Department of Chemistry, Federal University of Santa Catarina, 88040900, Florianópolis, SC, Brazil.
Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88040900, Florianópolis, SC, Brazil.
Carbohydr Polym. 2021 Mar 15;256:117589. doi: 10.1016/j.carbpol.2020.117589. Epub 2021 Jan 4.
The preconcentration of metal ions present at low concentration levels in aqueous systems and the selective removal of potentially toxic metals are important applications of adsorption processes. In this study, a heptadentate dinucleating ligand was anchored to chitosan for use in adsorption studies on Zn(II), Cu(II) and Ni(II) ions. The novel adsorbent was characterized by C NMR and FT-IR spectroscopy, TGA and BET surface area analysis. The degree of substitution of the ligand in chitosan, obtained from CHN analysis, was 0.73. The adsorption kinetics followed a pseudo-second-order model. The rate constants and the adsorption capacities for multicomponent systems decreased in the order Cu(II) >> Ni(II) ∼ Zn(II), indicating the preferential adsorption of Cu(II). For Cu(II) ions, the Langmuir model provided the best fitting to the experimental data, and the monolayer Cu(II) adsorption capacity was 0.404 mmol g, while the linear isotherm described Zn(II) and Ni(II) ion adsorption.
在水体系中，将低浓度水平的金属离子进行预浓缩，以及选择性地去除潜在毒性的金属，这是吸附过程的重要应用。在这项研究中，一种七齿双核配体被固定在壳聚糖上，用于研究 Zn(II)、Cu(II)和 Ni(II)离子的吸附。新型吸附剂通过 C NMR 和 FT-IR 光谱、TGA 和 BET 表面积分析进行了表征。从 CHN 分析中得到的配体在壳聚糖中的取代度为 0.73。吸附动力学遵循拟二级模型。对于多组分体系，速率常数和吸附容量的顺序为 Cu(II)>>Ni(II)∼Zn(II)，表明 Cu(II)的优先吸附。对于 Cu(II)离子，Langmuir 模型对实验数据提供了最佳拟合，单层 Cu(II)吸附容量为 0.404 mmol g，而线性等温线描述了 Zn(II)和 Ni(II)离子的吸附。
