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| Titel |
Impact of aftertreatment devices on primary emissions and secondary organic aerosol formation potential from in-use diesel vehicles: results from smog chamber experiments |
| VerfasserIn |
R. Chirico, P. F. DeCarlo, M. F. Heringa, T. Tritscher, Rene Richter, A. S. H. Prévôt, J. Dommen, E. Weingärtner, G. Wehrle, M. Gysel, M. Laborde, U. Baltensperger |
| 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 ; 10, no. 23 ; Nr. 10, no. 23 (2010-12-06), S.11545-11563 |
| Datensatznummer |
250008939
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| Publikation (Nr.) |
 copernicus.org/acp-10-11545-2010.pdf |
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| Zusammenfassung |
| Diesel particulate matter (DPM) is a significant source of aerosol in urban
areas and has been linked to adverse health effects. Although newer European
directives have introduced increasingly stringent standards for primary PM
emissions, gaseous organics emitted from diesel cars can still lead to large
amounts of secondary organic aerosol (SOA) in the atmosphere. Here we
present results from smog chamber investigations characterizing the primary
organic aerosol (POA) and the corresponding SOA formation at atmospherically
relevant concentrations for three in-use diesel vehicles with different
exhaust aftertreatment systems. One vehicle lacked exhaust aftertreatment
devices, one vehicle was equipped with a diesel oxidation catalyst (DOC) and
the third vehicle used both a DOC and diesel particulate filter (DPF). The
experiments presented here were obtained from the vehicles at conditions
representative of idle mode, and for one car in addition at a speed of 60 km/h.
An Aerodyne high-resolution time-of-flight aerosol mass spectrometer
(HR-ToF-AMS) was used to measure the organic aerosol (OA) concentration and
to obtain information on the chemical composition. For the conditions
explored in this paper, primary aerosols from vehicles without a particulate
filter consisted mainly of black carbon (BC) with a low fraction of organic
matter (OM, OM/BC < 0.5), while the subsequent aging by photooxidation
resulted in a consistent production of SOA only for the vehicles without a
DOC and with a deactivated DOC. After 5 h of aging ~80% of the
total organic aerosol was on average secondary and the estimated "emission
factor" for SOA was 0.23–0.56 g/kg fuel burned. In presence of both a DOC
and a DPF, only 0.01 g SOA per kg fuel burned was produced within 5 h
after lights on. The mass spectra indicate that POA was mostly a
non-oxidized OA with an oxygen to carbon atomic ratio (O/C) ranging from
0.10 to 0.19. Five hours of oxidation led to a more oxidized OA with an O/C
range of 0.21 to 0.37. |
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