Large contribution of fine carbonaceous aerosols from municipal waste burning inferred from distributions of diacids and fatty acids

To investigate the origins, other than fossil fuel combustion and biomass burning, of urban carbonaceosus aerosols, we studied the fine (PM 2.5 ) aerosols collected in Guiyang, Southwest China in winter (December 10–23) 2012 for organic carbon (OC), elemental carbon (EC) and water-soluble diacids, oxoacids, α -dicarbonyls and fatty acids as well as inorganic ions. Oxalic acid (C 2 ) found to be the most abundant diacid species followed by succinic (C 4 ) and terephthalic ( t -Ph) acids, respectively. Even-carbon numbered fatty acids showed high abundances with a peak at C 16 . OC, EC and most of diacids and related compounds, but not inorganic ions, showed a similar temporal pattern with a drastic rise in December 15 day- and night-time samples during the campaign. Based on molecular distributions of diacids and fatty acids, and linear relations of OC and EC with selected marker ions and diacid species, we found that the organics and EC in PM 2.5 are mainly derived from higher plant/cooking and municipal waste burning emissions in Guiyang. This study implies that municipal waste burning largely contributes to carbonaceous aerosols and warrants a need of further research on its role in aerosol loading and air quality in the urban atmosphere.