【在线发表】[2015-0856]羟基铁插层膨润土的制备及其对铀（VI）的吸附特性与机制

《复合材料学报》优先在线发表论文。

摘 要: 通过羟基铁对钠基膨润土插层改性制备了羟基铁插层膨润土 (OH—Fe-Bent)，用于去除废水中的U(VI)。实验考察了pH值、U(VI)初始浓度、温度、吸附时间对OH—Fe-Bent吸附U(VI)效果的影响，并进行吸附动力学和热力学分析。采用FTIR、SEM、XRD等手段分析相关吸附机制。实验结果表明，OH—Fe-Bent吸附U(VI)的最佳pH为4，在温度为15℃，投加量为0.8 g/L, U(VI)初始浓度为10mg/L时，OH-Fe-Bent对U(VI)的去除率达到99.55%，吸附平衡时间为90min。Langmuir等温吸附模型和准二级动力学模型（r2?1）均可较好地拟合其吸附过程，理论饱和吸附量可达97.09mg/g，OH—Fe-Bent对U(VI)是单分子层吸附。FTIR、SEM分析表明OH—Fe-Bent吸附U(VI)后自身结构没有改变，XRD分析表明羟基铁已经成功插入膨润土层间。

关键词:　羟基铁；插层；膨润土；吸附；铀

Abstract: Hydroxyl Fe（OH—Fe）intercalated bentonite（Bent） was prepared by Na-bentonite while using hydroxyl Fe as intercalated material. The synthesized OH—Fe-Bent composites applied to adsorb uranium(VI) from water solution. By changing the pH, initial U(VI) ions concentration, temperature and contact time, the optimum conditions of adsorption were determined, and the process of adsorption was investigated by kinetic and thermodynamic analysis. The prepared composites were characterized by SEM, FTIR and XRD. The results indicate that the maximum adsorption capacity occurs at pH 4 and the removal rate reaches 99.55% for initial U(VI) concentration of 10mg/L and adsorbent dosage of  0.8g/L at 15℃. Meanwhile the adsorption reaches equilibrium within 90min. The adsorption process fits well with the Langmuir isotherm model and pseudo second-order kinetic model(r2?1), and the saturated adsorption capacity for U(VI) irons is 97.09mg/g, adsorption mechanism of U(VI)  is a monolayer adsorption. The FTIR and SEM results show that the structure of OH—Fe-Bent has no change after absorbing U(VI) and the XRD result show  that the hydroxyl Fe has already intercalated bentonite. 

Keywords: hydroxyl Fe; intercalate; bentonite; adsorption; uranium

作者：陈 婧等，南华大学 污染控制与资源化技术湖南省高校重点实验室，湖南衡阳