Modeling water flux and salt rejection of mesoporous gamma-alumina and microporous organosilica membranes

作者：Farsi Ali; Boffa Vittorio; Qureshi Hammad F; Nijmeijer Arian; Winnubst Louis; Christensen Morten Lykkegaard^*

来源：Journal of Membrane Science, 2014, 470: 307-315.

DOI：10.1016/j.memsci.2014.07.038

• Inorganic membrane
• Nanofiltration
• Electroviscous effect
• Transport phenomena

The water and ion transport through a mesoporous gamma-alumina membrane and a microporous organosilica membrane was simulated using the extended Nernst-Planck equation combined with models for Donnan, steric and dielectric interfacial exclusion mechanisms. Due to the surface charge within the pore, the electroviscous effect was introduced in the model. The modified model fits well the rejection and permeability data for both membranes. The organosilica membrane shows a higher selectivity compared to the gamma-alumina membrane, but the permeate flux is lower. At low ionic strength the electroviscous effect lowers the water flux through the gamma-alumina membrane. The electroviscous effect is negligible for the organosilica membrane because its absolute surface potential (similar to 20 mV) is low compared to the gamma-alumina membrane (similar to 60 mV). The simulation shows that the electroviscous effect should be included for the membranes with high surface potential ( %26gt; 20 mV) and a pore size below 2-5 times of the electroviscous double layer thickness.

• 出版日期2014-11-15