Degradation Mechanism of Cyanobacterial Toxin Cylindrospermopsin by Hydroxyl Radicals in Homogeneous UV/H2O2 Process

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• 作者：Xuexiang He ; Geshan Zhang ; Armah A. de la Cruz ; Kevin E. O鈥橲hea ; Dionysios D. Dionysiou
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：April 15, 2014
• 年：2014
• 卷：48
• 期：8
• 页码：4495-4504
• 全文大小：511K
• 年卷期：v.48,no.8(April 15, 2014)
• ISSN：1520-5851

文摘

The degradation of cylindrospermopsin (CYN), a widely distributed and highly toxic cyanobacterial toxin (cyanotoxin), remains poorly elucidated. In this study, the mechanism of CYN destruction by UV-254 nm/H₂O₂ advanced oxidation process (AOP) was investigated by mass spectrometry. Various byproducts identified indicated three common reaction pathways: hydroxyl addition (+16 Da), alcoholic oxidation or dehydrogenation (鈭? Da), and elimination of sulfate (鈭?0 Da). The initiation of the degradation was observed at the hydroxymethyl uracil and tricyclic guanidine groups; uracil moiety cleavage/fragmentation and further ring-opening of the alkaloid were also noted at an extended reaction time or higher UV fluence. The degradation rates of CYN decreased and less byproducts (species) were detected using natural water matrices; however, CYN was effectively eliminated under extended UV irradiation. This study demonstrates the efficiency of CYN degradation and provides a better understanding of the mechanism of CYN degradation by hydroxyl radical, a reactive oxygen species that can be generated by most AOPs and is present in natural water environment.