Efficient activation of ozone by zero-valent copper for the degradation of aniline in aqueous solution

A series batch experiments were performed to explore the catalytic role of zero-valent metals, including Fe(0), Co(0), Al(0) and Cu(0), in ozonation degradation of aniline in aqueous solution. It was found that Cu(0) exhibited the best catalytic activity of ozonation: Approximately 98% of the initial aniline (10 mg/L) was destructed by ozone assisted with Cu(0) within 24 min. The dosage of Cu(0) and solution pH were two critical factors affecting aniline degradation. The increase of Cu(0) dosage promoted aniline degradation. And aniline could be effectively removed in an initial pH range of 4-10, whereas a lower or higher solution pH was not favorable for the degradation of aniline. Free radicals were investigated by electron paramagnetic resonance technique, which confirmed that center dot OH was the primary active oxidant responsible for the degradation of aniline. The further mechanism investigation revealed that the generation of center dot OH is ascribed to Fenton-like reaction between Cu(I) and H2O2, both of which are in situ yielded through a series subsequent of reactions starting with oxidation-reduction reaction between ozone and Cu(0). Based on the results obtained in this study, it can be inferred that ozone activated with Cu(0) is a promising approach to degrade organic pollutants. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.