BROMATE ION REMOVAL BY HEEB IRRADIATION

Proposed drinking water regulations will. specify a maximum contaminan t level of 0.01 mg/L for bromate ion (BrO3-). This study used high-ene rgy electron-beam irradiation to remove BrO3- after formation, when ot her control strategies are not as effective. BrO3- was reduced to brom ide ion (Br-), with bromine (HOBr/OBr-) as intermediate. A dose of 60 krads was sufficient to reduce 70 percent of BrO3- from an initial con centration of 100 mu g/L, The presence of electron scavengers such as hydrogen peroxide and nitrate significantly reduced BrO3- removal, whe reas the addition of the OH radical scavenger such as t-butanol did no t affect the removal of BrO3-. This indicates that aqueous electrons ( e(aq)(-)) are mainly responsible for BrO3- destruction. The presence o f natural organic matter decreased BrO3- reduction efficiency. The rea ction of e(aq)(-) with various bromine species in water was used to mo del and simulate experimental data for the destruction of BrO3-. Compu ter model predictions were in fairly good agreement with the experimen tal results.