Abstract: Liquid solution separation (e.g., concentration and/or desalination) methods and related systems involving membrane separators having at least one-semipermeable membrane are provided. In some instances, at least some of the membrane separators permit a portion of solute in a retentate side input stream to pass through the semi-permeable membrane. In some instances, multiple membrane separators are employed, with the membrane separators having different solute permeabilities (e.g., due to varying pore size and/or molecular weight cutoffs). The methods and systems may be configured such that the ratio of mass flow and/or concentration of solute entering the retentate sides of the membrane separators are relatively high compared to the mass flow and/or concentration of solute exiting the retentate sides of the membrane separators.

Abstract: A thin-film-composite hollow-fiber membrane includes a phase-inversion layer, which is in the form of a hollow fiber, and an active layer coated on the phase-inversion layer. The active layer selectively allows passage of water molecules but rejects at least some dissolved ions. The thin-film-composite hollow-fiber membrane can have an internal burst pressure of at least 4 MPa. In a method for forming the membrane, the polymer concentration in the spinning dope from which the hollow-fiber substrate is formed can have a polymer concentration no greater than 5% below the critical concentration.

Abstract: Liquid solution concentration systems, and related methods, are generally described. In some embodiments, the system is an osmotic system comprising a plurality of osmotic modules. For example, the osmotic system can comprise a feed osmotic module configured to produce an osmotic module retentate outlet stream having a higher concentration of solute than the retentate inlet stream transported to the feed osmotic module. The osmotic system can also comprise an isolation osmotic module fluidically connected to the feed osmotic module. The osmotic system can also optionally comprise a purification osmotic module fluidically connected to the feed osmotic module and/or the isolation osmotic module. Certain embodiments are related to altering the degree to which the feed osmotic module retentate outlet stream is recycled back to the retentate-side inlet of the feed osmotic module during operation.

Abstract: Provided herein are osmotic desalination methods and associated systems. According to certain embodiments, multiple osmotic membranes may be used to perform a series of osmosis steps, such that an output stream having a relatively high water purity—compared to a water purity of an aqueous feed stream—is produced. In some embodiments, multiple draw streams can be used to produce aqueous product streams having sequentially higher purities of water. Certain embodiments are related to osmotic desalination systems and methods in which forward osmosis is used to produce a first product stream having a relatively high water purity relative to an aqueous feed stream, and reverse osmosis is used to perform a second step (and/or additional steps) on the first product stream. In some embodiments, multiple reverse osmosis steps can be used in series to perform a net desalination process.

Abstract: Liquid solution concentration systems, and related methods, are generally described. In some embodiments, the system is an osmotic system comprising a plurality of osmotic modules. For example, the osmotic system can comprise a feed osmotic module configured to produce an osmotic module retentate outlet stream having a higher concentration of solute than the retentate inlet stream transported to the feed osmotic module. The osmotic system can also comprise an isolation osmotic module fluidically connected to the feed osmotic module. The osmotic system can also optionally comprise a purification osmotic module fluidically connected to the feed osmotic module and/or the isolation osmotic module. Certain embodiments are related to altering the degree to which the feed osmotic module retentate outlet stream is recycled back to the retentate-side inlet of the feed osmotic module during operation.

Abstract: An osmotic membrane comprises an active layer and a composite support layer. The active layer selectively allows passage of water molecules but rejects at least some dissolved ions. The composite support layer includes a side that is bonded to the active layer and comprises an electrospun-fiber sub-layer and a phase-inversion sub-layer.

Abstract: Described herein are systems and methods for removing boron from water. According to certain embodiments, an aqueous input stream comprising boron and at least one suspended and/or emulsified immiscible phase is supplied to a water treatment system comprising a chemical coagulation apparatus, a suspended solids removal apparatus, and a boron removal apparatus. Within the chemical coagulation apparatus, an amount of an inorganic coagulant, an amount of a strong base, and an amount of a polyelectrolyte may be added to the aqueous input stream to form a chemically-treated stream. In some embodiments, the chemically-treated stream, which may comprise a plurality of floes, may be directed to flow to the suspended solids removal apparatus. Within the suspended solids removal apparatus, at least a portion of the floes may be removed from the chemically-treated stream to form a contaminant-diminished stream having a lower concentration of contaminants than the aqueous input stream.

Abstract: Provided herein are osmotic desalination methods and associated systems. According to certain embodiments, multiple osmotic membranes may be used to perform a series of osmosis steps, such that an output stream having a relatively high water purity—compared to a water purity of an aqueous feed stream—is produced. In some embodiments, multiple draw streams can be used to produce aqueous product streams having sequentially higher purities of water. Certain embodiments are related to osmotic desalination systems and methods in which forward osmosis is used to produce a first product stream having a relatively high water purity relative to an aqueous feed stream, and reverse osmosis is used to perform a second step (and/or additional steps) on the first product stream. In some embodiments, multiple reverse osmosis steps can be used in series to perform a net desalination process.

Abstract: Provided herein are osmotic desalination methods and associated systems. According to certain embodiments, multiple osmotic membranes may be used to perform a series of osmosis steps, such that an output stream having a relatively high water purity—compared to a water purity of an aqueous feed stream—is produced. In some embodiments, multiple draw streams can be used to produce aqueous product streams having sequentially higher purities of water. Certain embodiments are related to osmotic desalination systems and methods in which forward osmosis is used to produce a first product stream having a relatively high water purity relative to an aqueous feed stream, and reverse osmosis is used to perform a second step (and/or additional steps) on the first product stream. In some embodiments, multiple reverse osmosis steps can be used in series to perform a net desalination process.

Abstract: Disclosed herein are systems and methods in which multivalent ions are selectively retained in an aqueous stream. 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 solubilized multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream contains—relative to the initial aqueous feed stream—a high amount of solubilized multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of solubilized multivalent ions to solubilized monovalent ions.

Abstract: 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 contains—relative to the initial aqueous feed stream—a 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.

Abstract: Provided herein are osmotic desalination methods and associated systems. According to certain embodiments, multiple osmotic membranes may be used to perform a series of osmosis steps, such that an output stream having a relatively high water purity—compared to a water purity of an aqueous feed stream—is produced. In some embodiments, multiple draw streams can be NI used to produce aqueous product streams having sequentially higher purities of water. Certain embodiments are related to osmotic desalination systems and methods in which forward osmosis is used to produce a first product stream having a relatively high water purity relative to an aqueous feed stream, and reverse osmosis is used to perform a second step (and/or additional steps) on the first product stream. In some embodiments, multiple reverse osmosis steps can be used in series to perform a net desalination process.

Abstract: Disclosed herein are systems and methods in which multivalent ions are selectively retained in an aqueous stream. 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 solubilized multivalent ions. The separations may be arranged, according to certain embodiments, to enhance the overall separation process such that the product stream contains—relative to the initial aqueous feed stream—a high amount of solubilized multivalent ions, a high amount of water from the aqueous feed stream, and/or a high ratio of solubilized multivalent ions to solubilized monovalent ions.

Abstract: 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 contains—relative to the initial aqueous feed stream—a 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.

Abstract: An osmotic membrane comprises an active layer and a composite support layer. The active layer selectively allows passage of water molecules but rejects at least some dissolved ions. The composite support layer includes a side that is bonded to the active layer and comprises an electrospun-fiber sub-layer and a phase-inversion sub-layer.