Systems and methods for the treatment of wastewater are provided. By incorporating one or more intermediate phosphate recovery reactors and manipulating the effluent and/or solid streams from those reactors, the systems and methods provide effluent and solid streams having customized phosphate content throughout the wastewater treatment process.

A process for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprises: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (iii) at least one metal chosen from manganese and aluminum with sodium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising sodium sulfate; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising sodium sulfate to an electromembrane process for converting the sodium sulfate into sodium hydroxide; and reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate.

Systems for water desalination are disclosed. The systems include a source of non-potable water, a low pressure nanofiltration device, a first electrodialysis unit, a second electrodialysis unit, and recycle conduits. Methods of water desalination including directing non-potable water to a low pressure nanofiltration device, a first electrodialysis unit, and a second electrodialysis unit are also disclosed. Methods of facilitating water desalination by providing a water desalination system are also disclosed.

The present invention is directed to a novel and advantageous process for the purification of biomass hydrolysate as well as the purified hydrolysate produced after the inventive process and the use of the purified hydrolysate as a fermentation medium.

Provided are water treatment systems and methods of treating water that include separating dissolved salts from a feed stream using an organic solvent brine stream. For example, described are water treatment systems comprising: an electrodialysis device comprising an inlet feed stream, an inlet brine stream, an outlet product stream, and an outlet brine stream; and a precipitation tank comprising an inlet stream and an outlet stream, wherein the inlet stream of the precipitation tank comprises the outlet brine stream of the electrodialysis device, and the inlet brine stream of the electrodialysis device comprises the outlet stream of the precipitation tank, and wherein inlet brine stream and outlet brine stream comprises an organic solvent.

A process for preparing metal oxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprising: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum with lithium hydroxide and optionally a chelating agent to obtain a solid comprising a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum, and a liquid comprising lithium sulfate, the metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising lithium sulfate to an electromembrane process for converting the lithium sulfate into lithium hydroxide; and reusing at least a first portion of said lithium hydroxide obtained by the electromembrane process for reacting with the metal sulfate; reacting at least a second portion of said lithium hydroxide obtained by the electromembrane process with the obtained metal hydroxide to obtain a mixture of metal hydroxides; and roasting said mixture of metal hydroxides to obtain the metal oxide.

There are provided processes for preparing lithium hydroxide. The processes comprise submitting an aqueous composition comprising lithium sulfate and/or lithium bisulfate to a first electromembrane process that comprises a two-compartment membrane process under suitable conditions for conversion of the lithium sulfate and/or lithium bisulfate to lithium hydroxide, and obtaining a first lithium-reduced aqueous stream and a first lithium hydroxide-enriched aqueous stream; and submitting the first lithium-reduced aqueous stream to a second electromembrane process that comprises a three-compartment membrane process under suitable conditions to prepare at least a further portion of lithium hydroxide and obtaining a second lithium-reduced aqueous stream and a second lithium-hydroxide enriched aqueous stream. There are also provided systems for preparing lithium hydroxide.

A method of recovering purified partly-hydrolyzed cellulose particles from a composition comprising agglomerated partly-hydrolyzed cellulose particles and an acid, using electrodialysis. The invention addresses the problem of reducing the acid to very low levels while avoiding the high capital and operating costs, high water usage and large filtration surface area or dilution time requirements of the prior art processes. Following dilution, concentration by centrifuging or settling, and/or dialysis of the composition, the composition is treated in an electrodialysis cell to remove ions, such as free sulfate from sulfuric acid. The method may include having an anion exchange resin in the feed compartment of the electrodialysis cell, adding a base to the receiving solution in the electrodialysis cell, and a second step of electrodialysis of the purified partly-hydrolyzed cellulose particles.

The present invention relates to a method and system for recovering carbonate from steel slag, in which it is possible to extract carbonate from steel slag and reuse the extracted carbonate, and to recycle steel slag and make use of CO.sub.2 gas without emission to the atmosphere. Since unreacted metal ions and an acidic solvent are reused in the method and system, it is possible to increase carbonate extraction efficiency and reduce an amount of waste.

A hybrid electro-pressure driven method for the recovery, purification, and concentration of lithium salts is described. A fractionating electrodialysis stack equipped with selective ion exchange membranes is s used to separate a lithium containing brine into a monovalent enriched fraction and a divalent enriched fraction. The monovalent enriched fraction is further processed to remove remaining impurities by use of pressure driven nanofiltration. An optional concentrating electrodialysis device may further concentrate the monovalent enriched fraction in lithium content. The method may be combined with a subsequent solvent extraction and electrolysis step to produce lithium hydroxide, a Li+ selective sorbent step for producing purified lithium chloride, or a Li+ selective sorbent and precipitative step to produce lithium carbonate.