title: Characterization of odor emission from alternating aerobic and anoxic activated sludge systems using real-time total reduced sulfur analyzer.
abstract: Anaerobic biodegradation of sulfur-containing compounds always generates volatile sulfur compounds (VSCs) including H2S, methyl mercaptan, and dimethyl sulfide (DMS). VSC emissions from wastewater treatment plants (WWTPs) result in odor complaints from people living nearby. To control odor-causing compounds in WWTPs, it is important to know the odor emission quantity particularly with continuous monitoring. Since modified activated sludge processes always include anaerobic, anoxic and aerobic conditions for nutrient removal, odor emission from these different environmental settings is expected. In this study, continuous monitoring of VSCs from the headspace of an alternating aerobic and anoxic (AAA) activated sludge process via total reduced sulfur (TRS) analyzer was performed. There is clear pattern of the initial TRS peak immediately after the initiation of the aeration in the AAA system and TRS concentration begins to drop through the remaining air-on cycle. On the other hand, during the air-off period, TRS concentrations increase with time. In particular, a clear inflection point in the TRS profile could be observed after complete removal of nitrate during air-off, meaning more VSCs formation. Since the highest odor emission occurs after the initiation of aeration, the future control of exhausted air should only deal with air collected during the initial aeration period (e.g., 30min), a similar concept for the treatment of first flush in combined sewer overflow. In addition, application of a control scheme to initiate aeration immediately after denitrification is completed during air-off should be beneficial in reducing odor emission.
authors.affiliation: Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Republic of Korea. Electronic address: h_kim@uos.ac.kr.
authors.forename: Hyunook
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Republic of Korea.
authors.forename: Hyunjoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Republic of Korea.
authors.forename: Eunsun
authors.initials: E
authors.lastname: Choi
authors.affiliation: Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Republic of Korea.
authors.forename: Il
authors.initials: I
authors.lastname: Choi
authors.affiliation: Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Republic of Korea.
authors.forename: Taesub
authors.initials: T
authors.lastname: Shin
authors.affiliation: Department of Energy and Environmental System Engineering, University of Seoul, Seoul, Republic of Korea.
authors.forename: Hyungjoon
authors.initials: H
authors.lastname: Im
authors.affiliation: Department of Environmental Science, University of Maryland-Baltimore County, Baltimore, MD, USA.
authors.forename: Soobin
authors.initials: S
authors.lastname: Ahn
mesh_terms: D000332:Aerobiosis; D000393:Air Pollutants / Q000032:analysis*; D000693:Anaerobiosis; D004784:Environmental Monitoring / Q000379:methods*; D009812:Odorants / Q000032:analysis*; D012722:Sewage; D013457:Sulfur Compounds / Q000032:analysis*; D014835:Volatilization; D014865:Waste Disposal, Fluid
chemical_list: D000393:Air Pollutants; D012722:Sewage; D013457:Sulfur Compounds
keywords: Alternative aerobic and anoxic (AAA) system; Dimethyl sulfide (DMS); Dimethyl sulfoxide (DMSO); Odor; Process control; Volatile sulfur compounds (VSCs)