Microbiologically influenced corrosion of wastewater pipeline and its mitigation by phytochemicals: Mechanistic evaluation based on spectroscopic, microscopic and theoretical analyses

• Published in: Journal of molecular liquids 2022-10, Vol.364, p.119960, Article 119960
• Main Authors: Jana, Arijit, Sarkar, Tarun K., Chouhan, Ajay, Dasgupta, Diptarka, Khatri, Om P., Ghosh, Debashish
• Format: Article
• Language: English
• Subjects: Bio-interfaces; Corrosion mitigation; Microbiologically influenced corrosion; Phytochemicals; Wastewater pipeline; XPS
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2022.119960

[Display omitted] •Microbiologically Influenced corrosion (MIC) of wastewater pipeline infrastructure is presented.•Plant extracts are demonstrated as sustainable alternatives to mitigate the MIC.•Molecular orbital theory showed excellent affinity of phytochemicals to steel substrate.•Phytochemicals suppressed the biofilm growth and minimized the corrosion of mild steel efficiently. A wastewater pipeline network is an essential infrastructure for social viability and economical sustainability. The corrosion of pipeline infrastructure can lead to leakage/outflow of toxic materials and pollute the environment, including water bodies. Sulfate-reducing bacteria (SRB) are primarily accountable for the corrosion of wastewater pipelines. The present study reveals microbiologically influenced corrosion (MIC) by a newly isolated SRB, i.e., Klebsiella pneumoniae (IIP-C3), from the wastewater pipelines over the mild steel surface. The IIP-C3 formed a bio-film over the mild steel surface. The FeS-based polymorphous materials are produced at bio-interface by reducing inorganic sulfates, which are readily oxidized/hydrolyzed to metal oxide as corrosion products. The methanolic extracts of Capsicum annuum (CA), Zingiber officinale (ZO), and Foeniculum vulgare (FV) are selected based on their antimicrobial activities. The ZO, FV, and CA-based protective coatings showed 91.1%, 77.2%, and 72.7% corrosion mitigation efficiencies for mild steel. The mechanistic interpretation of MIC and its mitigation based on the molecular structure of phytochemicals of plant extracts are further supported by molecular orbital theory. The application of plant extracts suppressed the bio-film growth and minimized the corrosion of mild steel. The present work represents the potential of phytochemicals as alternatives to toxic biocides to mitigate MIC.