Adsorption of Sb(III) from aqueous solution by QFGO particles in batch and fixed-bed systems

A composite of quartz sand coated with Fe3O4 and graphene oxide (QFGO) was prepared. SEM, FTIR, XRD and XPS measurements confirmed that smooth surface of the sand was modified with spherical latex beads and some flake-like materials which were attributed as coated Fe3O4 and graphene oxide (GO), respectively, and function groups of OH, C=O, C-O, Si-O, C=C, and Fe-O were also identified. Batch and continuous fixed-bed column studies were undertaken to evaluate the efficiency of the QFGO as an adsorbent for the removal of Sb(III) from aqueous solutions. The results showed that Sb(III) as well as its co-absorbates, As(III) and Hg(II), could be effectively adsorptive removed with the QFGO in batch test. The adsorption of Sb(III) on the QFGO followed the pseudo-first-order Kinetic and the Freundlich adsorption isotherm in batch study and Thomas models in column studies. Further, column tests under various parameters of bed depths (10-30 cm), Sb(III) concentrations (20-60 mg/mL), and flow rates (8-16 mL/min) showed that the removal of Sb(III) was effective with capacity of 2.88-6.09 mg/g, which was greater than that of many other current evaluated absorbents of MWCNTs, bentonite, and iron-oxide coated sand. The adsorptive exhausted column can be restored with EDTA. According to the facts established in the study, the QFGO based adsorption process could be a promise technology for remediation of Sb(III) contaminated waters. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.