Abstract: In this study, alkali molten salt electrochemical method was applied to degrade polychlorinated biphenyls (PCBs). Oxidizers and reductants can be generated in situ by this method by electrolyzing and promoting decomposition reaction due to high temperature and alkali molten salt. The optimum technical conditions for PCBs treatment were explored by examining the influences of technical parameters including PCBs concentration, molten salt system, reaction temperature, reaction time, electrolysis voltage on treatment efficiency. Research result indicated that the PCBs removal efficiency was improved with the climbing of reaction temperature and electrolysis voltage, but inhibited with the increase of PCBs concentration and reaction time. Moreover, the composition of molten salt system also observably affected the PCBs removal efficiency. In optimized conditions, the removal rates of PCBs reached 99% after pre-electrolysis for one hour. This study offers a novel approach for the treatment of chlorination aromatic hydrocarbons such as PCBs.

Key words: PCBs, molten salt electrochemistry, removal efficiency, chlorination aromatic hydrocarbons, pre-electrolysis