane conditions for upgrading and preparing an NF membrane.