摘要
为研究生物陶对酸性品红的吸附行为,对不同温度下(298、303、308、313、318 K)的吸附数据分别用Langmuir、Freundlich和Dubinin-Radushkevish方程进行拟合以确定其吸附模式,用准一级动力学方程和准二级动力学方程拟合了生物陶对酸性品红的吸附动力学过程,采用Web-Morris模型对吸附动力学机制进行探讨,并计算了其Gibbs自由能变(!G0)、焓变(!H0)和熵变(!S0)等热力学函数.结果表明,生物陶对酸性品红吸附能力随着温度的升高而升高;Langmuir方程更适合描述其吸附行为.Gibbs自由能变(!G0)小于0,焓变(!H0)和熵变(!S0)均大于0,说明此吸附过程为自发、吸热、且趋于无序.伪二级动力学方程可描述生物陶对酸性品红的吸附动力学过程,速率系数k2为0.089 g·mg-1·min-1.Web-Morris模型可很好地解释吸附动力学机制.
In order to investigate the dye adsorption properties of biopottery, acid fuchsin was chosen as the sorbate. The data obtained from different temperature （298, 303, 308, 313, 318K） were fitted with Langmuir, Freundlich and Dubinin-Radushkevish models to describe the equilibrium isotherms. The kinetics rates were modeled using pseudo-first-order and pseudo-second-order kinetic equations. Using web-morris model to explore mechanisms for adsorption kinetics. The Gibbs free energy （DG0）, enthalpy change （DH0） and entropy change （DS0） were calculated. The results revealed that the equilibrium adsorption amount increased with the increase of temperature. The adsorption could be well depicted by the Langmuir adsorption isotherm. The Gibbs free energy （DG0） was negative, while enthalpy change （DH0） and entropy change （DS0） were both positive, indicating that the adsorption was a spontaneous, endothermic and increasing entropy process. The adsorption kinetics followed pseudo-second-order kinetic equation, the rate k2 was 0.089 g·mg-1·min-1 . Web-Morris model can well explain the mechanism of adsorption kinetics and the intra-particle diffusion controls the adsorption rate.
出处
《环境化学》
CAS
CSCD
北大核心
2014年第5期805-811,共7页
Environmental Chemistry
基金
中国博士后科学基金(2013M540831)
北京市属高校高层次人才引进与培养计划和创新团队与教师职业发展计划-"青年拔尖人才培育计划"(CIT&CD201404076)
北京市优秀人才培养资助项目(2013D005017000004)
北京市自然科学基金重点项目(B类)暨市教委科技发展计划重点项目(KZ201410016018)资助
关键词
生物陶
酸性品红
吸附
热力学
动力学
biopottery
acid fuchsin
adsorption
thermodynamics
kinetics
