Temporal Variations in Gas and Odor Emissions from a Dairy Manure Storage Pond

Abstract. As dairy production evolves towards larger and more concentrated operations, air and water quality on and around dairy farms is becoming a significant concern. It is necessary to understand air emission temporal variations for development and implementation of effective abatement technologies and management practices. The objectives of this study were to understand temporal variations in H2S, NH3, and odor emissions from a dairy manure storage pond, the effects of manure characteristics and environmental conditions on gas emissions, and gas management need of dairy manure storage ponds. One representative Ohio dairy farm with a 675-cow free-stall barn and one outside earthen manure storage pond was selected as the experimental farm. Monthly measurements of H2S, ammonia, and odor emissions from the dairy manure storage pond were conducted using a convective flux chamber and gas analyzers. Surface manure was sampled for manure characteristics analysis. Manure temperature and weather conditions were measured. The data was analyzed using general statistical description, correlation, and regression analysis. The results showed there were large temporal variations in NH3, H2S, and odor emissions among months of the year. The daily mean NH3, H2S, and odor emission rates ranged from 5.7 to 174.8 µg s-1 m-2