In this work, an electrocatalytic membrane was prepared to degrade aqueous tetracycline (TC) using a carbon membrane coated with nano-TiO₂ via a sol-gel process. SEM, XRD, EDS, and XPS were used to characterize the composition and structure of the electrocatalytic membrane. The effect of operating conditions on the removal rate of tetracycline was investigated systematically. The results show that the chemical oxygen demand (COD) removal rate increased with increasing residence time while it decreased with increasing the initial concentration of tetracycline. Moreover, pH had little effect on the removal of tetracycline, and the electrocatalytic membrane could effectively remove tetracycline with initial concentration of 50 mg·L-1 (pH, 3.8-9.6). The 100% tetracycline and 87.8% COD removal rate could be achieved under the following operating conditions: tetracycline concentration of 50 mg·L-1, current density of 1 mA·cm-2, temperature of 25 °C, and residence time of 4.4 min. This study provides a new and feasible method for removing antibiotics in water with the synergistic effect of electrocatalytic oxidation and membrane separation. It is evident that there will be a broad market for the application of electrocatalytic membrane in the field of antibiotic wastewater treatment.
Keywords: electrocatalytic membrane; electrocatalytic oxidation; membrane separation; nano-TiO2; tetracycline.