| Abstract |
| The objectives of this study is to investigate the effects of bromate formation on ozone dosage, ozone contact time, pH, and ammonia nitrogen in the processes of advanced water treatment system (AWTS), which consisted of preozonation, cross-flow settler, rapid sand filter, postozonation, biological activated carbon (BAC) beds. As a result, when ozone dosage and ozone contact time for influent with Br- of 0.1-0.3mg/L were 0.5-2.0mg/L.min and 10 min., bormate concentration increased with increase of ozone dosage. The formational rate of bromate under pH 7-9 was 30-46% higher than that under pH 6 at ozone dosage of 1.4 mg/L.min. When ammonia nitrogen concentration increased 0.1mg/L to 0.4mg/L, bromate formation was decreased to about 38%. These results revealed that an increase of bromate formation depended on an increase of ozone concentration, pH, and bromide level. A decrease of bormate formation also depended on an increase of ammonia and dissolved organic carbon concentrations. Thus, the results of this study indicated that lower ozone dosage and longer contact time are needed to reduce bromate formation. |
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| Key Words |
| Bromate, bromide, ozone dosage, contact time, pH, ammonia nitrogen |
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