Abstract

A semi empirical model was developed to characterize the transport of cupric ions within the Nernst layer generated between electrolyte bulk and the membrane surface in an electrodialysis cell. The model was derived from fundamental equations and was reduced to a linear expression incorporating the cupric ion transport number in the Nernst layer (tBL+) and in the membrane (tM+). The model critical condition is tBL+ < 0.5 tM+. The model correctly fits the experimental data when tBL+ is 0.02. The model was validated with experimental results previously published by the authors and it accounts for a linear concentration gradient within the Nernst layer.