*Corresponding Biocidal Effects of Ozone, Sodium Hypochlorite and Formaldehyde, on Sulphate Reducing Bacteria Isolated from Biofilms of Corroded Oil Pipelines in the Niger Delta, Nigeria

Abstract

The performance of three biocides (ozone, sodium hypochlorite and formaldehyde) on Sulphate reducing bacteria was tested. The Sulphate reducing bacteria were isolated from biofilms of corroded oil pipelines under normal flow condition. The study was aimed at controlling these bacteria using the three biocides at different concentrations (0, 1, 2, 3, 4 and 5 percent) in order to reduce the economic losses normally encountered in the oil and gas industry due to the activities of Sulphate reducing bacteria. The results showed that ozone was effective from 1% concentration by completely eliminating Desulfuromonas acetoxidans, Desulfobulbus propionicus and Desulfosarcina variabilis followed by sodium hypochlorite and then formaldehyde being the least effective. For proper monitoring and control of microbiologically influenced corrosion caused by sulphate reducing bacteria, Ozone and one of the non-oxidizing biocides such as formaldehyde should be used