Solvent Decontamination of PCB Electrical Equipment

Polychlorinated biphenyls (PCB's) which are used as dielectric fluids in transformers and capacitors, are toxic relatively inert materials which are persistent and widespread in the environment and biomagnified in the food chain. Disposal of contaminated electrical equipment requires removal of the majority of PCB's. Various solvent cleaning techniques have been investigated for decontamination of intact transformers and shredded capacitors. The PCB content of transformers which originally contained 180-270 kg PCB was reduced by 99.72-99.96 percent. The relatively small amount of retained PCB resides primarily in the interstices and absorbent material of the core and coil assembly. Shredded power factor correction capacitors were decontaminated using trichlorethylene in a multistage concurrent batch extraction process. The PCB content was reduced by 99.9 percent, leaving a residual PCB content of 0.01 kg per capacitor.