Effective removal of uranium (VI) using magnetic acid functionalized Fe3O4@TiO2 nanocomposite from aqueous solutions

Abstract

The recovery and extraction of uranium is vital to ensure sustainability of nuclear energy production and safety of environment. Herein, we report a facile method to synthesise diglycolamic-acid-functionalized iron oxide@titanium dioxide magnetic nanocomposite (Fe3O4 @TiO2-DGA) as an efficient adsorbent for effective removal of uranium (VI) from aqueous medium. Fe3O4 @TiO2-DGA showed high uranium adsorption performance, with a sorption capacity of 371.8 mg g–1 at pH 6.0 and reached equilibrium within 40 min. The adsorption isotherm fits well with Langmuir and the kinetics follows pseudo-second-order model, respectively. The plausible mechanism of U(VI) adsorption involves the electrostatic interaction between the diglycolamic acid and hydrolysed uranium species. Thermodynamic studies revealed that the adsorption was spontaneous and exothermic in nature. The U(VI)-loaded Fe3O4 @TiO2-DGA could be conveniently separated from aqueous solutions using an external magnet, and further U(VI) is desorbed by adding dil. HCl. Fe3O4 @TiO2-DGA showed exceptional selectivity for U(VI) in presence of various coexisting metal ions and it can be effectively reused for more than 5 times with negligible change in sorption capacity. Thus, Fe3O4 @TiO2-DGA can be considered as an effective and potential sorbent for U(VI) remediation from aqueous solutions.