Sorption of thallium(III) ions from aqueous solutions using titanium dioxide nanoparticles

Titanium dioxide nanoparticles (NPs) were employed for the sorption of Tl(III) ions from aqueous solution. The process was studied in detail by varying the sorption time, pH, Tl(III) concentration, temperature, and amount of sorbent. The sorption was found to be fast and to reach equilibrium within 2 min, to be less efficient at low pH values, and to increase with pH and temperature. The sorption fits the Langmuir equation and follows a pseudo second order model. The mean energy of the sorption is approximately 15 kJ mol^?1 as calculated from the Dubinin–Radushkevich isotherm. The thermodynamic parameters for the sorption were also determined, and the ΔH ⁰ and ΔG ⁰ values indicate endothermic behavior.