In situ detection and characterization of biofilm in waters by electrochemical methods

Biofilm is considered with respect to mass transport as an inert porous lay er. The biofilm is developed in fresh water and in natural seawater on a di sk electrode in gold. Its thickness is determined by considering the limiti ng diffusion current measured on this electrode for different rotation spee ds. The same thickness is obtained when two different electrochemical trace rs are used: Fe(CN)(6)(3-) and oxygen which validates the technique and per mits the use of oxygen naturally present in natural water as an electrochem ical tracer. The dependence of the thickness on the rotation speed of the e lectrode shows the elastic behavior of the biofilm. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.