Interfacial Mass Transfer in Ligand Accelerated Metal Extraction by Liquid Surfactant Membranes

Abstract
Interfacial mass transfer rates were determined for the extraction of Co(II), Ni(II), and Cu(II) by di-(2-ethyl hexyl) phosphoric acid by using a modified Lewis cell. This allowed us to elucidate the effect of ligands on liquid surfactant membrane extraction of heavy metal ions by ligand addition to the external aqueous phase. The effects of different ligands on the kinetics of extraction and the influence of surfactant on interfacial resistance to mass transfer were then examined.