Assessment of particulate matter and ammonia emissions and respective plume profiles from a commercial poultry house

Authors: YAO, Q. - University Of Maryland; YANG, Z. - University Of Maryland; LI, H. - University Of Delaware; BUSER, M.D. - Oklahoma State University; Wanjura, John; Downey, Peter; ZHENG, C. - University Of Delaware; CRAIGE, C. - Oklahoma State University; TORRENTS, A. - University Of Maryland; MCCONNELL, L.L. - University Of Maryland; HOLT, G.A. - US Department Of Agriculture (USDA); Hapeman, Cathleen

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2018
Publication Date: 7/1/2018
Citation: Yao, Q., Yang, Z., Li, H., Buser, M., Wanjura, J.D., Downey, P.M., Zheng, C., Craige, C., Torrents, A., Mcconnell, L., Holt, G., Hapeman, C.J. 2018. Assessment of particulate matter and ammonia emissions and respective plume profiles from a commercial poultry house. Agriculture, Ecosystems and Environment. 238:10-16. https://doi.org/10.1016/j.envpol.2018.02.039.
DOI: https://doi.org/10.1016/j.envpol.2018.02.039

Interpretive Summary: Poultry-emitted air pollutants, including particulate matter and ammonia, have raised concerns due to 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 examine the emission plumes from a typical commercial poultry house. Specifically, we measured the concentrations of ammonia and particulate matter, characterized the size of the particulate matter, and examined the potential changes of the plume as affected by meteorological conditions. As expected, the particulate matter and ammonia emission concentrations decreased as distance from the poultry-house exhaust fan increased. Although the emission concentrations were similar in the daytime and nighttime, diurnal and nocturnal plume shapes were different due to the calmer wind conditions at night which makes the atmosphere more stable. The nighttime conditions resulted in longer and wider plume shapes especially for the particulate matter. For all the experiments, the distribution of smaller to larger particles did not change with distance from the fan indicating that the larger particles were not settling out of the airstream faster than smaller particles as would be expected. Overall, the direction of all the air pollutant emission plumes was dominated by the tunnel fan rate and direction instead of the ambient wind speed and direction. This finding is important because currently-available air dispersion models use ambient or modeled wind speed and direction. These results will also be useful in developing more effective pollutant remediation strategies for poultry house emissions.

Technical Abstract: Poultry-emitted air pollutants, including particulate matter (PM) and ammonia, have raised concerns due to 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 particles [TSP], particulate matter less than 10 µm in aerodynamic diameter [PM10], and particulate matter less than 2.5 um in aerodynamic diameter [PM2.5]) and ammonia emission-concentration profiles from a typical commercial poultry house. The average downwind concentrations in the emission plumes ranged from 103 - 2,740 ug m-3 for ammonia, 15 - 745 ug m-3 for TSP, 0.1 - 51.8 ug m-3 for PM10, and 0.01 - 1.07 µg m-3 for PM2.5. The emission factors of the poultry house, which were calculated using the concentrations and fan speed, were 0.66 (0.29– 0.99) g NH3-N bird-1d-1 for ammonia, 52 (44 - 168) g d-1AU-1 (AU = animal unit = 500 kg) for TSP, 3.48 (1.16 - 9.03) g d-1AU-1 for PM10, and 0.07 (0.00 – 0.36) g d-1AU-1 for PM2.5 which were consistent with previous studies. 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 improved stability of the atmosphere at night. Calmer wind conditions at night decreased turbulent diffusion of particles resulting in longer and wider plume shapes than the ammonia plumes. In addition, the shape of the ammonia emission plumes was influenced by molecular diffusion. Particle size distribution analysis revealed that, at a given height, the percentage of PM10 and PM2.5 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 all the 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 the input parameters. Thus, this study will be useful in evaluating dispersion models for ground-level, horizontally-released, point sources and in developing more effective pollutant remediation strategies for poultry house emissions.