Control of dimethyl sulfide and dimethyl disulfide odors during pig manure composting using nitrogen amendment

Effects of nitrogen electron acceptors on dimethyl sulfide (Me2S) and dimethyl disulfide (Me2SS) odor emission during composting was investigated. The chemicals and doses used included sodium nitrate (NO3− at 10 mM, 20 mM and 40 mM), sodium nitrite (NO2− at 10 mM, 20 mM and 40 mM) and sodium nitrite (10 mM, 20 mM and 40 mM) with hexaammonium heptamolybdate tetrahydrate (HHT). The results showed that the addition of these chemicals restricted the emission of Me2S and Me2SS. The emission reduction effect of NO2− was greater than NO3− at the same dosage. A greater reduction was observed when HHT was also added. With 2 mM HHT + 40 mM NO2− addition, the emission of Me2S and Me2SS was reduced by 92.3% and 82.3%, respectively. Comparison of compost maturity indices for treated and untreated composts indicated that none of the additives adversely affected compost quality. These results indicate that nitrogen chemical addition may provide an efficient method to control sulfur odors during composting.