Impact of bromide and iodide during drinking water disinfection and potential treatment processes for their removal or mitigation
Access Status
Authors
Date
2014Type
Metadata
Show full item recordCitation
Source Title
ISSN
School
Remarks
This research was supported by the Australian Research Council Funding scheme ARC LP100100285
Collection
Abstract
In this study, the impact of bromide and iodide on disinfected waters was examined and potential treatment technologies for their removal or mitigation were investigated. Distributed waters from two Western Australian drinking water sources were evaluated in terms of their bromide and iodide concentrations, disinfection by-product (DBP) formation, halogen-specific adsorbable organic halogen (AOX) formation and chlorinous odours after disinfection. In both systems, the brominated DBPs dominated the measured DBPs and, in both cases, the known DSPs accounted for only 30% of total organohalogens. Chloramination with a sufficient free chlorine contact time followed by ammonia addition, rather than preformed monochloramine, may be a viable mitigation strategy for the minimisation of I-OBPs, since exposure to free chlorine should promote the conversion of iodide to iodate, a safe form of iodine. This study has shown that bromide plays an important role in this process, mainly by enhancing the preferred conversion' of iodide to iodate. Ozone pre-treatment selectively oxidised iodide to iodate and minimised the formation of I-OB Ps. Complete conversion of iodide to iodate, while minimising the bromate formation to below the guideline value of 10 µg L-1 was achieved for a wide range of ozone concentrations in raw waters, including raw waters with high bromide concentrations.
Related items
Showing items related by title, author, creator and subject.
-
Criquet, J.; Allard, Sebastian; Salhi, E.; Joll, C.; Von Gunten, Urs; Heitz, A. (2012)The kinetics of iodate formation during chlorination of iodide-containing waters is a key factor in the formation of iodoorganic compounds. In contrast to bromate, iodate is considered to be non-toxic. A strategy to reduce ...
-
Allard, Sebastien; Nottle, C.; Chan, W.; Joll, Cynthia; Von Gunten, Urs (2013)The presence of iodinated disinfection by-products (I-DBPs) in drinking water poses a potential health concern since it has been shown that I-DBPs are generally more genotoxic and cytotoxic than their chlorinated and ...
-
Allard, Sebastian; Tan, J.; Charrois, Jeffrey; Joll, C.; Heitz, A.; Von Gunten, Urs (2014)Monochloramine (NH2Cl) is commonly used as an alternative to chlorine for disinfection because it is less reactive with the organic matrix, therefore forms less regulated DBPs and leads to a more stable residual. However, ...