Cellular-automata and individual-based approaches for the modeling of biofilm structures: Pros and cons

Fresh water shortage is one of the greatest problems of modern society; as a result, water desalination, particularly with membrane processes, is becoming increasingly important, since it makes possible the use of brackish water for potable water, or the reuse of lower-quality water for industrial, irrigation, or other uses. Membrane processes used in water desalination and wastewater treatment are often affected by the degradation of biofouling, in which biofilms play a critical role, thus making biofilm simulation models very relevant. Biofilms are highly complex and heterogeneous systems, containing cells distributed in a non-uniform manner in polymers. Two classes of models, the cellular-automata and the individual-based models, which are used to simulate the growth and development of biofilm structures as a result of microbial growth in different environmental conditions, are presented. After a short review of models presented in the last decade, we identify similarities and differences and present the environmental conditions that can be best simulated with each model type.