羟基铁锆改性复合膨润土的表征及其对水中硒酸根的吸附性能  

Characterization of hydroxyl Fe/Zr bentonite composite and its adsorption performance for selenium in aqueous solution

作　　者：黄丽[1,2] 陈征贤 黄怀国 庄荣传 王鸿辉[1] 董清木[1] 郭祥群[2] 

机构地区：[1]厦门出入境检验检疫局,福建厦门361012 [2]厦门大学化学与化工学院,福建厦门361005 [3]厦门紫金矿冶技术有限公司,福建厦门361101

出　　处：《功能材料》2015年第5期5136-5141,5146,共7页Journal of Functional Materials

基　　金：国家质检总局科技计划资助项目(2014IK254)

摘　　要：采用水热合成法制备羟基铁锆改性复合膨润土(Fe/Zr-Bent),通过SEM-EDS、TEM、XRD对样品的形貌、尺寸、晶型分布等进行了表征,并利用加盐法测定了样品的等电点,及其考察了改性前、后膨润土对水中硒酸根的吸附性能,分析吸附动力学和可能的吸附机理。结果表明,改性后Fe/Zr-Bent样品中形貌变得粗糙及铁元素和锆元素的存在、存在纳米级针状羟基铁锆晶体及其大部分分布于膨润土的表面。Fe/Zr-Bent的等电点由改性前膨润土的10.5降低至5.5,表面带正电荷,易于通过离子交换、络合、静电作用等方式吸附含氧阴离子硒酸根。改性前、后膨润土对水中硒的去除率由11.84%提高至86.66%,显著增强其吸附性能,其吸附过程符合伪二级动力学吸附模型(R2>0.997),平衡吸附量达到46.73mg/g。Hydroxyl Fe/Zr modified bentonite(Fe/Zr-Bent)was prepared by the hydrothermal method and the samples before and after modification were characterized by SEM-EDS,TEM and XRD.Isoelectric point(pHzpc)was measured by the adding salt law.Adsorption performance,adsorption kinetics and possible adsorption mechanism were investigated.The characterization data showed that compared with bentonite before modification,morphology of Fe/Zr-Bent became rougher observed from SEM-EDS and confirmed the existence of Fe and Zr elements,TEM and XRD confirmed that nanoscale needle-like crystals of hydroxyl Fe/Zr irregularly distributed on the surface of bentonite after modification.pHzpcof Fe/Zr-Bent decreased from 10.5to 5.5,which carried positive charge beneficial to adsorb oxyanions selenium via ion exchange,complication and electrostatic interaction.The removal efficiency of selenium in aqueous solution was raised from 11.84%to 86.66%,which significantly enhance its adsorption performance.Adsorption process of selenium was fitting pseudo second-order model(R2>0.997)and adsorption capacity was 46.73mg/g.

关 键 词：膨润土 硒酸根 表征 吸附动力学 可能的吸附机理 

分 类 号：X522[环境科学与工程—环境工程]