Equilibrium isotherms for harmful ions sorption using nano zirconium vanadate ion exchanger

Harmful ions such as cesium, cobalt and nickel were removed from aqueous solutions using nano zirconium vanadate ion exchangers that prepared using three different techniques and their organic hybrids. Different processing parameters that affect on sorption efficiency were studied. All prepared ion exchangers and their composites have high uptake affinity for cesium removal. The removal capacities of the ion exchangers either the inorganic ones or those that immobilized decreased in the acidic media, in contrast to the alkaline that enhances the ion exchange process. Both the temperature and agitation were found to be appropriate for maximum ions removal. The sorption data obtained for equilibrium conditions have been analyzed using the linear forms of Freundlich, Langmuir and Dubinin-Radushkevich isotherms and the applicability of these isotherm equations to the sorption systems was compared by judging the correlation coefficients, R-2. It was established that the equilibrium isotherms models' applicability follows the order: Langmuir>Freundlich>Dubinin-Radushkevich, in case of cesium removal using the different prepared inorganic ion exchangers. But the applicability for cobalt and nickel ions removal using the different prepared inorganic ion exchangers follows the order Freundlich>Langmuir>Dubinin-Radushkevich. The sorption processes for ions uptake using the different types of the prepared inorganic ion exchangers were found to be endothermic processes. (C) 2010 Elsevier B.V. All rights reserved.