[Degradation of transformer oils by photolysis in order to reduce occupational and environmental hazards]

ABSTRACT

Polychlorinated biphenyls [PCBs] are toxic, persistent, bio-accumulate and pose a risk of causing adverse effects on human health and to the environment. PCB compounds exert varios impacts on human depending upon age, route of entry, intensity and frequency of exposure. This study was conducted to determine the effect of UV-C, hydrogen peroxide and solvent on the photodegradation of PCBs. The photochemical reactor was of annular geometry [500 ml volume] with a cylindrical low-pressure mercury lamp emitting at 254 nm. The power emitted by the lamp was 6 W. The whole lamp was immersed into a reactor with temperature of 32 +/- 2 C. The PCBs were analyzed by GC/ECD equipment. The degradation of total PCBs in terms of one, two and three lamps was 77.5%, 82.9% and 85.2% respectively. The degradation of total PCBs in terms of not using of H[2]O[2] and using 10% and 20% of H[2]O[2] were 74.5%, 79% and 94.5% respectively. The results of this experiments showed that UVC-photolysis of H[2]O[2] leads to a degradation efficiency of PCBs only in the presence of ethanol