Cadmium removal from simulated groundwater using alumina nanoparticles: behaviors and mechanisms
Cadmium removal from simulated groundwater using alumina nanoparticles: behaviors and mechanisms
复制标题
使用氧化铝纳米粒子从模拟地下水中去除镉：行为和机制
DOI：
10.1016/j.envpol.2018.04.107
复制
发表时间：
2018-09-01
影响因子：
8.9
通讯作者：
Colombo, Claudio
中科院分区：
文献类型：
--
作者：
Koju, Neel Kamal;Song, Xin;Colombo, Claudio
镉(Cd)是地下水中毒性最强的污染物之一，对人类健康和生态系统造成严重威胁。在这项研究中，合成了氧化铝纳米颗粒，并对其高效去除模拟地下水中的镉进行了测试。此外，利用带负电荷的甘油成功地对合成的氧化铝纳米颗粒进行了修饰，以缓解其在地下水中的低迁移率对Cd去除的挑战。合成的氧化铝纳米颗粒和甘油修饰的氧化铝纳米颗粒的最大去除效率都在99%以上。合成和甘油修饰的氧化铝纳米粒子的吸附等温线和动力学数据分别符合Freundlich模型和准二级模型，表明Cd离子在两种氧化铝纳米粒子的非均相表面上的吸附是通过化学吸附机制进行的。X射线光电子能谱和能谱分析表明，两种吸附剂在与Cd接触后都出现了Cd峰。此外，MR分析表明，羟基参与了Cd在合成的和甘油修饰的氧化铝纳米颗粒上的吸附，而其他甘油缔合基团参与了甘油修饰的氧化铝纳米颗粒对Cd离子的去除。结果表明，合成的氧化铝纳米粒子和甘油修饰的氧化铝纳米粒子对Cd的去除分别主要是离子交换和静电吸引。解吸实验表明，两种纳米氧化铝都是修复污染地下水中Cd的有效且具有实用价值的吸附剂。然而，由于Cd与甘油修饰的氧化铝之间存在较强的键合作用，再加上表面的负电荷使其具有更高的迁移率，这使得甘油修饰的氧化铝纳米颗粒在修复Cd污染的地下水中具有比合成的氧化铝纳米颗粒更好的性能。(C)2018爱思唯尔有限公司。保留所有权利。
Cadmium (Cd), one of the most toxic contaminants in groundwater, can cause a severe threat to human health and ecological systems. In this study, alumina nanoparticles were synthesized and tested for high efficiency Cd removal from simulated groundwater. Furthermore, the synthesized alumina nanoparticles were successfully modified using negatively charged glycerol, to alleviate the challenge of its low mobility in groundwater for the Cd removal. The maximum removal efficiency of both synthesized and glycerol-modified alumina nanoparticles were more than 99%. The sorption isotherm and kinetic data of both synthesized and glycerol-modified alumina nanoparticles were best fitted to the Freundlich model and the pseudo-second-order model, respectively, indicating that the sorption of Cd ions occurs on heterogeneous surfaces of both alumina nanoparticles via the chemisorption mechanism. X-ray photoelectron spectroscopy and energy dispersive X-ray analysis revealed the presence of Cd peak in both sorbents after contact with Cd. In addition, the MR analyses demonstrated that hydroxyl group participated in the sorption of Cd on both synthesized and glycerol-modified alumina nanoparticles, while other glycerol associated groups contributed to the removal of Cd ions by the glycerol-modified alumina nanoparticles. It was concluded that Cd removal by synthesized and glycerol-modified alumina nanoparticles were mainly due to ion exchange and electrostatic attraction, respectively. Desorption experiment suggested that both alumina nanoparticles are effective and practically significant sorbents to remediate Cd from contaminated groundwater. However, the stronger bond between Cd and glycerol-modified alumina, plus its potential of higher mobility due to the negative charge on the surface, warrant glycerol-modified alumina nanoparticles a better performance in remediating Cd contaminated groundwater than that of the synthesized alumina nanoparticles. (C) 2018 Elsevier Ltd. All rights reserved.