Degradation of contaminants by Cu+-activated molecular oxygen in aqueous solutions: Evidence for cupryl species (Cu3+)

Yong Feng, Po Heng Lee, Deli Wu, Zhengyuan Zhou, Hangkong Li, Kaimin Shih

Research output: Journal article publicationJournal articleAcademic researchpeer-review

50 Citations (Scopus)

Abstract

� 2017 Elsevier B.V. Copper ions (Cu2+and Cu+) have shown potential as Fenton-like activators for the circumneutral removal of organic contaminants from aqueous solutions. However, the major active species (cupryl species (Cu3+) versus hydroxyl radical ([rad]OH)) produced during the activation of hydrogen peroxide by Cu+remain unclear. In this study, Cu+-O2oxidation, in which hydrogen peroxide is produced via the activated decomposition of dissolved molecular oxygen, was used to degrade sulfadiazine, methylene blue, and benzoic acid. The results showed that both sulfadiazine and methylene blue could be efficiently degraded by Cu+-O2oxidation in a wide effective pH range from 2.0 to 10.0. Quenching experiments with different alcohols and the effect of Br−suggested that Cu3+rather than [rad]OH was the major active species. Electron paramagnetic resonance detected 5,5-dimethyl-2-hydroxypyrrolidine-N-oxyl (DMPO-OH), which was probably produced by the oxidation of DMPO by Cu3+or [rad]OH formed as a product of Cu3+decomposition. 4-hydroxybenzoic acid was produced during the degradation of benzoic acid by Cu3+. The findings of this study may help to explain the inconsistency regarding the dominant active species produced by the interaction of Cu+and hydrogen peroxide.
Original languageEnglish
Pages (from-to)81-87
Number of pages7
JournalJournal of Hazardous Materials
Volume331
DOIs
Publication statusPublished - 1 Jan 2017

Keywords

  • Cu +
  • Cu 3+
  • EPR
  • Molecular oxygen
  • Non-radical mechanism

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

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