title: Formation of new brominated disinfection byproducts during chlorination of saline sewage effluents.
abstract: Chlorination could be the most cost-effective method for disinfecting saline sewage effluents resulting from toilet flushing with seawater. Upon chlorination, the high levels of bromide ions in saline sewage effluents (up to 32 mg/L) can be oxidized to hypobromous acid/hypobromite, which could then react with organic matter in the sewage effluents to form brominated disinfection byproducts (Br-DBPs). In this study, primary and secondary saline sewage effluents were collected and chlorinated at different chlorine doses, and a powerful precursor ion scan method using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry was adopted for detection and identification of polar Br-DBPs in these samples. With the new method, 54 major polar Br-DBPs were detected in the chlorinated saline effluents and six of them were newly identified as wastewater DBPs, including bromomaleic acid, 5-bromosalicylic acid, 3,5-dibromo-4-hydroxybenzaldehyde, 3,5-dibromo-4-hydroxybenzoic acid, 2,6-dibromo-4-nitrophenol, and 2,4,6-tribromophenol. The formation of polar Br-DBPs, especially those newly detected ones, during chlorination of the saline effluents was studied. For the secondary saline effluent, various polar Br-DBPs formed and reached their maximum levels at different chlorine doses, whereas for the primary saline effluent, the formation of polar Br-DBPs basically kept increasing with increasing chlorine dose. Compared with the secondary saline effluent, the primary saline effluent generated fewer and less Br-DBPs and rarely generated nitrogenous Br-DBPs.
authors.affiliation: Environmental Engineering Program, Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong.
authors.forename: Guoyu
authors.initials: G
authors.lastname: Ding
authors.forename: Xiangru
authors.initials: X
authors.lastname: Zhang
authors.forename: Mengting
authors.initials: M
authors.lastname: Yang
authors.forename: Yang
authors.initials: Y
authors.lastname: Pan
mesh_terms: D017605:Bromine Compounds / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004202:Disinfectants / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D054879:Halogenation; D054712:Salinity; D012722:Sewage / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D014865:Waste Disposal, Fluid; D018508:Water Purification
chemical_list: D017605:Bromine Compounds; D004202:Disinfectants; D012722:Sewage; D002713:Chlorine