IMPORTANCE OF MICROBIOLOGY TO COOLING

WATER SYSTEMS

Microorganisms cause fouling

Fouling leads to deposition and scaling

Microorganisms also cause corrosion

Reduced heat transfer and corrosion damage costs big $

1

PRIMARY BIOFOULING

MICROORGANISMS.

Algae

Fungi

Bacteria

3

4

Life forms in Cooling

Water System.

10

0

pH

Typical Range

Extended Range

Optimum Range 2

4

6

8

12

Bacteria Fungi Filamentous Algae

Unicellular Algae

pH range for microorganisms

BIOFILM DEVELOPMENT

Biofilm development:

Adsorption/Absorption of organic molecules on surface.

Transport of microorganisms from the water to the solid surface.

Adhesion of microorganisms at surface-water interface.

Replication of attached cells Production of exo-polymers Detachment of newly formed biofilm by flowing

water.

Repeated process of biofilm formation elsewhere