Abstract: Method of treating an aqueous solution of a non-volatile inorganic solute to produce a more concentrated solution or to crystallize solid solute from the solution. The solution is contacted at a higher temperature T.sub.1 with a suitable organic liquid to extract water and form an organic phase (organic liquid contacting water). The organic phase, separated, cooled and contacted at a lower temperature T.sub.2 with a drying medium to dry the organic liquid which is then re-used to treat a further quantity of aqueous solution. The drying medium may be a portion of the concentrated aqueous solution resulting from the first step, or it may be a concentrated aqueous solution or a slurry from an outside source, or it may be a combination of two such drying media.