Identification of Sulfur Gases Evolved from Animal Manures

Abstract

AbstractEvolution of volatile sulfur compounds from animal manures [beef cattle (Bos taurus), dairy cattle (Bos taurus), poultry (Gallus domesticus), sheep (Ovis aries), and swine (Sus scrofa)] was studied by gas chromatographic techniques permitting detection and identification of trace (nanogram) amounts of sulfur gases in the presence of nonsulfur gases known to be released through microbial decomposition of organic materials. All manures studied released hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide (CH3SCH3) when incubated under anaerobic conditions, and some released dimethyl disulfide (CH3SSCH3), carbonyl sulfide (COS), and/or carbon disulfide (CS2). Only trace amounts of one sulfur gas (dimethyl sulfide) could be detected in the gaseous products of decomposition of manures under aerobic conditions, and no evidence could be obtained that sulfur gases contribute to the odors of dried manures. Most of the sulfur volatilized when manures were incubated under anaerobic conditions was in the form of hydrogen sulfide and methyl mercaptan, and the amount of sulfur volatilized in 1 month at 23C represented < 1% of the total sulfur in the manures studied.