基于壳聚糖的吸附材料在六价铬吸附中的应用

Removal of Hexavalent Chromium by Chitosan-Based Adsorbents

铬作为在工业中广泛使用的一种过渡金属,具有重要的应用价值,但过量的铬会污染水和土壤,危害环境和人类健康。其中,六价铬是铬的氧化态中毒性最高的一种,利用吸附的方法将六价铬从污染水中去除是消除水体中铬污染的一种重要方法,而开发简单高效且不产生二次污染的吸附材料对六价铬进行去除十分必要。壳聚糖作为一种优良的天然绿色生物材料,具有良好的生物相容性和可降解性,近年来广泛被用于六价铬的吸附。由于单纯的壳聚糖存在酸性不稳定性、吸附位点不足等缺点,利用壳聚糖分子链中的氨基和羟基官能团对其进行改性和复合,可以生成更为稳定的改性壳聚糖,并显著提升其对六价铬的吸附能力。文中详细介绍了近年来报道的壳聚糖化学改性和复合改性的2种方法,以及其对六价铬的吸附性能的影响,并探讨了六价铬的吸附机理及其主要影响因素。

As a transition metal widely used in industry,chromium has important application value,but excessive chromium will pollute water and soil and endanger the environment and human health.Among them,hexavalent chromium is the most toxic in the oxidation state of chromium.The use of adsorption to remove hexavalent chromium from polluted water is an important method to eliminate chromium pollution in water.The development of simple and efficient adsorbents without secondary contamination is necessary to remove hexavalent chromium.As an excellent natural green biological material,chitosan has good biocompatibility and degradability,which has been widely used for the adsorption of hexavalent chromium in recent years.Due to the shortcomings of pure chitosan such as acid instability and insufficient adsorption sites,it can be modified and/or compounded through the amine and hydroxyl groups in the molecular chains of chitosan to form more stable modified chitosans and significantly enhance the adsorption capacity for hexavalent chromium.This paper introduced in detail the chemical modification and compound modification of chitosan reported in recent years,and their influence on the adsorption performance of hexavalent chromium.Besides,the adsorption mechanism of hexavalent chromium and the main influencing factors were also discussed.