College of Environment, Zhejiang University of Technology, Hangzhou, China.
Water Environ Res. 2021 Dec;93(12):2903-2913. doi: 10.1002/wer.1622. Epub 2021 Oct 14.
In this study, a magnetic nanocatalyst (Fe O @SiO @CeO ) was prepared and applied in the catalytic ozonation of methyldopa (MD). The effects of operational parameters on catalytic ozonation performance were investigated, including ozone dosage, catalyst dosage, initial MD concentration, and pH. The removal of MD was 45.2% in ozonation, whereas the efficiency was achieved to 83.0% with the addition of Fe O @SiO @CeO . The results showed that Fe O @SiO @CeO could significantly improve the catalytic ozonation performance. And the enhanced mechanism study showed that it was attributed to promotion of ozone decomposition to generate hydroxyl radical. The reaction model was explored, and the reaction rates were calculated for the MD degradation in catalytic ozonation. A higher degradation efficiency of MD in catalytic ozonation was attributed to the enhanced surface effect of the catalysts, which was confirmed by using TBA, PO , and p-BQ as scavengers of hydroxyl radical, surface reaction, and superoxide radical. The hydroxyl radical and superoxide radical played an important role in the degradation of MD. The mechanism of catalytic ozonation by Fe O @SiO @CeO was discussed via X-ray photoelectron spectroscopy (XPS) spectra and experimental data.
在本研究中，制备了一种磁性纳米催化剂（Fe3O4@SiO2@CeO2），并将其应用于甲多巴（MD）的催化臭氧化中。考察了操作参数对催化臭氧化性能的影响，包括臭氧用量、催化剂用量、初始 MD 浓度和 pH 值。臭氧化时 MD 的去除率为 45.2%，而添加 Fe3O4@SiO2@CeO2后效率达到 83.0%。结果表明，Fe3O4@SiO2@CeO2可显著提高催化臭氧化性能。增强机制研究表明，这归因于促进臭氧分解生成羟基自由基。探讨了反应模型，并计算了催化臭氧化中 MD 降解的反应速率。催化臭氧化中 MD 具有更高的降解效率归因于催化剂的增强表面效应，这通过使用 TBA、PO43-和 p-BQ 作为羟基自由基、表面反应和超氧自由基的清除剂得到证实。羟基自由基和超氧自由基在 MD 的降解中起重要作用。通过 X 射线光电子能谱（XPS）谱和实验数据讨论了 Fe3O4@SiO2@CeO2催化臭氧化的机理。
