What is Biocorrosion?

Introduction

Nature always seeks a steady state. This means that when something is unstable, a phenomenon occurs to work towards a more stable state. This is the case when a shaky house of cards falls on the table for example. Electrochemists are well-informed about this principle, as it is fundamental to understanding corrosion, among other phenomena. Indeed, corrosion is the result of the instability of a metallic material in its environment. Oxidation reactions occur at the interface of the material. Lots of factors are identified as corrosion boosters (material design, pH of the environment, ambient humidity, …).

At a glance: What is corrosion?

Corrosion is the alteration of a metal resulting from the oxidation of the material by its environment.

For more information please refer:

https://www.biologic.net/topics/corrosion-basics-dc-electrochemical-characterization/

https://www.biologic.net/topics/how-to-decode-the-standard-test-methods-for-corrosion/

What is Biocorrosion?

Biocorrosion is a specific type of corrosion that occurs under the influence of microorganisms. Biocorrosion is the junction between two intricate worlds: biology and electrochemistry. All industrial fields are impacted by this type of corrosion. It causes degradations in the mechanical properties of materials, so it needs to be studied and monitored to limit its effects.

At a glance: What is biocorrosion?

Biocorrosion, also referred to as MIC (Microbiologically Induced Corrosion), is a corrosion type induced by biological microorganisms.

Microorganisms can be defined as those organisms that are not visible to the human eye, requiring a microscope for detailed observation including bacteria, fungi, and microalgae. They need water, nutrients and electron acceptors, and they have developed several strategies for survival in natural environments:

• Spore formation
• Biofilm formation
• Dwarf cells
• A viable but non-culturable state

Biocorrosion mechanisms and analysis

Biofilms can be described as synergistic communities of microorganisms attached to a surface, forming flocks and aggregates. The microorganisms embedded in a biofilm can belong to one or different species, allowing them to grow on surfaces in a self-produced extracellular polymeric matrix (EPS).

The development of biofilms affects the interaction between metal surfaces and the environment and therefore, they can inhibit or accelerate the process of metal corrosion.

Bacterial adherence is the beginning of the process of colonization of a surface and its adhesion is influenced by several parameters which are broadly classed as microorganism characteristics, material properties and environmental factors. Analytical techniques such as infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD), optical and epifluorescence microscopy are used to detect and monitor biocorrosion. Classical electrochemistry techniques such as linear polarization measurements, electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN) can be used. Even if these methods have not been explicitly designed for biocorrosion analysis, they can be implemented.

https://www.biologic.net/topics/corrosion/

https://www.biologic.net/topics/what-does-scanning-probe-electrochemistry-reveal-about-corrosion/

https://www.biologic.net/topics/a-local-view-of-corrosion/

Conclusion

Biocorrosion represents a complex set of processes between microorganisms and material surfaces and its complexity requires a comprehensive approach to detection and monitoring. Understanding the processes behind biocorrosion is the first step to designing materials and initiating proactive measures to mitigate its effects.

References

[1] Mirul K. Pal, M. Lavanya, Journal of Bio- and Tribo-Corrosion, 8:76, (2022), 1-13

[2] Yen T. H. Dang, Aoife Power, Daniel Cozzolino, Khuong Ba Dinh, Binh Son Ha, Adam Kolobaric, Jitraporn Vongsvivut, Vi Khanh Truong, James Chapman, Journal of Bio- and Tribo-Corrosion, 8:50, (2022), 1-17

[3] Brenda J. Little, Jason S. Lee, Microbiologically Influenced Corrosion, Wiley-Interscience; 1st edition (March 30, 2007), 307