Abstract

Effects of van der Waals surface energy (γ ^LW ) on interfacial interactions in a submerged membrane bioreactor (MBR) were investigated by a series methods based on the extended Derjaguin- Landau-Verwey-Overbeek (XDLVO) theory in this study. Interfacial interactions in three different interaction scenarios, including two infinite planar system, particle-smooth surface membrane system, and particle-rough surface membrane system, were systematically assessed. The calculation results implicated that γ ^LW played a significant role in the interfacial interactions in all three interaction scenarios. There exists an energy barrier in the process of foulant particles’ adhesion on membrane surface. It was found that the energy barrier would disappear when a criticalγ ^LW was reached. Low γ ^LW would increase the energy barrier, and then benefit membrane fouling mitigation. Rough surface would significantly reduce interfacial interaction strength.

Keywords: Membrane bioreactor, membrane fouling, van der Waals surface energy, interfacial interactions.