Facile synthesis and characterization of gamma-AlOOH/PVA composite granules for Cr(VI) adsorption

gamma-AlOOH(boehmite)/PVA composite granules with high adsorption performance towards Cr(VI) were successfully synthesized by combining sol-gel and oil-drop methods. The gamma-AlOOH/PVA sample with 35 wt% PVA showed the highest Cr(IV) adsorption capacity of 35.91 mg/g, which was much higher than that of the pure gamma-AlOOH sample (17.08 mg/g). The adsorption behaviors of Cr(VI) ions onto the gamma-AlOOH and gamma-AlOOH/PVA granules were well described by the pseudo-second-order kinetic model, and the adsorption mechanisms included electrostatic attraction, ligand exchange and redox reaction. The recovery of Cr(VI) under basic conditions was conducted to evaluate the practical utility of the synthesized composite granules. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.