A large amount of contaminated industrial wastewater has aroused mounting concern by researchers and environmentalists. Dyes contained in industrial effluents are often quite persistent to biodegradation, which must be treated before being disposed of. In this context, the use of Fenton processes is a potential alternative to treat a wide range of dyes and other organic pollutants found in wastewater. Thus, several Fe₂O₃/MCM‐41 catalysts have been synthesized in the following molar ratio of SiO₂/Fe₂O₃: 10, 20, 40, 100, and 200. They were characterized by N₂ adsorption–desorption isotherm, X‐ray fluorescence (XRF), X‐ray diffraction (XRD), UV–vis spectroscopy and H₂ temperature‐programmed reduction (H₂‐TPR), and applied to degrade methyl orange dye (MO) via a heterogeneous Fenton reaction. Catalytic tests revealed that SiO₂/Fe₂O₃ = 10 reached the highest activity due to greater availability of active sites which generated a larger quantity of hydroxyl (^•OH) and perhydroxyl (^•OOH) radicals. Furthermore, 70% of color removal has been achieved after 120 min at room temperature. Moreover, the systems moderately enhanced organic matter mineralization according to chemical oxygen demand (COD) testing. There was also catalytic activity loss in consecutive reaction cycles, which is probably due to dye molecules adsorption on active sites.

中文翻译：

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Fe2O3 / MCM-41用作Fenton样反应降解甲基橙的催化剂

大量受污染的工业废水引起了研究人员和环保主义者的日益关注。工业废水中所含的染料通常对生物降解具有很强的持久性，必须对其进行处理后再进行处理。在这种情况下，使用芬顿工艺是处理废水中发现的各种染料和其他有机污染物的潜在替代方法。因此，已经按照以下SiO ₂ / Fe ₂ O _3的摩尔比合成了几种Fe ₂ O ₃ / MCM-41催化剂：10、20、40、100和200。它们的特征在于N ₂吸附-解吸等温线。 ，X射线荧光（XRF），X射线衍射（XRD），紫外可见光谱和H ₂程序升温还原（H ₂ -TPR），并用于通过非均相Fenton反应降解甲基橙染料（MO）。催化测试表明，SiO ₂ / Fe ₂ O ₃ = 10达到了最高活性，这是由于活性位点的可用性更高，这些活性位点产生了大量的羟基（^• OH）和过羟基（^• OOH）自由基。此外，在室温下放置120分钟后，已实现了70％的脱色。此外，该系统根据化学需氧量（COD）测试适度增强了有机物矿化作用。在连续的反应周期中也有催化活性的损失，这可能是由于染料分子吸附在活性位点上。