Repair of damaged vivianite coatings on mild steel using bacteria

Damaged or partly corroded vivianite (Fe-3(PO4)(2). 8H(2)O) coatings on mild steel could be rephosphated in cultures of Pseudomonas putida, required that trace elements were omitted from the cultivation medium. This indicated that siderophores played a role in the reaction. Restoration of the vivianite coating was accompanied by a drop of the surface potential. The corrosion resistance of bacterially repaired steel during three weeks of exposure to a corrosive medium was as good as of bacterially phosphated steel. Weight losses were roughly five times lower than those of unprotected mild steel coupons, Bacterial restoration might be considered for repairing corroded technical installations without disassembly. (C) 2001 Elsevier Science Ltd. All rights reserved.