REDUCTION OF GAS, ODOR AND DUST EMISSIONS FROM SWINE OPERATIONS WITH BIOFILTERS

Abstract

The intention of this investigation was to optimize biofilters for the use in livestock facilities,considering both economical (costs) and ecological factors (odor and gas reduction). Twodifferent phases were conducted. In phase A five different biofilter materials (biochips, coconutpeat,bark-wood, pellets+bark and compost) were tested with the aim to select the best materialregarding the odor reduction and over all efficiency. In conclusion of phase A biochips, a newfilter material, was selected due to its high average odor reduction (81 %) in combination with avery low flow resistance. A significant reduction of coarse particles was found for all filtermaterials. The main factors influencing the filtration characteristic are water vapor condensation,water content of the filter material and hygroscopical properties of the particles. In phase Bbiochips and coconut fiber peat were tested under different operating conditions (0.5 an 1m bulklayer; down and up flow air supply). The odor emission was in average reduced between 61 and75 %. The main factor could be found the high of odor concentration in the waste air as well asthe homogenous moisture distribution of filter materials. Biofilters were not suitable for a highammonia reduction (9 up to 26 %). All tested filter materials showed none or only a lowreduction potential for CO2 and CH4. Fine structured filter materials can increase the N2Oemission, probably due to anaerobic processes. All in all the investigation showed that theefficiency of biofilters can be optimized by using a new filter material and a appropriateoperating mode.