Biofiltration is a simple, low-cost technology that can reduce odours from ventilated airspace. A biofilter is a bed of organic material that consists of a mixture such as compost and wood chips. Odorous air passes through it and the microbes on the organic material convert odorous gases to carbon dioxide and water. The effectiveness of the biofilter is a function of the amount of time that the odorous air spends in the biofilter and its moisture content. The size of the biofilter depends on the amount of air needing treatment. Typically a biofilter requires 50 to 85 square feet per 1000 cubic feet per minute (cfm) of airflow. The depth of the bed is about 10 to 18 inches. The cost per 1000 cfm of air to be treated is from $150 to $225.
Alberta Agriculture, Food and Rural Development (AAFRD) have built and are testing a biofilter to see how livestock producers can use this technology successfully. To verify and improve current air dispersion models, field analysis of odour dispersion of pig barns is being done. The final results will be an observed plume of odour coming from the pig barn. This type of work will help to understand how odour plumes disperse from livestock facilities, which will then aid the construction of effective biofilters.