Photolysis of Low-Brominated Diphenyl Ethers and Their Reactive Oxygen Species-Related Reaction Mechanisms in an Aqueous System

PLoS One. 2015 Aug 14;10(8):e0135400. doi: 10.1371/journal.pone.0135400. eCollection 2015.

Abstract

To date, no report was concerned with participation of reactive oxygen species in waters during photolysis of low-brominated diphenyl ethers (LBDEs). Herein, we found that electron spin resonance (ESR) signals rapidly increased with increasing irradiation time in the solution of LBDEs and 4-oxo-TMP solutions. But this phenomenon did not occur in the presence of NaN3 (1O2 quencher) demonstrating generation of 1O2 in process of LBDEs photolysis. The indirect photolytic contribution rate for BDE-47 and BDE-28 was 18.8% and 17.3% via 1O2, and 4.9% and 6.6% via ·OH, respectively. Both D2O and NaN3 experiments proved that the indirect photolysis of LBDEs was primarily attributable to 1O2. The bimolecular reaction rate constants of 1O2 with BDE-47 and BDE-28 were 3.12 and 3.64 × 106 M-1 s-1, respectively. The rate constants for BDE-47 and BDE-28 (9.01 and 17.52 × 10-3 min-1), added to isopropyl alcohol, were very close to those (9.65 and 18.42 × 10-3 min-1) in water, proving the less indirect photolytic contribution of ·OH in water. This is the first comprehensive investigation examining the indirect photolysis of LBDEs in aqueous solution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electron Spin Resonance Spectroscopy
  • Halogenated Diphenyl Ethers / chemistry*
  • Photolysis*
  • Polybrominated Biphenyls / chemistry*
  • Reactive Oxygen Species / chemistry*
  • Water / chemistry*

Substances

  • Halogenated Diphenyl Ethers
  • Polybrominated Biphenyls
  • Reactive Oxygen Species
  • Water
  • 2,2',4,4'-tetrabromodiphenyl ether
  • tribromodiphenyl ether 28

Grants and funding

This work was jointly supported by the National Natural Science Foundation of China (21377100), the Natural Science Foundation of Zhejiang Province (LY13D010006 and LY15B070009), and the Analyzing and Testing Project of Zhejiang Province (2015C37006 and 2015C37033).