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.

A separator for an electrochemical deionization cell for removing ions from a solution stream. The separator includes an anion exchange membrane layer formed from an anion exchange membrane material. The anion exchange membrane layer has a first surface and an opposing second surface. The separator further includes a porous layer adjacent to the anion exchange membrane layer and formed from a porous material. The porous layer has a first surface and an opposing second surface. The first surface of the porous layer is adjacent to the first surface of the anion exchange membrane layer.

Water purification systems including an inlet chamber, a purification module, a purified water outlet, and an impure water outlet. The inlet chamber is configured to receive an input water stream. The purification module includes a purification chamber configured to divide the input water stream into a purified water stream fluidly coupled to the purified water outlet and an impure water stream fluidly coupled to the impure water outlet. The purification chamber includes a first hydrophilic surface and a second hydrophilic surface spaced from the first hydrophilic surface. The first hydrophilic surface and the second hydrophilic surface cooperate to establish purified zones of substantially pure water and an impure zone of impurity concentrated water from the input water stream. The purified water stream is supplied by substantially pure water from the purified zones and the impure water stream is supplied by the impurity concentrated water from the impure zone.

A solvent extraction process for desalination of seawater. The process uses a special class of polar organic solvents to preferentially dissolve salt-free water from salty water, which exhibits a reverse solubility-temperature behavior (i.e., the solubility of water in the solvent is high at room temperature but significantly lower at higher temperatures). The desalination process includes adding these special class of solvents to sea or salty water at room temperature, separating the solvent-water phase (organic phase) from the remaining mass of salt-rich water (aqueous phase), heating the solvent-water phase to a higher temperature and recovering the relatively salt-free water that separates out. The process is simple, fast, ecologically safe and energy efficient.

Provided are electrodialysis systems comprising a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices has a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream. The product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device. Further, a first portion of a feed stream is the brine inlet stream for the first electrodialysis device and a second portion of the feed stream is the brine inlet stream for the second electrodialysis device or a third electrodialysis device.

Plasma discharges and electromagnetic fields may be applied to a liquid, such as water, for desalinization purposes and to treat unwanted material in the liquid.

A novel Salt Repellent Technique is presented to remove all inorganic salts from seawater to get potable water. The repellent additives recommended throws out all salts of sodium, magnesium, calcium, potassium and the like ions from seawater and paves way to get salt free potable water. The conventional washing of ice crystals is completely avoided due to the presence of additives. This technique helps to remove last traces of salts from seawater and analogous waters, without undertaking the conventional washing process. The new salt repellent process assures of high water recovery, ease of operation, lesser pollution, smaller plants, simpler machinery and technology, lower energy cost, nil or lesser pre-treatment and recovery of valuable by-products. To reduce the TDS still lower, it is recommended to have a simplified reverse osmosis unit in addition, as a post-operative arrangement.

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.

A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.