AWWA WQTC71522

The oxidation of bromide during drinking water treatment often results in the formation of brominated disinfection products (DBPs) (Diehl et al. 1995; Heller - Grossman et al. 1999; Najm and Krasner 1995; Rebhun et al. 1990). For instance, the chlorination of bromide-containing waters results in brominated trihalomethanes (THMs) and haloacetic acids (HAAs). The Stage 2 Disinfectants and Disinfection Byproducts (D/DBP) Rule established maximum contaminant levels (MCLs) of 80 and 60 µg/L for THM4 and HAA5, respectively (USEPA 2006). The potential for regulation of individual THMs and HAAs is expected to place more emphasis on the brominated DBPs, which are considered to be more toxic than their chlorinated counterparts (Echigo and Minear 2006; Plewa et al. 2002). During chloramination, bromide accelerates chloramine residual demand/decay, possibly due to bromamine and bromochloramine formation (Gazda et al. 1993; Gazda and Margerum 1994; Trofe et al. 1980). Utilities disinfecting desalinated seawater have observed significant increases in chloramine decay as well as increases in brominated DBP concentrations. This paper details progress made on determining the role of bromamines in DBP formation and chloramine stability as well as initial results from a method to indirectly measure bromamine concentrations following chloramination. Includes 25 references, tables, figure.