Refractory organic matter in membrane bioreactor effluent resulting from landfill leachate treatment has a complex composition. This paper identified the transformation mechanism of organic matter in a flocculation-ultraviolet (UV)/peroxymonosulfate (PMS) system at the molecular level using electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the flocculation system was able to remove a large amount of dissolved organic matter (DOM) with high oxidation and unsaturation/saturation. UV radiation displayed a relatively strong reactivity for DOM with an electron-rich structure, which it can transform into DOM with lower aromaticity through photolysis and photosensitivity, although the effectiveness of the transformation was poor. In comparison, due to the action of reactive oxygen species, the UV/PMS system can enable reactions such as demethylation, dehydrogenation, decarboxylation, dehydroxylation, ring cleavage, and decarbonylation. It can remove approximately 60% quantity of the total DOM and produce DOM featuring a higher degree of oxidation and saturation than that of the UV system alone. The results showed that the UV/PMS system was a complementary of flocculation in DOM removal from the membrane bioreactor effluent, while the system also resulted in a large number of sulfuric compounds; thus, requiring further evaluation of its ecological effects.

垃圾渗滤液处理膜生物反应器出水中的难降解有机物成分复杂。本文使用电喷雾电离结合傅立叶变换离子回旋共振质谱法，在分子水平上确定了絮凝-紫外线 (UV)/过一硫酸盐 (PMS) 系统中有机物的转化机制。结果表明，絮凝系统能够去除大量具有高氧化性和不饱和/饱和度的溶解有机物（DOM）。紫外辐射对富电子结构的DOM表现出较强的反应性，可以通过光解和光敏作用将其转化为芳香度较低的DOM，但转化效果较差。相比下，由于活性氧的作用，UV/PMS系统可以实现脱甲基、脱氢、脱羧、脱羟基、裂环、脱羰等反应。它可以去除大约 60% 的总 DOM，并产生比单独使用 UV 系统具有更高氧化度和饱和度的 DOM。结果表明，UV/PMS 系统在膜生物反应器流出液中去除 DOM 是絮凝的补充，同时该系统也产生了大量的含硫化合物；因此，需要进一步评估其生态影响。它可以去除大约 60% 的总 DOM，并产生比单独使用 UV 系统具有更高氧化度和饱和度的 DOM。结果表明，UV/PMS 系统在膜生物反应器流出液中去除 DOM 是絮凝的补充，同时该系统也产生了大量的含硫化合物；因此，需要进一步评估其生态影响。它可以去除大约 60% 的总 DOM，并产生比单独使用 UV 系统具有更高氧化度和饱和度的 DOM。结果表明，UV/PMS 系统在膜生物反应器流出液中去除 DOM 是絮凝的补充，同时该系统也产生了大量的含硫化合物；因此，需要进一步评估其生态影响。