磁响应性β-环糊精有机膦酸包合物及重金属吸附性能研究

发布时间：2018-06-28 21:20

  本文选题：磁性纳米材料 + β-环糊精　； 参考：《西南石油大学》2017年硕士论文

【摘要】：本论文研究了具有磁响应性的环糊精有机膦酸包合物在处理废水中重金属离子方面的可能应用,基于此前对环糊精有机膦酸包合物的理论研究,本论文对该理论的实用价值进行了探讨,期望能在重金属离子去除方面提供一定的理论基础。本论文首先通过水热法合成了具有磁响应性的四氧化三铁纳米颗粒,为了改善纳米颗粒在溶液中的分散性和稳定性,使用Stober法在纳米颗粒外部包裹上一层二氧化硅外壳。随后用3-氨丙基三乙氧基硅烷对纳米颗粒表面氨基化处理,得到表面可修饰的Fe3O4@Si02@APTES,通过与单-6-(6-O-对甲苯磺酰基)-β-环糊精作用得到环糊精修饰的纳米颗粒,并于水溶液中与2-膦酸基-1,2,4-三羧酸丁烷进行包合,得到具有磁响应性的环糊精有机磷酸包合物(MNP-CD-PBTCA)。利用XRD、TGA、FTIR、SEM和TEM手段对产物进行结构表征和形貌研究。随后研究了 MNP-CD-PBTCA对Hg(ⅡI)和Pb(ⅡI)的吸附性能,对Hg(Ⅱ),考察了不同因素(pH、Hg(Ⅱ)浓度、温度、时间)对MNP-CD-PBTCA吸附Hg(Ⅱ)性能的影响,结果表明当溶液pH为4、Hg(Ⅱ)浓度70.00 mg·L/-1、温度55℃、吸附时间150 min时,吸附效果最好,最大吸附量为77.59 mg·g-1;对Pb(Ⅱ),考察了不同因素(pH、吸附剂用量、温度、时间)对MNP-CD-PBTCA吸附Pb(Ⅱ)性能的影响,结果表明当溶液pH为6、吸附剂用量8.00 mg、温度35 ℃、吸附时间10 min时,吸附量即达到最大值52.25 mg·g-1。动力学研究表两者均更符合拟二级动力学模型,即化学吸附占据主导位置。内扩散动力学研究表明Hg(Ⅱ)和Pb(Ⅱ)均通过两个阶段向MNP-CD-PBTCA表面扩散,在第一阶段由于浓度梯度作用快速吸附,随后吸附速率减缓,进入吸附平衡的第二阶段,同时研究还发现Hg(Ⅱ)的吸附速率比Pb(Ⅱ)要慢,这与两者之间生成不同配位数的配合物也有关系。在热力学研究中,Hg(Ⅱ)吸附过程更符合Langmuir单分子层吸附模型,Pb(Ⅱ)吸附过程更符合Freundlich吸附模型。热力学参数均表明,整个过程属于AH00的吸热过程,升温有利于吸附进行;吸附前后体系熵变AS°0,吸附剂表面脱附的水分子增加了系统的无序度;AG00,MNP-CD-PBTCA对Hg(Ⅱ)和Pb(Ⅱ)的吸附属于自发过程。本论文也研究了 MNP-CD-PBTCA的再生利用性能,结果表明在经过五次吸附-脱附循环后,吸附剂对Hg(Ⅱ)和Pb(Ⅱ)和吸附效率依然能分别保持在83.16%和88.42%,脱附效率则分别为68.35%和82.47%,说明吸附剂具有良好的循环利用价值,同时对Pb(Ⅱ)的吸附效果更好。
[Abstract]:In this paper, the possible applications of cyclodextrin organic phosphonic acid inclusion complexes with magnetic response in the treatment of heavy metal ions in wastewater were studied, based on previous theoretical studies on cyclodextrin organic phosphonic acid inclusion complexes. This paper discusses the practical value of the theory and expects to provide a theoretical basis for heavy metal ion removal. In this paper, magnetically responsive iron trioxide nanoparticles were synthesized by hydrothermal method. In order to improve the dispersion and stability of nanoparticles in solution, a layer of silica shell was coated with Stober method. The surface of nanoparticles was treated with 3-aminopropyltriethoxy silane, and the surface modifiable Fe3O4Si02APTES was obtained. The modified nanoparticles were obtained by interaction with single -6- (6-O- p-toluenesulfonyl)-尾 -cyclodextrin. The inclusion compound of cyclodextrin organic phosphoric acid (MNP-CD-PBTCA) with magnetic response was obtained by the inclusion of 2-phosphonic acid group with 2-phosphonic acid group -2o 2-tricarboxylic acid butane in aqueous solution to obtain the inclusion compound of cyclodextrin organic phosphoric acid (MNP-CD-PBTCA). The structure and morphology of the products were characterized by SEM and TEM. Then the adsorption properties of MNP-CD-PBTCA for Hg (鈪，

本文编号：2079381