摘要
采用2-乙基己基膦酸-2-乙基己基单酯(PC-88A)-CHCl3大块液膜体系,研究了搅拌速度、载体浓度、反应体系温度对Pb离子迁移的影响,原子吸收光谱法测定料液相和解析相中Pb离子浓度,获得了不同反应温度下的表观反应速率常数、Pb离子在膜相中的最大值以及出现最大值的时间、Pb离子在萃取与反萃取反应中进入和流出液膜的最大通量、萃取与反萃取表观反应活化能分别为31.65和23.11 kJ.mol-1。结果表明,实验值与理论值能够很好地吻合,Pb离子的迁移过程可以用两个串联的准一级不可逆过程描述,化学反应为控速步骤。
The effects of stirring speed, carrier concentration and reaction temperature on the transport of Pb（Ⅱ） ion through bulk liquid membrane were studied with chloroform as membrane solvent and 2-ethylhexyl phosphonic acid-mono-2-ethylhexy-lester as carrier. The Pb（Ⅱ ） ions concentrations of feed phase and stripping phase were assayed by atomic absorption spectroscopy. The kinetic parameters, including apparent rate constants of Pb（Ⅱ） ion extraction and re-extraction reactions, the maximum concentration of Pb（Ⅱ） ion in the liquid membrane, the time of the maximum value of maximum concentration of Pb（ Ⅱ ） ion in the liquid membrane and the maximum entry and exit fluxes of Pb（ Ⅱ ） ion through the liquid membrane of the extraction and stripping reactions, were evaluated. The apparent activation energy value is 31.65 kJ·mol^-1 for extraction and 23.11 kJ·mol^-1 for stripping. The results indicate that good agreement between experimental data and theoretical predictions could be achieved and the kinetics of Pb（ Ⅱ） transport could be evaluated by two consecutive irreversible pseudo-first order reactions. In this condition the chemical reaction is a procedure of controlled reaction rates.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2009年第7期1967-1971,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(50779055)
陕西省科技计划项目(2008K08-09)资助
