Sorption of Ce(III) by Silica SBA-15 and Titanosilicate ETS-10 from Aqueous Solution

Abstract

The adsorption capacity of two sorbents, silica SBA-15 and titanosilicate ETS-10, toward Ce(III) was tested. The obtained sorbents were characterized using X-ray diffraction, nitrogen adsorption-desorption, Scanning electron microscopy, and Fourier-transform infrared spectroscopy. The effects of solution acidity, cerium concentration, time of contact, and temperature on Ce(III) sorption were investigated. The maximum Ce(III) removal by silica SBA-15 was achieved at pH 3.0 and by titanosilicate ETS-10 at a pH range of 4.0–5.0. The Freundlich, Langmuir, and Temkin isotherm models were applied for the description of equilibrium sorption of Ce(III) by the studied absorbents. Langmuir model obeys the experimentally obtained data for both sorbents with a maximum sorption capacity of 68 and 162 mg/g for silica SBA-15 and titanosilicate ETS-10, respectively. The kinetics of the sorption were described using pseudo-first- and pseudo-second-order kinetics, Elovich, and Weber–Morris intraparticle diffusion models. The adsorption data fit accurately to pseudo-first- and pseudo-second-order kinetic models. Thermodynamic data revealed that the adsorption process was spontaneous and exothermic.