Kinetic and thermodynamic studies of adsorption of gallium(III) on nano-TiO2

Nano-TiO2 was employed for the adsorption of gallium from aqueous solution in batch equilibrium experiments to investigate its adsorption properties. It was found that the adsorption efficiency of Ga(III) was more than 96% at pH 3.0. The adsorption capacities and rates of Ga(III) onto nano-TiO2 were evaluated as a function of solution concentration and temperature. The results were analyzed using the Langmuir adsorption isotherms. Adsorption isothermal data could be well interpreted by the Langmuir model. The mean energy of adsorption, 15.81 kJ . mol(-1), was calculated from the D-R adsorption isotherm. The kinetic experimental data properly correlate with the pseudo-second-order kinetic model. The thermodynamic parameters for the process of adsorption have been estimated. The Delta H-(sic) and Delta G((sic)) values of gallium(III) adsorption on nano-TiO2 showed an endothermic and spontaneous nature of adsorption.