Portulaca oleracea as a Green Dual-Action Biocide and Corrosion Inhibitor Against Thiosulfate-Reducing Bacterial Biofilms on Carbon Steel

Microbially influenced corrosion poses a significant threat to the integrity and longevity of carbon steel infrastructure, particularly in environments conducive to biofilm formation by thiosulfate-reducing bacteria (TRB) to carbon steel. This study explores the potential of Portulaca oleracea, an edible plant species, as a dual-action biocide and green corrosion inhibitor for mitigating MIC adhesion. Through a comprehensive suite of experimental and analytical techniques, including electrochemical analysis, microbial analysis, gravimetric methods, and surface characterization, the efficacy of Portulaca oleracea extract is evaluated for its ability to inhibit TRB growth and biofilm formation while concurrently providing corrosion protection to carbon steel substrates. The electrochemical analyses reveal the extract’s capacity with the anodic reaction inhibition achieving 80%, thereby reducing the overall corrosion rate of carbon steel in the presence of TRB biofilms. Complementary microbial analyses, such as viable cell counting using test kits, elucidate the biocidal action of the extract, effectively suppressing TRB growth and biofilm development, with the presence of 20 ppm of the extract reducing bacterial growth. Surface characterization techniques provide insights into the adsorption behavior of the extract’s constituents on the carbon steel surface, forming a protective film that mitigates corrosion and biofilm adhesion. The adsorption of the extract at the interface between mild steel and the formation water adheres to Langmuir isotherm. Overall, the biocorrosion issue we are addressing in this work is crucial for ensuring the sustainability and efficiency of equipment, pipelines, and other metal-based systems.