Evaluation of a biocide effect upon microbiologically influenced corrosion of mild steel

• Published in: Materials and corrosion Vol. 56; no. 9; pp. 624 - 629
• Main Authors: Hernández Gayosso, M. J., Zavala Olivares, G., Ruiz Ordaz, N., García Esquivel, R.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.09.2005; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Applied sciences; biocide; biofilm; Corrosion; Corrosion environments; Corrosion mechanisms; EIS; electrochemical techniques; Exact sciences and technology; Metals. Metallurgy; Microbiologically influenced corrosion; Bacterial corrosion; Biocide; Carbon steel
• ISSN: 0947-5117; 1521-4176
• DOI: 10.1002/maco.200503867

The microbiologically influenced corrosion (MIC) is a very dangerous process, which affects the oil industry. The activity and microorganisms' growth at the pipelines steel cause surface modifications, which can induce a more complex corrosion process. The biocide evaluation for the MIC decrease has been normally based upon microbiological tests, and just a few references mention alternating methods which can be used as criteria for their evaluation. In this work, a commercial biocide was tested, using different electrochemical laboratory techniques, to determine its effect upon a biofilm generating bacteria consortium. Using microbiological techniques, the biocide lethal concentration was determined, and a concentration of 200 ppm was used to kill completely the consortium population in both, plancktonic and sessile parts. The electrochemical techniques: Polarisation Resistance (PR) and Electrochemical Impedance Spectroscopy (EIS), allowed describing the corrosion process associated to the microbial consortium and the biocide effect upon it.