Ingenieurwissenschaften und zugeordnete Tätigkeiten
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Erscheinungsjahr
- 2020 (2) (entfernen)
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- Englisch (2)
Referierte Publikation
- ja (2) (entfernen)
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- XANES (2)
- Cyclic Voltammetry (1)
- Electrochemistry (1)
- Iron (1)
- Iron reducing bacteria (1)
- Microbiological Corrosion (1)
- Microbiologically influenced corrosion (1)
- Stainless Steel (1)
Organisationseinheit der BAM
This paper reports results from in situ electrochemical X-ray absorption near-edge spectroscopy (XANES) studies of the corrosion processes on model thin iron films in the presence of iron reducing bacteria Shewanella putrefaciens. Here we investigate the electrochemical activity of two cultures grown in the presence and absence of Fe(III) citrate in the culture medium. The XANES spectra and the OCP data of the Fe sample incubated with the culture grown in absence of Fe(III) did not show any significant changes during twenty hours of monitoring. In the case of the culture grown in Fe(III) containing medium, an accelerated dissolution of the iron film was observed together with the formation of a mixed Fe(II)-Fe(III) hydroxide surface layer. The open circuit potential (OCP) steadily approached the free corrosion potential of iron in neutral chloride containing electrolytes, indicating a continuous dissolution process without passivation.
The effect of the presence of Fe(III) during the cultivation on the electrochemical activity and corrosion behaviour of dissimilatory iron reducing bacteria Shewanella putrefaciens was studied by means of ex situ and in situ X-ray absorption near-edge spectroscopy (XANES). Stainless steel AISI 304 and thin iron films were studied as substrates. XANES analysis indicated an accelerated iron dissolution and growth of an oxide/hydroxide film for the culture grown with Fe(III) in comparison to the culture grown in absence of Fe(III). Electrochemical Analysis indicated that the biofilm resulted in acceleration of the general corrosion but provides protection against local corrosion.