Biofiltration of odourous air from livestock barns using a horizontal airflow configuration
is possible. During the course of this research, two possible designs have been evaluated.
A pressurized headspace design functioned well, but may not be practical for a full-scale
commercial hog operation. Using the principle that “simpler is better”, a biofilter using a
non-pressurized headspace seems to eliminate some of the practical challenges associated
with the pressurized headspace design. Looking to the future, I see two potential applications of horizontal airflow biofilters. First, as we have demonstrated in this project, is a retrofit situation where the exhaust air from an existing barn is to be treated. I envision that individual biofilter units would be constructed in a factory setting and then transported to the barn for installation and
filling. Each biofilter unit could be custom-designed to either the airflow requirements of the exhaust fan, or the odour reduction desired by the owner. Construction of the units would be quick, easy, and inexpensive at a central, factory-like location. The dimensions of the units are such that they could be transported on a flat-deck trailer. Further work must be done to determine the best way to install the units within the limits imposed by insurance companies. The second potential application of a horizontal airflow biofilter is the integration of the biofilter with the barn at the time of construction. Specifically, the integration of the exhaust fan and the booster fan. By considering both the ventilation requirements for air quality within the barn and the airflow resistance characteristics of the biofilter, a single fan could be selected to satisfy both functions. With such integration at the design stage, there should be no need for insurance companies to be uptight about the presence of a
biofilter. During this project, much has been learned about the technology of biofiltration. At the
same time, much has been learned about the non-technical issues associated with biofiltration of hog odour. As evidenced by the response to the open house event, the general public is extremely interested in biofiltration if it can make the smell go away. Those within the hog industry are somewhat interested, but seem to be more skeptical. Companies that design livestock facilities are beginning to take notice of the technology because it may help to remove roadblocks to new expansion within the hog industry. Municipal officials are watching closely. And finally, the insurance companies are
concerned about increased liability.