Micro‐scale modelling of substrate removal kinetics in multicomponent fixed‐film systems

Modelling of fixed‐film reactors, as for suspended growth systems has to account for all the major components and biochemical processes responsible for the removal of substrate. Traditionally fixed‐film reactors are viewed as two‐component (substrate/biomass) systems interacting with the governing effect of molecular diffusion. Recent developments however have shown the importance of viability and product formation in the modelling of biological systems. This paper emphasizes these two new parameters and evaluates the kinetic relationships between the bulk substrate concentration and biofilm composition as it affects substrate removal and residual product formation.