Insights on pulsed bubble control of membrane fouling: Effect of bubble size and frequency

摘要: Abstract A three-dimensional Computational Fluid Dynamics (CFD) model was developed to study the shear stress induced by spherical cap bubbles on industrial scale hollow fibres. Simulations and experimental data were compared for water a 0.5 g/L xanthan gum solution that mimicked rheological behaviour of activated sludge. The built pilot-scale membrane tank configured with five 1.5 m long fibre membranes. 58–290 ml sparged into system at frequencies from 0.2 1 Hz. Volume (VOF) method coupled Realizable k–e turbulent used simulate transient rising in Newtonian viscous shear-thinning liquid. CFD prediction root mean square (RMS) pulsed exhibited an inverse relationship observations fouling. At constant flux 25 L/m2/h (LMH), fouling decreased 5.1 3.9 kPa/min as simulated RMS increased 0.04 0.25 Pa. Shear fluctuations, which are considered be beneficial cleaning membranes, less pronounced non-Newtonian fluid water. Increasing pulse bubble size 115 ml 290 ml led 80% increase stress, therefore improved control efficiency.