ABSTRACT

Aqueous solutions containing salts are of increasing importance and influence on separation processes in chemical engineering. The electrolyte influence must be considered both in process design and operation, because it can significantly change the equilibrium composition. Aqueous liquid-liquid equilibrium is the results of intermolecular forces, mainly of the hydrogen-bonding type; addition of a salt to such systems introduces ionic forces that affect the thermodynamic equilibrium. When the mutual solubility decreases due the salt addition, the size of the two-phase region increases, and this effect is called “salting-out”. In the opposite, when the solubility increases, the effect is called “salting-in”. According to Al-Sahhaf and Kapetanovic (1997), the salting-in effect can be used to remove organic compounds from water.