Sorption of perfluorooctane sulfonate on organo-montmorillonites.
Sorption of perfluorooctane sulfonate on organo-montmorillonites.
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DOI：
10.1016/j.chemosphere.2009.12.005
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发表时间：
2010-02
期刊：
影响因子：
8.8
通讯作者：
Qin Zhou;S. Deng;Qiang Yu;Qiaoying Zhang;Gang Yu;Jun Huang;Hongping He
中科院分区：
文献类型：
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作者：
Qin Zhou;S. Deng;Qiang Yu;Qiaoying Zhang;Gang Yu;Jun Huang;Hongping He
全氟化合物作为一种新兴的污染物，近年来引起了人们的极大关注。本研究制备了十六烷基三甲基溴化铵（HDTMAB）含量和排列方式不同的有机蒙脱土（organo-Mts），并将其作为去除水中PFOS的有效吸附剂。研究了吸附动力学、吸附等温线以及溶液pH对吸附的影响。Elovich和伪二级动力学模型被选择来拟合动力学数据，后者描述的吸附动力学更好。吸附等温线表明，蒙脱石对PFOS的吸附量随着HDTMAB负载量的增加而增加，表明疏水相互作用在吸附过程中起重要作用.通过对不同碳氟链长度和不同官能团的全氟化合物（PFCs）的吸附比较，进一步证实了疏水作用是PFCs在有机金属表面吸附的主要动力。X射线衍射（XRD）分析表明，PFOS吸附后，HDTMAB分子在有机蒙脱土层间发生了重排，层间距明显减小。PFOS分子首先通过疏水相互作用扩散到有机Mts中，然后通过两种表面活性剂之间的静电相互作用发生重排，导致有机Mts内部的微观结构发生变化。
Perfluorinated compound as one of the emerging pollutants has caused great attention in recent years. In this study, the organo-montmorillonites (organo-Mts) with different amounts and arrangements of hexadecyltrimethylammonium bromide (HDTMAB) were prepared as effective sorbents for PFOS removal from water. Batch sorption experiments including sorption kinetics, sorption isotherm as well as effect of solution pH were studied. The Elovich and pseudo-second-order models were selected to fit the kinetic data and the latter described the sorption kinetic better. Sorption isotherms showed that the sorption amount of PFOS increased with increasing amount of HDTMAB loaded in the montmorillonites, indicating that hydrophobic interaction played an important role in the sorption process. Comparative sorption of other perfluorinated compounds (PFCs) with different length of C–F chains and different functional groups further verified that hydrophobic interaction was the main force for the sorption of PFCs on the organo-Mts. X-ray diffraction (XRD) analysis demonstrated the significant decrease of interlayer distance after PFOS sorption, suggesting that the HDTMAB molecules were rearranged in the interlayer of organo-Mts. The PFOS molecules first diffused into the organo-Mts via hydrophobic interaction, and then the rearrangement occurred through electrostatic interaction between the two surfactants, resulting in the microstructure change within the organo-Mts.