Abstract View
NH3 and PM2.5 Characteristics at an Agricultural Site
JOONWOO KIM, Haebum Lee, Taewoong Gong, Kihong Park, Gwangju Institute of Science and Technology
Abstract Number: 349
Working Group: Aerosol Chemistry
Abstract
The majority of ammonia (NH3) is emitted from agricultural sites by fertilizer application and livestock waste. NH3 is one of the major precursors of particulate matter less than 2.5 μm (PM2.5) since NH3 reacts with acidic compounds in the atmosphere, producing ammonium (NH4+) salts. While NH3 affects the local environment with the lifetime of several hours, NH4+ have impacts on longer ranges with the lifetime of several days. NH3 is oxidized to NOx by soil bacteria activities in agricultural sites, which are important to O3 and secondary aerosol formation. Field studies in agricultural sites were barely conducted but are necessary to understand the relationship between NH3 and PM2.5 considering that agricultural sites have the NH3-rich atmosphere. In this study, the concentrations of NH3, NO2, and PM2.5 were measured downwind of swine feedlots at an agricultural site in Korea in June and July, 2020. The monitoring site was 0.7 km east of the center of swine concentrated animal feeding operations (CAFOs) containing ~50,000 head. The concentrations of NH3 and NO2 were recorded by an open-path ultraviolet differential optical absorption spectroscopy (DOAS). The concentrations of PM2.5 were measured using an optical particle counter. Wind speed, wind direction, temperature and relative humidity were also recorded using an automatic weather station (AWS). PM2.5 concentrations from national air quality monitoring network stations operated by Korea Environment Corporation within ~20 km from the sampling site were collected to examine regional distributions. The results of the field measurements on NH3, NO2, and PM2.5 concentrations will be displayed and the characteristics following meteorological conditions will be discussed. Further analysis on other measured parameters is ongoing and will be presented briefly.