Micro-patterning of membrane surface for the control of oil droplets attachment

Abstract

The limitation of conventional water resources urges the importance of paradigm shift to include unconventional water resources such as the reuse of oily wastewater in the water management strategies. However, the deformation and subsequent coalescence of oil droplets have been the most critical factors that increase the oil attachment on the membrane surface during the treatment of oily wastewaters. In this study, a direct observation technique was done to investigate the attachment of oil droplets on the membrane surface at various crossflow velocity (CFV). In order to explain the experimental data, the study is completed with a computational fluid dynamics (CFD) simulation that was used to simulate the change of flow trajectories and local flow behavior at the membrane surface. Subsequently, it is found that by generating more turbulence, oil fouling on the membrane surface can be minimized. In order to control the oil fouling, this study analyzed a micro-patterned modifications impact to the membrane performance. It is found that the geometry modification could increase the turbulence inside the membrane vicinity and the pattern’s valley, hence prevent the oil droplets attachment. To enhance the modification impact to reduce oil attachments, this study combined the topography modification with a surface coating. The combination could significantly enhance the anti-fouling effect of the membrane.