DOCSLIB.ORG

Metals, Microbes and Mic – a Review of Microbiologically Influenced Corrosion

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Metals, Microbes and Mic – a Review of Microbiologically Influenced Corrosion METALS, MICROBES AND MIC – A REVIEW OF MICROBIOLOGICALLY INFLUENCED CORROSION M Critchley* & R Javaherdashti** *CSIRO Manufacturing & Infrastructure Technology Clayton VIC **Monash University Clayton VIC Australia Summary: Microbiologically influenced corrosion (MIC) is the deterioration of materials caused by the presence and activity of micro-organisms. It is a complex problem that presents huge costs to industry. This review will describe the processes and micro-organisms involved in MIC as well as detection techniques. Mitigation methods against MIC will also be addressed Keywords: Biocorrosion, biofilms, microbiologically influenced corrosion 1 INTRODUCTION Microbiologically influenced corrosion (MIC), also known as biocorrosion, is the corrosion or deterioration of a material which is initiated and/or accelerated by the activities of micro-organisms. It affects not only metals but many materials including polymers, concrete and glass. MIC can manifest as pitting corrosion, crevice corrosion, stress corrosion, selective de- alloying and generalised corrosion, depending on the environment and micro-organisms present. It is a complex process and remains one of the least understood areas of corrosion science as it falls outside the traditional disciplines of both microbiology and corrosion. MIC presents huge costs for many industries. In the oil and gas industry, MIC causes pitting corrosion of pipelines and vessels and the plugging of reservoirs. In the water industry, MIC induces pipeline corrosion, pipe blockages and the corrosion of sewer mains. In the aviation industry, MIC can cause the corrosion of aircraft fuel tanks. MIC also causes the corrosion of heat exchangers, cooling towers and fire protection systems in the power industry. A recent NACE survey estimated the direct costs of corrosion to be 3.1% of US GDP, with indirect costs at 3% US GDP. MIC is estimated to account for at least 20% of corrosion, which calculates to approximately $US 55 billion/year (1). 2 BIOFOULING MIC is initiated by the fouling of surfaces, a process which naturally occurs in many environments (2). Biofouling is the undesirable formation of deposits on a surface. Biofouling comprises of both organic and inorganic components which include micro-organisms, precipitated materials, particulates and corrosion products. The biological component occurs from the formation of biofilms, where micro-organisms accumulate on surfaces and develop complex communities within a matrix of organic polysaccharides (2). Biofilms comprise of many different micro-organisms depending on the environment, including aerobic and anaerobic bacteria, fungi, algae and protozoa. The steps involved in the formation of biofilms are shown in Figure I (2). Organic conditioning films accumulate on surfaces upon exposure to the environment, changing the surface charge and hydrophobicity. Planktonic organisms associate with surfaces, with irreversible adhesion occurring through interactions with surface structures and charges. Attachment allows microbial colonies to develop where they can secrete extracellular materials and accumulate compounds from the bulk phase. Biofouling initially occurs on a micro-scale which allows the colonisation of very small areas such as crevices, weldments and surface imperfections. The structure of biofilms is complex. Biofilms contains structural and temporal variations such as gradients in pH, oxygen concentrations (Figure II) and nutrients (2). This creates microenvironments where the activity of certain micro-organisms may be enhanced. Underneath the biofilm, chemical properties such as the pH, dissolved oxygen and nutrient concentrations may be dramatically different from those in the bulk solution. This results in a shift in the open-circuit potential of passive metals in the noble direction (ennoblement). This has been well-documented for a range of metals and alloys, particularly stainless steel (3). Corrosion & Prevention 2004 Paper 037 Page 1 Biofouling causes many problems for industrial systems. One of the most important problems is it increases the retention time and allows the proliferation of micro-organisms within an environment where they may not normally accumulate. Biofouling is an important contributor to microbial corrosion, however, it is important to note that MIC can also occur from suspended, unattached micro-organisms present in the planktonic phase. STEPS IN BIOFILM FORMATION BIOFILM FORMATION ATTACHMENT GROWTH & ATTACHMENT SURFACE COLONISATION CONDITIONING Figure I. Steps involved in biofilm formation (Critchley 2001) BULK LIQUID PHASE O2 AEROBIC HETEROTROPHIC BIOFILM ANAEROBIC HETEROTROPHIC ACTIVITY OBLIGATE ANAEROBES METAL Figure II. Spatial relationships of micro-organisms within an established biofilm (Critchley 2001) 3 MICRO-ORGANISMS IMPLICATED IN MIC Micro-organisms can be classified in many ways including their cellular structure, morphology, source of energy and oxygen requirements (4). Numerous micro-organisms have been implicated in MIC, the most common are described briefly below: Corrosion & Prevention 2004 Paper 037 Page 2 3.1 Sulphate reducing bacteria Sulphate reducing bacteria (SRBs) are naturally found in the environment in soil and surface waters. They are anaerobic, growing under very low oxygen or completely oxygen depleted conditions (5). The optimum conditions for their growth are temperatures of 25 to 35°C and a pH range of 6 to 9.5 (5). Some species of SRBs are thermophilic (ie. Desulfotomaculum) and can survive at temperatures up to 60°C. SRBs use hydrogen, alcohols, lactates and acetates as sources