Effectiveness of short-term aeration in treating swine finishing manure to reduce odour generation potential

Abstract

Abstract The work presented here is to elucidate removals of organic matter, nitrogen and odour generation potential in swine manure treated by short-term aeration. The experiment was composed of a 4 × 3 factorial design, with solids levels ranging from 0.5 to 4.0% and aeration lengths from 0.5 to 4.0 days at an airflow rate of 1.2 L s−1 m−3. Manure samplings were conducted on days 5, 10, and 20 during the storage. Solids (TS: total solids; TVS: total volatile solids), 5-day biochemical oxygen demand (BOD5), total Kjeldahl nitrogen (TKN), and volatile fatty acids (VFAs) for manure samples were measured to characterize the effectiveness of aeration. According to this study, solids (TS and TVS), BOD5, TKN and VFAs were reduced in varying degrees with respect to the aeration length and storage time. Removal ratios of VFAs from 46.6 to 78.5, 49.4 to 86.9, and 48.8 to 95.6% were achieved under the aeration length of 0.5, 2.0, and 4.0 days, respectively. The variation of odour generation potential in the manure treated by short-term aeration can be linearly evaluated by the concentrations of solids, BOD5, and/or TKN, but the feasibility could be impaired for manure with high solids content. Meanwhile, foaming was found troublesome during the process of short-term aeration. Four-day aeration is recommended to treat manure with a total solids level of less than 2.0% for odour control because over 70% of VFAs removal efficiencies can be achieved.