Long Hang, Wu Pingxiao, Yang Lin, Huang Zhujian, Zhu Nengwu, Hu Zhixian
College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China.
College of Environmental and Energy, South China University of Technology, Guangzhou 510006, PR China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, PR China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, PR China.
J Colloid Interface Sci. 2014 Aug 15;428:295-301. doi: 10.1016/j.jcis.2014.05.001. Epub 2014 May 10.
Ethylamine modified vermiculite (Ethyl-VER) with high specific surface area and excellent pore structure was prepared to remove cesium from aqueous solution. The physic-chemical properties of the pristine and modified vermiculite were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), specific surface area (BET) and scanning electron microscopy/energy disperse spectroscopy (SEM/EDS). The corroding effect of ethylamine increased the specific surface area of vermiculite from 4.35 to 15.59 m(2) g(-1), and the average pore diameter decreased from 6.8 to 5.34 nm. Batch adsorption experiments were conducted as a function of pH, initial Cs(+) concentration, contact time, coexisting cations (K(+), Na(+), Ca(2+)) and low-molecular-weight organic acids (acetic acid, oxalic acid, citric acid) to illustrate the adsorption behavior. The study found that the adsorption capacity of cesium in aqueous solution was improved from 56.92 to 78.17 mg g(-1) after modification. The formation of micropores and mesopores and the increased surface area played a critical role in the enhancement of cesium adsorption. Kinetic experiments indicated that the adsorption process can be simulated well with a pseudo-second-order model. The presence of cations or low-molecular-weight organic acids inhibited cesium adsorption in different degrees. On the basis of our results, Ethyl-VER with good surface characteristics and high adsorption capacity is a suitable adsorbent for cesium removal from aqueous solution.
制备了具有高比表面积和优异孔结构的乙胺改性蛭石（Ethyl-VER），用于从水溶液中去除铯。通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、比表面积（BET）以及扫描电子显微镜/能谱分析（SEM/EDS）对原始蛭石和改性蛭石的物理化学性质进行了分析。乙胺的腐蚀作用使蛭石的比表面积从4.35增加到15.59 m² g⁻¹，平均孔径从6.8减小到5.34 nm。进行了批量吸附实验，考察了pH值、初始Cs⁺浓度、接触时间、共存阳离子（K⁺、Na⁺、Ca²⁺）以及低分子量有机酸（乙酸、草酸、柠檬酸）对吸附行为的影响。研究发现，改性后水溶液中铯的吸附容量从56.92提高到了78.17 mg g⁻¹。微孔和介孔的形成以及表面积的增加对铯吸附的增强起到了关键作用。动力学实验表明，吸附过程可以用准二级模型很好地模拟。阳离子或低分子量有机酸的存在不同程度地抑制了铯的吸附。基于我们的研究结果，具有良好表面特性和高吸附容量的Ethyl-VER是一种从水溶液中去除铯的合适吸附剂。
