A Theoretical Study of the Oxidation of Hg0 to HgBr2 in the Troposphere
The oxidation of elemental mercury (Hg 0 ) to the divalent gaseous mercury dibromide (HgBr 2 ) has been proposed to account for the removal of Hg 0 during depletion events in the springtime Arctic. The mechanism of this process is explored in this paper by theoretical calculations of the relevant ra...
| Published in: | Environmental Science & Technology |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2004
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| Subjects: | |
| Online Access: | https://portal.findresearcher.sdu.dk/da/publications/484958b0-df6c-11db-9628-000ea68e967b https://doi.org/10.1021/es034680s http://www.scopus.com/inward/record.url?scp=1642392614&partnerID=8YFLogxK |
| Summary: | The oxidation of elemental mercury (Hg 0 ) to the divalent gaseous mercury dibromide (HgBr 2 ) has been proposed to account for the removal of Hg 0 during depletion events in the springtime Arctic. The mechanism of this process is explored in this paper by theoretical calculations of the relevant rate coefficients. Rice-Ramsberger-Kassel-Marcus (RRKM) theory, together with ab initio quantum calculations where required, are used to estimate the following: recombination rate coefficients of Hg with Br, I, and O; the thermal dissociation rate coefficient of HgBr; and the recombination rate coefficients of HgBr with Br, I, OH, and O 2 . A mechanism based on the initial recombination of Hg with Br, followed by the addition of a second radical (Br, I, or OH) in competition with thermal dissociation of HgBr, is able to account for the observed rate of Hg 0 removal, both in Arctic depletion events and at lower latitudes. |
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