纳米零价镍去除溶液中U(VI)的研究

采用液相还原法制备纳米零价镍,并用来去除溶液中的U(VI)。通过SEM、EDS技术表征反应前后材料的形貌,从微观角度分析纳米零价镍去除溶液中U(VI)的机理,并进行了热力学分析。结果表明,纳米零价镍对溶液中U(VI)有良好的去除效果,在室温下,pH=4.0、接触时间60min、固液比0.3g/L和初始浓度50mg/L时,U(VI)的去除率和去除量分别达到了98.44%和182.372mg/g。新制备的纳米零价镍呈明显的球状,颗粒较为分散且粒径较均匀,反应后,材料表面形貌发生变化,呈不规则碎片堆积、粒径变大,且材料中出现了铀元素。热力学研究结果表明,该反应是自发吸热反应,同时也是不可逆的熵增反应。

Study on Removal of U(VI) in Aqueous Solution with Nano-zero-valent Nickel

Nano-zero-valent nickel was prepared by liquid-phase reduction method and used to remove U(VI) from aqueous solution. Micro-morphologies of the materials before and after reaction were characterized by SEM and EDS. Removal mechanism was studied based on thermodynamics. The results show that nano-zero-valent nickel has good removal effect on U(VI) from aqueous solution. Removal rate and capacity of U(VI) is 98.44% and 182.372 mg/g respectively under the conditions including room temperature, pH value of 4.0, contact time of 60 min, ratio of solid to liquid of 0.3 g/L, and initial concentration of 50 mg/L. Particle size of nano-zero-valent nickel is obviously spherical with uniform dispersion. After reaction, surface morphology of the material change to irregular fragments accumulation and particle sizes become larger, and U elements appear in the material. Thermodynamic studies show that the reaction is spontaneous endothermic and irreversible with increasing entropy.