Fabrication of PbO(2) Electrodes with Different Doses of Er Doping for Sulfonamides Degradation

In the present study, PbO(2) electrodes, doped with different doses of Er (0%, 0.5%, 1%, 2%, and 4%), were fabricated and characterized. Surface morphology characterization by SEM-EDS and XRD showed that Er was successfully doped into the PbO(2) catalyst layer and the particle size of Er-PbO(2) was reduced significantly. Electrochemical oxidation of sulfamerazine (SMR) in the Er-PbO(2) anode system obeyed te pseudo first-order kinetic model with the order of 2% Er-PbO(2) > 4% Er-PbO(2) > 1% Er-PbO(2) > 0.5% Er-PbO(2) > 0% PbO(2). For 2% Er-PbO(2), k(SMR) was 1.39 h(−1), which was only 0.93 h(−1) for 0% PbO(2). Effects of different operational parameters on SMR degradation in 2% Er-PbO(2) anode system were investigated, including the initial pH of the electrolyte and current density. Under the situation of an initial pH of 3, a current density of 30 mA·cm(−2), a concentration of SMR 30 mg L(−1), and 0.2 M Na(2)SO(4) used as supporting electrolyte, SMR was totally removed in 3 h, and COD mineralization efficiency was achieved 71.3% after 6 h electrolysis. Furthermore, the degradation pathway of SMR was proposed as combining the active sites identification by density functional calculation (DFT) and intermediates detection by LC-MS. Results showed that Er-PbO(2) has great potential for antibiotic wastewater treatment in practical applications.