Investigation of Biogenic Passivating Layers on Corroded Iron

Abstract

This study evaluates mechanisms of biogenic mineral formation induced by bacterial iron reduction for the stabilization of corroded iron. As an example, the Desulfitobacterium hafniense strain TCE1 was employed to treat corroded coupons presenting urban natural atmospheric corrosion, and spectroscopic investigations were performed on the samples’ cross-sections to evaluate the corrosion stratigraphy. The treated samples presented a protective continuous layer of iron phosphates (vivianite Fe2+3(PO4)2·8H2O and barbosalite Fe2+Fe3+2(PO4)2(OH)2), which covered 92% of the surface and was associated with a decrease in the thickness of the original corrosion layer. The results allow us to better understand the conversion of reactive corrosion products into stable biogenic minerals, as well as to identify important criteria for the design of a green alternative treatment for the stabilization of corroded iron.

Biocleaning of historical metal artworks: innovative green gels amended with microbial derivatives

“…To this purpose, previous studies demonstrated the efficacy and reliability of microorganisms exploited in conservation treatments (Junier and Joseph, 2017). Studies aiming to achieve stabilization of iron and copper archaeological artefacts using biomineralization revealed the additional potential of the selected microorganisms to remove undesired corrosion, achieving the so-called "bio-cleaning" of the metallic substrates (Comensoli et al, 2019). Nevertheless, the use of living organisms is tricky to be implemented in everyday CRs praxis, therefore research is also evaluating the use of metabolites that are extracted from microorganisms, such as siderophore chelators (Albelda-Berenguer et al, 2019;Cuvillier et al, 2023).…”

Effect of Magnesium and Ferric Ions on the Biomineralization of Calcium Carbonate Induced by Synechocystis sp. PCC 6803

“…Numerous investigations have been conducted on the ability of bacteria to induce mineral precipitation in both natural environments and controlled laboratory conditions [10][11][12][13][14][15]. Microbial metabolism can convert Ca 2+ ions, Mg 2+ ions, and iron ions (Fe 2+ and Fe 3+ ) in the surrounding environment into carbonate, sulfate, sulfide, oxide, and other forms of minerals [16][17][18][19][20][21][22]. As for Synechocystis sp.…”

Corrosion process assessment using a novel type of coupon installation

“…From the practical point of view, the corrosion test is carried out in artifi cially created conditions which imitate natural conditions. The acceleration of the corrosion processes in comparison with the operating conditions might be established by the changed conditions in the specially designed chambers or appratus 3 . The tests on the laboratory scale are realized using coupons which are placed in the liquids (the industrial liquids or the perpetrated solutions in the laboratory conditions).…”