Resumen

FERNANDEZ DE ROMERO, Matilde. Mechanisms proposal of action of the SRB in means loaded with ferrous ions. Rev. Téc. Ing. Univ. Zulia [online]. 2007, vol.30, n.Especial, pp.157-167. ISSN 0254-0770.

Different studies have been made using conventional electrochemical polarization techniques to establish the mechanism for the action of sulfate reducing bacteria (SRB) in microbiologically influenced corrosion (MIC). Nevertheless, there has been almost no detailed follow-up correlating the corrosive process with time and open circuit potential, corrosion products, sessile bacterial growth and morphological attack, to establish the mechanism of this bacterial action. This research project designed an experimental structure to make these correlations utilizing the hydrogen permeation technique as its principal electrochemical tool to follow the cathodic reaction, coupled with any other electrochemical, microbiological or chemical technique that would permit following the anodic reaction. The study began by reviewing the classic cathodic depolarization theory using an SRB strain identified as Desulfovibrio desulfuricans subespecie desulfuricans ATCC 7775 and an inert palladium sheet as a substrate with and without cathodic polarization. Later, corrodible sheets of carbon steel and iron were used to study the corrosive process, which permitted to establish the mechanism of this SRB on carbon steel when the medium has a high contamination of ferrous ions.

Palabras clave : MIC mechanism by SRB; Desulfovibrio desulfuricans; sessile growth; hydrogen permeation; morphological attack and corrosion products.