摘要
以高岭土为吸附剂,研究高岭土对水中U(Ⅵ)的吸附特征,对比探究了298.15 K、308.15 K、318.15 K和328.15 K下U(Ⅵ)的不同初始浓度、溶液pH和共存离子对其吸附的影响。吸附实验结果表明:随着U(Ⅵ)初始浓度增加,高岭土对U(Ⅵ)的吸附量增强,吸附热力学分析证明高岭土对U(Ⅵ)的吸附过程是自发的吸热过程,升温对高岭土吸附U(Ⅵ)产生促进作用;当pH为7时,高岭土对U(Ⅵ)的吸附效果最佳,相同pH条件下升温对高岭土吸附U(Ⅵ)产生促进作用;共存离子中Ca^(2+)、CO_3^(2-)和SO_4^(2-)对吸附有较大的抑制作用,相同离子条件下升温对高岭土吸附U(Ⅵ)产生促进作用;通过对不同温度条件下高岭土吸附前后的红外吸收光谱(Fourier Transform Infrared Spectrometer,FT-IR)对比发现:温度升高后吸收峰发生了移动和强度变化,并且有新峰出现,说明升温后高岭土对U(Ⅵ)的吸附不仅是物理吸附,还存在化学吸附。
[Background] The research on the disposal of clay rock in high-level waste is still in the initial stage, furthermore the research on the migration mechanism of nuclide in clay rock treatment system is weak. [Purpose] This study aims at the adsorption behavior of U（Ⅵ） onto kaolin, and provides reference for the safety evaluation system of high level waste disposal storehouse. [Methods] The effects of initial concentration of U（Ⅵ）, pH and coexisting ions on the adsorption of U（Ⅵ） onto kaolin are investigated at the temperatures of 298.15 K, 308.15 K, 318.15 K and 328.15 K. [Results] The results show that the adsorption of U（Ⅵ） onto kaolin is increasing with the increase of initial concentration of U（Ⅵ）. At the same concentration of U（Ⅵ）, the adsorption of U（Ⅵ） onto kaolin is increasing with the increase of temperature. When the pH was 7, the adsorption of U（Ⅵ） onto kaolin is best. At the same pH, the adsorption of U（Ⅵ） onto kaolin is increasing with the increase of temperature. The coexistent ions Ca2＋, CO32- and SO42- have a greater inhibitory effect on the adsorption, at the same time the adsorption of U（Ⅵ） onto kaolin is increasing with the increase of temperature. [Conclusion] with the increase of temperature, the adsorption capacity of kaolin on U（Ⅵ） is enhanced. The adsorption thermodynamic analysis proves that the adsorption of U（Ⅵ） onto kaolin is a spontaneous endothermic process. Through comparison of fourier transform infrared spectrometer（FT-IR）, it is found that the absorption peaks have shifted and the intensity changes and appears a new peak, which proves that the adsorption of U（Ⅵ） onto kaolin is not only physical adsorption, there is also chemical adsorption.
作者
张虹
冷阳春
王彦惠
刘建
庹先国
ZHANG Hong;LENG Yangchun;WANG Yanhui;LIU Jian;TUO Xianguo(School of National Defense of Science and Technology, Southwest University of Science and Technology, Mianyang 621010, China;College of Chemistry and Environmental Engineering, Sichuan University of Science ＆ Engineering, Zigong 643000, China)
出处
《核技术》
CAS
CSCD
北大核心
2018年第7期27-33,共7页
Nuclear Techniques
基金
国家自然科学基金(No.41630646)
国家自然科学青年基金(No.41603124)资助~~
关键词
U(Ⅵ)
高岭土
温度
吸附热力学
U（Ⅵ）
Kaolin
Temperature
Adsorption thermodynamics
