Fe3O4/高岭土磁性复合材料对Cu2+的吸附性能

为实现高岭土（Kaolin）在Cu²⁺废水处理中的实际应用，采用球磨方法制备了剥离Kaolin，并通过氧化沉淀法制备了Fe₃O₄/Kaolin磁性复合材料。通过激光粒度分析仪、SEM、XRD对Fe₃O₄/Kaolin磁性复合材料的形貌及组成进行表征，并通过测试Fe₃O₄/Kaolin磁性复合材料对Cu²⁺的饱和吸附量和磁分离回收率，确定了当Kaolin球磨4.0 h、掺量为3.0 g时所制备的Fe₃O₄/Kaolin磁性复合材料对Cu²⁺的吸附性能最佳，平衡吸附量为17.98 mg/g。磁滞回线结果表明，Fe₃O₄/Kaolin磁性复合材料具有较好的磁响应性，饱和磁化强度约为16.19 emu/g。此外，采用Langmuir和Freundlich吸附等温式对Fe₃O₄/Kaolin磁性复合材料的吸附数据进行拟合，结果表明，Fe₃O₄/Kaolin磁性复合材料对Cu²⁺的吸附行为基本符合Langmuir吸附等温模型和Freundlich吸附等温模型，既存在单分子层吸附，也存在多分子层吸附。

Adsorption properties of Fe3O4/Kaolin magnetic composites for Cu2+

To facilitate Kaolin which was used to remove Cu²⁺ from waste water, the stripped Kaolin was prepared by ball milling and the Fe₃O₄/Kaolin magnetic composite was prepared by oxidative precipitation method. The morphology and composition of Fe₃O₄/Kaolin magnetic composite were characterized by laser particle size analyzer, SEM and XRD, respectively. The saturation adsorption capacity and magnetic separation recovery of Cu²⁺ was tested. It is demonstrated that 3.0 g Fe₃O₄ is the optimal amount as additive in Fe₃O₄/Kaolin magnetic composite to achieve improved adsorption ability (17.98 mg/g). The saturation magnetization reaches about 16.19 emu/g by hysteresis loop, which shows excellent magnetic response. In addition, the adsorption data of the Fe₃O₄/Kaolin magnetic composite were fitted by Langmuir and Freundlich adsorption isotherm. It is found that the adsorption behavior of Fe₃O₄/Kaolin for Cu²⁺ is basically consistent with the Langmuir adsorption isotherm model and the Freundlich adsorption isotherm model, indicating both monolayer adsorption and multi-layer adsorption are existed in the adsorption behavior of the Fe₃O₄/Kaolin magnetic composite for Cu²⁺.