Chamber simulation on the formation of secondary organic aerosols (SOA) from diesel vehicle exhaust in China
- 1State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
- 2University of Chinese Academy of Sciences, Beijing 100049, China
- 3Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
- 4Division of Environment, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
- 5Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), CNRS, 45071 Orléans cedex 02, France
- 6Institut de Recherches sur la Catalyse et l’Environnement de Lyon (IRCELYON), CNRS, UMR5256, Villeurbanne F-69626, France
Abstract. In China primary particulate matter emission from on-road vehicles is predominantly coming from diesels, yet secondary organic aerosols (SOA) formed from diesel emission may be also of greater significance due to more intermediate volatile organic compounds (IVOC) in the exhaust. Here we introduced exhaust from in-use diesel vehicles under warm idling condition directly into an indoor smog chamber with a 30 m3 Teflon reactor, and investigated the SOA formation as well as chemical aging of organic aerosols during photo-oxidation. The emission factors of primary organic aerosol (POA) and black carbon (BC) for the three typical Chinese diesel vehicles ranged 0.18–0.91 and 0.15–0.51 g kg-fuel−1, respectively; and the SOA production factors ranged 0.50–1.8 g kg-fuel−1 with an average SOA/POA ratio of 1.6. Aromatic hydrocarbons could only explain less than 3 % of SOA formed during aging, and IVOC and oxygenated VOC might contribute substantially to SOA formation. High resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) resolved that POA dominated by CH classes (alkanes, cycloalkanes and alkenes) with high abundances of the CnH2n+1 and CnH2n-1 fragments, and after photo-oxidation the fraction of CH classes and the H/C ratios decreased, while the fraction of CHO, as well as the ratios of O/C and of organic matter to organic carbon (OM/OC), all increased. The plot of f44 (ratio of m/z 44 to the total signal in a mass spectrum) versus f43 indicated that diesel SOA were semi-volatile oxygenated organic aerosols (SV-OOA). The slopes of O:C versus H:C element ratios in the Van Krevelen diagram ranged from −0.47 to −0.68, suggesting a combination of carboxylic acid and alcohols/peroxides formed during the aging of diesel exhaust.
Wei Deng et al.
Wei Deng et al.
Wei Deng et al.
3 citations as recorded by crossref.
- Secondary organic aerosol formation from photo-oxidation of toluene with NO x and SO 2 : Chamber simulation with purified air versus urban ambient air as matrix W. Deng et al. 10.1016/j.atmosenv.2016.11.047
- Chemical Compositions of PM2.5 Emitted from Diesel Trucks and Construction Equipment Y. Liu et al. 10.1007/s41810-017-0020-2
- Characterization and source apportionment of carbonaceous PM2.5 particles in China - A review X. Wu et al. 10.1016/j.atmosenv.2018.06.025