Studies on the capability and behavior of adsorption of thallium on nano-Al2O3

A novel sorbent, nano-Al2O3 was employed for the removal of thallium from aqueous solution in batch equilibrium experiments, in order to investigate its adsorption properties. The removal percentage of thallium by the sorbent increased with increasing pH from 1 to 5. The adsorption capacities and removal percentage of Tl(III) onto nano-Al2O3 were evaluated as a function of the solution concentration and temperature. Results have been analyzed by the Langmuir, Freundlich adsorption isotherms. Adsorption isothermal data could be well interpreted by the Langmuir model. The mean energy of adsorption 9.32 kJ mol−1 was calculated from the Dubinin-Radushkevich (D-R) adsorption isotherm. The kinetic experimental data properly correlated with the second-order kinetic model. The thermodynamic parameters for the process of adsorption have been estimated. The ΔH0 and ΔG0 values of thallium(III) adsorption on nano-Al2O3 showed endothermic adsorption.