Degradation of perfluorinated compounds in wastewater treatment plant effluents by electrochemical oxidation with Nano-ZnO coated electrodes

Because perfluorinated compounds (PFCs) have been reported to be toxic and harmful to aquatic environments, it is imperative to remove residual PFCs from the effluents of wastewater treatment plants (WWTPs). In this work, an electrochemical oxidation reactor was employed for advanced treatment of PFCs in WWTP effluents. Four anode materials were tested: Al, stainless steel, Ti and Ti coated with nano-ZnO. The removal efficiencies achieved by Ti anode coated with nano-ZnO were much higher than the efficiencies achieved by other anodes. The removal efficiencies of target PFCs ranged from 39% to 66% with a reaction time of 40 min, a current density of 20 mA/cm2, and an electrode plate distance of 0.5 cm. The electrochemical durability of the Ti anode coated with nano-ZnO over 20 h indicated an outstanding stability for long-term electrochemical degradation of PFCs. Results suggest that electrochemical oxidation is a viable technology for removing PFCs from WWTPs effluent, but the choice of electrode materials has a strong effect on expected removal efficiencies.