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Titel |
Burning of olive tree branches: a major organic aerosol source in the Mediterranean |
VerfasserIn |
E. Kostenidou, C. Kaltsonoudis, M. Tsiflikiotou, E. Louvaris, L. M. Russell, S. N. Pandis |
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 ; 13, no. 17 ; Nr. 13, no. 17 (2013-09-03), S.8797-8811 |
Datensatznummer |
250085672
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Publikation (Nr.) |
copernicus.org/acp-13-8797-2013.pdf |
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Zusammenfassung |
Aerosol produced during the burning of olive tree branches was characterized
with both direct source sampling (using a mobile smog chamber) and with
ambient measurements during the burning season. The fresh particles were
composed of 80% organic matter, 8–10% black carbon (BC), 5%
potassium, 3–4% sulfate, 2–3% nitrate and 0.8% chloride. Almost
half of the fresh olive tree branches burning organic aerosol (otBB-OA)
consisted of alkane groups. Their mode diameter was close to 70 nm. The
oxygen to carbon (O : C) ratio of the fresh otBB-OA was 0.29 ± 0.04. The
mass fraction of levoglucosan in PM1 was 0.034–0.043, relatively low in
comparison with most fuel types. This may lead to an underestimation of the
otBB-OA contribution if levoglucosan is being used as a wood burning tracer.
Chemical aging was observed during smog chamber experiments, as f44 and
O : C ratio increased, due to reactions with OH radicals and O3. The
otBB-OA AMS mass spectrum differs from the other published biomass burning
spectra, with a main difference at m/z 60, used as levoglucosan tracer. In
addition to particles, volatile organic compounds (VOCs) such as methanol,
acetonitrile, acrolein, benzene, toluene and xylenes are also emitted.
Positive matrix factorization (PMF) was applied to the ambient organic
aerosol data and 3 factors could be identified: OOA (oxygenated organic
aerosol, 55%), HOA (hydrocarbon-like organic aerosol, 11.3%) and
otBB-OA 33.7%. The fresh chamber otBB-OA AMS spectrum is close to the PMF
otBB-OA spectrum and resembles the ambient mass spectrum during olive tree
branches burning periods. We estimated an otBB-OA emission factor of
3.5 ± 0.9 g kg−1. Assuming that half of the olive tree branches
pruned is burned in Greece, 2300 ± 600 tons of otBB-OA are emitted
every year. This activity is one of the most important fine aerosol sources
during the winter months in Mediterranean countries. |
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