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| Titel |
Validation of an experimental setup to study atmospheric heterogeneous ozonolysis of semi-volatile organic compounds |
| VerfasserIn |
M. Pflieger, M. Goriaux, B. Temime-Roussel, S. Gligorovski, A. Monod, H. Wortham |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 6 ; Nr. 9, no. 6 (2009-03-24), S.2215-2225 |
| Datensatznummer |
250007105
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| Publikation (Nr.) |
 copernicus.org/acp-9-2215-2009.pdf |
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| Zusammenfassung |
| There is currently a need for reliable experimental procedures to
follow the heterogeneous processing simulating the atmospheric
conditions. This work offers an alternative experimental device to
study the behaviour of semi-volatile organic compounds (SVOC) that
presumably exhibit extremely slow reactivity (e.g. pesticides)
towards the atmospheric oxidants such as ozone and OH. Naphthalene
was chosen as a test compound since it was widely studied in the
past and hence represents a good reference. Prior to ozone exposure,
the gaseous naphthalene was adsorbed via gas-solid equilibrium on
silica and XAD-4 particles. Then, the heterogeneous reaction of
ozone with adsorbed naphthalene was investigated in specially
designed flow tube reactors. After the reaction, the remaining
naphthalene (adsorbed on particles surface) was extracted, filtered
and analyzed by Gas Chromatography-Flame Ionization Detector
(GC-FID). Thus, the kinetics results were obtained following the
consumption of naphthalene. Using this procedure, the rate constants
of heterogeneous ozonolysis of naphthalene (kO3
silica=2.26 (±0.09)×10−17 cm3 molec−1 s−1 and kO3 XAD-4=4.29 (±1.06)×10−19 cm3 molec−1 s−1) were
determined for silica and XAD-4 particles, at 25°C and
relative humidity <0.7%. The results show that the nature of the
particles significantly affects the kinetics and that heterogeneous
ozonolysis of naphthalene is faster than its homogeneous ozonolysis
in the gas phase. |
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