Removal of Cr(VI) ions from aqueous solution using foundry waste material: Kinetic and equilibrium studies

Abstract

In the present paper, Cr(VI) ions removal from aqueous solutions by adsorption on waste mould (green) sand was investigated. Waste mould sand is byproduct of the grey iron foundry. Batch adsorption test was carried out to determine the removal characteristic for Cr(VI) ions from aqueous solution. The obtained results are promising in the use of waste mould sand as an efficient low cost and non-conventional adsorbent for the removal of Cr(VI) ions from aqueous solutions. The second order kinetics produced better fitting of results in terms of correlation coefficient which suggests that the adsorption kinetics of Cr(VI) ions on the waste mould sand followed the second order kinetic model. In the isotherm studies, Freundlich, Langmuir, Dubin–Radushevich and Redlich–Peterson isotherm models were applied and it was determined that the experimental data conformed to Langmuir isotherm model.