Sorption behavior of Florisil for the removal of antimony ions from aqueous solutions

Florisil was employed for the sorption of antimony ions from aqueous solutions. A detailed study of the process was performed by varying the sorption time, pH, and temperature. The sorption was found to be fast, equilibrium was reached within 15 min. Moreover, a maximum sorption has been achieved from solution when the pH ranges between 1–10. From kinetic experiments it follows that the process correlate with the second-order kinetic model. The overall rate process appears to be influenced by both boundary layer diffusion and intra-particle diffusion. The Langmuir and Dubinin-Radushkevich (D-R) type sorption isotherms can be applied to fit and interpret the sorption data. The mean energy of adsorption (9.73 kJ mol⁻¹) was calculated from the Dubinin-Radushkevich (D-R) adsorption isotherm at room temperature. Furthermore, the thermodynamic parameters for the sorption were also determined, and the ΔH⁰ and ΔG⁰ values indicate a spontaneous endothermic behavior.