Addition of powdery sulfur to pig slurry to reduce NH3 and GHG emissions after mechanical separation

Abstract

Agriculture is the cause of almost the 95% of total ammonia (NH3) emissions in Europe, where livestock manure and fertilizers are the main emitters. In Italy, manure management represents about the 46% of the total NH3 losses from the agricultural activities. The environmental impacts are greater in areas with high livestock density, where nutrient application rates on fields often exceed the crop uptakes. Mechanical separation of slurry into its solid and liquid components is widely used to ease the transport of nutrients surplus outside livestock dense areas towards livestock-free plantations. However, mechanical separation may increase greenhouse gases (GHG) and NH3 emission mainly due to high emissions during the solid fraction storage. The main objective of this research has been evaluating the effect of acidification by adding elementary sulfur (S) before slurry mechanical separation. Ammonia and GHG emissions were monitored during storage of raw slurry, solid and liquid fraction.