The characteristics of carbon, nitrogen and sulfur transformation during cattle manure composting—based on different aeration strategies

Abstract

This study aimed to investigate the characteristics of gaseous emission (methane—CH4, carbon dioxide—CO2, nitrous oxide—N2O, nitric oxide—NO, hydrogen sulfide—H2S and sulfur dioxide—SO2) and the conservation of carbon (C), nitrogen (N), and sulfur (S) during cattle manure composting under different aeration strategies. Three aeration strategies were set as C60, C100, and I60, representing the different combinations of aeration method (continuous—C or intermittent—I) and aeration rate (60 or 100 L·min−1·m−3). Results showed that C, N, S mass was reduced by 48.8–53.1%, 29.8–35.9% and 19.6–21.9%, respectively, after the composing process. Among the three strategies, the intermittent aeration treatment I60 obtained the highest N2O emissions, resulting in the highest N loss and greenhouse gas (GHG) emissions when the GHG emissions from power consumption were not considered. Within two continuous aeration treatments, lower aeration rates in C60 caused lower CO2, N2O, NO, and SO2 emissions but higher CH4 emissions than those from C100. Meanwhile, C and N losses were also lowest in the C60 treatment. H2S emission was not detected because of the more alkaline pH of the compost material. Thus, C60 can be recommended for cattle manure composting because of its nutrient conservation and mitigation of major gas and GHG emissions.