Electrochemical Removal of Chloride from Polychlorinated Biphenyls in an Oil/n-Butanol/HCl and an n-Propanol/HCl System

Abstract

We present an exploratory study that seeks to identify new routes for the treatment of transformer dielectric oils contaminated with polychlorinated biphenyls (PCBs), through the usage of direct reduction electrochemical methods, using Pb/PbO2 electrodes. It is known to be possible to prepare a PCB emulsion using tensoactive agents and perform the direct PCB reduction effectively (1). Nevertheless, this procedure has drawbacks. We are orienting this study towards identifying media capable of dissolving the contaminated oil and conferring enough conductivity to make the direct reduction of the PCBs or to make an extraction of the PCBs of the contaminated oil before the electrolysis. To reach this goal, n-butanol as a solubilization agent and n-propanol as an extraction agent in HCl environment were selected. The high electrical resistance of the environment avoided the direct reduction, while selective electrolysis of the PCBs, once extracted in Pb/PbO2 electrodes, could take place.