不溶性腐殖酸对钍的吸附性能研究

Study on Adsorption Characteristic of Thorium(VI) by Insolubilized Humic

摘要:

通过批试验研究了不溶性腐殖酸（Insoluble Humic Acid，IHA）对钍的吸附行为及吸附剂投加量、时间、pH、初始浓度、温度等试验条件对Th(IV)吸附的影响，分析了其动力学、吸附等温线和热力学过程，利用扫描电镜（Scanning Electron Microseope，SEM）和红外光谱（Fourier Transform Infra-Red Spectroscopy，FTIR）手段分析了相关吸附机理。试验结果表明：30.0 ?C下，1.00 g/L的IHA在pH为3.50大约6.00 可以对50 mg /L的Th(IV)的去除率达到78.6%；IHA 对Th(IV)的吸附是自发的吸热反应，符合Freundlich 等温吸附方程，曲线拟合的相关系数R2均达0.900以上；吸附动力学过程符合准二级吸附速率方程，相关系数R2为0.990；IHA吸附Th(IV)后表面形态发生了变化，与Th(IV)相互作用的基团主要是羧基和酚羟基，综合看来，IHA吸附Th(VI)的机理表现为离子交换界面配合。

Abstract:

Batch experiments were performed to study the dependence of Th(IV) absorption by insoluble humic acid (IHA) on IHA dosage, reaction time, pH、initial concentration and temperature etc. Absorption kinetics, Isotherms and thermodynamics were investigated. Absorption mechanics were also analysed with the help of Scanning Electron Microscope (SEM) and Fourier Transform Infra-Red Spectroscopy (FTIR). The experimental results of the maximum removal rate can be made to increase by 78.6% at an initial concentration of 50 mg/L，the pH value of 3.50 and in an adsorbent dose of 1. 00 g/L at 30.0 ?C till the equilibrium state is expected to arrive in approximately 6.00 hours. thermodynamic analysis suggests this reaction is endothermic and satisfies Freundlich Isotherms according to >0.900 correlation coefficient R2. Absorption kinetics agrees with pseudo-second-order kinetic plot, with R2=0.995. After carboxyl and phenolic hydroxyl reacted with Th(IV), IHA had a modified surface. From above, Th(IV) absorption by IHA can be considered as surface complex.