Laboratoire de Génie Chimique et Environnement de Skikda (LGCES), Université 20 Août 1955 Skikda, Skikda, BP 26 Route d'El Hadaiek, Algeria.
Laboratoire de PHysico-chimie des Electrolytes et Nanosystèmes InterfaciauX (PHENIX UMR 8234, UPMC-CNRS), Faculté des Sciences et Ingénierie, Sorbonne Université, Compus Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 5, France.
Environ Technol. 2021 Jan;42(1):43-57. doi: 10.1080/09593330.2019.1620865. Epub 2019 May 29.
Maghemite/silica nanocomposite microspheres (γ-FeO/SiO MS) have been tested as magnetically separable heterogeneous Fenton catalyst in beidellite clay slurries in the presence of methylorange (MO) as a model pollutant. Due to its strong magnetic susceptibility, the catalyst was easily recovered from the clay slurries by a selective magnetic sorting, even in highly concentrated slurries. The Fenton oxidation of MO was strongly enhanced in the clay slurries in comparison to the reaction in aqueous phase, highlighting a synergistic catalytic effect. The influence of different experimental parameters such as the presence of specific Reactive Oxygen Species (ROS) scavengers, pH, HO, catalyst and clay concentrations, on the catalytic activity was also evaluated. Contrary to what was observed in aqueous phase, generation of hydroxyl radicals via the Haber-Weiss mechanism was not the unique pathway that caused MO degradation in the beidellite slurries. We also observed that the synergistic effect is more marked at pH near neutrality and low amounts of HO and clay. Furthermore, the unchanged activity of the catalyst during five successive cycles together with the low level of iron leaching, makes it suitable candidate for an application as a magnetic heterogeneous Fenton catalyst in wastewater treatment, especially for surface waters or sludges naturally containing fine clay particles.
磁赤铁矿/二氧化硅纳米复合材料微球（γ-FeO/SiO MS）已被测试为在膨润土泥浆中作为可分离的非均相芬顿催化剂，在存在甲基橙（MO）作为模型污染物的情况下。由于其强的磁导性，即使在高浓度的泥浆中，催化剂也可以通过选择性的磁分离从泥浆中轻易回收。与在水相中的反应相比，MO 的芬顿氧化在泥浆中得到了强烈的增强，突出了协同催化作用。还评估了不同实验参数的影响，例如存在特定的活性氧物种（ROS）清除剂、pH、HO、催化剂和粘土浓度，对催化活性的影响。与在水相中的观察结果相反，通过 Haber-Weiss 机制生成羟基自由基并不是导致膨润土泥浆中 MO 降解的唯一途径。我们还观察到，在接近中性 pH 值和低浓度 HO 和粘土的情况下，协同效应更为显著。此外，催化剂在五个连续循环中的活性不变，以及铁浸出水平低，使其成为作为废水处理中磁性非均相芬顿催化剂的应用的合适候选物，特别是对于表面水或自然含有细粘土颗粒的泥浆。
