Sulfuric odorous compounds emitted from pig-feeding operations

The objective of the study was to quantify the concentration and emission levels of sulfuric odorous compounds emitted from pig-feeding operations. Five types of pig-housing rooms were studied: gestation, farrowing, nursery, growing and fattening rooms. The concentration range of sulfuric odorous compounds in these pig-housing rooms were 30–200 ppb for hydrogen sulfide (H2S), 2.5–20 ppb for methyl mercaptan (CH3SH), 1.5–12 ppb for dimethyl sulfide (DMS; CH3SCH3) and 0.5–7 ppb for dimethyl disulfide (DMDS; CH3S2CH3), respectively. The emission rates of H2S, CH3SH, DMS and DMDS were estimated by multiplying the average concentration (mg m−3) measured near the air outlet by the mean ventilation rate (m3 h−1) and expressed either per area (mg m−2 h−1) or animal unit (AU; liveweight of the pig, 500 kg) (mg pig−1 h−1). As a result, the emission rates of H2S, CH3SH, DMS and DMDS in the pig-housing rooms were 14–64, 0.8–7.3, 0.4–3.4 and 0.2–1.9 mg m−2 h−1, respectively, based on pigʹs activity space and 310–723, 18–80, 9–39 and 5–22 mg AU−1 h−1, respectively, based on pigʹs liveweight, which indicates that their emission rates were similar, whether based upon the pigʹs activity space or liveweight. In conclusion, the concentrations and emission rates of H2S were highest in the fattening room followed by the growing, nursery, farrowing and gestation rooms whereas those of CH3SH, DMS and DMDS concentrations were largest in the growing room followed by the nursery, gestation and farrowing rooms.