Characterization of nanoscale zero-valent iron supported on granular activated carbon and its application in removal of acrylonitrile from aqueous solution

In this study, nanoscale zero-valent iron supported on granular activated carbon (NZVI/GAC) was synthesized by liquid-phase reduction of Fe(II) and used to degrade acrylonitrile, to improve the effectiveness of GAC as a pre-treatment for biodegradation. The as-prepared composites were characterized by a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). NZVI nanoparticles with an average size of 20-80 nm were uniformly dispersed on the surface of GAC, but mainly in the pores. The SBET and total pore volume of NZVI/GAC were 478.7 m(2)/g and 0.522 cm(3)/g, which is about half that of GAC. NZVI/GAC had a remarkable removal capacity for acrylonitrile which resulted from the combined effects of reduction, adsorption and micro-electrolysis by the Fe/GAC system. The infrared spectra indicated that Fe and the Fe/GAC micro-electrolysis system played a significant role in degradation of acrylonitrile. Increased biodegradability of acrylonitrile was achieved by pre-treatment with NZVI/GAC before biological treatment. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.