Corrosion of Iron by Iodide-Oxidizing Bacteria Isolated from Brine in an Iodine Production Facility

Abstract

Elemental iodine is produced in Japan from underground brine (fossil salt water). Carbon steel pipes in an iodine production facility at Chiba, Japan, for brine conveyance were found to corrode more rapidly than those in other facilities. The corroding activity of iodide-containing brine from the facility was examined by immersing carbon steel coupons in "native" and "filter-sterilized" brine samples. The dissolution of iron from the coupons immersed in native brine was threefold to fourfold higher than that in the filter-sterilized brine. Denaturing gradient gel electrophoresis analyses revealed that iodide-oxidizing bacteria (IOBs) were predominant in the coupon-containing native brine samples. IOBs were also detected in a corrosion deposit on the inner surface of a corroded pipe. These results strongly suggested the involvement of IOBs in the corrosion of the carbon steel pipes. Of the six bacterial strains isolated from a brine sample, four were capable of oxidizing iodide ion (I(-)) into molecular iodine (I(2)), and these strains were further phylogenetically classified into two groups. The iron-corroding activity of each of the isolates from the two groups was examined. Both strains corroded iron in the presence of potassium iodide in a concentration-dependent manner. This is the first report providing direct evidence that IOBs are involved in iron corrosion. Further, possible mechanisms by which IOBs corrode iron are discussed.

Corrosion behavior of carbon steel in the presence of sulfate reducing bacteria and iron oxidizing bacteria cultured in oilfield produced water

“…IOB are known to enhance the corrosion of carbon steel aerobically [12,39]. However, the O 2 supply in each vial is limited, and the initial DO is only 4.2 mg/L, close to the DO in the oilfield produced water with about 1-3 mg/L.…”

Microbial extracellular electron transfer and its relevance to iron corrosion

“…In this case, oxidized forms of manganese [Mn(III/IV)] consume cathodic electrons in metallic iron and is reduced to Mn(II), which is oxidized back to Mn(III/IV) by manganese‐oxidizing bacteria. Iodide‐oxidizing bacteria isolated from brine in an iodide production facility stimulate iron corrosion in a similar manner with redox coupling of I − /I 2 (Wakai et al ., ).…”

Conceptual Model of Iodine Behavior in the Subsurface at the Hanford Site

“…Two environments in which iodide-oxidizing bacteria have been found include natural gas brines and marine environments (Amachi et al 2005b, Arakawa et al 2012, Žic et al 2008). Iodine-oxidizing bacteria have also been isolated from corroding pipes at an iodine production facility in China (Wakai et al 2014). Roseovarius tolerans is an iodide-oxidizing bacterium that was isolated from natural gas brines, where populations of iodide-oxidizing bacteria were up to 10 5 colony forming units per milliliter of water (Amachi et al 2005b).…”