Psychoactive substances abuse is a global issue, with the methamphetamine (METH) being the most used and produced illicit substance in recent years. METH has been recognized as emerging contaminants in aquatic ecosystems. Research on the removal of METH from surface water is still lacking in-depth exploration. The effects of key aqueous environmental factors on the photodegradation of METH were investigated in this study. NO₃^⁻, Fe³⁺ and dissolved organic matter (DOM) enhanced the photodegradation of METH, respectively, with degradation rates increasing as their concentrations increased. When HCO₃^⁻ coexisted with NO₃^⁻, it exhibited dual effects on METH photodegradation: low concentrations inhibited the process, whereas high concentrations promoted it. The primary photodegradation products of METH, such as OH-METH, (OH)₂-METH, AMP and NO₂-OH-METH, were identified. The latter two compounds were newly discovered in this study. The mechanism of NO₃^⁻, HCO₃^⁻ and Fe³⁺ accelerating the photodegradation of METH in water was proposed to proceed via the generation of hydroxyl radical (HO∙), leading to the oxidation of METH, along with the involvement of nitro radical (∙NO₂) and carbonate radical (CO₃^•-).

中文翻译：

---

深入了解 NO₃⁻、HCO₃⁻ 和 Fe3+ 驱动的地表水中甲基苯丙胺在阳光下诱导的光降解机制


精神活性物质滥用是一个全球性问题，甲基苯丙胺 （METH） 是近年来使用和生产最多的非法物质。METH 已被公认为水生生态系统中的新兴污染物。关于从地表水中去除 METH 的研究仍然缺乏深入的探索。本研究研究了关键水性环境因素对 METH 光降解的影响。NO₃^⁻、Fe³⁺ 和溶解有机物 （DOM） 分别增强了 METH 的光降解，降解速率随着其浓度的增加而增加。当 HCO^₃⁻ 与 NO^₃⁻ 共存时，它对 METH 光降解表现出双重影响：低浓度抑制了该过程，而高浓度则促进了该过程。鉴定了 METH 的初级光降解产物，如 OH-METH、（OH_）2-METH、AMP 和 NO 2-OH-METH。后两种化合物是本研究中新发现的。NO₃^⁻、HCO₃^⁻ 和 Fe³⁺ 加速水中 METH 光降解的机制通过产生羟基自由基 （HO∙） 导致 METH 氧化，同时硝基自由基 （∙NO₂） 和碳酸盐自由基 （CO₃^•-） 参与。