This study systematically investigates the formation of trichloronitromethane (TCNM) from 2 natural waters, 6 humic substances and 16 phenolic compounds during UV/monochloramine (UV/NH₂Cl) followed by post-chloramination. Using ¹⁵N-NH₂Cl as an isotope tracer, we found that ¹⁵N-TCNM accounted for 70.7–76.5% of total TCNM during UV/NH₂Cl treated 2 natural waters, which was significantly higher than the proportion of ¹⁵N-TCNM in chloramination (NH₂Cl alone). This is a direct evidence that NH₂Cl, rather than the nitrogenous matters in waters, was the predominant nitrogen source of TCNM during UV/NH₂Cl treatment. Phenol derivatives with meta-substituents and with electron-withdrawing groups facilitated the formation of TCNM precursors during UV/NH₂Cl treatment. Significant correlations were found between Hammett constants (σ) of substituents and TCNM formation potentials. The formation mechanisms of TCNM were revealed using resorcinol as a representative phenolic compound. During UV/NH₂Cl treatment, HO^•, reactive chlorine species and reactive nitrogen species contributed to 28.1%, 29.0% and 19.4% of resorcinol degradation. Five nitro(so)-intermediates were identified as the main TCNM precursors. The formation pathways of TCNM were proposed. Alkaline pH was recommended to reduce the formation of TCNM precursors during UV/NH₂Cl treatment.

本研究系统地研究了在紫外线/一氯胺 (UV/NH ₂ Cl) 和后氯胺化过程中，2 种天然水、6 种腐殖质和 16 种酚类化合物中三氯硝基甲烷 (TCNM) 的形成。使用¹⁵ N-NH ₂ Cl 作为同位素示踪剂，我们发现在 UV/NH ₂ Cl 处理 2 个天然水体过程中，¹⁵ N-TCNM 占总 TCNM 的 70.7-76.5%，明显高于¹⁵ N- TCNM 在氯胺化中（单独的NH ₂ Cl）。这是一个直接证据，表明 NH ₂ Cl，而不是水中的含氮物质，是 UV/NH ₂期间 TCNM 的主要氮源氯处理。具有间位取代基和吸电子基团的苯酚衍生物在 UV/NH ₂ Cl 处理过程中促进了 TCNM 前体的形成。在取代基的哈米特常数 (σ) 和 TCNM 形成潜力之间发现了显着的相关性。使用间苯二酚作为代表性酚类化合物揭示了 TCNM 的形成机制。在 UV/NH ₂ Cl 处理过程中，H2O ^•、活性氯物质和活性氮物质对间苯二酚降解的影响分别为 28.1%、29.0% 和 19.4%。五种硝基（so）-中间体被确定为主要的 TCNM 前体。提出了TCNM的形成途径。建议使用碱性 pH 值以减少 UV/NH 期间 TCNM 前体的形成₂ Cl处理。