摘要
用批式法研究了99Tc在ca-基膨润土中的吸附行为。大气条件下,99Tc在膨润土中的吸附比约为1.47 mL/g,随着溶液pH值、CO32-、Fe3+浓度的增大,99Tc在膨润土中的吸附比基本不变;随着添加剂Fe2O3和Fe3O4加入量以及Fe2+浓度的增大,99Tc在膨润土中的吸附比增大,吸附平衡后,99Tc主要以Tc(Ⅶ)的形式存在;随着添加剂Fe加入量的增大,99Tc在膨润土中的吸附比增大,吸附平衡后,99Tc主要以Tc(Ⅳ)的形式存在。低氧条件下,99Tc在膨润土中的吸附比约为84.84 mL/g,随着溶液pH值、CO32-浓度的增大,99Tc在膨润土中的吸附比减小;随着溶液Fe2+、Fe3+浓度以及添加剂Fe、Fe2O3和Fe3O4加入量的增大,99Tc在膨润土中的吸附比增大,低氧条件下99Tc主要以Tc(Ⅳ)的形式存在。大气与低氧条件下,99Tc在膨润土中的吸附行为均可用Freundlich吸附等温式表示。
The adsorption behaviors of 'Tc in bentonite were studied with batch methods under aerobic and anoxic conditions in this paper. The adsorption ratios is about 1. 47 mL/g under aerobic conditions. The adsorption ratio of 'Tc in bentonite is not affected by pH in the range of 5 -12 and the CO32-- , Fe3+ concentrations in the range of 10-8~10-2 mol/L in the solution. The adsorption ratio of Tc in bentonite increases with the increase of the mass percent of Fe2O3 and Fe3O4 and the Fe2+ concentration in the range of 10-8-10-2 mol/L. Tc exists ainly in the form of Tc(Ⅶ) after the adsorption equilibriums. The adsorption ratio of Tc in bentonite increase with the increase of the mass percent of Fe and Tc exists mainly in the form of Tc(Ⅶ) after the adsorption equilibriums. The adsorption ratio of Tc in bentonite is about 84. 84 mL/g under anoxic conditions. The adsorption ratios of 99Tc in bentonite decreases with the increase of pH in the range of 5~12 and the CO32- concentration in the range of 10-8~10-2 mol/L in the solution. The adsorption ratio of Tc in bentonite increases with the increase of the Fe3+ , Fe2+ concentration in the range of 10-8~10-2 mol/L and the mass percent of Fe, Fe2O3 and Fe3O4. Tc exists mainly in the form of Tc(Ⅳ) after the adsorption equilibriums. The adsorption isotherms of TcO4- in bentonite are all in fairly agree with the Fre-undlich's equation under aerobic and anoxic conditions.
出处
《核科学与工程》
CSCD
北大核心
2004年第2期144-151,111,共9页
Nuclear Science and Engineering
