Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China.
Chemosphere. 2022 Nov;307(Pt 3):135972. doi: 10.1016/j.chemosphere.2022.135972. Epub 2022 Aug 13.
A regenerable MgO-coated magnetic FeO@SiO (FSM) composite effectively avoided the agglomeration of nano-MgO, which was resoundingly used for efficient and rapid phosphorus removal from aqueous solutions. Based on an initial screening of synthesized FSM with different Mg/citric acid molar ratios in terms of phosphorus adsorption capacity, an FSM composite with a Mg-citric acid molar ratio of 1:1 (FSM-1:1) was determined as the optimal choice. Scanning electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) showed that the prepared FeO was triumphantly loaded and the nano-MgO nanoparticles were evenly distributed on the surface of magnetic mesoporous silica. N adsorption-desorption experiments manifested that FSM-1:1 had a large specific surface area of 124.3 m/g and the pore size distribution calculated based on the BJH model was centered at 9.36 nm. Furthermore, FSM-1:1 not only exhibited fast adsorption kinetics (60 min) but also had a high maximum theoretical adsorption capacity of 223.6 mg P/g, which was superior to all the other Mg-based adsorbents. Remarkably, due to the coating of MgO, FSM-1:1 exhibited ultra-high stability in the pH range of 3-11, a wider range than many other Mg-modified sorbents. Our adsorbents also showed excellent selectivity for phosphate anions even in the presence of various coexisting anions (e. g. NO, Cl and SO) with varying ionic strengths (0.01 and 0.1 M), good recyclability, the removal rate of phosphate still reached 89.0% after three cycles. Electrostatic attraction, Lewis acid-base interaction and the ligand exchange between Mg-OH and phosphate anions were responsible for the phosphate adsorption mechanisms.
一种可再生的 MgO 涂层磁性 FeO@SiO（FSM）复合材料有效地避免了纳米 MgO 的团聚，这在很大程度上被用于从水溶液中高效快速地去除磷。基于对不同 Mg/柠檬酸摩尔比的合成 FSM 进行的初始筛选，在磷吸附容量方面，确定具有 1:1（FSM-1:1）的 Mg/柠檬酸摩尔比的 FSM 复合材料是最佳选择。扫描电子显微镜（SEM）、傅里叶变换红外（FTIR）和 X 射线衍射（XRD）表明，成功负载了制备的 FeO，并且纳米 MgO 纳米颗粒均匀分布在磁性介孔硅的表面上。N2 吸附-脱附实验表明，FSM-1:1 具有 124.3 m/g 的大比表面积，根据 BJH 模型计算的孔径分布中心位于 9.36 nm。此外，FSM-1:1 不仅表现出快速的吸附动力学（60 min），而且具有 223.6 mg P/g 的高最大理论吸附容量，优于所有其他基于 Mg 的吸附剂。值得注意的是，由于 MgO 的涂层，FSM-1:1 在 3-11 的 pH 范围内表现出超高的稳定性，比许多其他改性的 Mg 吸附剂的范围更广。我们的吸附剂即使在存在不同离子强度（0.01 和 0.1 M）的各种共存阴离子（例如 NO、Cl 和 SO）的情况下，也对磷酸盐阴离子表现出优异的选择性，具有良好的可循环性，在三个循环后，磷酸盐的去除率仍达到 89.0%。静电吸引、路易斯酸碱相互作用以及 Mg-OH 和磷酸盐阴离子之间的配体交换是磷酸盐吸附机制的原因。
