title: Validation of computational non-Newtonian fluid model for membrane bioreactor.
abstract: Membrane bioreactor (MBR) systems are often considered as the wastewater treatment method of the future due to their high effluent quality. One of the main problems with such systems is a relative large energy consumption, compared to conventional activated sludge (CAS) systems, which has led to further research in this specific area. A powerful tool for optimizing MBR-systems is computational fluid dynamics (CFD) modelling, which gives researchers the ability to describe the flow in the systems. A parameter which is often neglected in such models is the non-Newtonian properties of active sludge, which is of great importance for MBR systems since they operate at sludge concentrations up to a factor of 10 compared to CAS systems, resulting in strongly shear thinning liquids. A CFD-model is validated against measurements conducted in a system with rotating cross-flow membranes submerged in non-Newtonian liquids, where tangential velocities are measured with a Laser Doppler Anemometer (LDA). The CFD model is found to be capable of modelling the correct velocities in a range of setups, making CFD models a powerful tool for optimization of MBR systems.
authors.affiliation: Department of Civil Engineering, Aalborg University, Sofiendalsvej 11, DK-9000, Aalborg, Denmark E-mail: las@civil.aau.dk.
authors.forename: Lasse
authors.initials: L
authors.lastname: Sørensen
authors.affiliation: Department of Civil Engineering, Aalborg University, Sofiendalsvej 11, DK-9000, Aalborg, Denmark E-mail: las@civil.aau.dk.
authors.forename: Thomas Ruby
authors.initials: TR
authors.lastname: Bentzen
authors.affiliation: Aalborg Forsyning Kloak A/S, Stigbords Brygge 5, 9400, Nørresundby.
authors.forename: Kristian
authors.initials: K
authors.lastname: Skov
mesh_terms: D019149:Bioreactors; D004867:Equipment Design; D057446:Hydrodynamics; D008567:Membranes, Artificial; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012722:Sewage; D033081:Shear Strength; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D012722:Sewage