The forward osmosis membrane and the preparation method thereof provided by the present invention, through fully cover the support mesh layer of the membrane with antibacterial nanoparticles, especially the mixture of nano-Ag and nano TiO2, ensures without reducing the strength, water flux and salt rejection, providing an effective, long-term and comprehensive antibacterial effect. In the present invention, the antibacterial nanoparticles, especially the mixture of nano-Ag and nano-TiO2, are used to carry out antibacterial modification on the support mesh of the forward osmosis membrane, so as to inhibit the growth of bacteria on the forward osmosis membrane, improves the forward osmosis and also improves the safety of the entire purification and filtration system. The antibacterial forward osmosis membrane of the present invention can be applied to the filtration and purification of complex water sources, especially the purification and filtration of eutrophic and bacteria-prone water sources.

Disclosed herein is a forward osmosis module for concentration and/or crystallization salts from an aqueous feed solution, the feed solution including seeds that surround an open semi-permeable membrane having free membrane portions forming an enclosure with a distribution pipe that introduces draw solution inside said enclosure. The feed solution penetrates into the enclosure as permeate from the feed side of the membrane to the draw solution side according to a Forward Osmosis process based on net driving pressure. The draw solution with permeate is evacuated from the enclosure via an outlet. A generator applies, at least periodically, a plurality of directional gauge pressure strokes PGs, directed from at least one of the draw solution inlet and outlet thereby effecting mechanical shaking of the free membrane portions for detachment of foulant.

The high water recovery hybrid membrane system for desalination and brine concentration combines nanofiltration, reverse osmosis and forward osmosis to produce pure water from seawater. The reject side of a nanofiltration unit receives a stream of seawater and outputs a brine stream. A permeate side of the nanofiltration unit outputs a permeate stream. A feed side of a reverse osmosis desalination unit receives a first portion of the permeate stream and outputs a reject stream. A permeate side of the reverse osmosis desalination unit outputs pure water. A draw side of at least one forward osmosis desalination unit receives the reject stream and outputs concentrated saline solution. A feed side of the at least one forward osmosis desalination unit receives a second portion of the permeate stream and outputs a dilute saline stream, which mixes with the first portion of the permeate stream fed to the reverse osmosis desalination unit.

An ocean alkalinity enhancement (OAE) system that reduces atmospheric CO.sub.2 and mitigates ocean acidification by electrochemically processing feedstock solution (e.g., seawater or brine) to generate an alkalinity product that is then supplied to the ocean. The OAE system includes a base-generating device and a control circuit disposed within a modular system housing deployed near a salt feedstock. The base-generating device (e.g., a bipolar electrodialysis (BPED) system) generates a base substance that is then used to generate the ocean alkalinity product. The control circuit controls the base-generating device such that the alkalinity product is supplied to the ocean only when (1) sufficient low/zero-carbon electricity is available, (2) it is safe to operate the base-generating device, and (3) supplying the alkalinity product will not endanger sea life. Modified BPED systems include features that facilitate autonomous system operations including enhanced maintenance cycle operations and a reduced reliance on external fresh water sources.

A method for synthesizing a water purification membrane is presented. The method includes stacking a plurality of graphene oxide (GO) nanosheets to create the water purification membrane, the stacking involving layer-by-layer assembly of the plurality of GO nanosheets and forming a plurality of nanochannels between the plurality of GO nanosheets for allowing the flow of a fluid and for rejecting the flow of contaminants. The method further includes cross-linking the plurality of GO nanosheets by 1,3,5-benzenetricarbonyl trichloride on a polydopamine coated polysulfone support.

A method for synthesizing a water purification membrane is presented. The method includes stacking a plurality of graphene oxide (GO) nanosheets to create the water purification membrane, the stacking involving layer-by-layer assembly of the plurality of GO nanosheets and forming a plurality of nanochannels between the plurality of GO nanosheets for allowing the flow of a fluid and for rejecting the flow of contaminants. The method further includes cross-linking the plurality of GO nanosheets by 1,3,5-benzenetricarbonyl trichloride on a polydopamine coated polysulfone support.

There is provided a thin film composite (TFC) hollow fibre membrane comprising a porous hollow fibre support layer formed of a polymer and a selective layer, formed of a cross-linked polyamide, on an inner circumferential surface of the hollow fibre support layer, wherein the TFC hollow fibre membrane has a power density of 25-50 W/m.sup.2 at a pressure of 30 bar. There is also provided a method of forming the TFC hollow fibre membrane.

A water purifier capable of stably discharging residual water from an extraction unit is disclosed. The water purifier (100) comprises: a filter unit (110) having a reverse osmosis membrane filter (113) for filtering incoming water; an extraction unit (160) for providing purified water filtered by the filter unit (110) to a user; and a residual water drainage unit (150) configured to drain, through the reverse osmosis membrane filter (113), residual water remaining in the extraction unit (160), by using an osmotic phenomenon of the reverse osmosis membrane filter (113) after completion of the extraction through the extraction unit (160).

A method of recovering draw agent utilised in a forward osmosis membrane cell, the method comprising the steps of passing diluted draw agent to a vapour-liquid separator; using the vapour-liquid separator to separate draw agent vapour and solvent; and condensing draw agent vapour.

An ultra high molecular weight polyethylene (UHMWPE) membrane has at least one nanoporous UHMWPE film, where each of the nanoporous UHMWPE film is biaxial oriented with a thickness of 0.1 to 12 μm and pores that exclude particles in excess of 10 nm with a total porosity of 65 to 75 percent. The nanoporous UHMWPE film can be coated or laminated by a hydrophilic polymer to form a Janus membrane and can be made with a multilayer composite structure. The UHMWPE membrane can be used in a device for molecular distillation (MD), reverse osmosis (RO), or forward osmosis (FO).