Degradation of Organic Compounds in Actual Wastewater by Electro-Fenton Process and Evaluation of Energy Consumption

We investigated the Fe-regeneration-based cathodic electro-Fenton process using commercial electrodes, to achieve reducing the initial Fe dose and consequent sludge accumulation. The obtained results provided insights into the cathodic electro-Fenton process using two-electrode electrochemical system. The grade 2 Ti mesh electrode could effectively regenerate Fe(II) at 1.2 V, whose potential was lower than those of the two other electrode systems reported in the literatures. In the actual wastewater treatment, compared with general-Fenton process, the reduction in the initial Fe injection was 33% and the sludge reduction was 38%. Furthermore, the removal efficiency using electro-Fenton was at least 5% higher than that of the general-Fenton process at the same initial dose. The low cell voltage (1.2 V) led to lower energy consumption (3.5 J mg⁻¹) relative to those of other electro-Fenton systems, i.e., anodic electro-Fenton and peroxide generation. With its competitive degradation performances, low energy consumption, and reduced initial Fe injection, the present cathodic electro-Fenton process was shown to be a promising route of waste treatment.