Rheology of Activated Sludge in Membrane Bioreactors

摘要

Activated sludge samples of nine different membrane bioreactors were investigated to examine their rheological behavior. All sludge samples showed strongly pseudoplastic behavior. Apparent viscosity increased up to factor 100 with decreasing shear rates. MLSS concentration was found to be a major parameter influencing apparent viscosity. Further influences could be EPS concentration and mechanical stress prior to measurement. Experimental data were interpreted using two different mathematical approaches. Based on the Ostwald equation, an empirical approach for estimating apparent viscosity as a function of MLSS concentration is given.