versión On-line ISSN 0718-0764
MORENO, Juan C y GIRALDO, Liliana. Thermodynamics Properties in the Pb2+ Adsorption Process on Activated Carbon at Different pH. Inf. tecnol. [online]. 2008, vol.19, n.5, pp. 61-72. ISSN 0718-0764. doi: 10.4067/S0718-07642008000500008.
Adsorption isotherms of Pb2+ on activated carbon and immersion enthalpies of the activated carbon in Pb2+ solutions of 100 mgL -1 were determined at different pH values. The maximum values for the adsorbed amount and for the immersion enthalpies are 27.6 mgg-1and 15.7 Jg-1 respectively, at pH=4. The results are analyzed with the Dubinin-Radushkevitch-Kaganer model (DRK) and the adsorbed amounts in monolayer and the characteristic energies were obtained. At the pH of maximum adsorption the immersion enthalpies were determined varying the Pb2+ solution concentration, finding a behavior similar to the adsorption isotherm. The free energy and the adsorption entropy are calculated at pH=4 observing that the process is enthalpically favoured
Palabras clave : activated carbon; adsorption isotherms; immersion enthalpy; DRK model.