Development of application of a dual-impedance radial diffusion model for the simulation of semi-volatile organic compound partitioning in combustion aerosols
- Univ. of North Carolina, Chapel Hill, NC (United States)
The fate of semi-volatile organic compounds in the atmosphere is largely dependent on their partitioning between the gas phase and sorption to particulate matter. Since real atmospheres have been shown to deviate significantly from gas-particle equilibrium, dynamic mass transfer models are needed to accurately predict partitioning. In this work, a dual-impedance radial diffusion model is presented that is able to accurately reproduce the partitioning of deuterated fluoranthene in wood and diesel soot atmospheres generated in a large outdoor Teflon-film chamber. It is shown that the dual-impedance model produces significantly better fits to the experimental results than a one-layer model, and that surface mass transfer is not rate limiting in these systems. This work lays the foundation for incorporating dynamic gas-particle partitioning models into larger atmospheric models, such as urban airshed models. By conducting experiments under various conditions (e.g., temperature and humidity), relationships for optimized apparent diffusivities as a function of compound, particle source, and atmospheric conditions may be developed. After including photochemical reactions, the model may be used to predict the fate of semi-volatile organic compounds in real atmospheres.
- OSTI ID:
- 617804
- Report Number(s):
- CONF-9704195--
- Country of Publication:
- United States
- Language:
- English
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