ZnCl2活化笋壳活性炭的制备及其对亚甲基蓝的吸附动力学研究

以笋壳为原料，采用氯化锌为活化剂制备活性炭，通过正交实验研究各影响因素对活性炭性能的影响。通过静态吸附实验研究ZnCl₂活化笋壳活性炭对亚甲基蓝的吸附特性，并从动力学角度探讨其吸附机理。结果表明，制备活性炭主要影响因素为活化温度，其次是ZnCl₂浓度，活化时间影响最小。制备活性炭的最佳条件是:ZnCl₂浓度为3 mol/L，活化温度控制在400 ℃，活化时间2 h。活性炭对亚甲基蓝的吸附符合准二级动力学方程和Elovich方程，吸附速率控制步骤主要为膜扩散控制。等温吸附曲线与Langmuir型和Freundlich型均拟合较好，吸附过程是优惠吸附。

Preparation of ZnCl2 activated carbon from bamboo shoot shell and its adsorption kinetics

Bamboo shoot shell was used as raw material, and activated carbon was prepared by ZnCl₂ activation. The effect of preparation condition was studied by orthogonal experiment. The adsorption equilibrium and kinetic behaviour of methylene blue onto activated carbon was investigated by conducting a series of batch adsorption experiments, the adsorption mechanism of which was discussed from kinetic point of view. The results show that the main preparation influential factor is activation temperature, followed by ZnCl₂ concentration, and the activation time. The optimum preparation conditions are: ZnCl₂ concentration of 3 mol/L; activation temperature of 400 ℃; activation time of 2h. The adsorption process follows the pseudo second order kinetic equation and the Elovich equation. The adsorption rate is mainly controlled by membrane diffusion. The adsorption curve fits well with both of the Langmuir and Freundlich isotherm, the process of which is a favourable adsorption.