Review Article
S. Rahman and M. S. Borhan
Abstract
Odorous air emissions from confined animal feeding operation are causing public nuisance. Accordingly, different odor mitigation technologies were designed, developed, and evaluated in the last decades to reduce odor emissions. The purpose of this paper is to review the previous research related to odor mitigation from swine rearing facilities and provide information on the effectiveness of currently available and emerging odor mitigation technologies. This review focused on odor mitigation approaches at different stages of swine production, manure storage and handling, and land application. Several odor mitigation technologies have been suggested and evaluated including diet manipulation, solid-liquid separation, additives, aeration, anaerobic digestion, lagoon covers, biofilters, acid scrubbing, shelterbelts, and manure injection. The effectiveness of these mitigation technologies varied widely; however, diet manipulation, biofilters, shelterbelts, and direct injection of manure have shown advantages over other odor mitigation methods. Diet manipulation is the first line of defense for odor mitigation. Biofilters and shelterbelts provide solutions for treating the odorous air before releasing to atmosphere, whereas additives, lagoon covers, aeration, and anaerobic digestion reduce or control odor emissions during manure storage and treatment. Direct injection of manure provides ultimate disposal solution and can reduce odor significantly compared to surface application.