硅基季铵化分离材料对Pu(Ⅳ)的吸附性能及机理研究

Adsorption Performance and Mechanism of Pu(Ⅳ) by Silica-Based Quaternary Ammonium Material

摘要: 研究了硅基季铵化分离材料（SiR₄N）在硝酸溶液中对Pu（Ⅳ）的吸附性能和机理。结果表明，SiR₄N对Pu(Ⅳ)的吸附等温线基本符合Langmuir吸附等温线，吸附为放热反应，ΔH ＝-7.23 kJ/mol。机理研究结果表明，分配比D与树脂功能基团SiR₄N⁺的关系式为：lg D =3.43+1.74lg n (SiR₄N⁺ )，其配位比接近于2，由此可推测SiR₄N在硝酸溶液体系主要吸附的是［Pu(NO₃)₆］^2-。

Abstract: The adsorption performance and mechanism of silicabased quaternary ammonium material (SiR₄N) were investigated by adsorption of Pu（Ⅳ） in 4 mol/L nitric acid solution. The adsorption isotherm of Pu（Ⅳ）on SiR₄N could be simulated well using Langmuir isotherm. According to Clausius-Claperon equation, adsorption heat estimated from the slope of ln K_dvs 1/ T plot is ΔH ＝-7.23 kJ/mol, which is exothermic reaction. Distribution ratios (D) and the amount of functional group can be expressed as lg D =3.43+1.74lg n (SiR₄N⁺ )，, and the slope is close to 2. It is concluded that the adsorption of Pu（Ⅳ） on SiR₄N in nitric acid solution belongs to anion ion exchange, and most of ［Pu(NO₃)₆］^2-are absorbed on SiR₄N.