Efficient sonoelectrochemical decomposition of sulfamethoxazole adopting common Pt/graphite electrodes: The mechanism and favorable pathways.
In this study, efficient degradation of sulfamethoxazole (SMX) with a high synergy factor of 14.7 was demonstrated in a sonoelectrochemical (US-EC) system adopting common Pt and graphite electrodes. It was found that the US-EC system could work effectively at broad pH range of 3-9, but would achieve good performances with appropriate electrochemical conditions at 20mA/cm2and 0.1M Na2SO4. Both OH attacking and the anode oxidation would be responsible for the SMX degradation in the US-EC system, while the multiple promotional roles of US would be played homogenously and heterogeneously. US could not only effectively accelerate the decomposition of cathode-generated H2O2into OH, but also lead to the enhancement in the heterogeneous reactions on the two electrodes, i.e. the cathode generation of H2O2as well as the anode oxidation of SMX and H2O/OH-. Besides, the US-EC system would decompose SMX molecule via similar and simple pathways, by using either Na2SO4or NaCl electrolytes. It was interesting to note that the US-EC system could successfully avoid the formation of complex chlorinated byproducts that detected in the referring EC system with NaCl. This finding would make the sonoelectrochemical processes favorable in treating practical wastewaters by alleviating the environmental impact of disinfection byproducts.
School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Yawei
Y
Huang
School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: zhoutao@hust.edu.cn.
Tao
T
Zhou
School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, PR China.
Xiaohui
X
Wu
School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, PR China.
Juan
J
Mao
Chlorinated intermediates; Electrochemistry; In-situ oxidation; Sulfamethoxazole; Ultrasound