水相环境中U(Ⅵ)在伊利石上的吸附特征

Adsorption Characteristic of U(Ⅵ) on Illite in Aqueous Environment

以伊利石为吸附剂,通过吸附实验探究U(Ⅵ)在伊利石上的吸附特征,分别考查了接触时间、吸附剂用量、U(Ⅵ)初始浓度、pH值及温度对吸附的影响。用FT-IR和SEM对吸附前后的伊利石进行表征,研究了U(Ⅵ)在伊利石上吸附的动力学和热力学过程。结果表明:吸附过程在10 h后达到动态平衡;在U(Ⅵ)初始浓度为50 mg/L时,吸附效果最好;最佳吸附剂用量为0.03 g;pH值对伊利石吸附铀的影响显著,最佳pH值为5~6;升高温度有利于U(Ⅵ)在伊利石上的吸附;准二级动力学模型和Langmuir等温吸附模型对U(Ⅵ)在伊利石上的吸附过程拟合效果较好,吸附过程主要为表面络合作用,属于单层吸附。

Taking illite as adsorbent,the adsorption characteristics of U(Ⅵ)on illite were investigated through static adsorption experiments.The effects of contact time,adsorbent quality,initial concentration of U(Ⅵ),pH and temperature on adsorption were investigated respectively.FT-IR and SEM were used to characterize illite before and after adsorption,and the kinetics and thermodynamics of U(Ⅵ)adsorption on illite were investigated.The results show that the adsorption process reaches dynamic equilibrium after 10 h.When the initial concentration of U(Ⅵ)is 50 mg/L,the adsorption effect is the best.The best adsorbent dosage is 0.03 g.pH has a significant effect on the adsorption of uranium on illite,and the optimal pH is 5-6.Increasing temperature is beneficial to the adsorption of U(Ⅵ)on illite.Quasi-second-order kinetic model and Langmuir isothermal adsorption model have good fitting effect on the adsorption process of U(Ⅵ)on illite.The adsorption process is mainly surface complexation,belonging to single-layer adsorption.