Secondary Organic Aerosol Formation and Gas/Aerosol Partitioning

[摘要] An intensive smog chamber study has revealed that secondary organic aerosol (SOA) formation follows Raoult's Law type gas/aerosol absorption thermodynamics. SOA formation was shown to occur via the gas/aerosol partitioning of semi-volatile, oxidation products rather than through the condensation of saturated, non-volatile products. The major consequence of this finding is that SOA yields are not constant, but rather are a function of the organic aerosol mass concentration. The theory has been used to successfully describe the aerosol formation potential of seventeen individual aromatic species, eight biogenic compounds, two different simple hydrocarbon precursor mixtures, and twelve different blends of whole gasoline vapor, in hundreds of smog chamber experiments. These results have been included in a 3-dimensional size- and chemically-resolved atmospheric chemical-transport model and used to simulate SOA formation in the South Coast Air Basin. The inherent dependence of SOA concentrations on primary organic aerosol (POA) concentrations, places strict constraints on organic and elemental carbon aerosol emissions inventories.

[发布机构] University:California Institute of Technology;Department:Engineering and Applied Science

[关键词] Environmental Engineering Science