Threshold levels for bromate formation in drinking water

Virtually any amount of bromide ion present can potentially be converted into bromate. In the absence of DOC, BrO₃^- is the only final product. At very low ozone doses, BrO₃^- will not form at levels above the detection limit. However, measurable bromate can form in water containing NOM (and whenever some ozone residual exists) at doses of ≃ 0.5 mg/mg DOC, and at doses of ≃ 1.0 mg/L in low-DOC waters. Water quality conditions most conducive to bromate formation include high Br-, low DOC, high pH, high alkalinity, and high temperature. Presently, treatment options include lowering pH or adding ammonia. Some potential may exist for peroxide addition as a control strategy under certain water quality conditions.