Formation of vivianite during microbiologically influenced corrosion of steels

Exposure of carbon and HY-80 high strength low alloy (HSLA) steels to anaerobic Postgate cultures containing sulfate reducing bacteria leads to production of mackinawite, Fe9S8 and vivianite, Fe3(PO4)2·8H2O, with minor amounts of other minerals, the vivianite being sometimes accompanied by siderite, FeCO3. The vivianite and mackinawite persist on exposure to air or oxygenated water. Green rust is a significant alteration product on some steels. The implications of these findings are discussed in light of present and possible future nuclear waste containers