Chapter 2 - Fluid Flow, Mass and Heat Transfer

Abstract

This chapter provides an understanding of the underlying principles of fluid flow, the associated mass transfer, and heat transfer, which can help recognize the factors that contribute to the complexity of the formation of biofilms. In general, the occurrence of biofilms in industrial equipment arises from a microbial-laden fluid, usually water, flowing across a surface. The accumulation of unwanted living matter on a surface, i.e., biofouling, involves the colonization of the surface by organisms transferred from the water flow to the surface by the process of mass transfer. In biofouling, this involves both the concentration differences of microorganisms and nutrients between the bulk water flow and the receptive surface. Mass transfer provides the means by which the waste products from the microbial activity are removed from the region of the biofilm into the main bulk of the flowing water, thereby assisting further biofilm development. Since the prevailing temperature also influences microbial populations the extent of a biofilm is dependent on the temperature of the transporting fluid (usually water). The amount of resident biofilm depends on the magnitude of the competing deposition and removal forces. Ultimately, the colonization and growth of living material on a surface in industrial equipment is greatly influenced by the fluid flow and mass transfer pertaining to the system. Finally, this chapter sheds light on how these problems may be overcome.