Department of Environmental Science and Engineering, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Environ Sci Pollut Res Int. 2023 Jun;30(30):75595-75609. doi: 10.1007/s11356-023-27778-5. Epub 2023 May 24.
In this work, FeS supported SBA-15 mesoporous silica catalyst (FeS@SBA-15) was synthesized successfully, characterized and first applied to persulfate (PS) activation for the degradation of imidacloprid in wastewater. The as-prepared 3.5-FeS@SBA-15 presented an impressive imidacloprid removal efficiency of 93.1% and reaction stoichiometric efficiency (RSE) of 1.82% after 5 min, ascribed to the synergetic effects of improved FeS dispersion and abundant surface sites by SBA-15. Electron paramagnetic resonance spectra and quenching experiments proved that both SO and ·OH were produced in FeS@SBA-15/PS system, and SO played a dominant role in the degradation process. The S can accelerate the cycling of Fe(III)/Fe(II) during activation and increase the steady-state concentration of Fe(II). More importantly, the constructed heterogeneous system exhibited an efficient and stable catalytic activity over a wide range of pH (3.0-9.0), temperature (283K-313K), inorganic ion (NO) and humic acid (1-20 mg/L). Moreover, the density functional theory calculations were conducted to predict the potential reaction sites of imidacloprid. Based on eighteen identified intermediates, four main degradation pathways were proposed: hydroxylation, dechlorination, hydrolysis, and the ring cleavage of the imidazolidine. ECOSAR analysis indicated hydroxylation and dechlorination played a key role in the detoxification of the formed compounds. These findings would provide new insights into the application of FeS@SBA-15 catalyst in wastewater treatment and the removal mechanism of imidacloprid from wastewater.
在这项工作中，成功合成了负载 FeS 的 SBA-15 介孔硅催化剂（FeS@SBA-15），对其进行了表征，并首次将其应用于过硫酸盐（PS）活化以降解废水中的吡虫啉。所制备的 3.5-FeS@SBA-15 在 5 分钟内表现出令人印象深刻的吡虫啉去除效率为 93.1%和反应计量效率（RSE）为 1.82%，这归因于 SBA-15 改善的 FeS 分散和丰富的表面位点的协同效应。电子顺磁共振谱和猝灭实验证明，在 FeS@SBA-15/PS 体系中产生了 SO 和·OH，并且 SO 在降解过程中起主导作用。S 可以加速 PS 活化过程中 Fe(III)/Fe(II)的循环，并增加 Fe(II)的稳态浓度。更重要的是，该构建的非均相体系在很宽的 pH（3.0-9.0）、温度（283K-313K）、无机离子（NO）和腐殖酸（1-20mg/L）范围内表现出高效和稳定的催化活性。此外，还进行了密度泛函理论计算以预测吡虫啉的潜在反应位点。基于鉴定出的十八个中间体，提出了四种主要的降解途径：羟基化、脱氯、水解和咪唑烷环的断裂。ECOSAR 分析表明，羟基化和脱氯在形成化合物的解毒中起关键作用。这些发现将为 FeS@SBA-15 催化剂在废水处理中的应用以及废水中吡虫啉的去除机制提供新的见解。
