Membrane Extraction and Electrodeposition of Zinc(II) and Lead(II) during Electrodialysis

Abstract

The processes of Zn2+ and Pb2+ extraction by bulk liquid membranes containing di (2-ethylhexyl) phosphoric acid and tri-n-octylamine during galvanostatic electrodialysis accompanied by electrodeposition of the metals were studied. The effects of the current density as well as of composition of the liquid membranes and aqueous solutions on the rate of zinc (II) and lead (II) transport were determined. It was demonstrated that a practically complete removal of zinc (II) and more than 90 % extraction of lead (II) from the feed solutions containing 0.01 M ZnSO4 or 0.01 M Pb (NO3)2 was achieved during 1.0 − 5.0 h of electrodialysis. A possibility of effective transfer of zinc (II) into dilute solutions of sulphuric, hydrochloric, perchloric and acetic acids was shown. Adherent zinc and lead coatings with a fine-grained structure have been deposited on the platinum cathode. More than 75% of zinc (II) and about 60% of lead (II) was deposited from solutions of sulfuric acid and perchloric acid, respectively.