Benguella B, Benaissa H
Département de Chimie, Faculté des Sciences, Université de Tlemcen, Algeria.
Water Res. 2002 May;36(10):2463-74. doi: 10.1016/s0043-1354(01)00459-6.
A fundamental investigation on the removal of cadmium ions from aqueous solutions by chitin was conducted in batch conditions. Kinetic data and equilibrium removal isotherms were measured. The influence of different experimental parameters such as time contact, initial concentration of cadmium, chitin mass, particles size, agitation speed, temperature and the nature of cadmium salt, on the kinetics of cadmium removal was studied. The main parameters that play an important part in removal phenomenon were initial cadmium concentration, particle size and chitin mass. Other parameters such as agitation speed, temperature and the nature of cadmium salt, showed a restricted effect on the removal kinetics. The process follows a pseudo second-order kinetics. The cadmium uptake of chitin was quantitatively evaluated using sorption isotherms. In order to describe the isotherm mathematically, the experimental data of the removal equilibrium were correlated by either the Langmuir or Freundlich equations. Results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich equation. Scanning electron microscopy coupled with a X-ray energy dispersed analysis for cadmium-equilibrated chitin, demonstrated that cadmium-containing nodules existed on the surface chitin.
在间歇条件下对甲壳素从水溶液中去除镉离子进行了基础研究。测定了动力学数据和平衡去除等温线。研究了不同实验参数，如接触时间、镉的初始浓度、甲壳素质量、颗粒大小、搅拌速度、温度以及镉盐的性质对镉去除动力学的影响。在去除现象中起重要作用的主要参数是镉的初始浓度、颗粒大小和甲壳素质量。其他参数，如搅拌速度、温度和镉盐的性质，对去除动力学的影响有限。该过程遵循准二级动力学。使用吸附等温线对甲壳素对镉的吸附进行了定量评估。为了用数学方法描述等温线，去除平衡的实验数据用朗缪尔方程或弗伦德利希方程进行关联。结果表明，与弗伦德利希方程相比，朗缪尔模型对实验数据的拟合更好。对镉平衡后的甲壳素进行扫描电子显微镜结合X射线能量色散分析，表明甲壳素表面存在含镉结节。
