Dynamics of Biofilm Processes

Biofilm accumulation on a surface is the net result of several physical, chemical, and biological processes. The objective of this study was to determine the effect of substrate loading and fluid velocity on the processes associated with biofilm accumulation. An annular reactor was used as the experimental system. Nutrients and glucose were added to the reactor to provide the necessary mineral, energy, and carbon requirements for microbial growth. Material balance relationships were developed that are useful in analyzing the interrelated processes contributing to biofilm accumulation. Rate expressions, which are a function of reactor substrate concentration and biofilm mass, are presented for the rates of glucose removal, biofilm accumulation, and biofilm detachment. The increase in fluid frictional resistance caused by biofilm accumulation was investigated and is discussed in the context of the energy losses that resulted.