Department of Civil and Environmental Engineering, University of Maryland, 1173 Glenn L. Martin Hall, College Park, MD, 20742, USA.
Department of Animal and Food Sciences, University of Delaware, 046 Townsend Hall, Newark, DE, 19716, USA.
Environ Pollut. 2018 Jul;238:10-16. doi: 10.1016/j.envpol.2018.02.039. Epub 2018 Mar 9.
Poultry-emitted air pollutants, including particulate matter (PM) and ammonia, have raised concerns due to potential negative effects on human health and the environment. However, developing and optimizing remediation technologies requires a better understanding of air pollutant concentrations, the emission plumes, and the relationships between the pollutants. Therefore, we conducted ten field experiments to characterize PM (total suspended particulate [TSP], particulate matter less than 10 μm in aerodynamic diameter [PM], and particulate matter less than 2.5 μm in aerodynamic diameter [PM]) and ammonia emission-concentration profiles from a typical commercial poultry house. The emission factors of the poultry house, which were calculated using the concentrations and fan speed, were 0.66 (0.29-0.99) g NH-N birdd for ammonia, 52 (44-168) g dAU (AU = animal unit = 500 kg) for TSP, 3.48 (1.16-9.03) g dAU for PM, and 0.07 (0.00-0.36) g dAU for PM. PM and ammonia emission concentrations decreased as distance from the fan increased. Although emission concentrations were similar in the daytime and nighttime, diurnal and nocturnal plume shapes were different due to the increased stability of the atmosphere at night. Particle size distribution analysis revealed that, at a given height, the percentage of PM and PM was consistent throughout the plume, indicating that the larger particles were not settling out of the airstream faster than the smaller particles. Overall, the direction of the measured air pollutant emission plumes was dominated by the tunnel fan ventilation airflow rate and direction instead of the ambient wind speed and direction. This is important because currently-available air dispersion models use ambient or modeled wind speed and direction as input parameters. Thus, results will be useful in evaluating dispersion models for ground-level, horizontally-released, point sources and in developing effective pollutant remediation strategies for emissions.
家禽排放的空气污染物，包括颗粒物 (PM) 和氨，由于对人类健康和环境可能产生负面影响而引起关注。然而，开发和优化修复技术需要更好地了解空气污染物浓度、排放羽流以及污染物之间的关系。因此，我们进行了十次现场实验，以描述来自典型商业家禽舍的 PM（总悬浮颗粒物[TSP]、空气动力学直径小于 10μm 的颗粒物[PM]和空气动力学直径小于 2.5μm 的颗粒物[PM]）和氨排放浓度分布。使用浓度和风扇速度计算得出家禽舍的排放因子为 0.66（0.29-0.99）g NH-N birdd 氨、52（44-168）g dAU（AU=动物单位=500kg）TSP、3.48（1.16-9.03）g dAU PM 和 0.07（0.00-0.36）g dAU PM。随着与风扇距离的增加，PM 和氨的排放浓度降低。尽管在白天和夜间排放浓度相似，但由于夜间大气稳定性增加，昼夜羽流形状不同。粒度分布分析表明，在给定高度处，整个羽流中 PM 和 PM 的百分比保持一致，这表明较大的颗粒没有比较小的颗粒更快地从气流中沉降出来。总体而言，测量的空气污染物排放羽流的方向主要由隧道风扇通风气流速率和方向决定，而不是环境风速和方向。这很重要，因为目前可用的空气扩散模型将环境或模拟风速和方向用作输入参数。因此，结果将有助于评估地面水平、水平释放、点源的扩散模型，并制定有效的污染物修复策略。
