Analysis of surrogate bacterial cell transport to nanofiltration membranes: Effect of salt concentration and hydrodynamics

Abstract

Biofouling is a significant operational impediment in pressure-driven membrane processes. The early stage of biofouling involves bacterial adhesion at the membrane-liquid interface where the physical and chemical conditions are very complex. This study employed a sophisticated model of bacterial adhesion and was combined with a computational fluid dynamics (CFD) model to investigate the role of concentration polarisation and hydrodynamics on adhesion processes in membrane fouling simulators (MFS). The CFD model calculated the mass transfer phenomena in the membrane channel incorporating the concentration polarization effect using an algorithm that improves on previous research. The model was validated experimentally using a cross-flow system, under well-defined conditions with polystyrene microbeads as surrogate bacterial cells. The model was effective in predicting the microbead deposition pattern and explaining the decline of permeate flux along the channel and the microbeads deposition pattern.