Effect of substrate sulfur state on MM and DMS emissions in landfill

Abstract

Methyl mercaptan (MM) and dimethyl sulfide (DMS) are typical landfill odorous gases that have received little attention compared with hydrogen sulfide (H2S). In this study, landfill MM and DMS emissions were investigated regarding their origin from substrates with different sulfur states, namely, intrinsic organic sulfur and external inorganic sulfur (SO42−). Substrates with high protein contents showed the highest potential for MM and DMS emissions, at 46.0 and 9.2 μL·g−1 substrate, respectively. Meanwhile, a comparable contribution by SO42− was achieved when the SO42− content comprised over 40% of the substrate. The substrate contribution to DMS emission was up to 10 times the SO42− contribution. Meanwhile, the SO42− contribution to MM emission was over 1000 times that to DMS emissions. MM and DMS can accumulate in landfill sites and then be transformed into H2S or sulfide (S2−). This research offers a comprehensive understanding of MM and DMS emissions in landfill and provides a basis for classification management methods in landfill sites.