A cost effective method for improving the quality of inland desalinated brackish water destined for agricultural irrigation

Calcite dissolution provides the water with carbonate alkalinity, Ca2+ and SO42−, while the ion exchange step adds Mg2+. Laboratory and theoretical investigations of the process show that it results in a high water quality, attained in a cost effective and environmentally friendly manner. Three case studies are presented in which the additional cost of supplying Mg2+ concentration of either 12 or 18 mg L− 1 using the process is estimated at less than $0.006 m− 3 product water. The results indicate that the process is feasible for brackish waters characterized by Mg2+ to Ca2+ concentration ratio higher than 1:1.