Odor emission and the role of microorganisms during composting

Abstract

In order to accelerate composting, aeration is applied to maintain aerobic conditions. However, if aeration is insufficient, anaerobic conditions develop. Large amounts of ammonia are generated under aerobic conditions. Conversely, anaerobic conditions result in the production of various forms of malodorous compounds that are mainly composed of partially oxidized organic compounds with low odor thresholds. Among malodors, nitrogen- and sulfur-containing compounds can be deodorized by oxidation through the action of nitrogen- and sulfur-oxidizing bacteria, although these bacteria exhibit extremely low activity under thermophilic composting conditions. Utilizing microorganisms for the reduction of odor emission during composting requires a thorough understanding of the composting mechanisms.