Abstract: A method of treating whey for demineralization purposes, the method comprising a stage of separating out salts by transfer through electrodialysis or nanofiltration membranes, wherein, upstream from this separation stage, the method comprises in succession at least one step of exchanging divalent cations for protons and at least one step of exchanging divalent anions for chloride ions.

Abstract: A process of demineralizing a liquid containing organic matter and inorganic salts in solution, in which the treatment of the liquid comprises the following steps:the liquid is percolated over a strong cationic ion exchange resin for monovalent ions;both a batch of liquid from the preceding step and a brine for receiving ions from that liquid are caused to circulate in loops through at least one "two-compartment" electrodialyzer comprising a plurality of anionic membranes interposed between a plurality of cationic membranes; andthe brine whose salt concentration lies in the range 90 grams per liter (g/l) to 110 g/l is used to regenerate the ion exchange resin.

Abstract: Skimmed milk is subjected to acidification by electrodialysis in one or two successive three-compartment electrodialyzers. The resulting milk is at a pH of 4.5 or 2.8. Milk at a pH of 4.5 may be used for obtaining refined casein as a substitute for rennin casein. Milk at a pH of 2.8 when sterilized and filtered to selectively extract a whey permeate and serum proteins becomes casein in its natural state soluble at a pH in the range 2.8 to 4, which casein may be neutralized in a two-compartment electrodialyzer. The acid permeate is passed over a strong cationic resin in order to be used as an acid agent in the initial electrodialyzers.