Influence of operating parameters on chromic ions removal from aqueous solution by liquid membranes

This paper presents the possibility of using liquid membranes as a separation and concentration technique to facilitate the recovery of Cr(VI) from water. Chromium(VI) being highly carcinogenic and mutagenic, it is necessary for risk assessment to remove and concentrate it in order to re-use it instead of reducing Cr(VI) to Cr(III). A separation scheme has been designed, using liquid membranes and rotating disk modules as contactors. Separation and enrichment can be simultaneously achieved in the same apparatus. Four operation parameters are considered : rotating disks speed, flow rate of chromium solution, initial chromium concentration and membrane volume. Experiments are performed in continuous mode. Estimation of the mass transfer coefficients is performed using macroscopic mass balances. (C) 2009 Elsevier B.V. All rights reserved.