Atmospheric peroxides in a polluted subtropical environment: Seasonal variation, sources and sinks, and importance of heterogeneous processes

Jia Guo, Andreas Tilgner, Chungpong Yeung, Zhe Wang, Peter K.K. Louie, Connie W.Y. Luk, Zheng Xu, Chao Yuan, Yuan Gao, Steven Poon, Hartmut Herrmann, Shuncheng Lee, Ka Se Lam, Tao Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

43 Citations (Scopus)

Abstract

Hydrogen peroxide (H2O2) and organic peroxides play an important role in atmospheric chemistry, but knowledge of their abundances, sources, and sinks from heterogeneous processes remains incomplete. Here we report the measurement results obtained in four seasons during 2011-2012 at a suburban site and a background site in Hong Kong. Organic peroxides were found to be more abundant than H2O2, which is in contrast to most previous observations. Model calculations with a multiphase chemical mechanism suggest important contributions from heterogeneous processes (primarily transition metal ion [TMI]-HOx reactions) to the H2O2budget, accounting for about one-third and more than half of total production rate and loss rate, respectively. In comparison, they contribute much less to organic peroxides. The fast removal of H2O2by these heterogeneous reactions explains the observed high organic peroxide fractions. Sensitivity analysis reveals that the role of heterogeneous processes depends on the abundance of soluble metals in aerosol, serving as a net H2O2source at low metal concentrations, but as a net sink with high metal loading. The findings of this study suggest the need to consider the chemical processes in the aerosol aqueous phase when examining the chemical budget of gas-phase H2O2.
Original languageEnglish
Pages (from-to)1443-1450
Number of pages8
JournalEnvironmental Science and Technology
Volume48
Issue number3
DOIs
Publication statusPublished - 4 Feb 2014

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

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