Li Jianping, Lin Qingyu, Zhang Xuehong, Yan Yan
Department of Material and Chemical Engineering, Guilin University of Technology, Guilin 541004, China.
J Colloid Interface Sci. 2009 May 1;333(1):71-7. doi: 10.1016/j.jcis.2009.02.021. Epub 2009 Feb 12.
The hyperaccumulative plant species Leersia hexandra Swartz, particularly, has been considered for its detoxification mechanism for phytoremediation of chromium-contaminated water environments. This study investigates the role of the adsorption mechanism of the L. hexandra Sw. biomass on the removal of chromium ions Cr(VI) and Cr(III) from an aqueous solution. The interaction between chromium ions and the L. hexandra Sw. biomass was characterized by using infrared spectroscopy. The results indicate that the binding process of the chromium ions involves the active participation of ligands present in the biomass, such as acylamide, carbonyl, amino, carboxyl, and hydroxyl groups, to immobilize the chromium ions. Equilibrium biosorption experiments were carried out to investigate the effects of pH values and contact time. Adsorption isotherms were modeled with the Langmuir and Freundlich equations and isotherm constants were calculated. Kinetic experiments showed the rapid process of biosorption and the pseudo-second-order model was successfully applied to predict the rate constant of biosorption. This study firstly discovered the kinetics equilibrium modelling of L. hexandra Sw. biomass on biosorption Cr(VI) and Cr(III).
特别是，超积累植物物种李氏禾已因其对铬污染水环境进行植物修复的解毒机制而受到关注。本研究调查了李氏禾生物质的吸附机制在从水溶液中去除铬离子Cr(VI)和Cr(III)方面的作用。利用红外光谱对铬离子与李氏禾生物质之间的相互作用进行了表征。结果表明，铬离子的结合过程涉及生物质中存在的配体（如酰酰胺、羰基、氨基、羧基和羟基）的积极参与，以固定铬离子。进行了平衡生物吸附实验以研究pH值和接触时间的影响。用朗缪尔和弗伦德利希方程对吸附等温线进行建模并计算等温线常数。动力学实验表明生物吸附过程迅速，且成功应用准二级模型预测生物吸附速率常数。本研究首次发现了李氏禾生物质对Cr(VI)和Cr(III)生物吸附的动力学平衡模型。
