高比表面积水葫芦活性炭及对铅离子的吸附

Adsorption of Pb(Ⅱ) on High Surface Area Activated Carbons Fabricated from Water Hyacinth

以水葫芦为原料,采用多聚磷酸活化法制备水葫芦活性炭.利用扫描电子显微镜(SEM)、比表面积测定仪(BET)和傅里叶红外光谱(FTIR)对活性炭进行表征,并将其用于吸附Pb(Ⅱ).结果表明:水葫芦活性炭其内部和表面存在着大量形态各异的孔隙,比表面积为1005.5m^2/g,平均直径为2.02nm;表面有羟基、磷酸基、羧基等基团,有利于对重金属离子的去除.水葫芦活性炭对Pb(Ⅱ)的吸附动力学和吸附等温线分别符合Elovich和Langmuir等温吸附方程,吸附过程属于单分子层吸附,饱和吸附量为133.33mg/g.

Activated carbons were prepared from water hyacinth using polyphosphoric acid activation.Characterizations of the activated carbon were performed using Brunauer-Emmett-Teller(BET),scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR).Also,activated carbons were used to eliminate Pb(II)in water.The activated carbon achieved a coarse porous surface with irregular pores.The BET surface area was 1005.5 m2/g and the average pore diameter was 2.02 nm.The presence of oxygen-containing functional groups including hydroxyl,carbonyl,carboxyl and phosphate groups renders the activated carbon a favorable adsorbent for Pb(II)with the maximum monolayer capacity 133.33 mg/g.The adsorption behavior follows Pseudo-second-order kinetic and Langmuir isotherm.