In this thesis, a rigorous theory of steady-state metal flux with one metal complex under both planar and spherical diffusions and ligand in-excess condition was firslty proposed. It was validated experimentally with Permeation Liquid Membrane (PLM) and metal complexes with different labilities. Dynamic parameter values have been compiled and theoretical approaches have been proposed to compute the missing parameter values. Dynamic metal speciation and metal fluxes of different metals to a planar perfect sink have been computed under typical natural freshwater conditions. The above results were compared to throse under the spherical diffusion and the same conditions.