Electrodialysis Extraction and Electrodeposition of Lead(II) in Systems with Liquid Membranes

Resumo

The extraction of lead(II) ions from nitric acid solutions through liquid membranes under galvanostatic electrodialysis with metal electrodeposition from the receiving solution of perchloric, nitric, or acetic acids is studied. The solitons of di(2-ethylhexyl)phosphoric acid with additives of tri-n-octylamine in 1,2-dichloroethane are used as liquid membranes. The effect of the current density of the electrodialysis and the composition of the initial aqueous solution and receiving solution (catholyte), as well as the composition of liquid membranes on the rate of membrane transport and electrodeposition of the lead(II) ions, is investigated. The optimal conditions of the process are determined. Fine-grained and highly adherent lead deposits are obtained on a platinum cathode during the deposition from perchloric acid solutions. It is shown that the degree of extraction of lead(II) ions from the initial aqueous solution is higher than 90% in the process, while the degree of electrodeposition amounts to 60% within 5 h of electrodialysis.