Abstract:

A series of activated carbons (ACs) were prepared from Alternanthera philoxeroides (AP) by K₂CO₃ one-step mixing activation. The effects of various process parameters, such as mixing mass ratio of K₂CO₃ to AP, activation temperature and period, on the adsorptive property and the yield of AC were investigated. The surface morphology of AC were characterized with scanning electron microscopy (SEM). The results indicate that the optimized activation conditions were 1.5 of K₂CO₃ to AP mixing mass ratio, 800℃ of activation temperature, 3.0 h of the activation time. The yield, iodine number and methylene blue (MB) number of AC were 13.79%, 1477 mg·g^-1, 384 mg·g^-1, respectively. The recovery ratios of K₂CO₃ were over 80% when the nitrogen flow rate was no more than 100 ml·min^-1. The SEM images of the ACs showed that the activation temperature has obvious effect on the porous structure.

Key words: activated carbon, Alternanthera philoxeroides, preparation, activation, adsorption

摘要：

以入侵生物空心莲子草为原料，以K₂CO₃为活化剂，经一步共混活化法制备活性炭。研究了K₂CO₃与空心莲子草质量比、活化温度及活化时间对活性炭得率及吸附性能的影响。利用扫描电子显微镜（SEM）对不同温度下得到的活性炭进行了表面形貌观察。实验结果表明，K₂CO₃活化空心莲子草的最佳活化条件为：质量比为1.5，活化温度及时间分别为800℃，3.0 h，此时活性炭得率为13.79%，其碘吸附值及亚甲基蓝吸附值分别为1477 mg·g^-1和384 mg·g^-1。当氮气流量在20～100 ml·min^-1范围内变化时，K₂CO₃的回收率相差不大，且其回收率均能达到80%以上。SEM结果表明活化温度对活性炭孔结构具有明显影响。

关键词: 活性炭, 空心莲子草, 制备, 活化, 吸附