Evaluation of preformed monochloramine for bromate control in ozonation for potable reuse.

Bromate, a regulated disinfection byproduct, forms during the ozonation of bromide through reactions with both ozone and hydroxyl radical. In this study, preformed monochloramine was evaluated for use as a bromate suppression method in pilot testing of wastewater reuse with an average bromide concentration of 422±20 µg/L. A dose of 3 mg/L NHCl-Cl decreased bromate formation by an average of 82% and was sufficient to keep bromate below the MCL at ozone doses up to 8.