Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, Texas, 77843, USA.
Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas 77843, USA.
Environ Sci Technol. 2023 Nov 28;57(47):19033-19042. doi: 10.1021/acs.est.3c03165. Epub 2023 Jun 29.
The increasing presence of antibiotics in water sources threatens public health and ecosystems. Various treatments have been previously applied to degrade antibiotics, yet their efficiency is commonly hindered by the presence of natural organic matter (NOM) in water. On the contrary, we show here that nine types of NOM and NOM model compounds improved the removal of trimethoprim and sulfamethoxazole by ferrate(VI) (FeO, Fe(VI)) under mild alkaline conditions. This is probably associated with the presence of phenolic moieties in NOMs, as suggested by first-order kinetics using NOM, phenol, and hydroquinone. Electron paramagnetic resonance reveals that NOM radicals are generated within milliseconds in the Fe(VI)-NOM system via single-electron transfer from NOM to Fe(VI) with the formation of Fe(V). The dominance of the Fe(V) reaction with antibiotics resulted in their enhanced removal despite concurrent reactions between Fe(V) and NOM moieties, the radicals, and water. Kinetic modeling considering Fe(V) explains the enhanced kinetics of antibiotics abatement at low phenol concentrations. Experiments with humic and fulvic acids of lake and river waters show similar results, thus supporting the enhanced abatement of antibiotics in real water situations.
抗生素在水源中的存在日益威胁着公众健康和生态系统。先前已经应用了各种处理方法来降解抗生素，但它们的效率通常受到水中天然有机物 (NOM) 的存在的阻碍。相比之下，我们在这里展示了在温和的碱性条件下，九种类型的 NOM 和 NOM 模型化合物可提高高铁酸盐 (FeO, Fe(VI)) 对甲氧苄啶和磺胺甲恶唑的去除率。这可能与 NOM 中存在酚类部分有关，这可以通过使用 NOM、苯酚和对苯二酚的一级动力学来证明。电子顺磁共振表明，在 Fe(VI)-NOM 体系中，NOM 通过单电子转移向 Fe(VI) 生成 Fe(V)，NOM 自由基在毫秒内生成。尽管 Fe(V)与 NOM 部分、自由基和水之间存在并发反应，但 Fe(V)与抗生素的反应优势导致抗生素的去除率提高。考虑 Fe(V)的动力学模型解释了在低酚浓度下抗生素去除率提高的动力学。对湖泊和河流水中的腐殖酸和富里酸的实验也得到了类似的结果，因此支持了在实际水情下抗生素去除率的提高。
