摘要
为研究山茶籽粉对亚甲基蓝的吸附行为,对不同温度下(298、303、308、313、318K)的吸附数据分别用Langmuir、Freundlich和Dubinin-Radushkevish模式进行拟合,用伪一级动力学方程和伪二级动力学方程描述山茶籽粉对亚甲基蓝的吸附动力学过程,并计算了Gibbs自由能变(ΔGθ)、焓变(ΔHθ)和熵变(ΔSθ)等热力学函数.结果表明,山茶籽粉对亚甲基蓝的吸附能力随着温度的升高而降低;Langmuir方程更适合描述其吸附行为.Gibbs自由能变(ΔGθ)、焓变("Hθ)和熵变(ΔSθ)均小于零,说明此吸附过程是自发进行的、放热的、趋于有序的吸附过程.伪二级动力学方程更适用于描述山茶籽粉对亚甲基蓝的吸附动力学过程.
In order to investigate the dye adsorption properties of tea seed powder,methylene blue was chose as the sorbate.The data obtained at different temperatures（298,303,308,313,318 K） 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.The Gibbs free energy（ΔGθ） 、enthalpy change（ΔHθ） and entropy change（ΔSθ） were calculated.The results revealed that the equilibrium adsorption amount decreased with the increase of temperature.The adsorption could be well depicted by the Langmuir adsorption isotherm.The Gibbs free energy（ΔGθ） 、enthalpy change（ΔHθ） and entropy change（ΔSθ） were negative,indicating that the adsorption was a spontaneous,exothermic and decreasing entropy process.The adsorption kinetics followed pseudo-second-order kinetic equation.
出处
《环境化学》
CAS
CSCD
北大核心
2013年第8期1539-1545,共7页
Environmental Chemistry
基金
北京市属市管高等学校人才强教计划项目(PHR201106124)
水体污染控制与治理科技重大专项(2010ZX07320-002)
北京建筑工程学院大学生科技研究项目
环境科学与环境工程教学专项(2013)资助
关键词
山茶籽粉
亚甲基蓝
吸附
热力学
动力学
tea seed powder
methylene blue
adsorption
thermodynamics
kinetics
