Simulation of membrane fouling considering mixed liquor viscosity and variation of shear stress on membrane surface

摘要

Simulation of membrane fouling in MBR was conducted considering accumulation, detachmentnand consolidation of extracellular polymeric substances accumulated on membrane surface.nThe fluctuation of shear stress working on membrane surface and the influence of the viscosity ofnmixed liquor were considered for the evaluation of shear stress. A flat-sheet-type membranenmodule was used and the change of trans-membrane pressure was measured in a laboratoryscalenMBR reactor. Shear stress working on membrane surface caused by aeration was measurednby a shear force sensor changing viscosity of bulk liquid. Effective shear stress on membranensurface was defined in the model as the sum of time-averaged shear stress and three times ofnstandard deviation. The increase in the trans-membrane pressure was accurately simulated by thendeveloped model suggesting validity of the developed fouling model and the idea of the effectivenshear stress on membrane surface.