Population balance modelling of flocculation of biological cells

The objective of this work is to model the flocculation process as encountered in many food- and biotechno-logical applications concerning solid-liquid separation. A population balance framework is used to couple the shear induced aggregation and breakage processes. To solve the population balance model efficiently, the model equations were recasted in moment form, and a 9-th order polynomial closure rule to approximate the missing fractal moments was applied as proposed by Som-mer et al. (2006). A parameter study was peformed using parameters for yeast flocculation as found in literature. The simulation results are qualitatively in agreement with experimental findings. Furthermore, we show how this model may be used to increase flocculation efficiency by applying a time-dependent shear rate.