An Approach to Reuse of PCB-Contaminated Transformer Oil Using Gamma Radiolysis Basic Decomposition Property of PCB and 1,2,4-Trichlorobenzene under Gamma Ray Irradiation

摘要

The radiolytic decompositions of low-concentration polychlorinated biphenyls (PCB) and 1,2,4-trichlorobenzene (TCBz) in a transformer oil have been studied using a ~(60)Co gamma ray irradiation facility. Significant decompositions of PCB and TCBz were observed in the oil at tens of kGy absorbed dose without any additive. We derived the required dose for KC500 decomposition in transformer oil using a power function, which indicates that oil with lower PCB concentration needs less dose to treat PCB wastes. We also observed that the gamma radiolyses of PCB and TCBz did not affect each other; the decompositions of PCB and TCBz proceed independently. Both PCB concentration analysis and total chlorine mass concentration analysis indicated that most dechlorinated chlorine atoms react to generate other chlorine compounds in the oil. We found that the gamma radiolysis without additional compounds in the oil can be a useful way of reusing PCB-contaminated transformer oil.