Laboratory studies of biocorrosion control using traditional and environmentally friendly biocides: an overview

Metal surfaces immersed in natural or industrial waters undergo a sequence of biological and inorganic changes that may result in biocorrosion due to the formation of a biofilm. Microbial adherence to metallic surfaces affects different industrial systems, such us cooling water systems, off shore oil industry, thermal power stations, hydroelectric, chemical and process industry, etc. The chemical agents generally used to prevent or protect metallic structures from biocorrosion are highly toxic and, after use, can have a negative impact on the environment. Environmental concerns have led to legislation which encourages the replacement of toxic biocides, widely used in the past (e.g. chlorine) with more readily degradable antimicrobial chemicals that are compatible with system operation and less toxic to the environment. One innovative attempt to accomplish this goal is the use of naturally-produced compounds, such as plant extract that are environmentally acceptable. The aim of this paper is to give an overview of different laboratory studies which used both traditional and environmentally friendly biocides against planktonic bacteria and sessile bacteria on different metal surfaces.