用一级动力学微分方程研究流动法中红壤吸附铜动力学

本文主要运用一级动力学微分方程研究流动法中红壤吸附铜的动力学特征。实验结果表明,反应过程总速率受扩散作用的限制。在低吸附量区域里总速率由外表面扩散速率决定;在高吸附量区域里总速率由内表面扩散速率决定。在恒定温度和pH值后,红壤吸附铜的理论饱和吸附量x_∞几乎不受流速、浓度的影响,基本为一定值;相反实测饱和吸附量x_∞受流速及浓度的影响。理论x_∞>实测x_∞。

Investigation on the Kinetic Characteristics of Copper Adsorption on Red Earth in Flow Method by Utilizing First-Order Kinetic Differential Equation

The kinetic characteristics of adsorption of copper on red earth in flow method was investigated by utilizing a first-orrder kinetic differential equation. Results show that the rate of copper adsorption is affected by diffusion. Specifically, the rate of the process is dominated by external diffusion when the adsorption is at lower levels and by the internal diffusion when the adsorption is at higher levels. At a given temperature and pH value, the theoretical saturated adsorption amount of copper is basically a constant and independent of flow rate and concentration of the solution under study. However, the experimentally determined saturated adsorption amount of copper was found to be significantly affected by the flow rate and concentration of the solution and smaller than the theoretical saturated adsorption amount.