Characterization and Fate of Ammonia from Poultry Operations: Their Emissions, Transport, and Deposition in the Chesapeake Bay.

BAKER, JORDAN LEE. Characterization and Fate of Ammonia from Poultry Operations: Their Emissions, Transport, and Deposition in the Chesapeake Bay. (Under the direction of Dr. Viney P. Aneja and Dr. S. Pal Arya). Poultry operations on the Maryland Eastern Shore contribute to approximately 99% of the total agricultural ammonia/nitrogen livestock emissions on the Delmarva peninsula. Emissions from poultry operations lead to the deposition of ammonia/nitrogen to the Chesapeake Bay causing detrimental environmental impacts as a result. The goal of this study is to determine how much ammonia/nitrogen is being deposited to the Chesapeake Bay from poultry operations from the Maryland Eastern Shore. Ammonia observations were taken from 23 sites across Maryland’s Eastern Shore to collect data for atmospheric transport and deposition model validation. Sussex County, Delaware and counties in Virginia were omitted from this study due to a lack of data availability. Based on the meteorology during the measurements, and using this data, a deposition velocity of 2.4 cm/s was selected via sensitivity analysis that is used to apply to an air quality model (AERMOD) simulation of 603 poultry facilities. Using AERMOD, a domain approximately 134 km by 230 km was simulated with a resolution of 2 km by 2 km to determine the fate of ammonia/nitrogen emitted from these poultry facilities. Emission factors from the U.S. Environmental Protection Agency in conjunction with Carnegie-Mellon University were used in the calculation of ammonia emission rate. Realistic terrain heights and meteorology observations were used by utilizing the data processing available with AERMOD, AERMAP and AERMET. A deposition velocity of 2.4 cm/s shows an overestimation of total deposition which is ~2 times the total emission. Therefore, a deposition velocity (0.15 cm/s) from similar studies are used to find total ammonia/nitrogen deposition. Using a deposition velocity of 0.15 cm/s, results from the AERMOD simulation show that approximately 1,284±0.24 tonnes (1,415±0.22 US tons) of nitrogen is deposited to both the Chesapeake Bay and the Delmarva peninsula landmass due to ammonia/nitrogen release from poultry AFOs. This is approximately 8.37% of the total emission from these facilities. Of the total deposition, about 397±0.01 tonnes of ammonia/nitrogen is deposited directly to the Chesapeake Bay with the remaining 886.5 tonnes being deposited to the Delmarva peninsula. It is difficult, to accurately determine the indirect deposition to the Chesapeake Bay from poultry AFOs. Meteorological conditions and deposition velocity affect deposition at a given time and can produce dramatic increases and decreases depending on atmospheric moisture, stability, and temperature. A seasonal analysis was performed to find the season with the highest average ambient concentration and deposition. Results show that spring is the season with the most deposition while winter is the season with the lowest. Autumn is the season with the third highest deposition calculation and summer is the season with the second highest seasonal deposition. It is important to note that modeled concentrations and deposition fluxes are calculated assuming that the same rate of ammonia/nitrogen is being emitted at all times. It is determined that the majority of ammonia/nitrogen (and nitrogen associated) is being transported through waterways from the land mass to the Chesapeake Bay. © Copyright 2018 by Jordan Baker All Rights Reserved Characterization and Fate of Ammonia from Poultry Operations: Their Emissions, Transport, and Deposition in the Chesapeake Bay