| Numéro |
J. Phys. IV France
Volume 107, May 2003
|
|
|---|---|---|
| Page(s) | 189 - 192 | |
| DOI | https://doi.org/10.1051/jp4:20030274 | |
J. Phys. IV France 107 (2003) 189
DOI: 10.1051/jp4:20030274
Atmospheric reactions of gaseous mercury with ozone and hydroxyl radical: Kinetics and product studies
P. Biswajit and A.A. ParisaDepartments of Chemistry, and Atmospheric and Oceanic Sciences, McGill University, Montréal, PQ, H3A 2K6, Canada
Abstract
The dominant form of mercury in the atmosphere is Hg
0. The oxidation processes are
of great importance since oxidized mercury undergoes deposition and can become subject to bioaccumulation.
Experimental data on the gaseous reactions of elemental mercury are very limited
with compare to the reactions of Hg
0 in solutions. We herein carried out kinetic and product
studies on the reactions of gaseous Hg
0 with O
3 and hydroxyl radical (HO) under near atmospheric
pressure (750
1 Torr) and room temperature (298
1 K) in air and N
2. O
3 was produced in a
silent discharge generator (OL 100/SB). Hydroxyl radicals were produced from the photolysis of
isopropyl nitrite in the presence of NO. Kinetics of the reactions with O
3/HO was studied using
absolute and relative techniques by gas chromatography with mass spectroscopic detection (GCMS).
The gas phase reaction between elemental Hg
0 with O
3 has been studied in different
surface-to-volume (s/v) ratios, and evidence for heterogeneous reactions was observed. Existence of
mercuric oxide, Hg
0 by the reaction of atomic Hg
0 with O
3 has been determined in the gas phase
from the suspended aerosols using high temperature mass spectrometry.
© EDP Sciences 2003