Simultaneous and fast removal of As3+, As5+, Cd2+, Cu2+, Pb2+ and F- from water with composite Fe-Ti oxides nanoparticles

This paper describes the ability of composite Fe-Ti oxides nanoparticles to simultaneously adsorb As5+, As3+, Cd2+, Cu2+, Pb2+ and F- ions from water. The nanoparticles were comprised of tightly bounded Fe3O4, Fe2TiO5 and amorphous FexTixOx crystallites having a mean size of 9 +/- 3 nm and a surface area of 208 m(2) g(-1). Despite the concentration of essayed pollutants in water was higher than that in the guidelines used as reference, outcomes revealed that the nanoparticles enabled the complete removal of As5+, As3+ and Cd2+ after only 1 min. This behavior was maintained for up to 25 min. Moreover, the maxima removal efficiencies for Cu2+ and F- were 85% and 45% respectively after 15 min. For the case of Pb2+, the percentage of removal was of 94% after 25 min. The observed effectiveness of the adsorbent was attributed to the high surface area and to the presence of multiple oxides in the synthesized material. The study of the thermodynamic equilibrium of the adsorption process was also carried out along with the determination of the capacity of adsorption for each ion. The adsorption free energy indicated that the interactions among the adsorbate and the adsorbent were of the physical type, i.e. physisorption process. The chemical composition analyses performed by XPS and EDXS to recovered nanoparticles confirmed the presence of the studied pollutants at the surface. Overall outcomes confirmed that the composite Fe-Ti oxides nanoparticles could be promising materials for water treatment. (C) 2018 Elsevier B.V. All rights reserved.