| Abstract: | Factors affecting the formation of by-products of ozonation during ammonia removal under the existence of bromide were investigated. The presence of reducible N compounds could significantly reduce the formation of bromate and brominated organics; however, it was difficult to completely prevent formation of the by-products. It was therefore concluded that while the method used in this study was an effective process to decompose ammonia, it should be applied to the treatment of wastewaters containing low concentration of TOC. For power plant condensate demineralization wastewater containing TOC of 3 to 4mg/L, TOX formed during ammonia removal ranged from 0.20 to 0.30 mgBr L?1. The only halogenated organic substance of the power plant wastewater detected on GC spectrum was bromoform, whose concentration varied from 0.11 to 0.14 mg L?1. Column test results indicated that bromate could almost completely be decomposed to bromide by activated carbon under proper space velocity and pH. Activated carbon was also very effective in adsorption of CHBr3: 1 g activated carbon adsorbed ca. 20.3 mg of CHBr3. |
