Equilibrium Extraction and Concentration of Multivalent Metal Ion Solutions by Using Winsor II Microemulsions

Abstract Experimental results on the selective extraction and concentration of bivalent copper into the aqueous core of a water-in-oil microemulsion in equilibrium with an aqueous phase are presented. We have developed an electrostatic model which describes this phenomenosn as a preferential substitutin of the conthe counterions of the surfactant by the introduced bivalent cations. We have assumed that the adsorption of counterions onto the charged surface of the reverse micelle can be modeled by the Stern double layer model. Comparisons of the theoretical predictions against the experimental results are encouraging. The positive features of the model and its limitations are discussed.