In this study, mineralization and color removal performance of electro-Fenton method was examined in water containing naphthol blue black (NBB), a diazo dye. NBB was totally converted to intermediate species in a 15-min electrolysis at 60 mA, but complete de-colorization took 180 min. A very high oxidation rate constant ((3.35 ± 0.21) x 10¹⁰ M⁻¹s⁻¹) was obtained for NBB, showing its high reactivity towards hydroxyl radicals. A very high total organic carbon (TOC) removal value (45.23 mg L⁻¹) was obtained in the first 60 min of the electro-Fenton treatment of an aqueous solution of NBB (0.25 mM) at 300 mA, indicating the mineralization efficiency of the electro-Fenton method. Mineralization current efficiency values obtained at 300 mA gradually decreased from 24.18% to 4.47% with the electrolysis time, indicating the presence of highly parasitic reactions. Gas chromatography-mass spectrometry analyses revealed that the cleavage of azo bonds of NBB led to formation of different aromatic and aliphatic oxidation intermediates. Ion chromatography analysis showed that ammonium, nitrate and sulfate were the mineralization end-products. The concentration of sulfate ion reached to its quantitative value at the 4th h of electrolysis. On the other hand, the total concentration of ammonium and nitrate ions reached to only 61% of the stoichiometric amount of initial nitrogen after a 7 h electrolysis. Finally, it can be said that the electro-Fenton method is a suitable and efficient method for the removal of NBB and its intermediates from water.

在这项研究中，在含有重氮萘酚蓝黑（NBB）的水中检查了电芬顿法的矿化和除色性能。NBB在60 mA的电流下经过15分钟的电解后完全转化为中间物种，但是完全脱色需要180分钟。对于NBB，获得了非常高的氧化速率常数（（3.35±0.21）x 10 ¹⁰  M ^-1 s ^-1），显示了其对羟基自由基的高反应性。很高的总有机碳（TOC）去除值（45.23 mg L ^-1）在300 mA的NBB（0.25 mM）水溶液的电子芬顿处理的前60分钟中获得），这表明电子芬顿方法的矿化效率。随着电解时间的增加，在300 mA下获得的矿化电流效率值从24.18％逐渐降低到4.47％，表明存在高度寄生反应。气相色谱-质谱分析表明，NBB的偶氮键断裂导致形成不同的芳族和脂族氧化中间体。离子色谱分析表明，铵，硝酸盐和硫酸盐是矿化的最终产物。在电解的第4小时，硫酸根离子的浓度达到其定量值。另一方面，电解7小时后，铵离子和硝酸根离子的总浓度仅为初始氮化学计量的61％。最后，可以说电芬顿法是一种从水中去除NBB及其中间体的合适而有效的方法。