Abstract: In a water treatment system described in this specification, an ED device (which may be an EDR device) is combined with an ion exchange unit and a bipolar electrodialysis (BPED) device. The ion exchange unit, for example a weak acid cation exchange unit, is placed upstream of the ED device and removes divalent cations from the feed water to the ED device. The BPED device receives the salt-concentrated solution from the ED device and produces a regenerating solution. This regenerating solution is used to recharge the ion exchange unit when required. The regenerating solution may be an acidic solution.

Abstract: A process has been found for demineralizing whey which results in usable by-product streams, comprising softening the whey, and then applying bipolar electrodialysis to the softened whey to recover valuable by-products and product streams, demineralized whey, dilute acid and dilute caustic.

Abstract: Improved electrodialysis (ED) stacks are disclosed having one or more components selected from the group:a) cation exchange membranes having ion exchange groups predominantly sulfonic acid groups and a minor amount of weakly acidic and/or weakly basic groups or membranes which are selective to monovalent cations and simultaneously therewith, cation exchange granules selective to monovalent cations as packing in the dilute compartments;b) anion exchange membranes having as ion exchange groups only quaternary ammonium and/or quaternary phosphonium groups and substantially no primary, secondary and/or tertiary amine and/or phosphine groups or membranes which are selective to monovalent anions simultaneously therewith, anion exchange granules selective to monovalent anions as packing in the dilute compartments;c) as packing in the dilute compartment, anion exchange granules which are selective to monovalent anions, or cation exchange granules which are selective to monovalent cations, or cation exchange granules

Abstract: Improved electrodialysis (ED) stacks are disclosed having one or more components selected from the group:a) cation exchange membranes having ion exchange groups predominantly sulfonic acid groups and a minor amount of weakly acidic and/or weakly basic groups or membranes which are selective to monovalent cations and simultaneously therewith, cation exchange granules selective to monovalent cations as packing in the dilute compartments;b) anion exchange membranes having as ion exchange groups only quaternary ammonium and/or quaternary phosphonium groups and substantially no primary, secondary and/or tertiary amine and/or phosphine groups or membranes which are selective to monovalent anions simultaneously therewith, anion exchange granules selective to monovalent anions as packing in the dilute compartments;c) as packing in the dilute compartment, anion exchange granules which are selective to monovalent anions, or cation exchange granules which are selective to monovalent cations, or cation exchange granules

Abstract: A process for demineralization of whey-based material using electrodialysis. The process involves increasing the conductivity of the diluting stream, i.e, the stream containing the material to be demineralized, at one or more points in time during the electrodialysis cycle. When removal of divalent ions is desired, the increased conductivity may occur by the addition of salts of monovalent ions.