Treatment of phenolic compound wastewater using CuFe2O4/Al2O3 particle electrodes in a three-dimensional electrochemical oxidation system

Three-dimensional electrochemical oxidation (3D-ECO) technology is considered as one of the most promising advanced oxidation processes for degrading refractory organic pollutants. However, the preparation of the particle electrodes (PEs) is a key factor for industrial applications. In this study, a new Al2O3-based PE was proposed for 3D-ECO system. The prepared PEs were characterized by scanning electron microscopy, energy-dispersive X-ray microscopy, and X-ray diffraction to examine their morphology, elementary composition, and amount of CuFe2O4 respectively. Experiments comparing different conditions showed that 3D-ECO system equipped with prepared PEs and persulphate (PS) was more efficient in degradingp-nitrophenol (PNP). Based on these results, the critical process parameters of the dosage of the PEs, initial PS concentration, and current density for 3D-ECO using the proposed PEs were examined. Under the optimized operations, the PNP removal rate reached 80.23% with a low electrical energy consumption of 3.97 kW h/mg PNP, which was significantly better than the 69.16% and 9.50 kW center dot h/mg PNP under conventional ECO process. Moreover, cycling experimental results indicated that the performance of the PEs had no declining trend during the 5 h test period, suggesting acceptable stability of the particles without particle damage or mass loss. These investigations provide a novel route for preparing high-efficiency PEs.