Carcinogenic N, N-Dimethylnitrosamine (NDMA) has been reported to generate significantly during ozonation of fuel additive unsymmetrical dimethylhydrazine (UDMH), the combined ozone/Peroxy-Monosulfate (O₃/PMS) technology was tried for reducing its formation in this study. The influence of PMS dosages, ozone concentrations, pH, Br^- and humic acid (HA) on NDMA formation from UDMH were investigated. In addition, the reduction mechanisms were explored by intermediates identification and Gaussian calculation. The results demonstrated that O₃/PMS technology was effective on NDMA reduction, reaching an efficiency of 81% with 80 μM PMS. Higher NDMA reduction rates were achieved by O₃/PMS with increasing pH within the scope of research (from 5 to 9), achieving a maximum of 69.9% at pH 9. The presence of bromide ion facilitated NDMA generation during ozonation, but the reduction efficiency by O₃/PMS slightly improved from 66.3% to 70.6%. The presence of HA reduced NDMA formation in O₃/PMS system. The contribution of SO₄^•− on NDMA reduction accounted for ~64%, which was higher than that of •OH (41.4%); however, its promotion role on conversing UDMH to NDMA was lower than O₃. Therefore, the technology could reduce NDMA formation effectively. In addition, the results of Gaussian calculation manifested that the N atom in -NH₂ group of UDMH was easily attacked not only by •OH but also by O₃, so it is the key path that determines final NDMA formation. This study would provide reference for reducing NDMA formation during ozonation of UDMH-containing water matrixes.

据报道，在燃料添加剂不对称二甲基肼 (UDMH) 的臭氧化过程中会显着产生致癌性N , N -二甲基亚硝胺 (NDMA) ，本研究尝试使用臭氧/过氧单硫酸盐 (O ₃ /PMS) 组合技术来减少其形成。研究了 PMS 剂量、臭氧浓度、pH、Br ^-和腐殖酸 (HA) 对来自 UDMH 的 NDMA 形成的影响。此外，还通过中间体识别和高斯计算探索了还原机制。结果表明，O ₃ /PMS 技术可有效减少 NDMA，使用 80 μM PMS 可达到 81% 的效率。O ₃实现了更高的 NDMA 减少率/PMS 在研究范围内随着 pH 的增加（从 5 到 9），在 pH 9 时达到最高 69.9%。溴离子的存在促进了臭氧化过程中 NDMA 的生成，但 O ₃ /PMS的还原效率从66.3% 到 70.6%。HA 的存在减少了 O ₃ /PMS 系统中NDMA 的形成。SO ₄ ^•−对NDMA 减少的贡献占~64%，高于•OH（41.4%）；然而，其对UDMH转化为NDMA的促进作用低于O ₃。因此，该技术可以有效地减少NDMA的形成。此外，高斯计算结果表明-NH ₂中的N原子UDMH 群不仅容易受到•OH 的攻击，也容易受到O _{3 的}攻击，因此它是决定最终NDMA 形成的关键路径。该研究可为减少含UDMH水基体臭氧化过程中NDMA的形成提供参考。