ABSTRACT
Microbial lms (hydrated layers of microorganisms and their extracellular products) develop in practically all natural and engineered aqueous systems. Often they are unwanted and, in such cases, the formation of bio lms is called biofouling. Biofouling is an operational de nition, referring to that amount of bio lm development that interferes with technical, aesthetic, or economical requirements. From the economic and environmental point of view, two of the most important examples of industrial biofouling occur in heat exchangers and membrane systems.
