Biofouling in cooling water intake systems: Ecological aspects

Abstract

Industrial cooling water systems employing natural aquatic systems as heat sink are prone to problems caused by the incursion of organisms into the cooling circuit. Surfaces exposed to water (fresh or saline) provide an opportunity for the settlement and growth of sessile organisms. In this chapter, we are concerned with organisms whose adult stages are characterised by macroscopic body size. This kind of biofouling, referred to as macrofouling, generally comprises of a vast diversity of organisms. According to an estimate, about 4,000 biological species are involved in the process of fouling (Marine biodeterioration: an interdisciplinary study. Naval Institute Press, Annapolis, pp. 103-126). Moreover, this number is increasing due to expanding worldwide human activities and industrialisation. However, it is observed that in industrial cooling water systems, only a handful of species dominate the community. Mussels, barnacles, oysters and such calcareous organisms are predominantly seen. These are organisms, which in their adult lives remain permanently attached to solid surfaces. They employ planktonic larvae as propagules for expanding their territorial colonisation. The internal surfaces of cooling water systems in industrial plants generally provide ideal habitats for many such species.