Turbulence and Lidar Measurements of Particulate Emissions near a Poultry Facility

The emission and dispersion of particulates and gases from concentrated animal feeding operations (CAFO's) is a current issue in science and society. The transport of particulates, odors and toxic chemical species from the source into the local boundary layer is largely determined by turbulence. Any current models that attempt to simulate the dispersion of particles must either specify or assume various statistical properties of the turbulence field. Statistical properties of turbulence are well documented for idealized boundary layers above uniform surfaces. However, a CAFO facility represents a complex surface of bluff bodies (buildings and shelterbelts) that distort the near-field turbulence properties encompassing the buildings. Previous Lidar studies of particulate dispersion over a similar facility indicated that plumes of particulates move in complex yet organized patterns that would not be explained by the properties of turbulence generally assumed in models. The objective of this study was to characterize near surface turbulence properties, statistics and particulate emissions in the flow field of a poultry facility. Eddy covariance towers were erected in the upwind, within the building array and downwind regions of the flow field. A particulate Lidar located away from the facility scanned the upwind, within complex and downwind portions of the facility for particulate concentrations. Substantial changes in turbulence characteristics were observed as the mean wind flow traversed from an upwind to near buildings and beyond the structures. Detailed spectral analysis and turbulence statistics will be presented. Lidar measurements of particulate concentration, plume evolution and dispersion as well as particulate emission flux will be shown.