板栗壳活性炭的制备及其对甲基橙和亚甲基蓝的吸附作用

Preparation of activated carbon from chestnut shell and its adsorption on methyl orange and methylene blue

为探讨板栗壳活性炭对印染染料的吸附作用,制备板栗壳活性炭,以振荡时间、pH和温度为因素,考察板栗壳活性炭对甲基橙和亚甲基蓝染料的吸附效果,分析了等温吸附过程并从动力学角度探讨了2种染料的吸附机理。结果表明:板栗壳活性炭对甲基橙染料的最佳吸附条件为pH 4、温度35℃、振荡时间150 min;对亚甲基蓝最佳吸附条件为pH 4、温度30℃、振荡时间120 min;板栗壳活性炭对甲基橙的吸附过程与Langmuir模型拟合程度更高,主要是单分子层吸附,而板栗壳活性炭对亚甲基蓝的吸附过程与Freundlich模型拟合度更高,主要是多分子层吸附;用准二级动力学方程(R^(2)>0.99)比准一级动力学方程描述板栗壳活性炭对这两种染料的吸附情况更好,板栗壳活性炭对2种染料的吸附以化学吸附为主。

In order to investigate the adsorption of chestnut shell activated carbon on printing and dyeing dyes,chestnut shell activated carbon was prepared.The adsorption effect of chestnut shell activated carbon on methyl orange and methylene blue dyes was investigated by taking oscillation time,pH and temperature as factors.The isothermal adsorption process was analyzed,and the adsorption mechanism of the two dyes was discussed from the perspective of kinetics.The results showed that the optimum adsorption conditions of methyl orange dye on chestnut shell activated carbon were pH 4,temperature 35 ℃ and oscillation time 150 min;The optimum adsorption conditions for methylene blue were pH 4,temperature 30 ℃ and oscillation time 120 min;The adsorption process of methyl orange on chestnut shell activated carbon was more closely fitted with Langmuir model,mainly monolayer adsorption,while the adsorption process of methylene blue on chestnut shell activated carbon was more closely fitted with Freundlich model,mainly multilayer adsorption;The quasi second-order kinetic equation(R^(2)>0.99) was better than the quasi first-order kinetic equation to describe the adsorption of the two dyes by chestnut shell activated carbon.The adsorption of the two dyes by chestnut shell activated carbon was mainly chemical adsorption.