SEPARATION OF SALTS FROM AQUEOUS SALINE SOLUTIONS - MODELING AND EXPERIMENTAL

A rigorous thermodynamic model based on the excess Henry's constant is applied by which the precipitation of salts from aqueous solutions upon the addition of miscible (strongly associated) organic solvents is described adequately. Wohl's expansion has been used to model the excess Gibbs free energy. The activity coefficients for solvent-solvent (aqueous-organic) interactions are estimated by using the original version of the UNIFAC. All precipitation data tested in this work are sufficiently described by the model. The model serves to give an insight into the basic fundamentals underlying the phase equilibrium behavior involved in the precipitation phenomenon.