Comparative sorption studies of chromate by nano-and-micro sized Fe2O3 particles

Abstract

The comparative adsorption studies of Cr (VI) on nano and micro-powder Fe2O3 were investigated using kinetics and batch adsorption techniques. The uptake of chromate onto both the oxides of iron was observed to be dependent on the pH, contact time, temperature, media dosage and concentration of chromate anions. The values of sorption maxima were higher in the case of Fe2O3 nanopowder than the micro-powder which can be ascribed to the high surface area and point of zero charge (PZC) of the former oxide. The Dubinin-Radushkivech and Langmuir models were found well fitted for the description of the batch adsorption data. The FTIR studies confirmed that the hexavalent chromium was adsorbed onto both the iron oxides in the form of the Cr2O72-.