Uptake of CrO42- ions by Fe-treated tri-calcium phosphate

Abstract

CrO42- ion adsorption on Fe-treated tri-calcium phosphate was studied by batch experiments as a function of contact time, initial concentration of metal ion and temperature. Adsorption results showed that at pH 5.5 and 1.0×10-4 M chromium concentration the adsorption capacity of Fe-treated tri-calcium phosphate for CrO42- ions was 7.10 × 10-3 mmol/g. Chromium adsorption data on Fe-treated tri-calcium phosphate at various initial concentration fitted the Freundlich isotherm. By temperature studies the thermodynamic parameters ΔH0, ΔG0 and ΔS0 were estimated and the obtained results showed that the adsorption reaction was endothermic and spontaneous. © 2010, Sociedad Química de México.