Odorous air pollution from animal feeding operation and ordor mitigation technologies in the world
Odorous air emissions from animal rearing operation are causing public nuisance. Therefore, many odor mitigation technologies were designed, developed, and assessed in the several decades to reduce odor emissions. The object of this paper is to review the previous research related to odor mitigation from animal feeding facilities and present information on the effectiveness of currently available and emerging odor mitigation technologies. This review focused on odor mitigation approaches at sheds, manure storage and handling, and land application. Several odor mitigation technologies have been suggested and evaluated including diet manipulation, supplementation of EM, additives, solid-liquid separation, aeration, anaerobic digestion, lagoon covers, biofilters, and manure injection. The effectiveness of these mitigation technologies varied widely; however, diet manipulation, EM supplement, and direct injection of manure have shown advantages over other odor mitigation methods. Diet manipulation and supplementation of EM are the first line of defense for odor mitigation. Biofilters provide solutions for treating the odorous air before releasing to atmosphere, whereas lagoon covers, aeration, and anaerobic digestion reduce or control odor emissions during manure storage and treatment. Direct injection of manure gives ultimate disposal solution and can reduce odor significantly compared to surface application.
