作　　者： ; ; ; ;

机构地区： 北京林业大学资源与环境学院森林培育与保护教育部重点实验室

出　　处： 《环境科学学报》 2005年第5期643-649,共7页

摘　　要： 建立了复杂分子吸附反应时指数h与分形子谱维数ds、分形介质的表面分形维数Ds 的关系式.对吸附动力学数据的模拟表明,不同温度下6种染料在颗粒活性炭表面的吸附过程符合非线性动力学.吸附速率一般随着温度的升高而增加,反应活化能在0 2 0～1 75kJ·mol- 1 之间.上述反应为快速反应.进一步分析表明,该吸附过程具有类分形动力学特征,吸附反应的逐时速率系数k与反应时间t呈指数关系;相应的分形子谱维数ds<2 .随着染料的初始浓度的增加,ds 也随之增加,而h和k0 值通常会随之降低.吸附3种酸性染料时,h和k0 值在本实验的温度范围内均随着温度的升高而增加;其它3种直接性染料也大都呈现h随着温度的升高而增加的趋势.上述吸附反应中有效反应级数x也与ds、Ds 有关。 To elucidate the adsorption kinetics of complex molecules onto fractal surfaces, the relations of reaction exponent h with both fractal spectrum dimension d_s and surface fractal dimension D_s were developed. The adsorption kinetic processes of six dye compounds onto granular activated charcoal (GAC) were studied. The simulation results showed that the adsorption behaviors of these compounds followed the experiential non-linear kinetic equations, and higher adsorption rate was observed at higher temperature generally. The calculated apparent activated energy (Ea) values were within the range of 0.20～1.75kJ·mol^(-1), demonstrating the adsorption processes were relatively fast. And further analysis indicated that the adsorption kinetic processes appeared the fractal-like characteristics. The stepwise rate coefficient (k) had a power-law relation with reaction time (t), and the corresponding spectral dimensions d_s were less than two. It was also noted that increasing the initial concentrations of dye compounds led to the increases of d_s values, and the decreases of the h and k_0 values. With regard to the adsorption of the three acid dye compounds, the kinetic parameters h and k_0 increased with increasing temperature. For the other three kinds of direct dye compounds, only the parameter h had the same trend. The effective reaction series x was also related to both d_s and D_s, and the relations indicate x could be a non-integer number.

关 键 词： 颗粒活性炭 吸附染料 活化能 类分形动力学特征 非整数有效反应级数

领　　域： [环境科学与工程]