This paper proposes a modified electrochemical Fenton method with a pair of iron electrodes, which Fe anode is electrodisolved supplying stoichiometric Fe²⁺. Then the electrodisolved Fe²⁺ reacts with H₂O₂ to generate hydroxyl radical (· OH). The experiment shows that 62.6% of chemical oxygen demand (COD) is removed and the ratio of the five-day biochemical oxygen demand (BOD₅) to COD increases from 0.17 to 0.45 under the optimal experimental conditions (current density of 30 mA/cm², electrolysis time of 15 min, H₂O₂ dosage of 75 mmol/L, pH 3.00 and stirring time of 2.5 hours). Meanwhile, the high concentration of metronidazole (1000 mg/L) is dramatically decreased (> 95%). In order to explore the mineralization pathway for metronidazole, the intermediate by-products of the modified electrochemical Fenton process are investigated by GC/MS, FTIR and HPLC. Good results are achieved in treatment of the real metronidazole wastewater by the proposed method, BOD₅/COD increases from 0.17 to 0.35. This method has been successfully applied to a large scale industrial treatment of real metronidazole wastewater as a pretreatment process for the biochemical treatment.

本文提出了一种改进的带有一对铁电极的电化学Fenton方法，该方法通过电溶解的Fe阳极提供化学计量的Fe ²⁺。然后，电溶解的Fe ²⁺与H ₂ O ₂反应生成羟基自由基（·OH）。实验表明，在最佳实验条件（电流密度为30 mA / cm ）下，去除了62.6％的化学需氧量（COD），五天生化需氧量（BOD ₅）与COD之比从0.17增加到0.45 ²，电解时间为15分钟，H ₂ O ₂用量为75 mmol / L，pH为3.00，搅拌时间为2.5小时）。同时，甲硝唑的高浓度（1000 mg / L）显着降低（> 95％）。为了探索甲硝唑的矿化途径，通过GC / MS，FTIR和HPLC研究了改良的电化学Fenton工艺的中间副产物。所提出的方法在处理甲硝唑废水中取得了良好的效果，BOD ₅ / COD从0.17增加到0.35。作为生化处理的预处理方法，该方法已成功地应用于大规模的甲硝唑废水的工业处理。