US EPA

2150827 

Journal Article 

Modeling urban films using a dynamic multimedia fugacity model 

Csiszar, SA; Diamond, ML; Thibodeaux, LJ 

2012 

Yes 

Chemosphere
ISSN: 0045-6535
EISSN: 1879-1298 

87 

9 

1024-1031 

English 

22280983 

10.1016/j.chemosphere.2011.12.044 

WOS:000303292700006 

A thin film coats impervious urban surfaces that can act as a source or sink of organic pollutants to the greater environment. We review recent developments in the understanding of film and film-associated pollutant behavior and incorporate them into an unsteady-state version of the fugacity based Multimedia Urban Model (MUM), focusing on detailed considerations of surface film dynamics. The model is used to explore the conditions under which these atmospherically-derived films act as a temporary source of chemicals to the air and/or storm water. Assuming film growth of 2.1 nm d(-1) (Wu et al., 2008a), PCB congeners 28 and 180 reach air-film equilibrium within hours and days, respectively. The model results suggest that the film acts as a temporary sink of chemicals from air during dry and cool weather, as a source to air in warmer weather, and as a source to storm water and soil during rain events. Using the downtown area of the City of Toronto Canada, as a case study, the model estimates that nearly 1 g d(-1) of ∑(5)PCBs are transferred from air to film to storm water. 

Surface films; Multimedia modeling; Unsteady-state systems; Polychlorinated biphenyls; Semi-volatile organic compounds; Urban environment