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46．73 mg/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 adsorp-tion mechanism were investigated.The characterization data showed that compared with bentonite before modi-fication,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 dis-tributed on the surface of bentonite after modification.pHzpc of Fe/Zr-Bent decreased from 10.5 to 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-or-der model (R2>0.997)and adsorption capacity was 46.73 mg/g.
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