Secondary organic aerosol formation from idling gasoline passenger vehicle emissions investigated in a smog chamber
Item
Title (Dublin Core)
Secondary organic aerosol formation from idling gasoline passenger vehicle emissions investigated in a smog chamber
Description (Dublin Core)
Gasoline vehicles have recently been pointed out as potentially the main source of anthropogenic secondary organic aerosol (SOA) in megacities. However, there is a lack of laboratory studies to systematically investigate SOA formation in real-world exhaust. In this study, SOA formation from pure aromatic precursors, idling and cold start gasoline exhaust from three passenger vehicles (EURO2–EURO4) were investigated with photo-oxidation experiments in a 6 m<sup>3</sup> smog chamber. The experiments were carried out down to atmospherically relevant organic aerosol mass concentrations. The characterization instruments included a high-resolution aerosol mass spectrometer and a proton transfer mass spectrometer. It was found that gasoline exhaust readily forms SOA with a signature aerosol mass spectrum similar to the oxidized organic aerosol that commonly dominates the organic aerosol mass spectra downwind of urban areas. After a cumulative OH exposure of ~5 × 10<sup>6</sup> cm<sup>−3</sup> h, the formed SOA was 1–2 orders of magnitude higher than the primary OA emissions. The SOA mass spectrum from a relevant mixture of traditional light aromatic precursors gave <i>f</i><sub>43</sub> (<i>mass fraction at m/z = 43</i>), approximately two times higher than to the gasoline SOA. However O : C and H : C ratios were similar for the two cases. Classical C<sub>6</sub>–C<sub>9</sub> light aromatic precursors were responsible for up to 60% of the formed SOA, which is significantly higher than for diesel exhaust. Important candidates for additional precursors are higher-order aromatic compounds such as C<sub>10</sub> and C<sub>11</sub> light aromatics, naphthalene and methyl-naphthalenes. We conclude that approaches using only light aromatic precursors give an incomplete picture of the magnitude of SOA formation and the SOA composition from gasoline exhaust.
Creator (Dublin Core)
Nordin, E. Z.
Eriksson, A. C.
Roldin, P.
Nilsson, P. T.
Carlsson, J. E.
Kajos, M. K.
Hellén, H.
Wittbom, C.
Rissler, J.
Löndahl, J.
Swietlicki, E.
Svenningsson, B.
Bohgard, M.
Kulmala, M.
Hallquist, M.
Pagels, J. H.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-13-6101-2013
https://acp.copernicus.org/articles/13/6101/2013/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
