Removal of Dichromate Anions with Nanofiltration‐Complexation by using Amino Calix[4]arene Derivative

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.

Keywords:

• Dichromate anions
• water‐soluble calixarene
• nanofiltration‐complexation
• nitrate anions
• membrane

Acknowledgement

We thank the Scientific Research Projects Foundation of Selcuk University (SUBAP‐Grant Number 2003‐187) for financial support of this work.