碳纳米管-羟基磷灰石对 Pb(II)、Cd(II)和 Cu(II)的吸附特性。

Adsorption characteristics of Pb(II), Cd(II) and Cu(II) on carbon nanotube-hydroxyapatite.

机构信息

Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi'an, People's Republic of China.

State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, People's Republic of China.

出版信息

Environ Technol. 2021 Apr;42(10):1560-1581. doi: 10.1080/09593330.2019.1674385. Epub 2019 Dec 6.

DOI:10.1080/09593330.2019.1674385

PMID:31566478

Abstract

Based on batch experiments, we investigate the adsorption characteristics of Pb(II), Cd(II) and Cu(II) on multi-walled carbon nanotube-hydroxyapatite (MWCNT-HAP) composites in detail and explore the effects of the solid-to-liquid ratio, pH, the ionic strength, reaction time and temperature on adsorption. The results show that the adsorption on MWCNT-HAP follows Pb(II)>Cu(II)>Cd(II). With an increasing solid-to-liquid ratio, the adsorption quantity of Pb(II), Cd(II) and Cu(II) on MWCNT-HAP decreases, whereas the removal efficiency increases. The optimal pH for adsorption is 4.0∼6.0. The effect of the ionic strength on the adsorption of Cd(II) is pronounced, whereas that on the adsorption of Pb(II) and Cu(II) is small. In the single-component system and ternary-component system, the adsorption processes for Pb(II), Cd(II) and Cu(II) on MWCNT-HAP have fast kinetics, and the pseudo-second-order kinetics model can well describe the adsorption kinetics of the three heavy metals. The adsorption of Pb(II), Cd(II) and Cu(II) on MWCNT-HAP is spontaneous and endothermic, and the Langmuir model can well simulate the isothermal adsorption of Pb(II) and Cu(II), whereas the Langmuir and Freundlich models can be used to describe the isothermal adsorption of Cd(II).

摘要

基于批量实验，我们详细研究了多壁碳纳米管-羟基磷灰石（MWCNT-HAP）复合材料对 Pb(II)、Cd(II)和 Cu(II)的吸附特性，并探讨了固液比、pH 值、离子强度、反应时间和温度对吸附的影响。结果表明，MWCNT-HAP 对 Pb(II)的吸附作用最强，其次是 Cu(II)，最弱的是 Cd(II)。随着固液比的增加，MWCNT-HAP 对 Pb(II)、Cd(II)和 Cu(II)的吸附量减小，而去除效率增加。吸附的最佳 pH 值为 4.0∼6.0。离子强度对 Cd(II)吸附的影响显著，而对 Pb(II)和 Cu(II)吸附的影响较小。在单一组分体系和三元组分体系中，MWCNT-HAP 对 Pb(II)、Cd(II)和 Cu(II)的吸附过程具有快速动力学特征，准二级动力学模型能够很好地描述三种重金属的吸附动力学。MWCNT-HAP 对 Pb(II)、Cd(II)和 Cu(II)的吸附是自发和吸热的，Langmuir 模型可以很好地模拟 Pb(II)和 Cu(II)的等温吸附，而 Langmuir 和 Freundlich 模型可用于描述 Cd(II)的等温吸附。