Abstract

The sorption on Aswan clay of Cr(III) and Cr(VI) from synthetic solution and tannery wastewater has been studied. The clay has been characterized and used for the removal of chrome. The adsorption was studied as a function of pH, contact time, adsorbate concentration, loading, temperature and interfering ions. The equilibrium data fitted well with a Freundlich adsorption isotherm, where the Kf and n values are 2.08 – 4.6 for Cr(VI), 14.45 – 2.5 for Cr(III) and 8.31 – 2.4 for tannery wastewater. In our study we choose Aswan clay, which is low in cost, to aid the economy of the process. Adsorption studies indicated that chrome removal is 77% for CrVI, 90% for CrIII and 75% for a tannery wastewater.