PhD Project: Reduction of Odor Source in and Emission from Swine Buildings

Danish farmers produce approximately 25 million pigs with only 5.4 million humans. More than 80% of this production is exported, and this makes Denmark one of the world’s largest exporters of pig meat. It also makes pig meat the country’s most im-portant export product, around 5% of total value exported. While pigs mean profits, they also cause some problems such as effects on the environment, influence on the neighbors and even on tourism business especially in summer because of the emis-sions of odorants. Therefore, all livestock producers with farms larger than 75 live-stock units must have an environmental authorization if they wish to establish new units or extend or modify existing units from January 1 of 2007. This new authoriza-tion procedure involves regulation of odor, phosphorus, ammonia emission and dis-charge of nitrite.
Odor emissions from swine buildings have been the topic for many research projects. The focus has primarily been on identification of odorants at the source, measure-ment of odor emissions from livestock production facilities, air cleaning of exhaust air using biofilters and scrubbers and atmospheric dispersion to the surroundings.
However, the interaction between air movements in the room and in the slurry chan-nel will affect the odorant concentration in the channel and in the room air. More in-formation about the exchange mechanisms between air and the slurry surface in the slurry channel and between air and solid surface is needed since local velocity, turbu-lent intensity, manure surface temperature, airflow rate, etc. have very important ef-fects on the emission of odorants. At the same time, little is known about the odor emission which is dependent on the air as transportation medium. Therefore, the objective of this PhD thesis is to investigate effects on odor emissions of airflow pat-terns and ventilation rates and to provide fundamental knowledge of the mass trans-fer processes of odorants in the air and slurry boundary layers.