A method of concentrating a lithium-containing aqueous solution, the method comprising: (i) providing a water-permeable structure having an inner surface and outer surface, wherein at least said outer surface is coated with a water-permeable hydrophilic polymer having a thermal stability of at least 100? C.; and (ii) flowing a lithium-containing aqueous feed solution having an initial concentration of lithium over said inner surface while said outer surface is in contact with an aqueous draw solution containing a higher overall ion concentration than said lithium-containing aqueous feed solution, to result in forward osmosis of water from said lithium-containing aqueous feed solution to said aqueous draw solution, and wherein said forward osmosis results in a lithium-containing aqueous product solution having an increased concentration of lithium relative to the initial concentration of lithium in the lithium-containing aqueous feed solution.

A hydrogel composite draw material for forward osmosis comprising: a porous elastic polymeric foam element including a three-dimensional continuous network of pores interpenetrated with a polymer hydrogel. In use, the hydrogel composite draw material draws a water flux of at least 3.5 L/m.sup.2h.

The present disclosure is directed to a forward osmosis system/process utilized primarily in conjunction with a subsurface irrigation system/process. Saline wastewater or naturally saline water is treated using forward osmosis membranes that draw at least partially purified water from the wastewater into an osmotic draw solution (draw solution). The resulting diluted osmotic draw solution is then circulated through the subsurface irrigation system including one or more tubular membranes that reject the draw solution while permitting water in the diluted draw solution to pass through.

The present invention discloses and claims a more efficient and economical method and system for osmotic energy production and capture using responsive compounds and molecules. The present invention is an energy harvest system enabled by stimuli responsive draw solutions that are competent in terms of energy production, geographic location flexibility, and the affordable, efficient and economical production and delivery of osmotic power. Specifically, the present invention is a novel osmotic power system that uses stimuli responsive draw solutions, economically feasible larger permeable membranes, and low grade heat sources to deliver osmotic power more efficiently and economically with less negative environmental impact, greater power output, and located in more geographically diverse areas of the world than previously thought possible for supporting such a power source.

The present invention discloses a novel hydrophilic and compressible aerogel as draw agent for purification water in forward osmosis (FO), which belongs to environmental pollution control engineering technical field. The improved performances are obtained by optimizing regeneration process of drawing and producing water by using this aerogel as a draw agent in FO technology. Herein, the aerogel complete avoid the draw solution's reverse diffusion and maintain a higher water flux that compensates for its structure characteristics. Moreover, the regeneration of the draw agent and production water should be accomplished through human compression without a complicated physical and chemical method. Simultaneously, this draw agent presents other advantages of wide raw material sources, low cost, wild preparation process, low poison and good film compatibility. It is an innovation as FO technology in portable water purifying device, especially in areas of military and emergency.

A multi-branched cationic phosphonium salt is provided. The multi-branched cationic phosphonium salt has a structure represented by formula (I):

{Z[P.sup.+(R.sup.1)(R.sup.2)(R.sup.3)].sub.n}(X.sup.).sub.n(I) wherein each of R.sup.1, R.sup.2, and R.sup.3 is independently a linear or branched C.sub.1C.sub.10 alkyl group, X.sup. is an organic or inorganic anion, and Z has a structure represented by Formula (IIb) or Formula (IIc):

##STR00001## wherein a is an integer of 115. In Formulas (IIb) and (IIc), Z is connected to [P.sup.+(R.sup.1)(R.sup.2)(R.sup.3)] at the position marked by an asterisk (*), and n is an integer of 34.

A system for crystallizing a material that is dissolved in a solvent includes: a crystallization device through which a solution that is to be concentrated flows, the solution including the solvent containing the material to be crystallized and dissolved in the solvent, and a liquid having a lower temperature than the solution to be concentrated. The system includes at least one flow channel guiding the solution to be concentrated and at least one flow channel guiding the liquid, where the inner space of each respective flow channel guiding the liquid is delimited at least in part by a membrane wall that is permeable for the vaporous solvent, where a vapor pressure difference enables the solvent to pass from the solution to be concentrated across the membrane wall.

Embodiments described herein relate to methods and systems for dewatering alcoholic solutions via forward osmosis.

Provided is a forward osmosis membrane-based water treatment system (including water desalination) using a switchable polar solvent as the draw solvent that is switched through the addition and removal of carbon dioxide. Provided is the use of a membrane system that designed to operate within the chemistry and properties of switchable polar solvents to promote water draw through the forward osmosis membrane, and a method of removing and reintroducing carbon dioxide to the switchable solvent.

A method of treating an aqueous liquid. The method comprises providing an aqueous feed liquid comprising water and at least one solute to a first side of a membrane. A draw solution comprising water and a draw solute comprising at least one of a phosphazene compound and a triazine compound is provided to a second side of the membrane. At least a portion of the water of the aqueous feed liquid is osmosed across the membrane and into the draw solution to form a diluted draw solution comprising water and the draw solute. The water of the diluted draw solution is separated from the draw solute of the diluted draw solution to form a purified water product. Draw solutes comprising phosphazene compounds and draw solutes comprising triazine compounds are also disclosed, as are methods of forming the draw solutes.