This specification describes membrane based filtration and softening systems and methods. A system has a microfiltration or ultrafiltration (MF/UF) membrane unit upstream of a nanofiltration or reverse osmosis (NF/RO) membrane unit, optionally with no intermediate tank. In some cases, the system and method may be used with feed water provided at municipal line pressure to the membranes. NF/RO permeate is collected in a tank and then pumped to a header. Treated water may be drawn from the header for use or recycled to the system, for example to backwash or flush one or both of the membrane units. In a combined process, NF/RO permeate flushes the feed side of the NF/RO unit and then backwashes the MF/UF unit. In another process, the MF/UF unit and NF/RO unit are filled with NF/RO permeate before being placed in a standby mode.

A method for preparing a nanofiltration membrane and a nanofiltration membrane prepared therefrom, the method comprising the following steps: dissolving a polymer in a solvent to prepare a polymer solution, and curing the polymer solution on a support material to form a base membrane; sequentially applying a first liquid-phase solution and a second liquid-phase solution on the base membrane to form a nascent membrane; densifying the nascent membrane by using a solution that contains an alkaline substance; processing the densified nascent membrane by using a solution that contains an acidic substance; and obtaining the nanofiltration membrane after post-processing and drying.

A plasma activated water production system includes a plasma reactor and a membrane concentrator. The plasma reactor includes an internal cavity, at least one electrically-conductive inlet capillary and outlet capillary. A mixing chamber has a feed gas inlet, a liquid inlet, and a mixed gas and liquid outlet. A power source is provided. The plasma reactor propagates a plasma discharge between the inlet capillary and the outlet capillary. A membrane concentrator includes a water flow channel with a water inlet and a water outlet, a dry gas inlet and a humidified gas outlet. An ion selective membrane is provided, and water will pass through the membrane into the dry gas, and the water leaving the membrane concentrator will have increased concentrations of nitrates, nitrites and hydrogen peroxide. An electrodialysis embodiment and a method of generating plasma activated with increased concentration of nitrates, nitrites and hydrogen peroxide are also disclosed.

A spiral wound membrane module has a brackish water RO or NF membrane combined with a permeate carrier having a narrow spacing between membrane contacting elements. The membrane may have water permeability (A-Value) of at least 8*10.sup.−5 cm/s/bar at 25° C. The membrane may have salt diffusion rate (B-Value) of at least 0.5*10.sup.−5 cm/s at 25° C. The permeate carrier may have a density of 54 wales per inch or more of a gap between adjacent ribs of 215 um or less. The permeate carrier may have a channel cross-sectional area of 16*10.sup.−9 m.sup.2 or more. Water is fed to the module at a high feed pressure, for example a pressure of at least 50 bar, optionally up to 120 bar. Retentate may be discharged at a concentration of 100 g/L, 130 g/L, or 150 g/L or more.

A system for generating electricity, heat, and desalinated water having a gas turbine system connected to a first electric generator, a waste heat recovery boiler (WHRB) system, a combined heat and power (CHP) generation system connected to a second electric generator, one or more solar powered energy systems, and a desalination system. The desalination system is connected to the CHP generation system and the WHRB system. The gas turbine system generates electricity and heat, the WHRB system is connected to and uses the exhaust of the gas turbine system to provide heat and steam power to the CHP generation system. The CHP generation system produces and provides electricity and heat to the desalination system, which produces product water, and at least one solar powered energy system provides thermal energy to one or more of the gas turbine system, the WHRB system, the CHP generation system, and the desalination system.

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.

Provided are methods, devices, and kits for the isolation of extracellular vesicles using silicon nanomembranes. A method for EV isolation includes the steps of collecting a biofluid sample, contacting the biofluid sample with a pre-filtration membrane, thereby forming a first filtrate and a first retentate, optionally, washing the first retentate of the pre-filtration membrane, contacting the first filtrate from the pre-filtration membrane with a capture membrane, thereby forming a second filtrate and a second retentate, optionally, washing the second retentate, and eluting the second retentate from the capture membrane or lysing the second retentate to recover the contents.

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.

A water filter cartridge includes a sediment filter, a carbon filter, and a core having a tubular body with openings that allow water to flow through the core. The core defines an open central area, and the core supports the sediment filter and the carbon filter. A nanofiltration unit is arranged within the open central area of the core. The nanofiltration unit includes a tubular filter element defining a central volume, and a plurality of filaments arranged within the central volume.

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%.