ABSTRACT
This chapter focuses on liquid surfactant membranes. Liquid surfactant membranes are effective and versatile tools for performing a large variety of separations. They are particularly attractive for metals extractions, where equilibrium considerations make solvent extraction methods less efficient. Extensive work has already been reported for liquid membrane metal extractions. The chapter reviews briefly the development of some diffusion-controlled models applied to metal extractions. The metal extraction by means of liquid surfactant membranes is based on the mechanism of carrier-mediated transport. Metal ions can be extracted through the oil membrane into the internal aqueous droplets of the emulsion. The increased consumption of metals has resulted in a need to improve the existing methods and to explore new technology for the recovery, separation, concentration, and purification of metals. A series of metal species including alkali, alkaline earth, transition, and heavy metals has been studied.
