| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
Advanced oxidation processes such as Ozone/UV, Ozone/Hydrogen peroxide have to be focused to decompose of organic toxic compounds. It has been known that UV especially has high activity of dehalogenation. However some researchers have reported that organic toxic compounds were decomposed, but TOX increased during AOPs. The reason has been thought that landfill-leachate often has halide ion at high level. This 'study was focused that formation of free chlorine and the by-products in the effluents
The leachates including chloride ion of 19,000 mg/L were treated by UV and UV/TiO2 processes. Free chlorines of 25 and 41 mg/L were detected in the UV and the UV/TiO2,effluents,' respectively. Therefore, chloroacetic acid, bromoacetic acid and other haloid compounds were also detected in the both effluents. This result shows that UV treatment can decompose halide organic compounds such as dioxins, but has potential to produce free chlorine at high level, if chloride ion is included at high level
During ozonation of aqueous solutions including chloride ion 1,000, 5,000, and 10,000 mg/L, free chlorine detected at 6,.32, and 75 90 of dissolved ozone (W/W), respectively. In the presence of organic compound (fulvic acid 5 mg C/L), free chlorine and total organic halide were also detected, However during ozonation in the co-existence of hydrogen peroxide, formations of free chlorine and organic halide compound were controlled
These results show that there is a potential of formation of free chlorine during UV, Ozone, and UV/Ozone treatments in the presence of chloride ion at high level such as over than 1,000 mg/1. However it is thought that AOPs in the co-existence of hydrogen peroxide can controlled the formation of free chlorine. From the experiment, it is also thought that development of simultaneous determination of oxidative species such as ozone, chlorine, and hydrogen peroxide is needed
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