FIELD: chemistry.
SUBSTANCE: invention relates to chemical engineering, as well as ecology and can be used to process natural and industrial water with high content of sulphate and calcium. Method involves successive stages of preliminary preparation, ion-exchange softening – decalcification of solutions with subsequent demineralisation of the softened solution by reverse osmosis to obtain fresh water and a concentrate. Mechanical cleaning is performed at the stage of preliminary cleaning. At the stage of ion-exchange softening, initial water is passed successively through a layer of cationite and anionite. Concentrate obtained after reverse osmosis is subjected to thermal distillation to obtain a condensate and a concentrate. After the decalcification operation, the concentrate is returned to the ionite regeneration for destruction of the oversaturated gypsum solution by passing it successively through the anionite and cationite in the direction opposite to the flow direction at the softening stage.
EFFECT: high efficiency of processing calcium- and sulphate-containing natural and industrial water, use of solutions obtained in the process in a closed recycling mode without using commercial reagents, and high environmental safety.
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