A microwave-induced hydrothermal reaction for the dechlorination of polychlorinated biphenyls

Microwave heating has been widely accepted in accelerating chemical reactions. A microwave-induced hydrothermal reaction was developed and tested for its effectiveness in the decomposition of polychlorinated biphenyls (PCBs) in this study. Three simple reactants participated in the microwave-induced hydrothermal reaction, namely iron powder, NaOH and H₂O. Under microwave heating, NaOH and H₂O absorbed microwave energy by space charge polarization and dipolar polarization, and the absorbed energy initiated the hydrothermal reaction. X-ray diffraction (XRD) analysis found Fe₃O₄/NaFeO₂ and confirmed the occurrence of microwave induced hydrothermal reaction, during which hydrogen was released. The newly produced hydrogen was used for the dechlorination of PCBs. The effects of important factors on the dechlorination degree were investigated, and the dechlorination mechanism was suggested.