A method and system for reducing ion concentration of a solution and converting gas. The system comprising a multi-chamber unitary dialysis cell comprising a gas chamber, a product chamber, and an acid chamber. Ion exchange barriers separate the chambers of the dialysis cell. A first anion exchange barrier is positioned between the product chamber and the acid chamber and a first cation exchange barrier is positioned between the product chamber and the gas chamber. Anions from the solution being treated associate with cations from the acid chamber to form an acid solution in the acid chamber, and cations from the solution being treated associate with anions from the fluid comprising gas to form salt, thereby reducing the ion concentration of the solution being treated and converting at least a portion of the gas into salt.

A method and system for electrochemically regenerating hydroxide (MOH) and carbon dioxide (CO.sub.2) from an alkali metal carbonate (M.sub.2CO.sub.3) via an electrochemical reactor that can replace a conventional thermochemical causticizing operation in a DAC system. The electrochemical reactor comprises: a cathode having an inlet for receiving an electrolyte feed stream comprising MOH, M.sub.2CO.sub.3 and H.sub.2O, and an outlet for discharging an electrolyte product stream comprising MOH, M.sub.2CO.sub.3, H.sub.2O and H.sub.2; a porous hydrophilic transport barrier in adjacent contact with the cathode; a porous hydrophilic anode in adjacent contact with the transport barrier configured and operable to generate CO.sub.2 in the presence of MOH while suppressing their recombination; a porous hydrophobic CO.sub.2 and O.sub.2 separation barrier in adjacent contact with the anode; and a product gas exit channel in adjacent contact with the CO.sub.2 and O.sub.2 separation barrier and for discharging an anode product stream comprising at least CO.sub.2.

The present disclosure describes a flow-electrode capacitive deionization (FCDI) desalination system and method of use. An FCDI desalination system is described employing one or more FCDI cells equipped with two coaxially oriented membranes mounted within a column housing capped with two end caps, each end cap comprising two carbon slurry ports and one water port. The column is lined with a chargeable sleeve capable of receiving a positive or negative charge. The annular space between the chargeable sleeve and the outside surface of the outer concentric membrane creates a flow path for a first carbon slurry to pass therethrough. The space between the inside surface of the outer concentric membrane and the outer surface of the inner concentric membrane creates a flow path for the saline water to be treated. The space within the inner annular portion of the inner concentric membrane creates a flow path for a second carbon slurry and contains a chargeable rod or wire capable of receiving an opposite charge. The first and second opposed end caps on the column are outfitted to continue these independent flow paths. As the saline water travels through its flow path, its salt ions are removed through the coaxial membranes via the two carbon slurries.

Provided are spacers, ion-exchange devices comprising spacers, and methods of preparing spacers for improved fluid distribution and sealing throughout an ion-exchange device. These spacers can include an internal cavity surrounded by a perimeter of the spacer. The perimeter can have a first opening and a second opening within the perimeter, and the first opening and the second opening can be located on opposite sides of the internal cavity. The spacers can also have a first and second plurality of channels located within the perimeter, wherein each channel of the first and second plurality of channels extends from the internal cavity towards the first opening or the second opening.

A wastewater treatment method includes: a soft water treatment 1 of crystallizing calcium carbonate from wastewater to remove the calcium carbonate therefrom; and an electrolysis 2 of electrolyzing some of the wastewater from which the calcium carbonate has been removed to obtain an acidic aqueous solution and an alkaline aqueous solution, wherein at least some of the alkaline aqueous solution is circulated to be used in the soft water treatment 1.

A wastewater treatment method includes: a soft water treatment 1 of crystallizing calcium carbonate from wastewater to remove the calcium carbonate therefrom; and an electrolysis 2 of electrolyzing some of the wastewater from which the calcium carbonate has been removed to obtain an acidic aqueous solution and an alkaline aqueous solution, wherein at least some of the alkaline aqueous solution is circulated to be used in the soft water treatment 1.

The present disclosure discloses a system and a method for solar-driven photothermal seawater desalination and ion electroosmosis power generation. In the system, a first reservoir is provided with a first electrode immersed in seawater; a second reservoir is connected to the first reservoir via a cation selective nanofilm; a third reservoir is provided with a second electrode immersed in seawater, and the third reservoir is connected to the second reservoir via an anion selective nanofilm; and an adjustable sun-visor shields the cation selective nanofilm to form a first preset part of solar illumination and shields the anion selective nanofilm to form a second preset part of the solar illumination. Therefore, the cation selective nanofilm and the anion selective nanofilm are each under an asymmetric illumination to generate a temperature gradient.

The present disclosure relates to a method for extracting lithium from a lithium-containing material. For example, the method can comprise leaching a roasted lithium-containing material under conditions suitable to obtain an aqueous composition comprising a lithium compound such as lithium sulfate and/or lithium bisulfate. The aqueous composition comprising lithium sulfate and/or lithium bisulfate can optionally be used, for example, in a method for preparing lithium hydroxide comprising an electromembrane process. The roasted lithium-containing material can be prepared, for example by a method which uses an aqueous composition comprising optionally lithium sulfate and/or lithium bisulfate which can be obtained from a method for preparing lithium hydroxide comprising an electromembrane process such as a two-compartment monopolar or bipolar electrolysis process.

The present disclosure relates to a method for extracting lithium from a lithium-containing material. For example, the method can comprise leaching a roasted lithium-containing material under conditions suitable to obtain an aqueous composition comprising a lithium compound such as lithium sulfate and/or lithium bisulfate. The aqueous composition comprising lithium sulfate and/or lithium bisulfate can optionally be used, for example, in a method for preparing lithium hydroxide comprising an electromembrane process. The roasted lithium-containing material can be prepared, for example by a method which uses an aqueous composition comprising optionally lithium sulfate and/or lithium bisulfate which can be obtained from a method for preparing lithium hydroxide comprising an electromembrane process such as a two-compartment monopolar or bipolar electrolysis process.

A method for separation and enrichment of lithium includes the following steps: pretreatment: diluting and filtering salina aged brine to obtain pretreated brine; separation: separating the pretreated brine via a nanofiltration separation system to obtain nanofiltration permeate and nanofiltration concentrate; first concentration: carrying out first concentration on the nanofiltration permeate via a reverse osmosis system to obtain reverse osmosis concentrate and reverse osmosis permeate; second concentration: carrying out second concentration on the reverse osmosis concentrate via an electrodialysis system to obtain electrodialysis concentrate and electrodialysis permeate, and the electrodialysis concentrate is solution enriching lithium ions. The present application couples several different membrane separation technologies by utilizing the advantages of different membrane separation technologies, thereby achieving the purposes of improving the separation efficiency of magnesium and lithium and improving the enrichment efficiency of lithium.