of energy. SRBs contain the hydrogenase enzyme which enables them to utilise hydrogen from the environment. For SRBs to flourish, sulphate concentrations of at least 50 to 100 ppm are required (5). SRBs reduce sulphates to sulphides which react with metals to produce metal sulphides. Corrosion by SRBs is usually detected by the hydrogen sulphide odour, blackening of waters or the presence of black coloured deposits (Plate 1). Common species of sulphate reducing bacteria include Desulphovibrio and Desulphotomaculum. Plate I. Corrosion cause by sulphate reducing bacteria (source unknown) 3.2 Iron oxidising bacteria Iron oxidising bacteria require the oxidation of Fe2+ to Fe3+ to produce energy for metabolism (6). Common species of iron oxidising bacteria include Gallionella, Sphaerotilus, Siderocapsa and Crenothrix. They generally grow in filamentous clumps and can be visually detected by microscopy by the presence of a twisted helical/sheath that are excreted by the cells and encrust them with their growth (Plate 2). For this reason, corrosion by iron bacteria often manifests as tubercles (7). Chloride ions can accumulate within these tubercles, which combine with corrosion products to produce ferric chloride. Ferric chloride is extremely corrosive to stainless steel (7). Tubercles additionally allow the development of anaerobic conditions and can lead to the growth of SRBs (7). Iron oxidising bacteria prefer pH ranges from neutral to acidic, oxygen concentrations from 0 to saturated and temperatures up to 90°C. Bacteria that oxidise manganese have also been identified and implicated in the corrosion of stainless steel (8). In contrast to this, there are bacteria that can accumulate iron and manganese which also have been associated with corrosion (9). Corrosion & Prevention 2004 Paper 037 Page 3 Plate II. SEM image of iron bacteria showing precipitated iron (Critchley 2003) 3.3 Acid producing bacteria Acid producing bacteria (APBs) generate acidic by-products with their metabolism that is corrosive to many materials. Clostridium spp. have been shown to produce acetic acids with fermentation and has been extensively isolated from industrial water systems (10). More importantly, bacteria which oxidise sulphur or sulphides including Thiobacillus and Beggiatoa can produce up to 10% sulphuric acid solutions (11). These bacteria have been widely implicated in the corrosion of reinforced concrete structures. Sulphur oxidisers are acid tolerant and are typical of microbes found in acid mine drainage systems. Sulphur oxidising bacteria are almost always found with SRBs, existing synergistically cycling sulphur. Biofilms allow the existence of both organisms due to the existence of microenvironments within its structure, where localised conditions are controlled. 3.4 Fungi Certain species of fungi are corrosive, mainly through the production of acids with metabolism. Hormoconis or Cladosporium resinae is a fungus notorious for corrosion in aluminium fuel systems (Plate 3)(12). It has presented major problems for the aviation industry as its growth in fuel systems causes significant corrosion and also operational problems such as errors in fuel gauging and filter blockages. Fungi have also been implicated in the corrosion of glass and more recently, compact discs (13). Fungi produce spores which enables them to survive environmental extremes only to regenerate when conditions are favourable. This makes the eradication of fungi extremely difficult. Other fungi that have been associated with corrosion include Aspergillus spp. (14) 3.5 Heterotrophic slime forming bacteria Heterotrophic bacteria are aerobic and use organic carbon as a nutrient source. They are commonly found in the environment particularly within biofilms. Many can produce copious amounts of exopolysaccharides or slime which causes many operational problems as well as corrosion (15). Polysaccharides can contain acidic groups which directly
Load more

Recommended publications
  • Sulfuric Acid Corrosion to Simulate Microbial Influenced Corrosion on Stainless
    Sulfuric Acid Corrosion to Simulate Microbial Influenced Corrosion on Stainless Steel 316L by Jacob T. Miller Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science in Engineering in the Chemical Engineering Program YOUNGSTOWN STATE UNIVERSITY December, 2017 Sulfuric Acid Corrosion to Simulate Microbial Influenced Corrosion on Stainless Steel 316L Jacob T. Miller I hereby release thesis to the public. I understand that this thesis will be made available from the OhioLINK ETD Center and the Maag Library Circulation Desk for public access. I also authorize the University or other individuals to make copies of this thesis as needed for scholarly research. Signature: Jacob T. Miller, Student Date Approvals: Dr. Holly J. Martin, Thesis Advisor Date Dr. Pedro Cortes, Committee Member Date Dr. Brett P. Conner, Committee Member Date Dr. Salvatore A. Sanders, Dean of Graduate Studies Date Abstract The continued improvement of additive manufacturing (3D printing) is progressively eliminating the geometric limitations of traditional subtractive processes. Because parts are built up in thin layers, such as in processes like Laser Powder Bed Fusion, complex parts can be manufactured easily. However, this manufacturing method likely causes the parts to have rougher surfaces and decreased density compared to their traditional counterparts. The effect of this difference has not been researched thoroughly, but may have a significant impact on the properties of the parts. For example, the 3D printed parts could more easily collect micro-organisms that produce sulfuric acid as byproducts of their metabolic processes. Uninhibited microbial growth on the sample surface could produce enough sulfuric acid to degrade the parts through hydrogen embrittlement.
