The corrosive power of golden mussel (L. fortunei) macrofouling on steel structuresg.

Abstract

Abstract In this study it was performed a detailed morphological-structural analysis of the corrosion products resulting from golden mussel (Limnoperna fortunei) macrofouling on steel structures. Scanning electron microscopy, without previous metallization of the observed structures, was utilized in the study. With this analysis it was possible to build a new scenario for understanding this corrosion process, as several important facts were observed. Firstly, the presence of at least three types of bacteria able to corrode metals was detected: sulphate reducing bacteria, iron-depositing bacteria, and Fe3+ reducing anaerobic bacteria which produce ferrous hydroxy carbonate from magnetite. The presence and proliferation of colonies of these micro-organisms can be in many ways favored by the dense mussel fouling. Also, the analysis of the cross-sectional structure of the corrosion layer allowed identifying the basic mechanism by which the metal is consumed by the corrosion process.