Pb (II) removal from aqueous media by EDTA-modified mesoporous silica SBA-15
Pb (II) removal from aqueous media by EDTA-modified mesoporous silica SBA-15
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DOI：
10.1016/j.jcis.2012.06.054
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发表时间：
2012-11-01
影响因子：
9.9
通讯作者：
Xu, Dongfang
中科院分区：
文献类型：
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作者：
Huang, Jin;Ye, Meng;Xu, Dongfang
以SBA-15为模板分子，采用两步后接枝法，分别以3-氨丙基三甲氧基硅烷（APTES）和亚硫酰氯（SOCl 2）为活化剂，乙二胺四乙酸（EDTA）为活化剂，合成了有机-无机杂化介孔氧化硅材料，并通过红外光谱（FT-IR）、X射线衍射（XRD）、元素分析（EA）、透射电镜（TEM）、氮气（N-2）吸附-脱附分析和返滴定。发现该材料具有介孔二氧化硅SBA-15和EDTA的有益性质。通过改变pH值、接触时间和金属初始浓度等实验条件，研究了该材料对水溶液中Pb（II）的吸附能力。在所研究的实验条件下，Pb 2+的去除效率较高。吸附反应在20 min内达到平衡，动力学数据可用准二级动力学模型和颗粒内扩散模型进行拟合。吸附剂表现出良好的性能，其最大吸附容量由Langmuir模型计算为273.2 mg g（-1）。循环使用实验表明，该吸附剂可以通过酸处理再生，而不改变其性能。用X射线光电子能谱（XPS）分析了吸附元素的化学状态。结果表明，该材料的吸附机理为钠铅离子交换和羧基为主的表面络合作用。(c)2012 Elsevier Inc. All rights reserved.
An organic-inorganic hybrid mesoporous silica material was synthesized by two-step post-grafting method of SBA-15 with 3-aminopropyltrimethoxy-silane (APTES) and thionyl dichloride (SOCl2) activated ethylenediaminetetraacetic acid (EDTA) in sequence and measured by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), elemental analysis (EA), transmission electron microscopy (TEM), nitrogen (N-2) adsorption-desorption analysis and back titration. The material was found having the beneficial properties of mesoporous silica SBA-15 and EDTA. Adsorption potential of the material for Pb (II) removal from aqueous solution was investigated by varying experimental conditions such as pH, contact time and initial metal concentration. The removal efficiency of Pb2+ was high under studied experimental conditions. The adsorption equilibrium could be reached within 20 min and the kinetic data were fitted well by pseudo-second-order and intraparticle diffusion model. The adsorbent exhibited a favorable performance and its maximum adsorption capacity calculated by the Langmuir model was 273.2 mg g(-1). Recycling experiments showed the adsorbent could be regenerated by acid treatment without altering its properties. The chemical states of the elements involved in the adsorption were analyzed by X-ray photoelectron spectroscopy (XPS). The results demonstrated that the adsorption mechanism of the material involved Na Pb ion-exchange and carboxyl group dominated surface complexation. (c) 2012 Elsevier Inc. All rights reserved.