Dissolved organic matters (DOM) are widely present in different water sources, causing significant effects on water treatment processes. Herein, the molecular transformation behavior of DOM during peroxymonosulfate (PMS) activation by biochar for organic degradation in a secondary effluent were comprehensively analyzed. Evolution of DOM was identified and inhibition mechanisms to organic degradation were elucidated. DOM underwent oxidative decarbonization (e.g., –C₂H₂O, −C₂H₆, –CH₂ and –CO₂), dehydrogenation (–2H) and dehydration reactions by ^·OH and SO₄^·−. N and S containing compounds witnessed deheteroatomisation (e.g., –NH, –NO₂+H, –SO₂, –SO₃, –SH₂), hydration (+H₂O) and N/S oxidation reactions. Among DOM, CHO-, CHON-, CHOS-, CHOP- and CHONP-containing molecules showed moderate inhibition while condensed aromatic compounds and aminosugars exhibited strong and moderate inhibition effects on contaminant degradation. The fundamental information could provide references for the rational regulation of ROS composition and DOM conversion process in a PMS system. This in turn offered theoretical guidance to minimize the interference of DOM conversion intermediates on PMS activation and degradation of target pollutants.

溶解有机物 (DOM) 广泛存在于不同的水源中，对水处理过程产生重大影响。本文综合分析了二次出水中生物炭活化过氧单硫酸盐 (PMS) 降解有机物过程中 DOM 的分子转化行为。鉴定了 DOM 的演变并阐明了对有机降解的抑制机制。DOM经历了氧化脱碳（例如， -C ₂ H ₂ O、-C ₂ H ₆、-CH ₂和-CO ₂）、脱氢（-2H）以及^· OH和SO ₄ ^{·-的脱水反应}. 含 N 和 S 的化合物发生去杂原子化（例如， -NH、-NO ₂ + H、-SO ₂、-SO ₃、-SH ₂）、水合作用（+H ₂O)和N/S氧化反应。在 DOM 中，含 CHO-、CHON-、CHOS-、CHOP- 和 CHONP 的分子显示出中度抑制作用，而稠合芳香化合物和氨基糖则对污染物降解表现出强和中度抑制作用。基础信息可为合理调控PMS系统中ROS组成和DOM转化过程提供参考。这反过来又为最大限度地减少 DOM 转化中间体对 PMS 活化和目标污染物降解的干扰提供了理论指导。