类分形修饰法研究活性炭对孔雀石绿的吸附动力学

Fractal-like Modification Used to Study Kinetics of Malachite Green Adsorption on Activated Carbon

研究了25~45℃下,3种活性炭对孔雀石绿的吸附动力学.与经典准一级和准二级动力学方程相比,类分形修饰后的方程对实验数据的拟合度均得到提高,这说明类分形原理用于分析吸附动力学具有一定的优越性.分形体的维数(d s)与吸附质分子的热运动状态有关,随着吸附温度的升高,d s越大,因此类分形修饰法的重要参数α,随吸附温度升高呈下降趋势.结果表明,类分形修饰准一级动力学模型(FL-PFO)的α符合该规律,并且该模型对所有实验数据的拟合度最高,这说明FL-PFO可能是分析孔雀石绿在活性炭上吸附动力学的一般性方法.

The adsorption kinetics of malachite green on three kinds of activated carbons are studied at the temperatures from 25 to 45℃.Compared with the classical pseudo-first and second order kinetics equations,the fractal-like modified equations have higher fitted degree for the experimental data,which indicates that the fractal-like principle has the advantage in the analysis of adsorption kinetics.The fractal dimension is related to the state of adsorbate molecular thermal movement.The d s increases with adsorption temperature increasing.Therefore,the key parameter(α)of fractal-like principle decreases with the increase of adsorption temperature.The pseudo-first order kinetics equation modified by fractal-like principle(FL-PFO)follows the above rule and has a higher fitted degree for the three kinds of activated carbons.It can be concluded that the FL-PFO may have the general application for analyzing the kinetics of malachite green adsorption on activated carbons.