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为了揭示吸附剂的吸附效能与其组成、结构及表面性质之间的关系,本研究对两种壳核结构磁性颗粒Fe_3O_4/Mn O2与Fe-Mn/Mn O2的形貌特征、表面性质进行了系统表征,并对铜在磁性颗粒表面的吸附行为与机制进行了详细研究.表征结果表明磁核Fe_3O_4与Fe-Mn具有相似的尖晶石类晶体结构,包覆Mn O2后,晶体结构均未发生明显变化.但Mn的引入,增强了磁核与外壳间的结合作用,Fe-Mn比Fe_3O_4包覆MnO_2的量更多、更均匀,进而使Fe-Mn/Mn O2具有更高的比表面积与更低的等电点.吸附实验结果表明,Fe-Mn的最大铜吸附容量33.7 mg·g-1(pH 5.5)高于Fe_3O_4的17.5 mg·g-1(pH 5.5);包覆MnO_2以后,铜吸附性能显著增强,Fe-Mn/MnO_2最大铜吸附容量升高至58.2 mg·g-1(p H 5.5),为Fe_3O_4/MnO_2的2.6倍,且优于多数文献报道的磁性吸附剂.机制研究表明铜在Fe_3O_4/Mn O2与Fe-Mn/MnO_2的表面发生了特性吸附,形成了内层表面络合物.综上所述,磁性颗粒的吸附效能与其组成成分、形貌结构及表面性质之间具有显著的相关性.
In order to reveal the relationship between the adsorption efficiency of adsorbents and their composition, structure and surface properties, the morphologies and surface properties of two kinds of Fe ~ 3O_4 / Mn O2 and Fe-Mn / Mn O2 magnetic particles were systematically studied And the adsorption behavior and mechanism of copper on the surface of magnetic particles were studied in detail.The characterization results show that the magnetic nuclei Fe_3O_4 and Fe-Mn have similar spinel crystal structure, and the crystal structure does not occur after coating MnO2 However, the introduction of Mn enhanced the binding between the magnetic core and the outer shell, Fe-Mn was more and more uniform than the Fe_3O_4-coated MnO_2, so that the Fe-Mn / MnO 2 had higher specific surface area and Lower isoelectric point.The adsorption experiments showed that the maximum copper adsorption capacity of Fe-Mn 33.7 mg · g-1 (pH 5.5) was higher than that of Fe_3O_4 17.5 mg · g-1 (pH 5.5) The adsorption capacity of copper increased significantly, and the maximum copper adsorption capacity of Fe-Mn / MnO 2 increased to 58.2 mg · g-1 (p H 5.5), which was 2.6 times that of Fe 3 O 4 / MnO 2 and better than most magnetic adsorbents reported in the literature. The results show that copper is adsorbed on the surface of Fe_3O_4 / MnO2 and Fe-Mn / MnO_2, forming the inner surface of the complex. The adsorption performance of the magnetic particles and its components, a significant correlation between topography and surface properties.