Ammonia emissions from slurry stores

Emission measurements from slurry stores under environmental conditions are sparse. This might conflict with the needs of emission inventory calculations which rely on representative emission factors. Therefore, we quantified the emissions from a 1558 m3 open storage tank containing dairy cattle slurry over one year. Ammonia (NH3) concentrations were measured as continuous, line-integrated concentrations across the tank using a miniDOAS and with weekly exposed passive samplers in a vertical profile at the center of the tank. Moreover, meteorological parameters were measured and management-operations recorded. NH3 emissions were determined by a simplified mass balance approach. Emissions from the uncovered slurry tank carried out over one year were on average 0.06 g NH3 m-2 h-1 which compare well with data from the literature. The emission level responded in a plausible manner to important influencing parameters, e.g. natural crust at the slurry surface. At the end of April 2017, an impermeable plastic floating cover was installed. The measurements will be continued for one year after covering the tank. The present study provides a unique dataset in order to investigate emissions from slurry tanks and interactions thereof related to operations and meteorological conditions as occurring in practice.