Removal of metal-complex dyestuffs by croatian clinoptilolite

Abstract

One of the most significant commercial applications of natural zeolites is the removal of metal ions from wastewater 1–5 . Some metal-complex dyes used for wool dyeing are copper and chromium complexes 6,7 . Chromium has the advantage over copper because of its greater stability to acids and alkalis. This paper deals with the possibility of eliminating of metal-ions from metal complex dyestuffs after the dyeing process by natural zeolites. The sorption properties of pre-treated and raw clinoptilolite for copper(II) and chromium(III) ions from metal complex dyes were investigated. The copper(II) complexes were prepared with two ligands: a 2-(2-pyridylmethylene-amino) phenol (PMAP) and 2-(2-quinolylmethylene-amino) phenol (QMAP) 8 . The chromium(III) complexes were prepared with 3-methyl-1-phenyl-5-pyrazolone (C. I. 18744) and 1-amino-2-naphtol-4-sulfonic acid (C. I. 14880). It was shown that various factors influence the Cu 2+ and Cr 3+ bonding capacities to natural zeolites, including chemical treatment of natural zeolite and particle size of zeolites. This study demonstrated that the pre-treated and raw clinoptilolite can be used as an effective adsorbent for the treatment of wastewater containing copper(II) and chromium(III) ions from metal compex-dyestuff.