[ effect of hydrogen peroxide and solvent on photolysis of PCBs to reduce occupational exposure]

ABSTRACT

Polychlorinated biphenyls [PCBs] are toxic bio-accumulate components and may increase risk of adverse effects on human health and the environment. For different social, technical and economic reasons, significant quantities of PCBs contaminated transformer oil are still in use or storied. The study aimed to determine the effect of hydrogen peroxide and solvent on photolysis of PCBs to reduce occupational exposure. The photochemical annular geometry [500 ml volume] reactor was designed with a cylindrical low-pressure mercury lamp [UV-C Cathodeon TUV 6WE] with emission at 254 nm. The radiant power emitted by the lamp was 6w. The whole lamp was immersed in a reactor thermostat controlling of temperature at 32 +/- 2 oC. The PCBs was determined using GC/ECD and data was analyzed by SPSS. Degradation of total PCBs in terms of%10 and%20 of volume of H2O2 were 41%, 75% and 94%, respectively. The degradation of total PCBs in terms of ratio to solvent with oil transformer in 11, 21 and 31 was 61%, 75% and 94%, respectively. Our study show that UV-C photolysis of H2O2 leads to a degradation efficiency of PCBs only in the presence of isooctane, therefore indicating that the intermediates formation after ethanol oxidation are able to initiate PCBs degradation