Sorption Characteristics of Cr(III) onto Florisil: Kinetics, Thermodynamics and Equilibrium Studies

Abstract

In this study, the efficiency of florisil was investigated for the removal of Cr(III) using batch type sorption under different experimental conditions namely pH, sorbent amount, contact time and temperature. The maximum sorption capacity of florisil for Cr(III) ions was determined as 67.5 mg g -1 , at pH 6.0, with a contact time of 60.0 minutes at 25°C. The equilibrium kinetics, isotherms, and thermodynamics of Cr(III) ion sorption onto florisil were also studied and it was evaluated that the sorption kinetics of Cr(III) on florisil followed pseudo-second-order model. The equilibrium data were in good agreement with the Langmuir isotherm model indicating monolayer coverage on the sorbent surface. In addition, thermodynamic studies revealed that the sorption of Cr(III) onto florisil was spontaneous and exothermic. The presented method was applied to the determination of Cr(III) in ultra – pure, tap, bottled drinking and waste water samples and high recoveries obtained confirmed the accuracy of the proposed study. The overall results have demonstrated that florisil is a promising and efficient sorbent and a good candidate for the removal of Cr(III) from aqueous solutions.