A system and method for increasing the water production efficiency of a desalination plant and producing concentrated calcium and magnesium is provided. A saline source water is preferably subjected to a first treatment such a passage through a first desalination unit, followed by dual treatment of the first treatment reject stream using physicochemical adsorption and electrodialysis to remove scale-forming calcium and magnesium. The reject stream from the dual treatment may then be received by a second desalination unit. Due to the removal of the majority of the saline source water's scale-forming minerals, the second desalination unit may be operated at higher operating limits than in conventional desalination units without significant concern for fouling due to scaling. The approach of the present system and method efficiently increases the fresh water production ratio from the source saline water while generating commercially attractive concentrated calcium and magnesium products.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

A method of recovering metal compounds from solid oxide fuel cell scrap includes processing the solid oxide fuel cell scrap to form a powder, digesting the processed scrap, extracting lanthanum oxide and cerium oxide from a solution containing the digested processed scrap, extracting a zirconium compound from the solution after extracting the lanthanum oxide and cerium oxide, and extracting scandium compound from the solution extracting the zirconium compound from the solution.

A method includes: (1) using a chelating agent, extracting divalent ions from a brine solution as complexes of the chelating agent and the divalent ions; (2) using a weak acid, regenerating the chelating agent and producing a divalent ion salt solution; and (3) introducing carbon dioxide to the divalent ion salt solution to induce precipitation of the divalent ions as a carbonate salt. Another method includes: (1) combining water with carbon dioxide to produce a carbon dioxide solution; (2) introducing an ion exchanger to the carbon dioxide solution to induce exchange of alkali metal cations included in the ion exchanger with protons included in the carbon dioxide solution and to produce a bicarbonate salt solution of the alkali metal cations; and (3) introducing a brine solution to the bicarbonate salt solution to induce precipitation of divalent ions from the brine solution as a carbonate salt.

A method of recovering metal compounds from solid oxide fuel cell scrap includes processing the solid oxide fuel cell scrap to form a powder, digesting the processed scrap, extracting lanthanum oxide and cerium oxide from a solution containing the digested processed scrap, extracting a zirconium compound from the solution after extracting the lanthanum oxide and cerium oxide, and extracting scandium compound from the solution extracting the zirconium compound from the solution.

Materials, methods of making, and methods of using a stable and regenerable immobilized amine sorbents for rare earth element and heavy metal recovery from liquid sources. Embodiments of the invention relate to the novel combination of different polyamines, primarily polyethylenimine Mw=800 (PEI.sub.800), and an epoxysilane, namely 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECTMS), covalently immobilizing theREE and heavy metal-adsorbing amine sites within low cost, porous silica particles.

Materials, methods of making, and methods of using a stable and regenerable immobilized amine sorbents for rare earth element and heavy metal recovery from liquid sources. Embodiments of the invention relate to the novel combination of different polyamines, primarily polyethylenimine Mw=800 (PEI.sub.800), and an epoxysilane, namely 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECTMS), covalently immobilizing the REE and heavy metal-adsorbing amine sites within low cost, porous silica particles.

A novel process for treatment of low quality or brackish water that allows increased recovery of high quality water, recovers commodity minerals and reduces the volume of water and mass of solids that are disposed from the process.

Systems and methods for separating Y and Sr are provided. The systems and methods provide combinations of solutions, vessels, and/or media that can provide Y solutions of industrially beneficial concentration.

The present invention relates to a process for separating BaCl.sub.2 from a CaCl.sub.2) brine solution.