Odor impact assessment of trace sulfur compounds from working faces of landfills in Beijing, China.

Odor pollution from landfills is causing a growing number of public complaints and concerns. Compared with hydrogen sulfide (H2S) and ammonia (NH3), odor impacts of trace sulfur compounds (TSCs) are arousing concerns due to their low odor threshold values (OTVs). Working face on landfill sites has been claimed as major source of odor impacts. This study estimated the odor impacts of fugitive TSCs from the working face of a large typical municipal solid waste (MSW) landfill in Beijing, China. A modified wind tunnel system was introduced to estimate emission rates of TSCs, which is a basic requirement for odor impact assessment. The odor activity value (OAV) method was introduced for odor evaluation. Fieldwork in the selected landfill was conducted from 2014 to 2015. Methyl mercaptan (CH3SH), dimethyl sulfide, dimethyl disulfide (DMDS), and carbon disulfide (CS2) were the TSCs studied in this work. The spatial concentration distributions of the TSCs were calculated on the basis of the Gaussian dispersion model in a "normal case" scenario and a "worst case" scenario. DMDS showed the highest emission rate (7.18 μg m-2 s-1), and CH3SH was the dominant odorous compound with an average emission rate of 4.58 μg m-2 s-1. The dispersion modeling indicated that the odor impact distances of the TSCs in the studied landfill for the normal case and worst case scenarios were 495 ± 96 m and 9230 m at the downwind regions, respectively. Results of this study can benefit the formulation of strategies for odor control and abatement in landfill sites.