부산대학교 도서관

Ammonia is the primary basic gas in the atmosphere and has the most important role in the neutralization of atmospheric acids generated by fossil fuel combustion. The reaction product forms a NH4+ aerosol, which is a major component of atmospheric particulates. These NH4+ particulates are part of at- mospheric haze and may be transported long distances from the production site before returning to the surface by dry deposition or scavenged by precipitation. Animal production produces a significant component of anthropogenic NH3 emissions and the National Academy of Sciences concluded that NH3 emissions estimates from animal feeding operations have not been characterized sufficiently, leading the US Environmental Protection Agency to institute studies in the United States to obtain NH3 emissions from animal feeding operations under the US Environmental Protection Agency Air Consent Agreement. The objective of this study is to obtain additional broiler NH3 emissions estimates using a backward Lagrangian stochastic technique. This technique uses NH3 concentrations measured upwind and downwind of the farm, wind observations, and atmospheric dispersion model calculations to obtain whole-farm emissions. Ammonia emissions were low at bird placement and increased steadily after about the third week of growth. At the end of the flock (47 d, ∼297,000 birds), cumulative emissions for the flock cycle period were 0.016 kg of NH3•bird-1•flock-1. Be- tween-flock emissions, including bird harvest, cleanout, temporary storage of litter outside of the buildings, and downtime (buildings closed), added another 0.003 kg of NH3•bird-1.flock-1. Emissions from this broiler farm were less than from some eastern US broiler farms but were comparable to broiler farms in Europe. Based on the results of this study and a similar winter study at this same farm, total flock wintertime and summertime (flock cycle plus between-flock) NH3 emissions from this farm represented 7.8 and 8.3% of feed N as NH3-N, respectively, or an annual average of 8.1%. [ABSTRACT FROM AUTHOR]