AWWA WQTC69356

Previous research has shown that bromine incorporation into trihalogenated acetic acids (TXAAs) was similar to that of the trihalomethanes (THMs). Likewise, occurrence data for other trihalogenated disinfection byproducts (DBPs) (e.g., halonitromethanes [HNMs], haloacetaldehydes [HAs]) demonstrated similar or lower bromine incorporation as that of the THMs. Moreover, bromine incorporation patterns into dihalogenated DBPs (e.g., haloacetic acids [HAAs], haloacetonitriles [HANs], HNMs, HAs) were similar or higher for the HANs. Some of the differences may have been due to steric hindrance (i.e., trihalogenated DBPs containing bromine), relative instability of some DBPs, and/or the presence of DBPs at low levels relative to their minimum reporting levels. However, even when there was lower bromine incorporation into some DBP subclasses, the trend was consistent (i.e., in most cases, the regression between DBP subclasses had a high coefficient of determination). The relative formation of dihalogenated HAAs (DXAAs) and TXAAs has been related to the nature of the organic matter and/or the disinfectant(s) used. This was also observed for various DBP classes. In addition, the relative degree of halogenation was related to the instability of certain DBP species. Understanding the relative formation of different DBP species can be used in predicting the formation of DBPs for which not all standards are available (e.g., haloacetamides) and in improving exposure assessments. Includes 23 references, tables, figures.