偕胺肟基改性碳纳米管对铀的吸附性能研究

Removal of Uranium by Adsorption of Amidoxime Group Modified Carbon Nanotubes

对多壁碳纳米管（MWNTs）进行偕胺肟基改性,采用透射电子显微镜（TEM）和傅里叶变换红外光谱仪（FTIR）进行表征,研究了改性前后MWNTs在不同条件下对铀的吸附性能。结果表明,在pH=2～8的范围内,未改性的碳纳米管（raw-MWNTs）与偕胺肟基改性碳纳米管（AO-MWNTs）对铀的吸附容量均是先增大后降低,pH值为5时达到最大。随着铀初始浓度的增大,raw-MWNTs和AO-MWNTs对铀的吸附容量逐渐升高。当铀初始浓度为10 mg/L时,AO-MWNTs对铀振荡吸附30min后达到平衡,吸附容量可达18.93mg/g,而raw-MWNTs对铀振荡吸附60min后趋于稳定,吸附容量可达9.59mg/g。AO-MWNTs对铀的吸附符合Langmuir和Freundlich模型,最大理论吸附容量为106.38mg/g。

AO-MWNTs were obtained through multi-walled carbon nanotubes（MWNTs）modified by amidoxime group,and characterized by transmission electron microscope（TEM）and fourier transform infrared spectrometer（FTIR）.The adsorption experiments of uranium on the raw-MWNTs and AO-MWNTs were studied under different conditions.The results show that the adsorption capacities of uranium on raw-MWNTs and AO-MWNTs primarily increase and then decrease over the range of pH=2-8,and reach the maximum at pH=5.With the increase of initial concentration of uranium,theadsorption capacities of uranium on the two materials gradually increase.When the initial concentration of uranium is 10mg/L,the adsorption of uranium on AO-MWNTs balances after oscillating 30 min,and the adsorption capacity reaches 18.93mg/g,while the raw-MWNTs tend to be stable after 60 min,and the adsorption capacity is9.59mg/g.The adsorption capacity of uranium on AO-MWNTs can be described by Langmuir and Freundlich models,and the theoretical maximum adsorption capacity can reach 106.38mg/g.