Faculty of Physical and Chemical Engineering, Le Quy Don Technical University, Hanoi 100000, Vietnam; Department of Energy Engineering, Konkuk University, Seoul 05029, Korea.
Faculty of Physical and Chemical Engineering, Le Quy Don Technical University, Hanoi 100000, Vietnam.
J Environ Sci (China). 2023 Feb;124:379-396. doi: 10.1016/j.jes.2021.10.008. Epub 2022 Feb 3.
Wastewater containing an azo dye Orange G (OG) causes massive environmental pollution, thus it is critical to develop a highly effective, environmental-friendly, and reusable catalyst in peroxymonosulfate (PMS) activation for OG degradation. In this work, we successfully applied a magnetic MnFeO/α-MnO hybrid fabricated by a simple hydrothermal method for OG removal in water. The characteristics of the hybrid were investigated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller method, vibrating sample magnetometry, electron paramagnetic resonance, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The effects of operational parameters (i.e., catalytic system, catalytic dose, solution pH, and temperature) were investigated. The results exhibited that 96.8% of OG degradation was obtained with MnFeO/α-MnO(1:9)/PMS system in 30 min regardless of solution pH changes. Furthermore, the possible reaction mechanism of the coupling system was proposed, and the degradation intermediates of OG were identified by mass spectroscopy. The radical quenching experiments and EPR tests demonstrated that SO, O, and O were the primary reactive oxygen species responsible for the OG degradation. The hybrid also displayed unusual stability with less than 30% loss in the OG removal after four sequential cycles. Overall, magnetic MnFeO/α-MnO hybrid could be used as a high potential activator of PMS to remove orange G and maybe other dyes from wastewater.
含偶氮染料橙 G (OG) 的废水会造成严重的环境污染，因此，开发一种高效、环保且可重复使用的催化剂，用于过一硫酸盐 (PMS) 活化以降解 OG，这一点至关重要。在这项工作中，我们成功地应用了一种通过简单水热法制备的磁性 MnFeO/α-MnO 杂化物，用于水中 OG 的去除。通过 X 射线衍射、扫描电子显微镜、能量色散 X 射线光谱、傅里叶变换红外光谱、Brunauer-Emmett-Teller 法、振动样品磁强计、电子顺磁共振、热重分析和 X 射线光电子能谱对杂化物的特性进行了研究。考察了操作参数（即催化体系、催化剂量、溶液 pH 值和温度）的影响。结果表明，在 30 分钟内，MnFeO/α-MnO(1:9)/PMS 体系可使 OG 降解 96.8%，而不受溶液 pH 值变化的影响。此外，还提出了耦合体系的可能反应机制，并通过质谱鉴定了 OG 的降解中间产物。自由基猝灭实验和 EPR 测试表明，SO、O 和 O 是导致 OG 降解的主要活性氧物质。该杂化物还表现出异常的稳定性，经过四次连续循环后，OG 去除率仅损失了不到 30%。总的来说，磁性 MnFeO/α-MnO 杂化物可用作 PMS 的高效潜在激活剂，可从废水中去除橙 G 及可能的其他染料。
