Removal of Chromium (VI) Ions by Adsorption Using Riverbed Sand from Tamilnadu – A Kinetic Study

Abstract

Various methods adopted for removal of heavy metals include chemical precipitation, membrane separation, ion exchange and adsorption. In case of adsorption, the generally used adsorbents are expensive. This has prompted the use of riverbed sand as adsorbents in order to develop cheaper alternatives. Effect of various experimental parameters such as initial concentration of Cr (VI) ions, adsorbent dosage, contact time, pH of solution and agitation speed were studied. The equilibrium data were analyzed by Freundlich, Langmuir, Tempkin and Dubinin- Radushkevich isotherms. The kinetics of chromium (VI) ions was studied which showed that the adsorption followed pseudo second order reaction. Studies revealed that intra-particle diffusion played important role in the mechanism of Cr (VI) adsorption.