Transition metal catalyzed sulfite auto-oxidation is a promising technology used in water and wastewater treatment for the elimination of contaminants. In the literature, this process has been reported to be efficient only in the presence of oxygen. However, in this study, we unexpectedly found that the degradation of diatrizoate (DTZ) by a system based on the combination of copper ion and sulfite (Cu(II)/S(IV)) reached over 95% under anaerobic conditions, but was considerably retarded under aerobic conditions at pH 7. Furthermore, it was found that Cu(I), generated from the cleavage of the CuSO₃ complex, was the main reactive species responsible for the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions. In fact, the absence of oxygen promoted the accumulation of Cu(I). The concomitant release of the iodide ion with the degradation of DTZ indicated that the anaerobic degradation of DTZ by the Cu(II)/S(IV) system mainly proceeded through the deiodination pathway, which was also confirmed by the detection of deiodinated products. The anaerobic degradation of DTZ was favored at higher initial concentrations of Cu(II) or sulfite in this system. Since the CuSO₃ complex, the precursor of Cu(I), was formed mainly at pH 7, the highest anaerobic degradation of DTZ was achieved at pH 7. An increase in reaction temperature considerably enhanced the degradation of DTZ by the Cu(II)/S(IV) system with an apparent activation energy of 119.4 kJ/mol. The presence of chloride, bicarbonate and humic acid slightly influenced the anaerobic degradation of DTZ. The experiments with real water samples also demonstrated the effectiveness of the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions.

过渡金属催化的亚硫酸盐自氧化是一种有前途的技术，可用于水和废水处理中以消除污染物。在文献中，据报道该方法仅在氧气存在下才有效。但是，在这项研究中，我们出乎意料地发现，在厌氧条件下，基于铜离子和亚硫酸盐（Cu（II）/ S（IV））组合的系统对泛影酸盐（DTZ）的降解达到95％以上，但是在pH 7的好氧条件下，Cu（I）明显受阻。此外，还发现由CuSO ₃裂解产生的Cu（I）络合物是在厌氧条件下通过Cu（II）/ S（IV）系统降解DTZ的主要反应物种。实际上，缺氧促进了Cu（I）的积累。碘离子的释放伴随DTZ的降解表明，Cu（II）/ S（IV）系统对DTZ的厌氧降解主要通过去碘途径进行，这也被检测到的碘化产物所证实。在此系统中，较高的初始浓度的Cu（II）或亚硫酸盐有利于DTZ的厌氧降解。自CuSO ₃络合物，主要是在pH 7下形成Cu（I）的前体，在pH 7下实现了DTZ的最高厌氧降解。反应温度的升高大大增强了Cu（II）/ S（IV）对DTZ的降解。表观活化能为119.4 kJ / mol。氯化物，碳酸氢盐和腐殖酸的存在对DTZ的厌氧降解产生了轻微影响。用真实水样进行的实验还证明了在厌氧条件下通过Cu（II）/ S（IV）系统降解DTZ的有效性。