This invention relates to uses of graphene oxide, and in particular graphene oxide on a porous support, and a membrane comprising these materials. This invention also relates to methods of dehydration, which include vapour phase separation and pervaporation. Pervaporation is a method of separating mixtures of liquids using a membrane. Pervaporation consists of two basic steps: permeation of the permeate through the membrane and evaporation of the permeate from the other side of the membrane. Pervaporation is a mild which can be used to separate components which would not survive the comparatively harsh conditions needed for distillation (high temp, and/or low pressure).

The present invention discloses high selectivity copolyimide membranes for gas, vapor, and liquid separations. Gas permeation tests on these copolyimide membranes demonstrated that they not only showed high selectivity for CO.sub.2/CH.sub.4 separation, but also showed extremely high selectivities for H.sub.2/CH.sub.4 and He/CH.sub.4 separations. These copolyimide membranes can be used for a wide range of gas, vapor, and liquid separations such as separations of CO.sub.2/CH.sub.4, He/CH.sub.4, CO.sub.2/N.sub.2, olefin/paraffin separations (e.g. propylene/propane separation), H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, iso/normal paraffins, polar molecules such as H.sub.2O, H.sub.2S, and NH.sub.3 mixtures with CH.sub.4, N.sub.2, H.sub.2. The high selectivity copolyimide membranes have UV cross-linkable sulfonyl functional groups and can be used for the preparation of UV cross-linked high selectivity copolyimide membranes with enhanced selectivities. The invention also includes blend polymer membranes comprising the high selectivity copolyimide and polyethersulfone. The blend polymer membranes comprising the high selectivity copolyimide and polyethersulfone can be further UV cross-linked under UV radiation.

An organic solvent purification system that separates an organic solvent having a boiling point of more than 100 C. at 1 atm, such as N-methyl-2-pyrrolidone (NMP), from a liquid mixture containing the organic solvent and water and purifies the organic solvent includes: a heater that heats the liquid mixture; a pervaporation apparatus that includes a pervaporation membrane, and is provided at subsequent position of the heater, the pervaporation apparatus separating the organic solvent from the water; a vacuum evaporator to which the organic solvent collected from a concentration side of the pervaporation apparatus is supplied; and piping that supplies the heater with the organic solvent vaporized in the vacuum evaporator as a heat source of the heater. The heater heats the liquid mixture using concentration heat of the organic solvent vaporized by the vacuum evaporator.

A system and method for passive capture of ammonia in an ammonia-containing liquid effluent. The invention allows for the passage of ammonia through microporous hydrophobic gas-permeable membranes and its capture in a circulated stripping solution with concomitant production of a concentrated non-volatile ammonium salt.

This disclosure provides water processing apparatuses, systems, and methods for recovering water from wastewater such as urine. The water processing apparatuses, systems, and methods can utilize membrane technology for extracting purified water in a single step. A containment unit can include an ionomer membrane, such as Nafion, over a hydrophobic microporous membrane, such as polytetrafluoroethylene (PTFE). The containment unit can be filled with wastewater, and the hydrophobic microporous membrane can be impermeable to liquids and solids of the wastewater but permeable to gases and vapors of the wastewater, and the ionomer membrane can be permeable to water vapor but impermeable to one or more contaminants of the gases and vapors. The containment unit can be exposed to a dry purge gas to maintain a water vapor partial pressure differential to drive permeation of the water vapor, and the water vapor can be collected and processed into potable water.

An organic solvent purification system that separates an organic solvent having a boiling point of more than 100 C. at 1 atm, such as N-methyl-2-pyrrolidone (NMP), from a liquid mixture containing the organic solvent and water and purifies the organic solvent includes: a heater that heats the liquid mixture; a pervaporation apparatus that includes a pervaporation membrane, and is provided at subsequent position of the heater, the pervaporation apparatus separating the organic solvent from the water; a vacuum evaporator to which the organic solvent collected from a concentration side of the pervaporation apparatus is supplied; and piping that supplies the heater with the organic solvent vaporized in the vacuum evaporator as a heat source of the heater. The heater heats the liquid mixture using concentration heat of the organic solvent vaporized by the vacuum evaporator.

Presented herein are membranes for use in separating solids including salts from water. One application of such membranes is in a sub-surface irrigation system that that utilizes a saline or tainted water as a feed source. In various embodiments, the membranes operate on a solution diffusion principle. In other embodiments the membranes operate on an ultrafiltration principle and/or a solution diffusion principle. In any embodiment, the membranes operate similar to pevaporation membranes suitable for non-pressure driven systems. The membranes are designed to provide increased flux rate while separating solids such as salts from water.

According to one embodiment, a water treatment method is a method configured to use a working medium that includes a draw solution and a water-containing solution to be treated. The draw solution is a hyperosmotic solution which generates an osmotic pressure difference with water. The method includes generating a flux of a mixture of water and a draw solution by an osmotic pressure difference generated between a solution to be treated and the draw solution in an osmotic pressure generator compartmentalized by an osmosis membrane, transferring the flux of the mixture to a vaporization-separation unit, separating the mixture into the water and the draw solution by a pressure difference, and recycling the draw solution separated by the vaporization-separation unit.

Disclosed herein is a method and apparatus that uses a brine from a well that is used to both generate electricity and recover valuable minerals present in the brine. The method and apparatus uses a hydrophobic membrane to separate water vapor from the brine to concentrate the brine that is then used to recover the minerals.

This disclosure provides water processing apparatuses, systems, and methods for recovering water from wastewater such as urine. The water processing apparatuses, systems, and methods can utilize membrane technology for extracting purified water in a single step. A containment unit can include an ionomer membrane, such as Nafion, over a hydrophobic microporous membrane, such as polytetrafluoroethylene (PTFE). The containment unit can be filled with wastewater, and the hydrophobic microporous membrane can be impermeable to liquids and solids of the wastewater but permeable to gases and vapors of the wastewater, and the ionomer membrane can be permeable to water vapor but impermeable to one or more contaminants of the gases and vapors. The containment unit can be exposed to a dry purge gas to maintain a water vapor partial pressure differential to drive permeation of the water vapor, and the water vapor can be collected and processed into potable water.