A 2D Cellular Automaton Biofilm Detachment Algorithm

A cellular-automaton based two-dimensional biofilm detachment module is developed. The module is an improvement of previously presented methodologies for modeling biofilm detachment under the influence of hydrodynamic forces of the moving fluid in which biofilm develops. It uses biofilm mechanical properties that are variable in time and space and are determined by the percentage of each biofilm solid substance—active biomass, extracellular polymeric substance (EPS) and residual dead biomass—and pores that are contained in each cellular automaton compartment in the biofilm column. A methodology is presented that estimates wall shear stresses applied on the biofilm by the fluid for different hydrodynamic conditions and an association with the biofilm mechanical properties is created to predict its detachment. The module is applied in samples created by the UMCCA model [Laspidou and Rittmann, Water Res 38 (2004), 3362-3372].