花型及泡沫状磁性纳米材料的制备及其去除有机染料污染物的研究

发布时间：2018-06-30 00:36

本文选题：磁性纳米粒子 + 有机染料　；参考：《兰州大学》2015年硕士论文

【摘要】：近几十年来,水污染问题已经发展成为影响人类生存发展的最大威胁,由于工业和人类生活的飞速发展,不可避免地带来了大量的污染物,主要包括固体垃圾,工农业污水,温室气体等。其中,工业废水的任意排放,对江河湖泊及地下水造成了严重污染；而且其成分复杂,降解难度大,给废水处理带来了巨大压力。工业废水中的有害成分主要包括染料、色素、重金属(铅,汞,铬等)以及悬浮固体等。这些均会对人类及动植物健康造成危害,如若不能有效地控制和管理,人类的生存发展必将会遭受更大的威胁。磁性微纳米材料因其具有良好的磁响应性,而且形态多样,比表面积大等特点,受到了研究者们的广泛关注。此外,还可以进行多种改性,使材料携带丰富的官能团,拓宽应用范围。然而传统的吸附、催化材料在使用过程中会有流失现象,而且后处理困难。新兴的磁分离技术可以在很大程度上改善上述问题。磁分离技术与吸附,降解等污水处理手段的有效结合,有望成为一种高效简便的水净化手段。因此,设计合成一类尺寸均一,形貌规整及功能性高的新型微纳米材料,成为本论文的主要研究目的。本学位论文的主要研究内容如下：1.花型磁性纳米吸附剂的制备及其对废水中染料和重金属离子的去除本章设计并通过一步法合成了花型磁性吸附剂(FMAs),确定了FMAs的可能的形成机制；并通过透射电镜(TEM),扫描电镜(SEM), XRD, BET等表征手段对其结构进行了表征分析。FMAs具有较高的比表面积(71.6 m2/g),大的饱和磁化强度(44.41 emu/g),和丰富的官能团(羧基,羟基和疏水性基团)等。基于以上特性,将得到的FMAs作为一种新型吸附剂,详细研究了微纳米材料对亚甲基蓝、孔雀石绿以及Pb2+和Cr6+的吸附。考察了FMAs对亚甲基蓝,孔雀石绿及Pb2+和Cr6+吸附动力学和等温吸附模型,探讨了材料对染料/金属离子二元体系的吸附效果等。实验结果表明,制备得到的FMAs具备优良的吸附性能。2.泡沫状磁性铁基纳米催化剂的制备及其在类Fenton反应中的应用本章设计制备了一种具有空腔结构的铁氧化物复合纳米粒子(FexOy@FexOy/C),所有的制备步骤简单且易于控制。空腔结构可以增大纳米粒子的比表面积,提高其表面能,所以相对于传统的Fenton催化剂,由于空腔结构的存在,为反应物与催化剂接触提供了两种方式(由活性成分组成的核和壳均可与反应物接触而使其被催化降解)。此外,高温煅烧过程中会在催化剂的核与壳中形成零价铁(Fe0)-铁氧化物纳米复合材料,由于Fe0和铁氧化物中的Fe3+可以发生电子转移,在此过程中又重新产生了Fe2+,这对Fenton反应是十分有利的。因此,相对于传统的Fenton催化剂,具有空腔结构的核壳型FexOy@FexOy/C纳米催化剂有望改善其催化性能。为了验证以上设想,选定亚甲基蓝作为污染物模型来评价FexOy@FexOy/C纳米粒子的Fenton催化性能。结果表明,FexOy@FexOy/C纳米材料具有非常优异的催化性能和稳定性,并没有显现出传统催化剂在均相或非均相类Fenton体系中所表现出的劣势。
[Abstract]:In recent decades, the problem of water pollution has been the greatest threat to the survival and development of human beings. Due to the rapid development of industry and human life, a large number of pollutants are inevitably brought in, including solid waste, industrial and agricultural sewage, greenhouse gas and so on. Among them, the waste of industrial waste water is made to rivers, lakes and groundwater. The harmful ingredients in industrial waste water are mainly dyestuffs, pigments, heavy metals (lead, mercury, chromium, etc.) and suspended solids, all of which are harmful to human and animal and plant health, such as if it is not effectively controlled and managed, human beings There will be a greater threat to the development of survival. Magnetic micronanomaterials have been widely concerned because of their good magnetic responsiveness, diversity and large surface area. In addition, a variety of modifications can be carried out to make materials carry rich functional groups and broaden their application. However, traditional adsorption and catalytic materials The new magnetic separation technology can improve the above problems to a great extent. The effective combination of magnetic separation technology and adsorption, degradation and other sewage treatment means is expected to be a highly efficient and simple means of water purification. The main purpose of this thesis is the new micro nano materials with high function. The main contents of this dissertation are as follows: 1. the preparation of the magnetic nano adsorbent and the removal of the dye and heavy metal ions in the wastewater and the synthesis of the flower type magnetic adsorbent (FMAs) by one step method. The possibility of FMAs is determined. By means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), XRD, BET and other characterization methods, the structure of.FMAs has high specific surface area (71.6 m2/g), large saturation magnetization (44.41 emu/g), and rich functional groups (carboxyl, hydroxyl and hydrophobic groups). Based on the above properties, the obtained FMAs will be obtained. For a new type of adsorbent, the adsorption of methylene blue, malachite green, Pb2+ and Cr6+ was studied in detail. The adsorption kinetics and isothermal adsorption model of FMAs on methylene blue, malachite green and Pb2+ and Cr6+ were investigated. The adsorption effect of the materials on the two element system of dye / metal ions was discussed. The experimental results showed that the preparation was obtained. The FMAs has excellent adsorption properties and the preparation of.2. foam like magnetic iron based nano catalyst and its application in Fenton like reaction. This chapter has designed a kind of iron oxide composite nanoparticles with cavity structure (FexOy@FexOy/C). All the preparation steps are simple and easy to control. The cavity structure can increase the particle size. The surface energy is higher than the surface area, so relative to the traditional Fenton catalyst, the presence of the cavity structure provides two ways for the reaction of the reactant to the catalyst (the core and the shell of the active component can be exposed to the reactant to be degraded). In addition, the high temperature calcination process will be formed in the core and the shell of the catalyst. Zero valent iron (Fe0) - iron oxide nanocomposites, due to the electronic transfer of Fe3+ in Fe0 and iron oxide, reproduced Fe2+ again in this process, which is very beneficial to the Fenton reaction. Therefore, relative to the traditional Fenton catalyst, the nuclear shell type FexOy@FexOy/C nano catalyst with a cavity structure is expected to improve its catalytic activity. In order to verify the above assumption, methylene blue is selected as a pollutant model to evaluate the Fenton catalytic performance of FexOy@FexOy/C nanoparticles. The results show that the FexOy@FexOy/C nanomaterials have excellent catalytic performance and stability, and the traditional catalysts are not shown in the homogeneous or heterogeneous Fenton systems. Inferiority.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X788;TB383.1

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