山竹壳活性炭吸附亚甲基蓝性能研究

The Performance of Mangosteen Shell Activated Carbon Adsorb Methylene Blue

以山竹壳为原料,采用磷酸—硫酸活化法制备了比表面积为1730m^2·g^(-1)的活性炭。研究了山竹壳活性炭吸附亚甲基蓝的吸附性能,考察了亚甲基蓝溶液的pH、不同初始浓度、吸附时间、温度等条件对吸附效果的影响。应用准一级动力学方程、准二级动力学方程模拟了山竹壳活性炭吸附亚甲基蓝的动力学过程,结果表明准二级动力学方程适合描述整个吸附过程。用Langmuir和Freundlich模型模拟吸附等温线,Langmuir方程更适合描述此吸附过程,在298K下最大单层吸附量为526.31mg·g^(-1)。计算了吉布斯自由能(ΔG^0)、焓变(ΔH^0)、熵变(ΔS^0)等热力学参数,ΔG^0、ΔH^0、ΔS^0均小于0,说明此吸附过程是一个自发进行的、放热的、趋于有序的吸附过程。

Activated carbon was prepared from mangosteen shell by using H3PO4-H2SO4activating reagent,the activated carbon have specific surface areas of1730m2·g-1.This paper mainly focuses on the absor ption performance of activated carbon absorbing methylene blue in different pH,different initial concentration,and different time and different temperature.Using quasi-order kinetic equation,quasi-second-order equation separately to simulate the kinetics process of activated carbon adsorbing methylene blue,the result shows that the pseudo-second kinetic equation is suitable for describing the whole adsorption process.Using Langmuir equation and Freundlich equation to simulate the kinetics process of activated carbon adsorbing methylene blue,it shows that Langmuir equation is more suitable for describing the adsorption process and the maximum monolayer adsorption capacity is526.31mg·g-1at298K.It shows that△G0,△H0,△S0are less than0by calculating the thermodynamic parameters of Gibbs free energy(△G0),enthalpy(△H0),entropy change(△S0),which indicating that this adsorption process is a spontaneous,exothermic,nearly ordered adsorption process.