Divalent heavy metals adsorption onto different types of EDTA-modified mesoporous materials: Effectiveness and complexation rate
Divalent heavy metals adsorption onto different types of EDTA-modified mesoporous materials: Effectiveness and complexation rate
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DOI：
10.1016/j.micromeso.2015.03.013
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发表时间：
2015-08-01
影响因子：
5.2
通讯作者：
Kazpard, Veronique
中科院分区：
文献类型：
--
作者：
Ezzeddine, Zeinab;Batonneau-Gener, Isabelle;Kazpard, Veronique
研究了三种有序介孔二氧化硅（KIT-6、SBA-15和SBA-16）对污染水中重金属的去除效果。用3-氨基丙基三甲氧基硅烷和乙二胺四乙酸（EDTA）两步接枝方法对材料进行了功能化。采用x射线衍射（XRD）、透射电镜（TEM）、氮（N-2）吸附-解吸分析、傅里叶变换红外光谱（FT-IR）和热重分析对改性吸附剂进行了表征。修改后支架的顺序不受影响。由于其结构特性，KIT-6和SBA-15比SBA-16更有效。然后在不同的实验条件下进行吸附实验，如pH、接触时间和初始金属浓度。得到的二价金属的动力学吸附数据符合准二阶模型，表明其为误吸附。各金属离子的交换速率（K-w）是控制吸附速率和选择性的主要因素，其中Cu2+和Pb2+的吸附速率高于Ni2+和Cd2+。最大吸附量由Langmuir模型计算，与固定化EDTA的量密切相关。(C) 2015爱思唯尔公司版权所有。
The removal of heavy metals from contaminated water was investigated using three types of ordered mesoporous silica (KIT-6, SBA-15 and SBA-16). The materials were functionalized with 3-aminopropyltrimethoxy-silane and ethylenediaminetetraacetic acid (EDTA) via two steps post grafting methods. Then the modified adsorbents were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen (N-2) adsorption-desorption analysis, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis. The ordering of the supports was not affected after modification. KIT-6 and SBA-15 were found to be more efficient than SBA-16 due to their structural characteristics. The adsorption experiments were then conducted under different experimental conditions, such as pH, contact time and initial metals concentrations. The kinetic adsorption data obtained for the divalent metals followed the pseudo-second-order model indicating chmisorption. The exchange velocity (K-w) of each metallic ion is the main factor controlling both the adsorption rate and the selectivity which were higher for Cu2+ and Pb2+ than for Ni2+ and Cd2+. The maximum adsorption capacities were calculated by Langmuir model and were highly dependent on the amount of immobilized EDTA. (C) 2015 Elsevier Inc. All rights reserved.