CTMAB-磷石膏对Cr(Ⅵ)的吸附动力学研究  

Study on the Adsorption Kinetics of Cr(Ⅵ)Ions on CTMAB-phosphogypusum

作　　者：石磊[1] 杨月红[1] 宁平[1] 程杨[1] 

机构地区：[1]昆明理工大学环境科学与工程学院,云南昆明650500

出　　处：《化学世界》2015年第5期297-302,共6页Chemical World

基　　金：国家科技部科技人员服务企业行动计划项目(2009GJF30019);云南省科技强省计划项目(2008AA010)

摘　　要：在微波环境下,制备了十六烷基三甲基溴化铵(CTMAB)修饰的CTMAB-磷石膏,并对其结构进行了表征。通过静态吸附实验,研究了CTMAB-磷石膏对Cr(Ⅵ)的吸附特性,探讨了吸附机理,结果表明:CTMAB-磷石膏对Cr(Ⅵ)的吸附符合Langmuir和Freundlich吸附等温模型,但Langmuir吸附等温模型能更好地描述吸附等温曲线。Lagergren准一级吸附动力学方程、Lagergren准二级吸附动力学方程、Elovich吸附方程以及粒子内扩散模型均可较好地描述吸附初始阶段,而整个吸附过程更好地符合Lagergren准二级吸附动力学方程,CTMAB-磷石膏对Cr(Ⅵ)的平衡吸附量为16.3225mg/g,吸附过程由物理吸附、化学吸附及络合沉淀作用共同控制。Phosphogypusum was modified with the surfactant of hexadecyl trimethyl ammonium bromide （CTMAB） under microwave irradiation to obtain organic-modified CTMAB- phosphogypusum. The structure of the products were characterized. With the static adsorption experiments, the adsorption properties of CTMAB- phosphogypusum for Cr （ VI ） ions from aqueous solutions were studied, and the adsorption mechanism was discussed from the kinetics point of view. The results indicate that the adsorption data fit both the Langmuir and the Freundlich models, however, the Langmuir equation describes the adsorption results better. The initial stage of adsorption could be mirrored with the Lagergren pseudo-first-order kinetics, Lagergren pseudo-second-order kinetics, Elovich adsorption equation and intra-particle diffusion model. The absorption of Cr（VI） on CTMAB-phosphogypusum keeps in accordance with Lagergren pseu-do-second-order kinetics in the entire adsorption stage and the greatest adsorption capacity of Cr （VI） is 16. 3225 mg · g^-1. The absorption behaviors of Cr（VI ） on CTMAB- phosphogypusum are controlled by the common effect of physical adsorption, chemical adsorption and complex precipitation.

关 键 词：CTMAB 磷石膏 Cr(Ⅵ) 吸附动力学 

分 类 号：TD985[矿业工程—选矿]