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内蒙古大学本科毕业论文 分类号 _ 单位代码 _ 学 号 00814065 密 级 _ 本科毕业论文蒙脱石/零价铁纳米复合材料处理模拟 废水中 Zn2+研究院(系)名称: 环境与资源学院 专业名称: 环境科学 年 级: 2008 级 姓 名: 指导教师: 2012 年 6 月 1 日内蒙古大学本科毕业论文 第 i 页蒙脱石蒙脱石/ /零价铁纳米复合材料处理模拟废水中零价铁纳米复合材料处理模拟废水中 Zn2+研究研究摘 要纳米材料具有许多异于本体物质的独特物理、化学性质,已在基础研究和诸多实际应用中得到广泛关注。零价铁纳米颗粒更是以其卓越的磁性能和巨大的应用潜力备受瞩目。然而,零价铁纳米颗粒容易团聚,严重影响了其实际应用性能。本文以蒙脱石为载体和稳定剂,研究通过硼氢化钠化学液相还原法制备蒙脱石/零价铁纳米复合材料的可行性,并将该复合材料用于废水中 Zn2+污染物的去除,结合 X 射线衍射分析、电镜分析、元素分析等多种手段,得出以下结论:1、通过 NaBH4化学液相还原 Fe3+可成功制备蒙脱石/零价铁纳米复合材料,蒙脱石作为载体和分散剂可以起到良好的分散作用,有效降低铁纳米颗粒团聚程度。制备所得的铁颗粒尺寸较为均匀,具核壳结构,大体呈球状形貌,在蒙脱石表面分散良好。2、在室温且 pH 中性条件下,蒙脱石/零价铁纳米复合材料对 Zn2+吸附率达 89%以上,而单纯蒙脱石对 Zn2+的吸附率只有 50%左右;吸附 Zn2+的动力学过程符合准二级模型,热力学过程符合 Freundlich 经验吸附模型。复合材料对 Zn2+吸附作用本质较为复杂,主要是蒙脱石的阳离子交换作用,并可能存在由零价铁衍生的羟基化的氧化铁表面对溶液中 Zn2+的吸附作用。关键词:纳米复合材料;蒙脱石;零价铁;Zn2+;吸附内蒙古大学本科毕业论文 第 ii 页Montmorillonite/Zero Valent Iron Nanocomposite for Removing Zn2+ from Simulated WastewaterAuthor JING Guidong Tutor FAN MingdeAbstractNanomaterials exhibit novel physical and chemical properties that differ considerably from those of the bulk state, and consequently have attracted much attention both in academic study and in practical application. Zerovalent iron nanoparticles (ZVINs), as a nanomaterials, are important for their prominent magnetic properties and great potential in application. Nevertheless, ZVINs are easy to agglomerate and to oxidize, which makes them difficult to prepare, study, and apply. In the present study, ZVINs have been successfully synthesized using sodium borohydride solution reduction of Fe3+ in the presence of montmorillonite (Mt) as an effective protective reagent and support as well; and thus obtained Mt/ZVINs nanocomposite is used for removing Zn2+ from simulated wastewater. With a combination of X-ray diffraction, electron microscopic, and elemental analyses, the main conclusions of this study are made as follows:1. Mt/ZVINs nanocomposite has been successfully synthesized using sodium borohydride solution reduction of Fe3+ in the presence of Mt. With high monodispersity and spherical morphology, these hybridized ZVINs are well dispersed on Mt surface and have -Fe core-iron oxide shell structure.2. Under room temperature and neutral pH conditions, the obtained Mt/ZVINs nanocomposite is more effective than Mt for removing Zn2+ from simulated wastewater. The removal efficiency as to the nanocomposite reaches 90%, whereas the removal efficiency as to Mt was 50%. The adsorption of Zn2+ onto the nanocomposite can be fitted with pseudo-second order kinetics model and Freundlich isotherm, respectively. The related mechanisms would involve the cationic exchange reaction of Mt with Zn2+ and the adsorption of Zn2+ on the surface hydroxyl groups of iron oxide derived from the corrosion of ZVINs.Keywords: Nanocomposite; Montmorillonite; Zerovalent Iron; Zn2+; Adsorption.目 录内蒙古大学本科毕业论文 第 iii 页摘要.iiAbstract .iii1 引言.12 实验部分.42.1 实验样品.42.2 复合材料制备.42.3 吸附实验.42.4 表征手段.53 结果与讨论.63.1 蒙脱石/零价铁纳米复合材料.63.2 复合材料处理模拟废水中 Zn2+.73.2.1 复合材料吸附 Zn2+动力学研究.73.2.2 Zn2+初始浓度对吸附的影响.93.2.3 蒙脱石与复合材料吸附性能比较.133.2.4 反应温度对吸附的影响.144 结论.15致谢.
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