PHOTOCATALYTIC DEGRADATION OF HARMFUL COM POUNDS IN GAS-PHASE BY THE ILLUMINATION WITH SHORT-WAVELENGTH UV

Several gaseous compounds were degraded photocatalytically on the surf ace of TiO2 by the illumination with a low pressure mercury lamp (185 and 254 nm). The compounds can be apparently classified into the follo wing three groups according to the effect of 185 nm light and photocat alyst on the degradation: (1) Degradation is effected by 185 nm light with little contribution of photocatalyst. (2) Both 185 nm light and p hotocatalyst contribute to the degradetion additively. (3) The degrada tion rate is much larger than the simple sum of the rates by 185 nm li ght and photocatalyst. It was thus shown that the gaseous compound cou ld be degraded by either 185 nm light, photocatalyst or the combinatio n of both. Therefore this method is usefull for the degradation of the mixture of several harmful compounds.