Removal of Pb(II) from aqueous solutions by adsorption on magnetic bentonite
Removal of Pb(II) from aqueous solutions by adsorption on magnetic bentonite
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DOI：
10.1007/s11356-018-3652-0
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发表时间：
2018-11
影响因子：
5.8
通讯作者：
Chenglong Zou;Wei Jiang;Jiyan Liang;Xiaohang Sun;Yinyan Guan
中科院分区：
文献类型：
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作者：
Chenglong Zou;Wei Jiang;Jiyan Liang;Xiaohang Sun;Yinyan Guan
膨润土是一种多孔粘土材料，对重金属等污染物具有良好的吸附性能，可用于废水修复。在我们前期的研究中，我们制备了磁性膨润土(M-B)来解决分离问题，提高了可操作性。在本研究中，我们考察了各种参数对M-B吸附铅(II)的影响，并表现出有效的吸附性能。吸附初始浓度为200 mg/L，吸附温度为40℃，pH为5，吸附时间为90min，吸附脱色率为98.9%。吸附动力学符合准二级模型，90min内符合内扩散模型。此外，用Langmuir等温式成功地再现了吸附数据，最大吸附容量为80.40 mg/g，铅(II)离子与M-B的作用机理为离子交换、表面络合和静电作用。热力学研究表明，铅(II)在M-B上的吸附反应是吸热的自发反应，升高温度有利于吸附。本研究可望为膨润土材料处理含铅废水提供参考和理论依据。
Bentonite is a porous clay material that shows good performance for adsorbing heavy metals and other pollutants for wastewater remediation. In our previous study, magnetic bentonite (M-B) was prepared to solve the separation problem and improve the operability. In this study, we investigated the influence of various parameters on the Pb(II) adsorption of M-B, and it showed effective performance. About 98.9% adsorption removal rate was achieved within 90 min at adsorbent dose of 10 g/L for initial Pb(II) concentration of 200 mg/L at 40 °C and pH 5. The adsorption kinetic fit well by the pseudo-second-order model, and also followed the intra-particle diffusion model up to 90 min. Moreover, adsorption data were successfully reproduced by the Langmuir isotherm; the maximum adsorption capacity was calculated as 80.40 mg/g. The mechanism of interaction between Pb(II) ions and M-B was ionic exchange, surface complexation, and electro-static interactions. Thermodynamics study indicated that the reaction of Pb(II) adsorption on M-B was endothermic and spontaneous; increasing the temperature promoted adsorption. This study was expected to provide a reference and theoretical basis for the treatment of Pb-containing wastewater using bentonite materials.