H_3PO_4活化制备喜旱莲子草基活性炭及性能表征

Preparation and characterization of activated carbon from Alternanthera philoxeroides by H_3PO_4 activation

为了解决喜旱莲子草入侵带来的环境污染和生态破坏问题,探索了综合利用其制备价廉、质优活性炭的可能性、在正交实验的基础上,对实验结果进行了单因素方差分析,结果表明,控制因素对活性炭得率和碘吸附值的影响大小均依次为:炭化温度>炭化时间>浸渍时间>浸渍比,且前三者有显著影响、极差分析表明最佳制备工艺组合为:浸渍比4∶1、浸渍时间6 h、炭化温度873 K和炭化时间1 h。在最佳制备条件下制得的喜旱莲子草基活性炭得率和碘吸附值为:37.44%和752.36 mg/g;其比表面积、总孔体积、平均孔径和中孔率分别为:1 100.720 m2/g、0.610 cm3/g、2.216 nm、72.00%。红外光谱分析表明,活性炭形成了大量表面官能团,主要有以下几种:羧基、酚基、醚基等、正交实试和物理特性表征均表明,喜旱莲子草是良好的中孔活性炭制备原料。

The feasibility of using an invasive plant Alternanthera philoxeroides to prepare activated carbon was investigated in the present study. Results showed that the order of the controlling factors for the yield and iodine number of the synthetic activated carbon was carbonization temperature > carbonization time > impregnation time > impregnation ratio,and the first three factors had significant impacts. The optimal preparation conditions were 4∶ 1 for impregnation ratio; 6 h for impregnation time; 873 K for carbonization temperature and 1 h for carbonization time,under which the activated carbon prepared from alligator weed had a yield ratio of 37. 44%and iodine adsorption amount of 752. 36 mg / g. The surface area,the total pore volume,the average pore size and the ratio of mesoporous were 1 100. 720 m2/ g,0. 610 cm3/ g,2. 216 nm and 72. 00%,respectively. FT-IR analysis revealed that abundant functional groups were formed on the surface of the prepared activated carbon,including carboxyl,phenol and ether group. These results indicated that A. philoxeroides might be a promising biomass material for the preparation of mesoporous activated carbon.