The present study deals with the purification of spent chromium bath contaminated by trivalent chromium, iron and aluminum. The ionic transfer of Fe(III) depends on the presence of chloride ions on the pH while aluminum transfer is not affected by chromium(III) chloride. Five different commercial cation-exchange membranes were used. Nafion (R) and PC-SK membranes showed the best results for trivalent iron and aluminum transfer. (C) 2007 Elsevier B.V. All rights reserved.