Roles of Dynamic Metal Speciation and Membrane Permeability in Metal Flux through Lipophilic Membranes: General Theory and Experimental Validation with Nonlabile Complexes

Article Article scientifique Article Roles of Dynamic Metal Speciation and Membrane Permeability in Metal Flux through Lipophilic Membranes: General Theory and Experimental Validation with Nonlabile Complexes eng 2007-03-29 2007-04-24 author Zhang Zeshi 531669 author Buffle Jacques 24673 author Van Leeuwen Hermanus Paulus 133633 5216-5226 10.1021/la063568f 17391055 0743-7463 The study of the role of dynamic metal speciation in lipophilic membrane permeability in aqueous solution requires accurate interpretation of experimental data. To meet this goal, a general theory is derived for describing 1:1 metal complex flux, under steady-state and ligand excess conditions, through a permeation liquid membrane (PLM). The theory is applicable to fluxes through any lipophilic membrane. From this theory, fluxes in the three rate-limiting conditions for metal transport are readily derived, corresponding, namely, to (i) diffusion in the source solution, (ii) diffusion in the membrane, and (iii) the chemical kinetics of formation/dissociation of the metal complex in the interfacial reaction layer. The theory enables discussion of the reaction layer concept in a more general frame and also provides unambiguous criteria for the definition of an inert metal complex. The theoretical flux equations for fully labile complexes were validated in a previous paper. The general theory for semi- or nonlabile complexes is validated here by studying the flux of Pb(II) through PLMs in contact with solutions of Pb(II)-NTA and Pb(II)-TMDTA at different pHs and flow rates. Hydrogen-Ion Concentration Kinetics Lead / chemistry Ligands Lipids / chemistry Membranes, Artificial Models, Chemical Nitrilotriacetic Acid / chemistry Permeability Solutions / chemistry Surface Properties Water / chemistry Dewey 540 40 Département de chimie minérale, analytique et appliquée 145 false Langmuir 23 9 2257e6b6-160d-4698-a056-47f9af006e61 Article (Published version) Restricted la063568f.pdf 226380 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie minérale, analytique et appliquée

Title	Published in	Year	Views	Downloads

Dynamic metal speciation in natural waters : theory, experimental validation and flux computations		2008	1,121	601
Roles of Dynamic Metal Speciation and Membrane Permeability in Metal Flux through Lipophilic Membranes: General Theory and Experimental Validation with Nonlabile Complexes	Langmuir	2007	132	0

Archive ouverte UNIGE

Zhang, Zeshi