Products obtained by microbially-induced corrosion of steel in a marine environment: role of green rust two

An unusual low-water corrosion of steel sheet piles has been systematically investigated in a channel harbour (Boulogne sur Mer, France). An analysis of the environment reveals that all sampling of dark rust taken at different heights above marine sediments and kept in anaerobic conditions present unusual concentrations of sulfate-reducing bacteria. The rust products have been characterized by Moessbauer spectroscopy and X-ray diffraction, comprising the ferrous-ferric sulfated compounds of formula 4Fe(OH)2 . 2FeOOH . FeSO4 . nH2O, called green rust 2, mixed sometimes with magnetite and a small amount of ferrous sulfide. (orig.)