Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan.
Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan.
J Hazard Mater. 2014 Jul 30;277:44-52. doi: 10.1016/j.jhazmat.2013.12.004. Epub 2013 Dec 12.
The uptake of amitriptyline (AMI) from aqueous environment by Ca-montmorillonite (SAz-2) was studied in a batch system under different physicochemical conditions. The adsorbent was characterized by X-ray diffraction and Fourier transform infrared (FTIR) analyses. The AMI adsorption on SAz-2 obeyed the Langmuir isotherm with a capacity of 330mg/g (1.05mmol/g) at pH 6-7. The adsorption kinetics was fast, almost reaching equilibrium in 2h, and followed a pseudo-second-order kinetic model. Desorption of exchangeable cations correlated with the AMI adsorption well, indicating that cation exchange was the major mechanism. X-ray diffraction patterns showing significant expansions of the d001 spacing and characteristic FTIR band shifts toward higher frequencies after AMI adsorption onto SAz-2 indicated that the adsorbed AMI molecules were intercalated into the interlayers of the mineral. Thermodynamic parameters based on partitioning coefficients suggested that the AMI adsorption was an endothermic physisorption at high adsorption levels. At low and higher AMI adsorption levels, the intercalated AMI molecules take a horizontal monolayer and bilayer conformation, respectively. The higher adsorption capacity suggested that SAz-2 could be a good candidate to remove AMI from wastewater and would be an important environmental sink for the fate and transport of AMI in soils and groundwater.
在不同的物理化学条件下，采用批处理系统研究了钙蒙脱石（SAz-2）从水相环境中摄取阿米替林（AMI）的情况。通过 X 射线衍射和傅里叶变换红外（FTIR）分析对吸附剂进行了表征。在 pH 值为 6-7 时，SAz-2 对 AMI 的吸附符合 Langmuir 等温线，容量为 330mg/g（1.05mmol/g）。吸附动力学很快，在 2 小时内几乎达到平衡，符合准二级动力学模型。可交换阳离子的解吸与 AMI 的吸附很好地相关，表明阳离子交换是主要机制。X 射线衍射图谱显示，在 AMI 吸附到 SAz-2 后，d001 间距显著扩展，特征 FTIR 带向高频移动，表明吸附的 AMI 分子被插入到矿物的层间。基于分配系数的热力学参数表明，在高吸附水平下，AMI 的吸附是一种吸热的物理吸附。在低和高 AMI 吸附水平下，插层的 AMI 分子分别采取水平单层和双层构象。较高的吸附容量表明，SAz-2 可能是从废水中去除 AMI 的良好候选物，并且将是 AMI 在土壤和地下水中的命运和迁移的重要环境汇。
