Degradation of phenol by UV light-assisted electrocatalytic treatment

In this experiment, the degradation of phenol was carried out in a three-dimensional electrode–UV light synergistic oxidation system. The effects of five variables (electrolyte dosage, electrode spacing, voltage, initial pH and aeration) on the removal rate of the chemical oxygen demand of phenol and the optimal reaction conditions for the degradation of the COD of phenol under the synergistic effect of electrocatalysis and photocatalysis were analyzed. In the reactor, a three-dimensional electrode–ultraviolet oxidation method was used to perform the removal rate experiments with the phenol simulation solution. Experiments were designed to determine the best reaction conditions, and the results were analyzed by ultraviolet‒visible spectral scanning. The optimum reaction conditions were as follows: a Na 2 SO 4 electrolyte dosage of 1 g/L, an electrode plate spacing of 10 cm, a voltage of 15 V, an initial pH of 3.0 and an aeration rate of 11 L/min. Under these optimum conditions, the maximum COD degradation rate of phenol was 83.56%. During the reaction, phenol was degraded to quinones, which then formed other intermediates that were ultimately oxidized to small-molecule compounds, as observed by UV‒Vis spectroscopy. The kinetic equation for degradation by the three-dimensional electrode–UV light synergistic oxidation system was C t = C 0 exp(-1.05 × 10 –12 F 1.7284 G 1.2279 H 0.9842 I 0.9316 J 1.4918 t). The treatment of phenol with a three-dimensional electrode and ultraviolet light had a good effect. These results provide a basis for the treatment of phenol wastewater by electrocatalysis and photocatalysis.