5. Biofouling

5.1 Origin of biofilm

Water, whatever its origin, or the air that makes up our environment, is rich in bacteria, viruses, fungi, algae, protozoa, ciliates and more. Cooling systems provide ideal conditions for their growth due to :

• the temperature range in which the water in a cooling circuit operates (between 20 and 40°C);

• pH ;

• ventilation conditions.

Organic or mineral nutrients present in make-up water, brought in by process leakage or air, constitute the carbon source that biological species need to ensure their growth. This growth takes the form of their development as free plankton in the water or as sessile organisms attached...