Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA) - Facultad de Ingeniería, Universidad Nacional de Mar del Plata (UNMdP) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), J. B. Justo 4302, 7600 Mar del Plata, Argentina.
Universitat Autònoma de Barcelona, Centre GTS, Department of Chemistry, 08193 Bellaterra, Barcelona, Spain.
Int J Biol Macromol. 2020 Dec 15;165(Pt A):1286-1295. doi: 10.1016/j.ijbiomac.2020.09.244. Epub 2020 Oct 3.
Films made from neat chitosan and chitosan with magnetic nanoparticles (MNPs) were tested as adsorbents of arsenate ions. Sorption equilibrium and sorption kinetics studies are reported, including different models applied to enlighten experimental observations and predict results. The sorption of As (V) was reasonably explained using Freundlich isotherm for neat chitosan film although it was better represented by Langmuir equation for the composite sample. The experimental kinetics results showed that the adsorption of arsenate ions is very fast during the first minutes and then the composite seems to reach saturation, while a slow desorption in the chitosan film was observed and acceptably fitted with a pseudo first order reversible model. The adsorbent containing MNPs presented higher adsorption capacity, which was associated to the additional adsorbent capacity provided by the MNPs and its much more irregular surface area that leads to an enhanced adsorption surface. For instance, at 10 mg/L equilibrium concentration, which corresponds to an initial concentration of As (V) much higher than the normal concentration of arsenate in natural water, chitosan-MNP sample exhibits a removal capacity of 10.4 mg/g that is more than six times higher than the 1.6 mg/g shown by the chitosan film.
由纯壳聚糖和负载磁性纳米颗粒（MNPs）的壳聚糖制备的薄膜被用作砷酸盐离子的吸附剂。本文报告了吸附平衡和吸附动力学研究，包括应用不同的模型来阐明实验观察结果和预测结果。对于纯壳聚糖薄膜，砷（V）的吸附可以用 Freundlich 等温线合理地解释，尽管对于复合样品，Langmuir 方程能更好地表示。实验动力学结果表明，砷酸盐离子的吸附在最初的几分钟内非常快，然后复合样品似乎达到饱和，而在壳聚糖薄膜中观察到缓慢的解吸，并且可以用准一级可逆模型进行较好地拟合。负载 MNPs 的吸附剂具有更高的吸附容量，这与 MNPs 提供的额外吸附容量及其更不规则的表面积有关，这导致了增强的吸附表面。例如，在 10mg/L 的平衡浓度下，这对应于砷酸盐初始浓度远高于天然水中砷酸盐的正常浓度，壳聚糖-MNP 样品的去除能力为 10.4mg/g，比壳聚糖薄膜的 1.6mg/g 高 6 倍以上。
