Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China.
Faculty of Foreign Languages and Cultures, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China.
Environ Sci Pollut Res Int. 2019 Feb;26(5):5094-5110. doi: 10.1007/s11356-018-3989-4. Epub 2019 Jan 3.
In this study, the novel adsorbent PVA-TA-βCD was synthesized via thermal cross-linking between polyvinyl alcohol and β-cyclodextrin. The characterization methods SEM-EDS, FTIR, and XPS were adopted to characterize the adsorbent. The effect of pH, contact time, initial concentrations, and temperature during the adsorption of Pb(II), Cd(II), and Mn(II) onto the PVA-TA-βCD was also investigated. In a single-component system, the data fitted well to pseudo-second-order, and film diffusion and intra-particle diffusion both played important roles in the adsorption process. As for isotherm study, it showed a heterogeneous adsorption capacity of 199.11, 116.52, and 90.28 mg g for the Pb(II), Cd(II), and Mn(II), respectively. Competition between the ions existed in a multi-component system; however, owing to the stronger affinity of the PVA-TA-βCD for Pb(II) relative to Cd(II) and Mn(II), the Pb(II) adsorption onto the PVA-TA-βCD was less affected by the addition of the other metals, which could be effectively explained by the hard and soft acid and base theory (HSAB). Furthermore, PVA-TA-βCD showed good reusability throughout regeneration experiments.
在这项研究中，通过聚乙烯醇和β-环糊精之间的热交联合成了新型吸附剂 PVA-TA-βCD。采用 SEM-EDS、FTIR 和 XPS 等表征方法对吸附剂进行了表征。还考察了 pH、接触时间、初始浓度和温度对 PVA-TA-βCD 吸附 Pb(II)、Cd(II)和 Mn(II)的影响。在单一组分体系中，数据拟合良好的准二级动力学方程，表明膜扩散和内扩散在吸附过程中均起重要作用。对于等温吸附研究，结果表明 PVA-TA-βCD 对 Pb(II)、Cd(II)和 Mn(II)的吸附容量分别为 199.11、116.52 和 90.28mg/g，呈现出异质吸附能力。在多组分体系中存在离子间的竞争，但由于 PVA-TA-βCD 对 Pb(II)的亲和力强于 Cd(II)和 Mn(II)，因此 Pb(II)的吸附受其他金属的添加影响较小，这可以通过硬软酸碱理论（HSAB）得到很好的解释。此外，PVA-TA-βCD 在再生实验中表现出良好的可重复使用性。
