有机改性蛭石的特性及其对Hg2＋吸附性能的研究

Characteristics of organic modified vermiculites and the adsorption of Hg^(2+)

以巯基乙胺(MEA)为改性剂制备有机改性蛭石(MEA-VER),研究其对Hg2+的吸附行为,并用XRD、FTIR、BET、Zeta potentials等技术对有机改性蛭石进行表征与分析.XRD、FTIR、BET、Zeta potentials等分析结果显示,MEA成功负载到蛭石上.吸附实验结果表明,改性蛭石对Hg2+的吸附量明显增加,吸附基本在2 h内达到平衡,在p H为5~10范围内都有较好的吸附效果.改性蛭石对Hg2+的吸附更符合Langmuir等温吸附模型和Pseudo-second-order动力学模型.改性蛭石对Hg2+的吸附机理主要为配位吸附、电荷吸附.

In this study, 2-aminoethanethiol （MEA） modified vermiculite was prepared as the adsorbent for removal of Hg2＋ in aqueous solution. The characteristics of the obtained organo-vermiculite were determined by X-ray diffraction （XRD）, Fourier transform infrared （FFIR） spectroscopy, BET analysis and zeta potential analysis. XRD, FTIR, BET and zeta analysis results revealed that MEA was successfully grafted into the vermiculite. Moreover, batch experiments were conducted to examine the adsorption behaviors of Hg2＋ onto MEA-VER and VER. The results indicated that the adsorption capacities of Hg2 significantly increased after modification and adsorption equilibriums were achieved in 2 hours. The uptake of Hg2＋ by the MEA-VER maintained high efficiencies in a wide pH range of 5.0 - 10.0. The adsorption of Hg2＋ onto MEA-VER could be well described by Langmuir adsorption isotherm equation and Pseudo-second-order model. The mechanisms of the adsorption of Hg2＋ onto organo-vermiculite were mainly coordination and charge adsorption.