Papers by Author: R. C. de Campos

Abstract: Cadmium uptake by hydroxyapatite from aqueous solution was studied in time intervals between 2 minutes and 96 hours, using different Cd2+ concentrations (21 to 768 mg L-1). The solution pH after Cd2+ uptake was assessed. Dissolution experiments at fixed pH were performed in order to evaluate the ion exchange process. Cd2+sorption by hydroxyapatite is fast and it happens simultaneously by different mechanisms. Ion exchange is the main mechanism, where mechanism Cd2+ present in aqueous solution replaces Ca2+ from hydroxyapatite structure.