AMMONIA AND OTHER NITROGEN EMISSIONS FROM SWINE WASTE LAGOONS IN THE U.S. SOUTHEASTERN COASTAL PLAINS

Authors: Harper, Lowry; Sharpe, Ronald; ROBARGE, W

Submitted to: Atmospheric Nitrogen Compounds II Chapel Hill North Carolina Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/13/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Large-scale animal production facilities improve efficiency and economics but large concentrations of animals also present challenges to manage the wastes to avoid negative environmental impact. The purpose of this research was evaluate emissions from swine waste lagoons appropriate to the U.S. Coastal Plains. Ammonia emissions varied on a daily basis and were related to lagoon concentration, acidity, and water temperature and to the intensity of winds over the surface. A statistical model was developed from our emissions data and from lagoon and environmental factors. These emission factors, needed by regulators and designers, were developed on the USDA, NRCS steady-state live animal weight basis. Our factors were compared to conventional factors based on animal numbers and different lagoons and seasons. They were much closer between management types and geographical areas. Much smaller ammonia emissions than previously thought twere found leaving the measured lagoons but significant quantities of iner nitrogen gas losses were observed. These dinitrogen emissions may account for much of the reduction of nitrogen in these lagoons.

Technical Abstract: Large-scale animal production facilities result in increased production efficiency, improved production economics, and a better industry support system; however, they also present challenges in management of wastes to minimize ammonia losses which can have potential short- and long-term effects on the surrounding environment. The purpose of this research was to determine emissions and emission factors of ammonia from swine waste lagoons appropriate for the regional climate, geography, and swine production systems in the southeastern U.S. Coastal Plains. Ammonia emissions varied on a daily and seasonal basis and were related to lagoon ammonium concentration, acidity, water temperature, and wind turbulence. A statistical model was developed from emissions data obtained from three effluent lagoons in two states. Comparison of factors based on animal numbers from these lagoons showed the danger of basing emissions strictly on animal numbers. A suggested emissions factor based on the USDA, NRCS steady-state live animal weight showed similar emission factors for all lagoons measured in both states (0.013-0.014 kg NH3-N per kg steady state live weight per year). Emissions of inert nitrogen gas were also measured in all lagoons. The quantities of gas leaving the lagoons in this form indicate substantial amounts of ammonium in the lagoon are being converted to inert dinitrogen gas in anaerobic swine waste lagoons.