Resumo

SERRANO-GOMEZ, Juan et al. Uptake of CrO₄^2- Ions by Fe-Treated Tri-Calcium Phosphate. J. Mex. Chem. Soc [online]. 2010, vol.54, n.1, pp. 34-39. ISSN 1870-249X.

CrO₄^2- 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 CrO₄^2- 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.

Palavras-chave : Fe-treated tri-calcium phosphate; chromate ions; adsorption; isotherm; thermodynamics parameters.