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| Titel |
Characterization of particulate matter emissions from on-road gasoline and diesel vehicles using a soot particle aerosol mass spectrometer |
| VerfasserIn |
T. R. Dallmann, T. B. Onasch, T. W. Kirchstetter, D. R. Worton, E. C. Fortner, S. C. Herndon, E. C. Wood, J. P. Franklin, D. R. Worsnop, A. H. Goldstein, R. A. Harley |
| 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 ; 14, no. 14 ; Nr. 14, no. 14 (2014-07-29), S.7585-7599 |
| Datensatznummer |
250118909
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| Publikation (Nr.) |
 copernicus.org/acp-14-7585-2014.pdf |
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| Zusammenfassung |
| Particulate matter (PM) emissions were measured in July 2010 from on-road
motor vehicles driving through a highway tunnel in the San Francisco Bay
area. A soot particle aerosol mass spectrometer (SP-AMS) was used to measure
the chemical composition of PM emitted by gasoline and diesel vehicles at
high time resolution. Organic aerosol (OA) and black carbon (BC)
concentrations were measured during various time periods that had different
levels of diesel influence, as well as directly in the exhaust plumes of
individual heavy-duty (HD) diesel trucks. BC emission factor distributions
for HD trucks were more skewed than OA distributions (N = 293), with the
highest 10% of trucks accounting for 56 and 42% of total measured BC
and OA emissions, respectively. OA mass spectra measured for HD truck
exhaust plumes show cycloalkanes are predominate in exhaust OA emissions
relative to saturated alkanes (i.e., normal and iso-paraffins), suggesting
that lubricating oil rather than fuel is the dominant source of primary
organic aerosol (POA) emissions in diesel vehicle exhaust. This finding is
supported by the detection of trace elements such as zinc and phosphorus in
the exhaust plumes of individual trucks. Trace elements were emitted
relative to total OA at levels that are consistent with typical weight
fractions of commonly used additives present in lubricating oil. A
comparison of measured OA and BC mass spectra across various sampling
periods revealed a high degree of similarity in OA and BC emitted by
gasoline and diesel engines. This finding indicates a large fraction of OA
in gasoline exhaust is lubricant-derived as well. The similarity in OA and
BC mass spectra for gasoline and diesel engine exhaust is likely to confound
ambient source apportionment efforts to determine contributions to air
pollution from these two important sources. |
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