[Transport kinetics of Pb(II) through bulk liquid membrane using PC-88A as carrier].
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-ethylhexylester 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 x 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.
Yu
Xiao-Jiao
XJ
Department of Applied Chemistry, Xi'an University of Technology, Xi'an 710048, China. yxjw@xaut.edu.cn
Yao
Bing-Hua
BH
Zhou
Xiao-De
XD
Zheng
Huai-Li
HL
Zhang
Jian-Feng
JF