BROMIDES EFFECT ON DBP FORMATION, SPECIATION AND CONTROL .2. BIOTREATMENT

The effect of bromide concentration, ozone dosage, and biotreatment on the control of disinfection by-products (DBPs) was evaluated. Althoug h total trihalomethane precursors were better controlled by ozonation and they precursors of six haloacetic acids were better controlled by biological treament, the combined processes were effective for the con trol of all halogenated DBP precursors. Ozone's conversion of bromide to bromate and the chemical or biological oxidation of organic matter changed the ratio of bromide to dissolved organic carbon. Increases in this ratio increased the formation of some brominated DBPs, but these DBP increases were offset by the precursor oxidation provided by the combination of the two processes.