响应面法优化ZnCl_(2)/AlCl_(3)改性生物炭吸附甲基紫工艺

Response surface methodology optimization of ZnCl_(2)/AlCl_(3) modified biochar for adsorption of methyl violet

利用高温热解法制备ZnCl_(2)/AlCl_(3)改性生物炭,将其用于吸附甲基紫染料。探究ZnCl_(2)/AlCl_(3)-AC投加量、溶液pH、甲基紫浓度、反应时间和吸附温度这5个因素对甲基紫吸附率的影响。利用Plackett-Burman设计联合响应面分析法,筛选优化出对甲基紫吸附率影响较为显著的因素,并探究各因素间的交互影响作用,确定ZnCl_(2)/AlCl_(3)-AC吸附甲基紫的最佳工艺条件。结果表明:在选取的五个因素中,对甲基紫吸附率影响显著的因素为ZnCl_(2)/AlCl_(3)-AC投加量>甲基紫浓度>吸附温度;其中ZnCl_(2)/AlCl_(3)-AC投加量和吸附温度对甲基紫吸附率影响最明显,甲基紫浓度和吸附温度影响最不显著;ZnCl_(2)/AlCl_(3)-AC吸附甲基紫最佳工艺条件为:活性炭投加量为47.00 mg、甲基紫溶液浓度为82.00 mg/L、吸附温度为22.90℃,pH为7、反应时间为120 min,其甲基紫吸附率可达到93.04%,与模型预测值的误差仅为3.51%。

The modified biochar prepared by high temperature pyrolysis is modified by ZnCl2/AlCl3,which is used to adsorb methyl violet.The impact of methyl violet adsorption rate with the five factors of biochar dosage,pH,methyl violet concentration,reaction time and adsorption temperature is explored.They are analyzed by Plackett-Burman design combined with response surface methodology to screen and optimize the factors that have significant influence on the methyl violet adsorption rate and to explore the interaction between the factors.In addition,the best process conditions for activated carbon adsorption of methyl violet are determined.The results show that the factors influencing the response value are:the amount of biochar>the concentration of methyl violet solution>the adsorption environment temperature,among which,biochar dosage and adsorption temperature have the most obvious effect on the adsorption rate of methyl violet,and the concentration of methyl violet and adsorption temperature have the least significant effect.And the optimum adsorption conditions are:the amount of biochar of 47.00 mg,the concentration of methyl violet solution of 82.00 mg/L,the adsorption environment temperature of 22.90℃,the pH of 7 and the reaction time of 120 min.The optimum adsorption rate of methyl violet could reach 93.04%and the error with the model predicted value is only 3.51%.