二光源式気相直接光化学分解法によるトリクロロエチレンの処理―難分解性副生成物に対する2光源照射の効果

抄録

During the direct photodegradation treatment of trichloroethylene by a low-pressure mercury lamp (254 and 185 nm) in a dry air atmosphere, combined irradiation by Black-Light fluorescent lamps (300-400 nm) that emit relatively low energy of photon was found to be markedly effective in the depression of by-products such as carbon monoxide, ozone and phosgene; the production of these by-products is the most serious issue associated with such treatment. A decrease in the production of carbon monoxide of 80% was observed at the maximum, and the production of ozone was almost completely depressed, compared with the case using the low-pressure mercury lamp alone. In addition, the degradation rate of phosgene was also found to increase through the combined irradiation. This method of dual-light-source direct photodegradation reported in this paper should solve effectively the fatal issue of photodegradation treatment. These effects are thought to be due to an increase in the concentration of chlorine radical; this was formed by Black-Light fluorescent lamp irradiation from molecular chlorine generated as a by-product of the trichloroethylene photodegradation. Mechanisms in which chlorine radical reacts with these by-products and accelerates their depression were also proposed in this paper.