Crystals (Mar 2024)

Effect of Sulphate-Reducing Bacteria Activity on the Performance of Thermally Sprayed Aluminium and Polyurethane Coatings

  • Iñigo Santos-Pereda,
  • Virginia Madina,
  • Elena Rodriguez,
  • Jean-Baptiste Jorcin,
  • Esther Acha

DOI
https://doi.org/10.3390/cryst14030260
Journal volume & issue
Vol. 14, no. 3
p. 260

Abstract

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In the present work, we studied whether the exposure of synthetic seawater with anaerobic sulphate-reducing bacteria (SRB) on some steel samples generates a bacterial biofilm in their surfaces. Bare steel belonging to a mooring chain as well as two coating systems applied on the steel surface were studied: polyurethane (PU) and thermally sprayed aluminium (TSA) with and without an epoxy-based sealant. After 30 days of immersion in SRB-inoculated synthetic seawater, a bacterial count was attained, and the samples were observed using scanning electron microscopy (SEM) and locally analysed using X-ray scattered energy spectroscopy (EDS). A biofilm developed on every tested surface (continuous or in the form of pustules), with evidence of metabolic activity of the SRB. Finally, a mechanism of degradation for TSA in the presence of SRB is proposed for environments with a high concentration of bacteria.

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