Identification of New Drinking Water Disinfection Byproducts Formed in the Presence of Bromide

Abstract

Using a combination of mass spectrometry and infrared spectroscopy, disinfection byproducts were identified in ozonated drinking water containing elevated bromide levels and in ozonated water treated with secondary chlorine or chloramine. Only one brominated byproductdibromoacetonitrilewas found in the water treated with only ozone. This compound was found only in one of the three treatment rounds and was also present in the untreated, raw water but at levels 20 times lower than in the ozonated water. Many more byproducts were identified when secondary chlorine or chloramine was applied after ozonation. A number of these byproducts have not been reported previously. When comparing low-bromide water to water with elevated bromide, a tremendous shift in speciation was observed for samples treated with secondary chlorine or chloramine. Without high bromide levels, chlorinated species dominate (e.g., chloroform, trichloroacetaldehyde, tetrachloropropanone, dichloroacetonitrile, trichloronitromethane); with elevated bromide levels (1 mg/L), these shift to brominated species (e.g., bromoform, tribromoacetaldehyde, tetrabromopropanone, dibromoacetonitrile, tribromonitromethane). An entire family of bromo- and mixed chlorobromopropanones was identified that was not present in library databases and has not been reported previously. They were observed mainly in the ozone−chloramine samples but were also present in ozone−chlorine-treated water. These brominated byproducts were also observed in water treated with only chloramine or chlorine.

Mammalian cell cytotoxicity and genotoxicity analysis of drinking water disinfection by‐products

“…Although there are obvious differences among the endpoints among the assays, these results suggest that S. typhimurium cannot quantitatively predict the relative cytotoxic or genotoxic risk of DBPs in mammalian cell systems. Bromate is of concern because when present in raw waters it can cause the generation of brominated DBPs after disinfection processes [Richardson et al, 1999]. The U.S. EPA regulated bromate in drinking water as a probable human carcinogen based on animal data [EPA, 1998].…”

Method optimization for the determination of carbonyl compounds in disinfected water by DNPH derivatization and LC–ESI–MS–MS

“…Trihalomethanes (THM) were the first to be identified and are most abundant organic DBP in chlorinated water [1,2]. In addition to THM numerous compounds have been identified after application of chlorine and ozone-based chemicals [3,4]. A mass balance taking into account known DBP reveals that approximately 50% of halogenated DBP are missing compared with the total organic halogen (TOX) and, after ozone application, approximately 40% of oxidized DBP are missing compared with the assimilable organic carbon (AOC) [5].…”

Disinfection byproduct formation resulting from settled, filtered, and finished water treated by titanium dioxide photocatalysis

“…However, in low bromide waters, such as those typically encountered in central Arizona, chlorinated species tend to dominate (Richardson et al, 1999). In this study, the maximum bromide concentration observed was 32 lg L À1 , which substantially limited the formation of brominated DBPs.…”