Physico-chemical study of the dead sea waters. I. Activity coefficients of major ions in dead sea water

Conventional single-ion activity coefficients of major ions in Dead Sea brines, and their osmotic coefficients, have been estimated using Pitzer's thermodynamic treatment of mixed electrolyte solutions. For these calculations, higher-order terms have been taken into consideration. It has been shown that Pitzer's equations are applicable to such natural concentrated brines. The problem of gypsum solubility in the Dead Sea was examined. Dead Sea brines were shown to be oversaturated with respect to gypsum, and the degree of oversaturation increased very significantly during the last 20 years.