Author(s)

Henry F. Bonifacio¹, Ronaldo G. Maghirang^2*, Steven L. Trabue³, Laura L. McConnell⁴, John H. Prueger³, Edna R. Bonifacio²

¹Pasture Systems and Watershed Management Research Unit, USDA Agricultural Research Service, University Park, PA, USA.
²Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, KS, USA.
³National Laboratory of Agriculture and the Environment, USDA Agricultural Research Service, Ames, IA, USA.
⁴Bayer Crop Science, 2 T.W. Alexander Dr., Research Triangle Park, NC, USA.

Large commercial cattle feedlots are significant sources of particulate matter (PM) emissions. This research compared WindTrax and the flux-gradient technique in estimating emissions of PM with aerodynamic diameter < 10 μm (PM₁₀) from cattle feedlots. Meteorological conditions were measured and PM₁₀ concentrations were profiled vertically (i.e., 2.0 to 7.62 m) at a large commercial beef cattle feedlot in Kansas from May through September 2011. Results show that between the two methods evaluated, WindTrax was least sensitive to changes in heights and number of heights used in the emission estimation, with calculated PM₁₀ emission rates varying by up to 18% only. On the other hand, PM₁₀ emission rates produced by the flux-gradient technique varied by almost 56% when changing either heights and/or number of heights in emission calculation. Both methods were sensitive to height settings, with their respective PM₁₀ emission rates higher when the lowest height setting (2.0 m) was included. Calculating PM₁₀ emission rates with the 7.62-m height led to lower estimates for the flux-gradient technique but no significant change in estimates was observed for WindTrax. As demonstrated in this study, for the flux-gradient technique, settings for the lowest and highest heights were the most critical in emission estimation; exclusion of other heights in between showed only to 2% to 6% change in calculated PM₁₀ emission rates. In general, the higher PM₁₀ emission rates were obtained with the flux-gradient technique. However, eliminating the lowest height (2.0 m) in the calculation and, at the same time, using a specific set of formulations for the flux-gradient technique made its calculated PM₁₀ emission rates slightly lower (but not significantly different) than those from WindTrax.

PM₁₀ Emission Rates, Cattle Feedlots, Emission Rate Estimation, WindTrax, Flux-Gradient Technique

Bonifacio, H. , Maghirang, R. , Trabue, S. , McConnell, L. , Prueger, J. and Bonifacio, E. (2016) Determination of Particulate Matter Emissions from Cattle Feedlots Using Wind-Trax and the Flux-Gradient Technique. Journal of Environmental Protection, 7, 176-189. doi: 10.4236/jep.2016.72016.