Electrochimica Acta, Vol.277, 77-87, 2018
Degradation of sulfadiazine in drinking water by a cathodic electrochemical membrane filtration process
In this study, a novel electrochemical membrane filtration (EMF) process was proposed to degrade sulfadiazine (SDZ) in drinking water, and the oxidation mechanisms, kinetics, byproducts and primary impact factors were investigated. In the EMF process, a novel membrane was used as the cathode and two graphite plates were used as anodes. Five oxidation byproducts including 4-OH-sulfadiazine or 5OH-sulfadiazine, 2-aminopyrimidine, 4-amino-N-carbamimidoyl benzene sulfonamide and 2,5dihydroxypyrimidine were identified. Possible degradation pathways for SDZ were proposed, and . OH and were recognized to be the major reactive oxygen species contributed for SDZ degradation. The degradation of SDZ by EMF followed pseudo-first-order kinetics in batch experiment and the rate constant increased as the applied voltages increased. Compared with the batch experiment, the flowthrough mode of EMF slowed SDZ degradation, and the degradation rate also decreased as the flux increased. However, on the base of mass balance calculations more SDZ was degraded in flow-through mode as compared with that in batch experiment. Finally, the degradation of SDZ in natural waters from a municipal drinking water treatment plant was investigated with flow-through mode, and the result shows that the degradation rate (79%) was slightly lower than that obtained for deionized water due to the low conductivity of real-world water systems. (C) 2018 Elsevier Ltd. All rights reserved.
Keywords:Electrochemical membrane filtration;process;Electron-Fenton;Sulfadiazine;Drinking water;Energy consumption