Disclosed herein are systems and methods in which ion-selective separation and multi-stage osmotic separation is used to produce multivalent-ion-rich process streams. According to certain embodiments, multiple separations may be used to process an aqueous feed stream containing solubilized monovalent ions and solubilized multivalent ions to produce a stream enriched in the multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream containsrelative to the initial aqueous feed streama high amount of multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of multivalent ions to monovalent ions.

Various embodiments disclosed relate to methods of separating volatile compounds from a liquid feed mixture comprising an emulsion. In various embodiments, the method includes contacting a first side of a first membrane with a liquid feed mixture including an emulsion having a polymer, and at least one volatile compound. The method can also include contacting a second side of the first membrane with a sweep medium including at least one a sweep fluid to produce a permeate mixture on the second side of the first membrane and a retentate mixture on the first side of the first membrane, wherein the permeate mixture is enriched in the volatile compound, and the retentate mixture is depleted in the volatile compound.

The present disclosure relates to a hybrid AD-DCMD desalination system, where two subsystems, such as AD and DCMD, are integrated synergistically to maximize freshwater production. The waste heat released from an AD condenser is used to drive the DCMD subsystem in a first configuration of the hybrid AD-DCMD system, while another configuration relies on the heat released due to an exothermic adsorption process in an adsorption bed. The DCMD subsystem is included to exploit the waste heat of the AD subsystem to enhance performance. In both these configurations, seawater is used to release the heat from the AD subsystem, which is then fed into the DCMD subsystem. The hybrid AD-DCMD system configurations demonstrate improved performance in terms of GOR, specific daily water production (SDWP), and freshwater cost reduction.

Apparatus for energy-efficient conductive-gap membrane distillation includes a feed-liquid source and a distillation module. The distillation module includes a feed-liquid chamber in fluid communication with the feed-liquid source. The feed-liquid chamber includes a selectively porous material that allows a component of the feed liquid to pass through the selectively porous material and exit the feed-liquid chamber in vapor form but not in liquid form. The distillation module also includes a conductive-gap chamber adjacent to the selectively porous material on an opposite side of the selectively porous material from the feed-liquid chamber; a heat-transfer surface maintained at a lower temperature than the feed liquid in the feed-liquid chamber, wherein the heat-transfer surface is in thermal contact with the conductive-gap chamber; and a thermally conductive material extending across the conductive-gap chamber.

Methods and systems for the separation of isotopes from an aqueous stream are described as can be utilized in one embodiment to remove and recover tritium from contaminated water. Methods include counter-current flow of an aqueous stream on either side of a separation membrane. The separation membrane includes an isotope selective layer (e.g., graphene) and an ion conductive supporting layer (e.g., Nafion). An electronic driving force encourages passage of isotopes selectively across the membrane to enrich the flow in the isotopes.

Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

A humidifier comprising a wound portion wrapped around a central axis and comprising enclosures, a first one the enclosures comprising a first pair of semipermeable membranes separated by a first spacer layer to form one among wet-gas channels, and a second one of the enclosures comprising a second pair of semipermeable membranes separated by a second spacer layer to form one among dry-gas channels. The dry-gas channels are configured to receive a dry gas through at least part of a first frontal area of the wound portion and in an axial direction along the dry-gas channels. The wet-gas channels are configured to receive a wet gas through at least part of a second frontal area of the wound portion and in the axial direction along the wet-gas channels, the second frontal area being opposite to the first frontal area.

Described herein are methods of recovering lithium from dilute lithium sources. The methods include extracting lithium from an extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate, performing one or more concentration operations, each concentration operation concentrating an input stream to yield an output feed, wherein the input stream is obtained from the lithium intermediate and/or the extraction feed is obtained from the output feed. At least one of the concentration operations includes a membrane separation operation having a plurality of reactors in series each having a semi-permeable membrane, such as a counter-flow reverse osmosis operation. Methods may also include generating a low TDS stream as a permeate from any of the one or more concentration operations, wherein the low TDS stream is recycled or used as fresh water.