玉米秸秆活性炭的制备及其吸附动力学研究

Preparation of activated carbon from corn straw and research of adsorption kinetics

以玉米秸秆为原材料,采用ZnCl2活化法制备玉米秸秆活性炭,吸附次甲基蓝染料废水,进行动力学分析。本实验用Langmuir和Freundlich模型对吸附等温线进行拟合,结果表明,玉米秸秆活性炭对次甲基蓝的吸附与Langmuir方程拟合良好,R2=0.9857。采用Lagergren准一级速率模型、Lagergren准二级速率模型、Bangham动力学方程和Elovich动力学方程分别对秸秆活性炭吸附次甲基蓝溶液进行吸附动力学拟合,通过分析得出吸附过程与Lagergren准二级速率模型拟合最好,R2=0.9979。秸秆活性炭对次甲基蓝的最大吸附量达到909.09 mg/g,具有很高的吸附能力。

Corn straw was used to prepare activated carbon by ZnCl2 activation in this experiment. Then the activated carbon was used to adsorb methylene blue dye and the adsorption kinetics was studied. Langmuir equations and Freundlich equations were respectively fitted with the adsorption isotherm. The results indicated that the adsorption process accorded with Langmuir equation,R2= 0. 9857. The adsorption kinetics equations were modeled with Pseudo-first-order reaction rate equation,Pseudo-second-order reaction rate equation,kinetic equation of Bangham and kinetic equation of Elovich. Compared with other equations,Pseudo-second-order reaction rate equation could more clearly describe the absorption mechanism in methylene blue process by straw activated carbon,R2= 0. 9979. The maximum adsorption capacity achieved 909. 09 mg /g.