Influence of the hydrodynamics on the biofilm formation by mass transport analysis

Biofilm are formed wherever there is some water in our environment: pipes, pipelines, tap water systems, air conditioning systems... Furthermore, the ecological and economical consequences are very important: energy losses, b acterial contamination, material deterioration. The aim of this work is to develop a new method to detect and monitor the biofilm formation. This meth od can also determine some mechanical properties of the biofilm. An applica tion of this method is a realization of a biofilm sensor. Biofilm is considered as an inert porous layer with respect to mass transpo rt. In our experiment, the biofilm is grown on a gold electrode in natural seawater. Its thickness is determined by considering the oxygen diffusion l imiting current measured for different rotation speeds on this electrode. T wo different incubators are used during the biofilm development: one, with a laminar flow, permits the rotation of the electrode during the biofilm fo rmation, and for the second, a tube is used under turbulent conditions duri ng the biofilm formation. This experiment allows us to characterize the mec hanical behavior (thickness, elasticity, rigidity) of the biofilm in functi on of different conditions of development. (C) 2000 Elsevier Science S.A. A ll rights reserved.