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

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:lgD=3.43+1.74lgn(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-。

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 SiR4 N could be simulated well using Langmuir isotherm. According to Clausius-Claperon equation, adsorption heat estimated from the slope of In Kd vs 1/T plot is AH=--7.23 kJ/mol, which is exothermic reaction. Distribution ratios （D） and the amount of functional group can be expressed as 1g D= 3.43＋1. 741g 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 SiR4 N.