改性椰壳对Cr（Ⅵ）的吸附动力学与热力学研究
Kinetics and Thermodynamic of Cr(Ⅵ)onto modified.coconut shell
刘亚坤1
作者信息
摘要
研究了改性后的椰壳从水中吸附Cr（Ⅵ）的吸附特性及Cr（Ⅵ）吸附动力学和热力学，采用伪一级动力学方程、伪二级动力学方程、颗粒内扩散模型对实验数据进行拟合。结果表明，椰壳在初始的3h内吸附较快。椰壳对Cr（Ⅵ）的吸附符合伪二级动力学方程。颗粒间扩散模型拟合显示，椰壳在整个吸附过程中存在颗粒间扩散现象，并不是速率控制阶段。Freundlich等温模式能较好的描述椰壳对Cr（Ⅵ）的等温吸附效果，说明椰壳的吸附是多分子层吸附，且该吸附过程为优惠吸附。由0?G 、0?H 可知该吸附为自发的吸热反应。
Abstract
A batch adsorption study was carried out to investigate the properties,kinetics and thermodynamics of adsorption process of Cr(Ⅵ)on coconut shell.The results showed that in the first 3 hours the reaction of adsorption by coconut shell was fast.The adsorption followed pseudo-second-order kinetics.The intraparticle transport of Cr(Ⅵ)showed that intra-particle diffuse was exit at the whole adsorption process,but it was not the major rate-limiting step for coconut.The adsorption studies revealed that the adsorption validated Freundlich adsorption.So this adsorption process was a multi-molecular layer adsorption.The negative values of ? 0G indicated that adsorption process was spontaneous in nature.Positive? 0H values indicated the adsorption process to be endothermic.
关键词
椰壳/吸附动力学/吸附热力学Key words
coconut shell/adsorption kinetics/adsorption thermodynamics引用本文复制引用
出版年
2014
NETL
NSTL
万方数据