海胆状Fe3O4@TiO2磁性纳米介质对Pb^2＋的选择吸附特性  

Selective adsorption of Pb^(2+) by sea urchin magnetic nano-Fe_3O_4@TiO_2

作　　者：王耀强 赵怡琳 李玲慧 苏海佳[1] 

机构地区：[1]北京化工大学,北京市生物加工过程重点实验室,北京100029

出　　处：《化工学报》2018年第1期446-454,共9页CIESC Journal

基　　金：国家自然科学基金项目(21525625);国家重点基础研究发展计划项目(2014CB745100);国家高技术研究发展计划项目(2013AA020302).

摘　　要：耦合溶胶-凝胶技术与水热法,制备具有核壳结构的海胆状Fe_3O_4@TiO_2磁性纳米介质(sea urchin magnetic nanoparticles,SUMNPs)。采用TEM、SEM等方法对SUMNPs的形貌等性质进行表征,证实该材料呈现出以Fe_3O_4为核,以TiO_2为壳的海胆状结构,壳层直径约400 nm,比表面积高达236.082 m2·g-1,表面孔径约6.274 nm。SUMNPs对重金属离子选择吸附的结果表明,基于Pb^(2+)离子半径大、电子层数多等物化特点,在Pb^(2+)、Cu^(2+)、Ni^(2+)、Zn^(2+)、Cd^(2+)5种金属离子混合体系中,SUMNPs可以高容量、高选择性快速吸附Pb^(2+),而对其他4种重金属离子几乎无吸附活性。单一Pb^(2+)吸附可在5 min内快速平衡,平衡吸附容量为283 mg·g-1。吸附过程符合Langmuir等温吸附模型,SUMNPs对Pb^(2+)的最大饱和吸附容量为458.72 mg·g-1。经EDTA二钠解吸,Na OH再生后的SUNMPs可以重复使用8次以上。SUMNPs对Pb^(2+)具备优异的选择性吸附性能,在处理水体铅污染、恢复水体生态领域具有良好的应用前景。The sea urchin magnetic nano-Fe3O4@TiO2 particles （SUMNPs） with core-shell structure were prepared by sol-gel technique combined with hydrothermal method. The morphologies and surface areas of SUMNPs were characterized by methods such as TEM and SEM. It was confirmed that the sea-urchin magnetic nanomaterial exhibit Fe3O4 microsphere as core and TiO2 as shell, the diameter of the particles is about 400 nm, the specific surface area is 236.082 m2·g-1, and the surface pore size is about 6.274 nm. The adsorption on heavy metal ions showed that, based on the Pb2＋ ion radius is large and the layers of elections is more, in the mixed system of Pb2＋, Cd2＋, Cu2＋, Zn2＋ and Ni2＋, SUMNPs could adsorb Pb2＋ with high capacity and high selectivity, and almost no adsorption of other four heavy metal ions. The single Pb2＋ adsorption could be fast equilibrium in 5 min and the equilibrium adsorption capacity was 283 mg·g-1. The adsorption process is in accordance with the Langmuir isothermal adsorption model, and the saturated adsorption capacity is up to 458.72 mg·g-1. After desorbed and regenerated by EDTA disodium and NaOH, SUMNPs can be reused more than 8 times. In summary, SUMNPs have excellent selectivity for Pb2＋, and have good application prospect in the treatment of pollution and restoration of water ecological environment.

关 键 词：水热合成 磁性纳米粒子 多孔介质 重金属吸附 热力学性质 

分 类 号：X52[环境科学与工程—环境工程]