Corrosion and biofouling tendency of carbon steel in anoxic groundwater containing sulphate reducing bacteria and methanogenic archaea

Pauliina Rajala^a,b, Elina Huttunen-Saarivirta^c, Malin Bomberg^d, Leena Carpén^a

VTT Technical Research Centre of Finland Ltd., Materials Performance, Kemistintie 3, FI-02044, VTT, Finland.

Abstract

The corrosion of carbon steel in groundwater with or without of sulphate reducing bacteria (SRB) and/or methanogenic archaea (MA) was examined in a 12-month experiment simulating a geological underground repository for nuclear waste. In the abiotic environment, cumulative corrosion rate was lowest among the studied systems, 1 μm/a. In biotic environments, the cumulative corrosion varied between 5 μm/a and 10 μm/a, being highest in SRB enriched system and lowest in SRB + MA system. However, localised corrosion was more intensive in all biotic systems. Microbial community differed between environments from betaproteobacterial taxa dominated (SRB) to Desulfovibrionales and Methanobacteriales rich in SRB + MA/MA.

Keywords: A. Carbon steel, B. EIS, SEM, Weight loss, XRD, C. Microbiological corrosion.