Submitted to: American Association for Aerosol Research
Publication Type: Abstract Only
Publication Acceptance Date: 4/18/2018
Publication Date: 9/16/2018
Citation: Silva, P.J. 2018. Formation and growth of aerosol from agricultural emissions. American Association for Aerosol Research. Paper No. 1.
Technical Abstract: Particulate matter influences on the environment from agriculture are usually considered to be dominantly coarse mode dust with some secondary component in the fine mode from the impact of ammonia emission. Indeed, some scientists have started investigating whether and how ammonia can interact with anthropogenic and biogenic hydrocarbons to form secondary aerosol. But agricultural emissions include many reactive volatile organic compounds that may potentially contribute to secondary aerosols with or without ammonia. We have performed several field sampling experiments at a poultry house, a dairy, and a hog farm to find evidence for secondary aerosol formation, including new particle formation at the source. We use a scanning mobility particle sizer (SMPS) to acquire size distributions of particles from 10 nm – 0.5 um in 5-min intervals. Data from the SMPS indicates that particle growth and new particle formation events are observed at all facilities by the SMPS very near source. Some formation and growth events are rapid with particle growth of up to 40 nm per hour. Some data for gas phase measurements of nitrogen- and sulfur-containing compounds will be discussed in terms of whether it is impacting the presence of particle formation or growth events. These data suggest that agricultural emissions may be underestimated as a source for new particulate matter in rural areas and that it is not just the interaction of ammonia with the urban plume that produces secondary aerosol.