Characterizing ammonia emissions from a commercial mechanically ventilated swine finishing facility and an anaerobic waste lagoon in North Carolina

Emissions of atmospheric ammonia–nitrogen [NH3–N, where NH3–N = (14/17) NH3] were measured from a commercial anaerobic swine waste treatment lagoon and from an on–site finishing swine confinement house at the same location. Continuous measurements were made at each potential NH3–N source for ~1 week during four different seasons. Results presented here represent measurements made for the second year of a multi–year experiment. Barn emissions were estimated to be 2 604 ± 660 g NH3–N day−1, 1 761 ± 1 087 g NH3–N day−1, 1 657 ± 1 506 g NH3–N day−1, and 2 659 ± 1 194 g NH3–N g day−1 in summer, fall, winter, and spring respectively. NH3–N barn emission factors were calculated to be 1.32 ± 0.32 kg NH3–N animal−1 yr−1, 0.78 ± 0.49 kg NH3–N animal−1 yr−1, 1.55 ± 1.40 kg NH3–N animal−1 yr−1, and 1.35 ± 0.61 kg NH3–N animal−1 yr−1 in summer, fall, winter, and spring respectively. Average NH3–N flux from lagoon was greatest in the summer, >3 943 μg m−2 min−1, and lowest in the winter, 981 ± 210 μg m−2 min−1. Fall and spring average NH3–N flux values were >1 383 μg m−2 min−1 and 1 641 ± 362 μg m−2 min−1, respectively.