chemical engineering, semnan university
Department of Chemistry, Payame Noor University, Tehran, Iran.
chemical engineering, Malek-Ashtar University of Technology (MUT), Tehra
In this research, the zeolite sodalite, as an inorganic ion exchange material, was chemically produced in the template-free synthesis and evaluated in order to facilitate the sorption of strontium ions from aqueous solutions in batch operations onto acid treated zeolite with dilute H2SO4 solutions. The following indicates what the batch experiments included: a sorbent amount of 0.25 g in 100 mL of strontium solution (50 mg/L), a contact time of 80 min, pH 6 and a 20 oC temperature. To study the kinetics of removal process, three equations, i.e. Morris–Weber, Lagergren (pseudo first order) and pseudo second order were used. The sorption data were applied to the Langmuir, Freundlich, Dubnin-Randkovich (D-R) and Temkin models in order to estimate the sorption capacity, intensity and energy. An evaluation of the thermodynamic parameters ΔH, ΔS and ΔG was done. It was found out from thermodynamic parameters that the sorption of strontium onto zeolite was feasible, spontaneous and endothermic under studied conditions.