Selective separation of chromium (VI) from acidic solutions containing various metal ions through emulsion liquid membrane using trioctylamine as extractant

Abstract

Chromium compounds have received considerable attention because of used extensively in such industrial applications as electroplating, tanning of leather goods, steelmaking, and corrosion inhibition. In this work, selective separation and concentration of Cr (VI) ions from acidic solutions containing various metal ions through emulsion liquid membrane (ELM) containing trioctylamine (TOA) as extractant was studied. The membrane phase consists of kerosene as diluent, ECA 4360J as surfactant, TOA as extractant and 0.5 M (NH4)(2)CO3 solution as stripping phase. The effect of acid type and concentration of the feed solution, initial Cr (VI) concentration of the feed solution, mixing speed, type and concentration of the stripping solution, surfactant concentration, extractant concentration and phase ratio was examined and optimum conditions was determined. After the optimum conditions were determined, it was possible to selectively extract 99% of Cr (VI) from the feed solutions containing Cu, Zn, Co, Ni and Cd ions. (C) 2008 Elsevier B.V. All rights reserved.