A new atmospheric aerosol phase equilibrium model (UHAERO): organic systems

[摘要] In atmospheric aerosols, water and volatile inorganic and organic speciesare distributed between the gas and aerosol phases in accordance withthermodynamic equilibrium.Within an atmospheric particle, liquid and solidphases can exist at equilibrium.Models exist for computation of phaseequilibria for inorganic/water mixtures typical of atmospheric aerosols;when organic species are present, the phase equilibrium problem iscomplicated by organic/water interactions as well as the potentially largenumber of organic species.We present here an extension of the UHAEROinorganic thermodynamic model (Amundson et al., 2006c) to organic/watersystems.Phase diagrams for a number of model organic/water systemscharacteristic of both primary and secondary organic aerosols are computed.Also calculated are inorganic/organic/water phase diagrams that show theeffect of organics on inorganic deliquescence behavior.The effect of thechoice of activity coefficient model for organics on the computed phaseequilibria is explored.

[学科分类] 大气科学