Ammonia Emission Rates from Covered Concrete Manure Tanks in Eastern Canada

Abstract

Manure storage is a well known source of anthropogenic ammonia emissions and has been the subject of numerous studies in Western Europe and the U.S. However, climate and manure management practices differ widely in Canada. In this study, commercial dairy and swine manure storages covered by floating geomembranes were monitored for periods exceeding six months in Canada. The swine manure storage emitted negligible amounts of ammonia over the summer, from 5.8 10-3 to 0.13 g m-2 s-1, much lower than emission rates found in the literature for swine manure, which ranged between 45 and 875 g m-2 s-1. The most substantial ammonia emissions at the swine facility occurred during manure mixing operations. A structural difference in the covering technology at the dairy manure storage rendered it less airtight than at the swine manure storage. The dairy manure storage emitted more substantial amounts of ammonia when unfrozen (91 to 171 g m-2 s-1) then when frozen during winter (1.9 to 16 g m-2 s-1). These emission rates are lower in magnitude than values found in the literature for dairy manure, which ranged between 10 and 864 g m-2 s-1. Average relative uncertainties of emission rate measurements were estimated to be 8%, 26%, and 26%, respectively, for unfrozen dairy manure, frozen dairy manure, and swine manure.