A bipolar electrodialysis (BPED) cell is able to bipolar convert salt solutions into acid and base solutions. However, protons migrate through the anion exchange membranes and tend to neutralize the base solution. In a bipolar electrodialysis system described herein, multiple BPED cells are arranged to provide a multi-stage treatment system. Up to half, or up to one third, of the stages have cells with acid block anion membranes. The one or more stages with acid block anion membranes are located at the acid product output end of the system, where the acid concentration in the system is the highest. Replacing the traditional anion membranes in some of the stages with acid block anion membranes allows higher concentration products to be produced with moderate increase in energy consumption.

The present disclosure provides devices and methods of using same for cleansing a solution (e.g., a salt or used dialysis solution) of urea via electrooxidation, and more specifically to cleansing a renal therapy solution/dialysis solution of urea via electrooxidation so that the renal therapy solution/dialysis solution can be used or reused for treatment of a patient. In an embodiment, a device for the removal of urea from a fluid having urea to produce a cleansed fluid includes a urea decomposition unit and an electrodialysis unit.

The water treatment device according to the present disclosure includes: an electrochemical cell having electrodes including a positive electrode and a negative electrode, and a bipolar membrane; a tank; a power supply configured to apply power to the electrodes; a water circulation flow path having at least the tank and the electrochemical cell and through which water circulates; a circulation device configured to circulate water in the water circulation flow path; a raw water supply path configured to supply raw water to the water circulation flow path; and a control device. In performing water softening treatment in the electrochemical cell where power is applied to the electrodes so as to remove ions from raw water and soft water is produced, the control device drives the circulation device so as to circulate water in the water circulation flow path.

The present invention relates to a method for manufacturing lithium hydroxide and lithium carbonate, and a device therefor. The present invention provides a method for manufacturing lithium hydroxide, comprising: a step of dissolving lithium phosphate in an acid; a step of preparing a monovalent ion selective-type electrodialysis device disposed in the order of a cathode cell containing a cathode separator, a monovalent anion selective-type dialysis membrane for selectively permeating a monovalent anion, a monovalent cation selective-type dialysis membrane for selectively permeating a monovalent cation, and an anode cell containing an anode separator, injecting the lithium phosphate dissolved in the acid between the anode separator of the anode cell and the monovalent cation selective-type dialysis membrane, and between the cathode separator of the cathode cell and the monovalent anion selective-type dialysis membrane, respectively, and injecting water between the monovalent cation selective-type dialysis membrane and the monovalent anion selective-type dialysis membrane; a step of obtaining an aqueous lithium chloride solution, and at the same time, obtaining a phosphoric acid aqueous solution formed as a byproduct, by applying an electric current to the monovalent ion selective-type electrodialysis device; and a step of converting the obtained aqueous lithium chloride solution into an aqueous lithium hydroxide solution.

Systems and methods of making lactobionic acid are described. The systems include two-compartment cation bipolar electrodialysis assemblies having at least one cell that includes a cation ion-exchange membrane and a bipolar membrane. The membranes define the borders of a pair of flow channels for a separate (i) caustic stream and (i) purified lactobionic acid stream. Lactobionate ions in the lactobionic acid stream do not cross a membrane in the electrodialysis assembly, which reduces membrane fouling. The methods include passing a lactobionate salt through a two-compartment cation bipolar electrodialysis assembly. The electrodialysis assembly includes at least one two-compartment cation bipolar membrane cell, and separates the lactobionate salt into a caustic compound and the lactobionic acid. The assembly is designed so the lactobionate ions do not cross an ion exchange membrane in the assembly to form the lactobionic acid, which reduces membrane fouling.

The present invention relates to a method for producing lithium hydroxide and lithium carbonate, wherein the lithium hydroxide and the lithium carbonate can be produced by a series of steps of: performing bipolar electrodialysis of a lithium-containing solution from which divalent ion impurities have been removed; concentrating lithium in the lithium-containing solution and at the same time, converting the lithium to lithium hydroxide; and carbonating the lithium hydroxide to obtain lithium carbonate.

Wastewater containing scale components, organic substances, inorganic ions, and the like, such as human effluent, generated in a closed system space, such as a nuclear shelter, a hazardous shelter, a space station or a moon-Mars mission manned spacecraft, or a lunar base is efficiently treated by a simple structural apparatus, so that water is recovered. After a hardness component is removed from water to be treated, such as human effluent, by a softening device, and heat exchange is performed between softening treated water and electrolysis treated water by a heat exchanger, by a high-temperature and high-pressure electrolysis device, organic substances, urea, ammonia, and the like are removed by electrolysis performed under high-temperature and high-pressure conditions. After the electrolysis treated water is processed by a deaeration treatment using a deaeration membrane device, a desalting treatment is performed by acid/alkali manufacturing electrodialysis devices and provided in series at two stages.

Disclosed is a process for enriching silicate content in drinking water that includes separating raw water via reverse osmosis into a permeate comprising demineralised raw water and a retentate comprising mineral enriched raw water. The permeate is mixed with a water glass solution comprising sodium silicate and/or potassium silicate. An ion exchange process is used to reduce the concentration of sodium and/or potassium ions in at least part of the mixture. At least part of the retentate is supplied to the mixture after reducing the concentration of sodium and/or potassium ions to provide a silicate-enriched drinking water. Also disclosed is an apparatus for producing a drinking water enriched with silicate. The apparatus includes a reverse osmosis unit, a mixing unit, an ion exchanger, and a feed unit for feeding at least part of the retentate to the mixture after reducing the concentration of sodium and/or potassium ions.

An energy efficient, environmentally greener process that converts alkali salts to various salt/fertilizer compounds and chloride/sulfate compounds is disclosed. The process uses bipolar membrane electrodialysis or multi-compartment electrolysis to initially convert potassium, sodium and lithium salts to their respective alkali and acid components. The alkali is subsequently reacted with sulfur or phosphoric acid or other acid to produce thiosulfate, phosphate, acetate or other salt products. The acid coproduct is concurrently converted to compounds such as calcium chloride, lysine hydrochloride, ammonium sulfate through solvent extraction and subsequent stripping of the loaded solvent with an appropriate alkali.

The present disclosure provides devices and methods of using same for cleansing a solution (e.g., a salt or used dialysis solution) of urea via electrooxidation, and more specifically to cleansing a renal therapy solution/dialysis solution of urea via electrooxidation so that the renal therapy solution/dialysis solution can be used or reused for treatment of a patient. In an embodiment, a device for the removal of urea from a fluid having urea to produce a cleansed fluid includes a urea decomposition unit and an electrodialysis unit.