Sorption of a diverse set of organic vapors to diesel soot and road tunnel aerosols

In a traffic-dominated environment sorption of organic pollutants to exhaust aerosols can strongly determine their further fate. The sorption properties of two aerosol samples representing different exhaust sources have been determined for a large set of diverse organic vapors. For pure diesel soot we could identify adsorption to elemental carbon (EC) as the dominant sorption process. We used our experimental equilibrium adsorption coefficients to derive a predictive model for adsorption on soot in line with adsorption models for other surfaces published earlier. On road tunnel aerosols, both adsorption to EC and absorption in organic matter (OM) governed the observed sorption and the data could not be further evaluated in terms of a specific sorption mechanism.