Electrochemical degradation of 2-diethylamino-6-methyl-4-hydroxypyrimidine using three-dimensional electrodes reactor with ceramic particle electrodes

The removal of 2-diethylamino-6-methyl-4-hydroxypyrimidine (DTMHP) in simulated wastewater was investigated using a three-dimensional electrodes reactor with ceramic particles serving as packed bed particle electrodes, lead alloy as anode, and stainless steel as cathode. The particle electrodes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET). It was showed that the particle electrodes have porous structure. Comparable experiments indicated the high catalytic activity and current efficiency of three-dimensional electrochemical reactor with ceramic particle electrodes. The effects of initial pH, cell voltage on the degradation efficiency were also studied. A removal of 83.45% pyrimidine ring and 35.17% COD were obtained within 150 min under initial pH of 3 and cell voltage of 15 V. Special attention was paid to the target pollutant degradation pathway in this system. It was found that the organic carbon of the pollutant could be degraded effectively, but the mineralization of organic nitrogen was relatively inefficient. The mineralization process could be dramatically promoted by the presence of NaCl, which might be transformed into active chlorine under electrochemical conditions resulting in indirect oxidation. A possible catalytic mechanism of the three-dimensional reactor was also proposed. Overall, the three dimensional electrode method could be considered as a viable alternative for the treatment of pesticide wastewater.