Data on air emissions from open-lot beef cattle (Bos taurus) feedlots are limited. This research was conducted to determine fluxes of particulate matter with an aerodynamic diameter =10 mm (PM10) from a commercial beef cattle feedlot in Kansas using the fluxgradient technique, a widely used micrometeorological method for air emissions from open sources. Vertical PM10 concentration profiles and micrometeorological parameters were measured at the feedlot using tapered element oscillating microbalance PM10 samplers and eddy covariance instrumentations (i.e., sonic anemometer and infrared hygrometer), respectively, from May 2010 through September 2011, representing feedlot conditions with air temperatures ranging from -24 to 39°C. Calculated hourly PM10 fluxes varied diurnally and seasonally, ranging up to 272 mg m-2 h-1, with an overall median of 36 mg m-2 h-1. For warm conditions (air temperature of 21 ± 10°C), the highest hourly PM10 fluxes (range 116-146 mg m-2 h-1) were observed during the early evening period, from 2000 to 2100 h. For cold conditions (air temperature of -2 ± 8°C), the highest PM10 fluxes (range 14-27 mg m-2 h-1) were observed in the afternoon, from 1100 to 1500 h. Changes in the hourly trend of PM10 fluxes coincided with changes in friction velocity, air temperature, sensible heat flux, and surface roughness. The PM10 emission was also affected by the pen surface water content, where a water content of at least 20% (wet basis) would be sufficient to effectively reduce PM10 emissions from pens by as much as 60%.
ASJC Scopus subject areas
- Environmental Engineering
- Water Science and Technology
- Waste Management and Disposal
- Management, Monitoring, Policy and Law