Production of Hydroxylated Polybrominated Diphenyl Ethers (OH-PBDEs) from Bromophenols by Manganese Dioxide

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• 作者：Kunde Lin ; Chao Yan ; Jay Gan
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：January 7, 2014
• 年：2014
• 卷：48
• 期：1
• 页码：263-271
• 全文大小：546K
• ISSN：1520-5851

文摘

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are of significant concern because of their enhanced toxicological effects compared to PBDEs. Research to date has attributed the origin of OH-PBDEs to biological metabolism of PBDEs and natural production in the environment. However, it is unclear how OH-PBDEs are formed naturally. In this study, we explored the formation of OH-PBDEs via the oxidative transformation of simple bromophenols (BPs, e.g., 4-BP, 2,4-DBP, and 2,4,6-TBP) by birnessite (未-MnO₂). Results showed that OH-PBDEs were readily produced by 未-MnO₂ with BPs as precursors. For example, oxidation of 2,4-DBP by 未-MnO₂ yielded 2鈥?OH-BDE-68 and 2鈥?5鈥?OH-BDE-25. Other OH-PBDEs, such as 6-OH-BDE-13, 2鈥?5鈥?OH-BDE-3, 4鈥?OH-BDE-121, and 2鈥?5鈥?OH-BDE-69, were detected from the reaction with 4-BP and 2,4,6-TBP. The formation of OH-PBDEs likely resulted from the oxidative coupling of bromophenoxy radicals. Mild acidic conditions enhanced while coexisting cations (e.g., Na⁺, Mg²⁺, and Ca²⁺) suppressed the transformation. Given the ubiquity of BPs and 未-MnO₂, oxidation of BPs by 未-MnO₂ and other metal oxides is likely an abiotic route for the formation of OH-PBDEs in the environment.