Column study on the sorption of Cr(VI) using quaternized rice hulls

The potential of quaternized rice hulls in removing Cr(VI) from synthetic s olution, chrome electroplating waste and wood preservative waste was invest igated in column experiments. Increase in column bed depth resulted in a lo nger service time at C-t/C-o = 0.5 breakthrough. The presence of SO42-, whi ch is commonly present in the wastes, interfered with the sorption process and resulted in earlier breakthrough. The sorption process was flow-rate in dependent within the scope of this study. In the regeneration study, Cr(VI) could be recovered almost quantitatively by eluting with a 0.5 M NaOH solu tion and the column could be used repeatedly for at least five cycles. (C) 1998 Elsevier Science Ltd. All rights reserved.