Title: Measurement of particulate matter emission fluxes from a beef cattle feedlot using Flux-gradient technique Authors
Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 22, 2013
Publication Date: N/A
Interpretive Summary: Large confined animal feeding operations can be a significant source of dust to surrounding communities. Very fine dust particles are often called particulate matter (PM) and dust particles that have a size smaller than 10 microns are called PM10. PM10 is a type of pollution that is regulated as part of the Clean Air Act. PM10 pollution from cattle feedlots has been identified as an environmental concern, and scientists are currently working to more fully understand the magnitude of the problem and the best ways to reduce PM10 pollution. This study measured PM10 concentrations from stations upwind of a large cattle feedlot and also from a multiple heights above the surface of the feedlot. These measurements were made periodically over approximately 15 months. Using precise measurements of wind speed, wind direction, temperature, and other factors, the scientists in this study were able to estimate the rate at which the PM10 pollution was being released to the atmosphere. They examined factors that contributed to higher rates of release. An important finding was that managing the water content of the cattle pens can be an effective approach to reducing PM10 pollution. Results of this work will be used to advise producers on the best approaches to reduce dust pollution on their farms.
Technical Abstract: Data on air emissions from open-lot beef cattle feedlots are limited. This research was conducted to determine PM10 emission fluxes from a commercial beef cattle feedlot in Kansas using the flux-gradient technique, a widely-used micrometeorological method for gaseous emissions from open sources. Vertical PM10 concentration profiles and micrometeorological parameters were measured at the feedlot using Tapered element oscillating microbalance (TEOM) PM10 samplers and eddy covariance instrumentations, respectively, from May 2010 through September 2011. For warm conditions (temperature of 21 + 10 'C), highest hourly PM10 emission fluxes within the day were observed during the early evening period, from 8:00 p.m. to 9:00 p.m. (198 and 227 mg/m2-hr, respectively). For cold conditions (temperature of -2 + 8 'C), highest PM10 emission fluxes (range of 18 to 32 mg/m2-hr), were observed in the afternoon, from 11:00 a.m. to 3:00 p.m. The hourly trend of PM10 emission fluxes was apparently influenced by friction velocity, temperature and sensible heat flux. PM10 emission flux also was affected by the pen surface water content; a water content of 20% (wet-basis) would be sufficient to effectively reduce PM10 emissions from pens.