Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China.
Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, 430070, China; Xianghu Laboratory, Hangzhou, 311231, China.
Environ Pollut. 2024 Oct 15;359:124681. doi: 10.1016/j.envpol.2024.124681. Epub 2024 Aug 10.
Developing non radical systems for antibiotic degradation is crucial for addressing the inefficiency of conventional radical systems. In this study, novel magnetic-modified sludge biochar (MASBC) was synthesized to significantly enhance the oxidative degradation of sulfamethoxazole (SMX) by ferrate (Fe (VI)). In the Fe (VI)/MASBC system, 90.46% of SMX at a concentration of 10 μM and 49.34% of the total organic carbon (TOC) could be removed under optimal conditions of 100 μM of Fe (VI) and 0.40 g/L of MASBC within 10 min. Furthermore, the Fe (VI)/MASBC system was demonstrated with broad-spectrum removal capability towards sulfonamides in single or mixture. Quenching experiments, EPR analyses, and electrochemical experiments revealed that direct electron transfer (DET) and •O were mainly responsible for the removal of SMX, with functional groups (e.g., -OH, C=O) and Fe-O (redox of Fe (III)/Fe (II)) acting as the active sites, while the probe experiments showed that Fe (IV)/Fe (V) made a minor contribution to the degradation of SMX. Benefiting from the DET, the Fe (VI)/MASBC system exhibited a wide pH adaptation range (e.g., from 5.0 to 10.0) and strong anti-interference ability. The N atoms and their neighboring atoms in SMX were the prior degradation sites, with the cleavage of bond and ring opening. The degradation products showed low or non-toxicity according to ECOSAR program assessment. The removal of SMX remained within a reasonable range of 71.33%-90.46% over five consecutive cycles. Also, the Fe (VI)/MASBC system was demonstrated to be effectively applied for successful SMX removal in various water matrices, including ultrapure water, tap water, lake water, Yangtze River water, and wastewater. Therefore, this study offered new insights into the mechanism of Fe (VI) oxidation and would contribute to the efficient treatment of organic pollutants.
开发非自由基体系用于抗生素降解对于解决传统自由基体系效率低下的问题至关重要。在这项研究中，合成了新型的磁性改性污泥生物炭（MASBC），以显著增强高铁酸盐（Fe（VI））对磺胺甲恶唑（SMX）的氧化降解作用。在 Fe（VI）/MASBC 体系中，在最佳条件下（Fe（VI）浓度为 100 μM，MASBC 用量为 0.40 g/L），在 10 min 内可去除浓度为 10 μM 的 SMX 中 90.46%和总有机碳（TOC）的 49.34%。此外，Fe（VI）/MASBC 体系对单一组分或混合体系中的磺胺类物质具有广谱去除能力。猝灭实验、EPR 分析和电化学实验表明，直接电子转移（DET）和•O 是 SMX 去除的主要原因，而功能基团（如-OH、C=O）和 Fe-O（Fe（III）/Fe（II）的氧化还原）则作为活性位点，而探针实验表明 Fe（IV）/Fe（V）对 SMX 的降解贡献较小。得益于 DET，Fe（VI）/MASBC 体系具有较宽的 pH 适应范围（例如，从 5.0 到 10.0）和较强的抗干扰能力。SMX 中的 N 原子及其相邻原子是优先降解的位点，键和环的断裂。根据 ECOSAR 程序评估，降解产物的毒性较低或无毒性。在五个连续循环中，SMX 的去除率保持在合理范围内（71.33%-90.46%）。此外，Fe（VI）/MASBC 体系在各种水基质（包括超纯水、自来水、湖水、长江水和废水）中成功去除 SMX 也得到了有效应用。因此，本研究为 Fe（VI）氧化机制提供了新的见解，并将有助于有机污染物的有效处理。
