Emission characteristics of odorous volatile sulfur compound from a full-scale sequencing batch reactor wastewater treatment plant

Volatile sulfur compounds (VSCs) generated and discharged as air pollutants from wastewater treatment plants (WWTPs) pose a threat to human health and the environment. This study characterized VSC emissions from a full-scale sequencing batch reactor (SBR) WWTP at the water-air interface for one year. Results demonstrated that higher ambient temperatures and aeration contributed significantly to VSC emissions as the highest emissions occurred over summer during the feeding synchronous aeration period. VSC emissions were related to chemical oxygen demand and sulfate concentrations in wastewater, and empirical formulas based on these values were proposed that can be used to model VSC emission fluxes from SBR WWTP. VSC emission factors (μg·ton^-1 wastewater) throughout the SBR treatment process were: 361 ± 101 hydrogen sulfide (H₂S), 82 ± 76 methyl mercaptan (MT), 61 ± 31 dimethyl sulfide, 17 ± 5 carbon disulfide, and 46 ± 24 dimethyl disulfide. H₂S and MT were the dominant odors released. Findings from this study may be applicable for calculating VSC emissions during SBR wastewater treatment stages, and may be beneficial for determining methods and strategies to reduce VSCs.