Revisiting the Oxidizing Capacity of the Periodate-H2O2Mixture: Identification of the Primary Oxidants and Their Formation Mechanisms

Yelim Kim, Hongshin Lee, Hoon Oh, Zeeshan Haider, Jaemin Choi, Yong Uk Shin, Hyoung Il Kim, Jaesang Lee

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

This study reexamined the mechanisms for oxidative organic degradation by the binary mixture of periodate and H2O2(PI/H2O2) that was recently identified as a new advanced oxidation process. Our findings conflicted with the previous claims that (i) hydroxyl radical (OH) and singlet oxygen (1O2) contributed as the primary oxidants, and (ii) OH production resulted from H2O2reduction by superoxide radical anion (O2•-). PI/H2O2exhibited substantial oxidizing capacity at pH < 5, decomposing organics predominantly by OH. The likelihood of a switch in the major oxidant under varying pH conditions was revealed. IO4-as the major PI form under acidic conditions underwent one-electron reduction by H2O2to yield radical intermediates, whereas H2I2O104-preferentially occurring at pH > 7 caused 1O2generation through two-electron oxidation of H2O2. PI reduction by O2•-was suggested to be a key reaction in OH production, on the basis of the electron paramagnetic resonance detection of methyl radicals in the dimethyl sulfoxide solutions containing PI and KO2, and the absence of deuterated and 18O-labeled hydroxylated intermediates during PI activation using D2O and H218O2. Finally, simple oxyanion mixing subsequent to electrochemical PI and H2O2production achieved organic oxidation, enabling a potential strategy to minimize the use of chemicals.

Original languageEnglish
Pages (from-to)5763-5774
Number of pages12
JournalEnvironmental Science and Technology
Volume56
Issue number9
DOIs
Publication statusPublished - 2022 May 3

Keywords

  • electrochemical production
  • hydrogen peroxide
  • hydroxyl radical
  • periodate
  • singlet oxygen

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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