Selective lead ion recovery from multiple cation waste streams using the membrane–electrode process

Abstract

Abstract Selective cation recovery from dilute, aqueous, multi-cation waste streams addresses a solution method to a class of problems with worldwide implications. The absence of large scale systems to handle such waste streams and severe limitations of conventional technologies have been the motivating forces behind the development of the membrane–electrode (M–E) process. Thus far, the M–E process has been effectively demonstrated for selective recovery of Pb 2+ and Cu 2+ ions from dilute aqueous binary cation solutions [V. Gopal, G.C. April, V.N. Schrodt, Selective removal of copper from multi-cation dilute aqueous solutions using the membrane–electrode process, J. Sep. Sci. Technol. 33 (5) (1998) in press]. This paper extends coverage to Pb 2+ ion recovery from a mixture containing Pb 2+ ions and Fe 2+ ions. It is found that the applied cathodic potential is the parameter controlling the rate and selectivity of ion-exchange in the M–E process. An inverse relationship exists between the applied cathodic potential and rate of ion-exchange, while a direct relationship exists between the applied cathodic potential and Pb 2+ ion selectivity.