Reducing NOx Emissions to Reduce Conc. of Ammonium Nitrate, PM2.5 Conc. in San Joaquin Valley
Channel: Livestock & Poultry Environ. Learning Community
Date: 2015-05-14

The full proceedings paper is at: www.extension.org/72879

Recently there has been increased interest in regulating ammonia emissions to reduce PM2.5 ("fine" particles with an aerodynamic diameter less than 2.5 micrometers)  concentrations.  However, understanding the quantity of and interactions between ammonia and nitrogen oxide (NOx) is necessary in determining whether controlling ammonia is an effective strategy for reducing PM2.5 in a particular region.  Research from the California Regional Particulate Air Quality Study and other studies has demonstrated the relative abundance of ammonia in comparison to the limited concentrations of the other key precursor, nitric acid formed by NOx emissions.  As a result, NOx acts as the primary limiting precursor for the formation of secondary ammonium nitrate in the San Joaquin Valley (SJV).  Modeling based on data from these studies also found that controlling NOx was the most effective strategy to reduce ammonium nitrate particulate in the SJV and controlling ammonia had little effect on PM2.5 concentrations.