• Sukhraj Punar
• Jagdish Ram
• Monica Chamoli
• Manisha Choudhary
• Raaz K Maheshwari

This review discusses the state-of-the-art of research into biocorrosion and the biofouling of metals and alloys of industrial usage and finishes with suggestions on what needs to be done to further our understanding of MIC (Microbiologically influenced corrosion) which is a major concern in a wide range of industries, with claims that it contributes 20% of the total annual corrosion cost. The focus of this present work is to review critically the most recent proposals for MIC mechanisms, with particular emphasis on whether or not these make sense in terms of their electrochemistry. It is determined that, despite the long history of investigating MIC, we are still a long way from really understanding its fundamental mechanisms, especially in relation to non-sulphate reducing bacterial (SRB) anaerobes. Nevertheless, we do know that both the cathodic polarization theory and direct electron transfer from the metal into the cell are incorrect. Electrically conducting pili also do not appear to play a role in direct electron transfer, although these could still play a role in aiding the mass transport of redox mediators. However, it is not clear if the microorganisms are just altering the local chemistry or if they are participating directly in the electrochemical corrosion process, albeit via the generation of redox mediators. The key concepts needed to understand the main effects of microorganisms on metal decay, and current trends in monitoring and control strategies to mitigate the deleterious effects of biocorrosion and biofouling are also described. Several relevant cases of biocorrosion studied by our research group are provided as examples: (i) biocorrosion of aluminum and its alloys by fungal contaminants of jet fuels; (ii) sulfate-reducing bacteria (SRB)-induced corrosion of steel; (iii) biocorrosion and biofouling interactions in the marine environment; (iv) monitoring strategies for assessing biocorrosion in industrial water systems; (v) microbial inhibition of corrosion; (vi) use and limitations of electrochemical techniques for evaluating biocorrosion effects. Future prospects in the field are described with respect to the potential of innovative techniques in microscopy (environmental scanning electron microscopy, confocal scanning laser microscopy, atomic force microscopy), new spectroscopic techniques for the study of corrosion products and biofilms (energy dispersion X-ray analysis, X-ray photoelectron spectroscopy, electron microprobe analysis) and electrochemistry (electrochemical impedance spectroscopy, electrochemical noise analysis).This manuscript brings into focus the problems posed by microbial infestations in industrial cooling water system and the other water handling equipments along with monitoring, diagnostic procedures, preventive measures and investigation strategies, and role of green corrosion inhibitors.

MIC, CIM, SRB, EPS, Biofilms , Biocides, EFAMCs , TEM, XRD

"A COMPREHENSIVE APPRAISAL OF MICROBIOLOGICALLY INFLUENCED CORROSION: ITS DETECTION, PREVENTION AND ROLE OF GREEN CORROSION INHIBITORS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.9, Issue 4, page no.f489-f524, April-2022, Available :http://www.jetir.org/papers/JETIR2204564.pdf

"A COMPREHENSIVE APPRAISAL OF MICROBIOLOGICALLY INFLUENCED CORROSION: ITS DETECTION, PREVENTION AND ROLE OF GREEN CORROSION INHIBITORS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.9, Issue 4, page no. ppf489-f524, April-2022, Available at : http://www.jetir.org/papers/JETIR2204564.pdf