KOH活化花生壳生物质炭对亚甲基蓝吸附性能研究

以花生壳生物质炭(P-BC)为原料,KOH为活化剂,采用化学活化法制得活化生物质炭(K-BC),通过考察对亚甲基蓝的吸附性能,研究了花生壳生物质炭的最佳活化条件,并利用N2吸附-脱附实验、SEM等对最佳活化条件下的生物质炭进行表征.结果表明,K-BC活化的最佳条件为碱炭比为1.5:1,活化温度为800℃,活化时间为90 min,此时K-BC的比表面积达到597.93 m2/g,总孔容达到0.76 cm3/g.并考察了亚甲基蓝初始浓度、pH等对K-BC吸附亚甲基蓝的影响,随着初始浓度的增加,吸附平衡时间显著延长,亚甲基蓝去除率显著降低;当pH=6时,K-BC对亚甲基蓝的吸附量最大;K-BC对亚甲基蓝的吸附动力学曲线符合伪二阶动力学模型,吸附平衡时K-BC对亚甲基蓝的吸附能力为80~149.95 mg/g.

Adsorption of methylene blue by peanut shell bio-char with KOH activated

The activation bio-char (K-BC) was prepared by peanut shell bio-char with KOH activated. The best activation conditions were studied by testing the adsorptive capacity of methylene blue. The character and pore structure of the K-BC were characterized with N2 adsorption-desorption, SEM and so on. The considerable preparation conditions were obtained as follows: impregnation ratio of 1.5:1, activation temperature of 800℃, and an activation time of 90min.The BET surface area of K-BC was 597.93 m2/g, and its total pore volume was 0.76 cm3/g. The effects of pH and the initial concentration on the K-BC removal of methylene were studied. The results showed that the removal of methylene blue significantly decreased with increasing initial concentration of methylene blue, and the adsorption time increased with K-BC adsorption. When the pH was 6, the K-BC adsorption methylene blue capability was the best. And the kinetic curves of K-BC adsorbed methylene blue were fitted with Pseudo-second-order kinetic model, the adsorption capacity was 80~149.95 mg/g.