water treatment process including reverse osmosis decarbonation of a concentrate and remineralization of a filtrate.

The invention relates to a water processing method containing at least calcium salts and / or magnesium through reverse osmosis type membrane, said method comprising at least a step of recovering an at least partially water desalted, a step of recovering a concentrate from said membranes and containing bicarbonates, a CO2 injection step or an acid in said water at least partially desalinated, and one of said water remineralization step of at least partially desalted in a remineralization reactor. According to the invention such a method comprises: - a concentrate of said decarbonation step so as to form carbonates, and - a step of recycling at least a portion of said carbonates remineralization within said reactor.