Am(Ⅲ)胶体稳定性及其在膨润土胶体上的吸附行为

Stability of Am(Ⅲ)Colloid and Its Adsorption Behavior on Bentonite Colloids

以北山BS03#地下水为水相,探究Am(Ⅲ)胶体形成及其在膨润土胶体上的吸附行为。通过Zeta电位激光粒度分析仪与不对称流场流分离检测仪(AF4)和批式实验法探究多种因素,如pH值、不同CO_(2)浓度氛围、离子强度和温度对胶体稳定性和吸附行为的影响。结果表明:Am(Ⅲ)胶体的形成及稳定性和Am(Ⅲ)的水溶液化学性质息息相关,升高温度或增大离子强度会减小Am(Ⅲ)胶体的稳定性,而CO_(2)浓度升高和pH增大则有利于Am(Ⅲ)胶体的形成与稳定性;随着pH的增大,Am(Ⅲ)-膨润土胶体颗粒密度增大,而Am(Ⅲ)的吸附率先减小后增大;离子强度升高有利于Am(Ⅲ)的吸附,但胶体颗粒密度下降;气相CO_(2)浓度升高对颗粒密度和Am(Ⅲ)吸附具有促进作用。

The formation of Am(Ⅲ)colloid and its adsorption behaviors on bentonite colloid were investigated in Beishan 03 groundwater.A series of influencing factors,such as,pH,CO_(2) concentration in gas atmosphere,ionic strength and temperature,on colloidal stability and adsorption behavior were explored using Zeta potential laser particle size analyzer,asymmetric flow field flow fractionation system(AF4)and batch experimental method.The results show that the formation and stability of Am(Ⅲ)are closely dependent on the chemical natures of aqueous solution.Increasing temperature or increasing ionic strength will reduce the stability of Am(Ⅲ)colloids,while the increase of carbon dioxide concentration and pH will be beneficial to the stability of Am(Ⅲ)colloid.In addition,with the increase of pH,the density of Am(Ⅲ)-bentonite colloid particles increases,while the Am(Ⅲ)adsorption rate first decreases and then increases;the increase of ionic strength is favor of Am(Ⅲ)adsorption,but the density of colloidal particles decreases;the increase of CO_(2) concentration in gas phase has a promoting effect on particle density and Am(Ⅲ)adsorption.