Dramatically Enhanced Aerobic Atrazine Degradation with Fe@Fe2O3 Core鈥揝hell Nanowires by Tetrapolyphosphate

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• 作者：Li Wang ; Menghua Cao ; Zhihui Ai ; Lizhi Zhang
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：March 18, 2014
• 年：2014
• 卷：48
• 期：6
• 页码：3354-3362
• 全文大小：467K
• 年卷期：v.48,no.6(March 18, 2014)
• ISSN：1520-5851

文摘

In this study, the effects of an inorganic ligand tetrapolyphosphate on the molecular oxygen activation and the subsequent aerobic atrazine degradation by Fe@Fe₂O₃ core鈥搒hell nanowires were investigated systematically at a circumneutral to alkaline pH range (pH 6.0鈥?.0). We interestingly found that the addition of tetrapolyphosphate could enhance the aerobic atrazine degradation rate 955 times, which was even 10 times that of the traditional organic ligand ethylenediamine tetraacetate. This tetrapolyphosphate induced dramatic aerobic atrazine degradation enhancement could be attributed to two factors. One was that the presence of tetrapolyphosphate strongly suppressed hydrogen evolution from the reduction of proton by Fe@Fe₂O₃ core鈥搒hell nanowires through proton confinement, leaving over more electrons for the reduction of Fe(III) to Fe(II) and the subsequent molecular oxygen activation. The other was that the complexation of tetrapolyphosphate with ferrous ions not only guaranteed enough soluble Fe(II) for Fenton reaction, but also provided another route to produce more 鈥H in the solution via the single-electron molecular oxygen reduction pathway. We employed gas chromatography鈥搈ass spectrometry and liquid chromatography鈥搈ass spectrometry to identify the atrazine degradation intermediates and proposed a possible aerobic atrazine degradation pathway. This study not only sheds light on the promotion effects of ligands on the molecular oxygen activation by nanoscale zerovalent iron, but also offers a facile and green iron-based method for the oxidative atrazine removal.