Current Trends and Future Developments on (Bio-) Membranes: "Application of computational fluid dynamics technique in membrane bioreactor systems"

A membrane bioreactor (MBR) is a technology that integrates both a biological reaction process and a separation membrane process. These reactors have been used successfully in biological wastewater treatment for effective solids-liquid separation. Besides various advantages of MBRs such as good sustainability, lower energy, and high efficiency, some common problems such as fouling could be encountered in these reactors, which highlights the requirement of frequent membrane cleaning or replacement. These problems may limit the full-scale application of MBRs and a comprehensive study should be done to solve and minimize these problems. Recently, modern tools such as computational fluid dynamics (CFD) is recommended to diagnose problems and understand the design, hydrodynamics, flow regime, process configurations, simulation of fluid on the membrane surface and pores, modeling mass transfer rate, and further predicting the fouling layer in an MBR besides proper experimental validation. These numerical modeling methods provide invaluable insight into the analysis of complex multiphase flow in municipal-scale MBR. In this chapter MBR design and fundamental aspects are introduced and a comprehensive overview is provided over application of CFD theory and modeling techniques for two or multiphase flows.