Mathematical sigmoid-model approach for the determination of limiting and over-limiting current density values

作者：Doyen Alain^*; Roblet Cyril; L'Archeveque Gaudet Adam; Bazinet Laurent

来源：Journal of Membrane Science, 2014, 452: 453-459.

DOI：10.1016/j.memsci.2013.10.069

• Limiting current density determinations
• Sigmoidal curve
• Potential difference
• Ion-exchange membrane
• Ultrafiltration membrane

The effect of successive limiting current density (LCD) determination procedures on electrodialysis with ultrafiltration membrane (EDUF) system was studied in order to evaluate their impact on ion-exchange (IEM) and ultrafiltration membranes (UFM) integrity by measuring in situ the membrane potential difference. In the first protocol, two successive LCD determination procedures were carried-out by increasing the voltage by 2 V from 0 to 40 V, spaced by a rest period of 60 min. In the second protocol, the LCD determination procedures were performed every 20 min during 60 min. For both protocols, voltage-current curves were plotted for IEM and UFM and I-lim values were determined. Results showed that only anion-exchange membrane (AEM) showed a typical sigmoidal curve for both protocols. Moreover, it was demonstrated that a rest time period of 60 min between two successive LCD determination procedures had no impact on system current density and membrane potential difference while four successive LCD determinations spaced by a constant rest period of 20 min allowed delaying the appearance of I-lim and over-limiting current region. A mathematical sigmoid-model approach was also proposed allowing for the first time the calculation of the different parameters typical of water splitting phenomenon from a voltage-current curve.

• 出版日期2014-2-15