Prospects of reverse osmosis (RO) desalination of Azov seawater and brackish water of the Berda River have been studied. It was shown that the efficiency of seawater desalination enhances with the increase of the ratio of retentate to permeate fluxes, operating pressure and temperature of feed water. It was concluded that the complex treatment of brackish water at inland conditions via a combination of RO with other chemical methods is the most cost effective and environmentally appropriate way. The technological scheme for desalination of brackish water of sulphite type and for prevention of brine discharge has been developed. It permits production of both potable water and valuable mineral fertilizers as concentrated solution of K2SO4 with KCl additives.