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

摘要

The processes of Zn(II) and Pb(II) 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 composition of the liquid membranes and aqueous solutions on the rate of Zn(II) and Pb(II) transport were determined. It was demonstrated that practically complete removal of Zn(II) and more than 90 % extraction of Pb(II) from the feed solutions containing 0.01 M ZnSO_4 or 0.01 M Pb(NO_3)_2 was achieved in 1.0-5.0 h of electrodialysis. A possibility of effective transfer of Zn(II) into dilute solutions of sulphuric, hydrochloric, perchloric and acetic acids was shown. Adherent Zn and Pb coatings with a fine-grained structure were deposited on the platinum cathode. More than 75 % of Zn(II) and about 60 % of Pb(II) was deposited from solutions of sulfuric acid and perchloric acid, respectively.