Methods and systems are provided for desalting wash water treatment and recycling processes and control of those processes. More specifically, treatment of wash water and wastewater streams using forward osmosis are provided. Additional methods and systems for desalting processes are provided, including recycling wash water. Methods for controlling operations of desalting systems and processes are provided.

A draw solute for a forward osmosis process, the draw solute comprising: a thermally responsive ionic compound having at least one of: a lower critical solution temperature (LCST) and an upper critical solution temperature (UCST), the draw solute being regeneratable from a diluted aqueous draw solution after forward osmosis via one of: liquid-liquid phase separation and solid-liquid phase separation, the draw solute being regeneratable when the diluted aqueous draw solution is at a temperature selected from one of: above the LCST and below the UCST

Draw compounds and draw solutions comprising said draw compounds for use in forward osmosis solvent purification systems. The draw compound may be a linear random, sequential, or block molecular chain consisting of at least one oxide monomer or diol monomer and have a temperature-dependent affinity with a feed solvent. The draw compound may further include a first terminal group and a second terminal group, at least one of the first terminal group and the second terminal group selected from the group consisting of a hydroxyl group, an amine group, a carboxylic group, an allyl group, and a C1 to C14 substituted and unsubstituted alkyl group. The draw compound may also be a branched random, sequential, or block molecular chain consisting of at least one oxide monomer or diol monomer.

An aqueous feed stream having a first total dissolved solids (TDS) level is flowed to a forward osmosis separator. The aqueous feed stream includes seawater. An aqueous draw stream having a second TDS level is flowed to the forward osmosis separator. The second TDS level is greater than the first TDS level. A disposal stream and an injection fluid stream is produced by the forward osmosis separator by allowing water to pass from the aqueous feed stream to the aqueous draw stream through a membrane of the forward osmosis separator based on a difference between the first TDS level and the seconds TDS level. The injection fluid stream is flowed from the osmosis separator to a subterranean formation.

[PROBLEM] To provide an evaluation method and evaluation device with which the practical performance of a forward osmosis membrane can more accurately be measured.

[SOLVING MEANS] Provided is a method for evaluating a forward osmosis membrane module. The method includes the steps of, in a forward osmosis membrane module having spaces which are partitioned by a forward osmosis membrane including a porous support body and a separation function layer stacked thereon, connecting a feed solution line to a space on the separation function layer side, and connecting a draw solution line to a space on the porous support body side, and moving a solvent in the feed solution into the draw solution via the forward osmosis membrane while adjusting a physical pressure differential across the forward osmosis membrane to a constant value within the range of more than 0 kPa to 200 kPa.

Methods and systems of lowering a concentration of divalent cations in lithium-containing brines are described. A method includes diluting saturated salar brine such that sodium chloride concentration is at most about 80% of saturation. The method also includes feeding the diluted salar brine to a high pressure nanofiltration system operating at pressure above about 60 bar effective to form a permeate and a concentrate. The method also includes collecting the permeate having a lower concentration of divalent cations relative to the saturated salar brine.

Methods and systems are provided for desalting wash water treatment and recycling processes and control of those processes. More specifically, treatment of wash water and wastewater streams using forward osmosis are provided. Additional methods and systems for desalting processes are provided, including recycling wash water. Methods for controlling operations of desalting systems and processes are provided.

A high salinity water purification system and process, including a forward osmosis system and a reverse osmosis or nanofiltration system. A concentrated brine of a zinc or iron complex combined with a salt or acid draws pure water across the FO membrane from the influent water. The diluted brine is pumped through a vessel holding an anionic adsorption media to remove the zinc or iron complex and the resultant brine is passed through the RO or nanofiltration system to obtain purified water and a concentrated brine stream. The adsorption media is regenerated by a rinse cycle using fresh water or water from the RO system, removing the zinc or iron complex adhered to the media. The resultant brine is stored and mixed with the output of the RO system. Charged membrane can be used as a standalone membrane in FO process or in combination with resin or resin embedded membrane.

A method and system for reversibly converting water between an initial ionic strength and an increased ionic strength, using a switchable additive, is described. The disclosed method and system can be used, for example, in distillation-free removal of water from solvents, solutes, or solutions. Following extraction of a solute from a medium by dissolving it in water, the solute can then be isolated from the aqueous solution or “salted-out” by converting the water to a solution having an increased ionic strength. The solute then separates from the increased ionic strength solution as a separate phase. Once the solute is, for example, decanted off, the increased ionic strength aqueous solution can be converted back to water having its original ionic strength and reused. Switching from lower to higher ionic strength is readily achieved using low energy methods such as bubbling with CO.sub.2, CS.sub.2 or COS. Switching from higher to lower ionic strength is readily achieved using low energy methods such as bubbling with air, heating, agitating, introducing a vacuum or partial vacuum, or any combination or thereof.

Embodiments described herein relate to methods and systems for dewatering alcoholic solutions via forward osmosis, where the concentration of alcohol in the draw stream is equal to or greater than the concentration of the alcohol in the feed stream. As the feed stream is concentrated the alcohol is retained in the feed stream.