Removal and recovery of Cr(VI) from polluted ground waters: a comparative study of ion-exchange technologies.

ABSTRACT

The focus of this work has been the study of Cr(VI) removal from ground waters and the simultaneous concentration for its reuse using three different technological alternatives anion-exchange resins, liquid-liquid extraction assisted by hollow fibre membranes and emulsion pertraction. The viability of the considered objectives, i.e., Cr(VI) separation (<0.5 g/m3) and concentration for reuse (>20,000 g/m3) has been checked and a comparative analysis of the three technologies has been performed. Although the flexibility and ease of operation of non-dispersive solvent extraction, anion-exchange resins and emulsion pertraction lead to higher velocities of chromium removal, yet still maintaining similar concentration efficiencies.