Emission factors and characteristics of ammonia, hydrogen sulfide, carbon dioxide, and particulate matter at two high-rise layer hen houses.

Air pollutants emitted from confined animal buildings can cause environmental pollution and ecological damage. Long-term (>6 months) and continuous (or high frequency) monitoring that can reveal seasonal and diurnal variations is needed to obtain emission factors and characteristics about these pollutants. A two-year continuous monitoring of ammonia (NH 3 ), hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ) and particulate matter (PM 10 ) emissions from two 218,000-hen high-rise layer houses (H-A and H-B) in Indiana, USA was conducted from June 2007 to May 2009. Gaseous pollutant concentrations were measured with two gas analyzers and PM 10 concentrations were measured with three Tapered Element Oscillating Microbalances. The operation and performance of ventilation fans were continuously monitored with multiple methods. Only the emission rates calculated with valid data days (days with more than 18 h, or 75%, of valid data) are reported in this paper. The two-house and two-year mean ± standard deviation emissions per day per hen for NH 3 , H 2 S, CO 2 , and PM 10 were 1.08 ± 0.42 g, 1.37 ± 0.83 mg, 76.7 ± 14.6 g, and 20.6 ± 22.5 mg, respectively. Seasonal emission variations were demonstrated for NH 3 and CO 2 , but not evident for H 2 S and PM 10 . Ammonia and CO 2 emissions were higher in winter than in summer. Significant daily mean emission variations were observed for all four pollutants between the two houses (P < 0.05), and between the two years from the same house (P < 0.01) except for CO 2 at one house. Carbon dioxide originated from manure decomposition was >9% of that from bird respiration. Emissions of CO 2 during molting were about 80% of those during normal egg production days. Emissions of H 2 S were not a major concern due to their very low quantities. Emissions of PM 10 were more variable than other pollutants. However, not all of the emission statistics are explainable. [ABSTRACT FROM AUTHOR]