Emission of Greenhouse Gases and Odorants from Pig Slurry - Effect on the Environment and Methods of its Reduction

Pig slurry is classified as a natural liquid fertilizer, which is a heterogeneous mixture of urine, faeces, remnants of feed and technological water, used to remove excrement and maintain the hygiene of livestock housing. The storage and distribution of pig slurry on farmland affect the environment as they are associated with, among others, the emission of various types of gaseous pollutants, mainly CH₄, CO₂, N₂O, NH₃, H₂S, and other odorants. Methane (CH₄), carbon dioxide (CO₂) and nitrous oxide (N₂O) are greenhouse gases (GHGs) which contribute to climate change by increasing the greenhouse effect. Ammonia (NH₃) and hydrogen sulfide (H₂S) are malodorous gases responsible for the occurrence of odour nuisance which, due to their toxicity, may endanger the health and lives of humans and animals. NH₃ also influences the increase of atmosphere and soil acidification. The article presents the environmental impact of greenhouse gases and odorous compounds emitted from pig slurry. Key gaseous atmospheric pollutants such as NH₃, H₂S, CH₄, CO₂ and N₂O have been characterized. Furthermore, methods to reduce the emission of odours and GHGs from pig slurry during its storage and agricultural usage have been discussed.