Abstract
Herein the removal and recovery of chromium anions from aqueous solutions by using nanofiltration pilot‐scale equipment (Osmonics Sepa CF Membrane Cell) with a water‐soluble amino calix[4]arene derivative was studied. To understand the selectivity, the authors also examined the retention of chromium anions in the presence of Cl−, NO3 −, SO4 2−, HSO4 −, CO3 2−, PO4 3−, H2PO4 − anions in nanofiltration‐complexation. From the results water‐soluble amino calix[4]arene was effective and selective ligand for dichromate anions over nitrate anions, in a nanofiltration‐complexation system at pH 2.5. Moreover, the recovery and reusability studies of dichromate and nitrate anions and also ligand were performed.
Acknowledgement
We thank the Scientific Research Projects Foundation of Selcuk University (SUBAP‐Grant Number 2003‐187) for financial support of this work.