This study found that peroxymonosulfate (PMS) oxidation without activation has the potential to generate a suspected human carcinogen, N-nitrosodimethylamine (NDMA), in water containing N,N-dimethylhydrazine compounds. Considerable amounts of NDMA formed from three compounds by PMS oxidation were observed. 1,1,1′,1′-Tetramethyl-4,4′-(methylene-di-p-phenylene) disemicarbazide (TMDS), which is an industrial antiyellowing agent and light stabilizer, was used as a representative to elucidate the kinetics, transformation products, mechanism and NDMA formation pathways of PMS oxidation. TMDS degradation and NDMA formation involved direct PMS oxidation and singlet oxygen (¹O₂) oxidation. The oxidation by PMS/¹O₂ was pH-dependent, which was related to the pH-dependent characteristics of the reactive oxygen species and intermediates. The degradation mechanism of TMDS mainly included the side chain cleavage, dealkylation, and O-addition. NDMA was generated from TMDS mainly via O-addition and 1,1-dimethylhydrazine (UDMH) generation. The cleavage of amide nitrogen in O-addition products and primary amine nitrogen in UDMH are likely the key steps in NDMA generation. The results emphasized that the formation of harmful by-products should be taken into account when assessing the feasibility of PMS oxidation.

这项研究发现，未经活化的过氧单硫酸盐 (PMS) 氧化有可能在含有 N,N-二甲基肼化合物的水中产生疑似人类致癌物 N-亚硝基二甲胺 (NDMA)。观察到通过 PMS 氧化由三种化合物形成的大量 NDMA。以工业抗黄变剂和光稳定剂1,1,1',1'-Tetramethyl-4,4'-(methylene-di-p-phenylene) disemicarbazide (TMDS)为代表阐明动力学PMS氧化的转化产物、机理和NDMA形成途径。TMDS 降解和 NDMA 形成涉及直接 PMS 氧化和单线态氧 ( ¹ O ₂ ) 氧化。^{PMS/ 1} O ₂氧化是pH依赖性的，这与活性氧和中间体的pH依赖性特征有关。TMDS的降解机理主要包括侧链裂解、脱烷基化和O-加成。NDMA 主要通过 O-加成和 1,1-二甲基肼 (UDMH) 生成从 TMDS 生成。O-加成产物中酰胺氮的裂解和 UDMH 中伯胺氮的裂解可能是 NDMA 生成的关键步骤。结果强调，在评估 PMS 氧化的可行性时，应考虑有害副产物的形成。