Tuesday, 15 January 2002
Measuring and Modeling NO Emissions from Biosolid Amended Soils
Fluxes of nitric oxide (NO) were calculated for a field site amended with municipal waste biosolids. An NO Flux algorithm, based on soil temperature, was developed for this field site [NO Flux (ng N m-2 s-1)=1.07exp(0.1365*Tsoil); R2=0.81, n=837] and compared to results using the existing Biogenics Emissions Inventory System (BEIS2) model. Results indicate that for this particular field site the BEIS2 model, which provides the NO input data to many air quality models, would have underestimated NO emissions by a factor of 26. This study was then extrapolated to the biosolid amended soils throughout the state of North Carolina to examine the impacts of neglecting this land-use class on existing air quality models. The study revealed that on average, NO emissions from biosolid amended soils in North Carolina represent approximately 1% of the total biogenic budget. However on smaller scales, such as on the county level and smaller (grid cells in model domain are 4 km X 4 km), NO emissions can comprise a more significant fraction of the biogenic budget. For example, in the 5 counties of North Carolina which received the largest application of biosolids, NO emissions would have been underestimated by approximately 12% when using the existing BEIS2 model. Results of a 13-day ozone episode using BEIS2 generated NO input data and modified input data from this study will be presented.