Odor assessment of NH3 and volatile sulfide compounds in a full-scale municipal sludge aerobic composting plant

Methods for assessing odors in municipal sewage sludge aerobic composting plants (MSSACPs) have been ineffective. This study identified the emission amount of typical odor-producing compounds, including NH3 and volatile sulfide compounds from a full-scale MSSACP, and evaluated risks of odor emissions based on odor intensity and odor active value. Results revealed all sampling sites (i.e. sludge stacking yard, composting workshop, and screening workshop) produced serious odors, especially in the composting workshop. In the composting workshop, the amounts of DMDS (174.59 mu g.dry kg(-1)) and DMS (71.64 mu g.dry kg(-1)) emitted were far lower than that of NH3 (6062.56 mu g.dry kg(-1)). However, DMDS and DMS showed a similar intensity as NH3 according to odor intensity assessment. Furthermore, both of their odor active values were higher than that of NH3. Using results from both odor intensity and odor active value were more reliable for the assessment of odors from MSSACPs.