    [Show full text]
  • Sulphate-Reducing Bacteria's Response to Extreme Ph Environments and the Effect of Their Activities on Microbial Corrosion
    applied sciences Review Sulphate-Reducing Bacteria’s Response to Extreme pH Environments and the Effect of Their Activities on Microbial Corrosion Thi Thuy Tien Tran 1 , Krishnan Kannoorpatti 1,* , Anna Padovan 2 and Suresh Thennadil 1 1 Energy and Resources Institute, College of Engineering, Information Technology and Environment, Charles Darwin University, Darwin, NT 0909, Australia; [email protected] (T.T.T.T.); [email protected] (S.T.) 2 Research Institute for the Environment and Livelihoods, College of Engineering, Information Technology and Environment, Charles Darwin University, Darwin, NT 0909, Australia; [email protected] * Correspondence: [email protected] Abstract: Sulphate-reducing bacteria (SRB) are dominant species causing corrosion of various types of materials. However, they also play a beneficial role in bioremediation due to their tolerance of extreme pH conditions. The application of sulphate-reducing bacteria (SRB) in bioremediation and control methods for microbiologically influenced corrosion (MIC) in extreme pH environments requires an understanding of the microbial activities in these conditions. Recent studies have found that in order to survive and grow in high alkaline/acidic condition, SRB have developed several strategies to combat the environmental challenges. The strategies mainly include maintaining pH homeostasis in the cytoplasm and adjusting metabolic activities leading to changes in environmental pH. The change in pH of the environment and microbial activities in such conditions can have a Citation: Tran, T.T.T.; Kannoorpatti, significant impact on the microbial corrosion of materials. These bacteria strategies to combat extreme K.; Padovan, A.; Thennadil, S. pH environments and their effect on microbial corrosion are presented and discussed.
    [Show full text]
  • Beating the Bugs: Roles of Microbial Biofilms in Corrosion
    Beating the bugs: roles of microbial biofilms in corrosion The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Li, Kwan, Matthew Whitfield, and Krystyn J. Van Vliet. "Beating the bugs: roles of microbial biofilms in corrosion." Corrosion Reviews 321, 3-6 (2013); © 2013, by Walter de Gruyter Berlin Boston. All rights reserved. As Published https://dx.doi.org/10.1515/CORRREV-2013-0019 Publisher Walter de Gruyter GmbH Version Author's final manuscript Citable link https://hdl.handle.net/1721.1/125679 Terms of Use Creative Commons Attribution-Noncommercial-Share Alike Detailed Terms http://creativecommons.org/licenses/by-nc-sa/4.0/ Beating the bugs: Roles of microbial biofilms in corrosion Kwan Li∗,‡, Matthew Whitfield∗,‡, and Krystyn J. Van Vliet∗,† ∗Department of Materials Science and Engineering and †Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 USA ‡These author contributed equally to this work Abstract Microbiologically influenced corrosion is a complex type of environmentally assisted corrosion. Though poorly understood and challenging to ameliorate, it is increasingly appreciated that MIC accelerates failure of metal alloys, including steel pipeline. His- torically, this type of material degradation process has been treated from either an electrochemical materials perspective or a microbiological perspective. Here, we re- view the current understanding of MIC mechanisms for steel – particularly those in sour environments relevant to fossil fuel recovery and processing – and outline the role of the bacterial biofilm in both corrosion processes and mitigation responses. Keywords: biofilm; sulfate-reducing bacteria (SRB); microbiologically influenced cor- rosion (MIC) 1 Introduction Microbiologically influenced corrosion (MIC) can accelerate mechanical failure of metals in a wide range of environments ranging from oil and water pipelines and machinery to biomedical devices.
    [Show full text]
  • Laboratory Based Investigation of Stress Corrosion Cracking of Cable Bolts
    Laboratory Based Investigation of Stress Corrosion Cracking of Cable Bolts Saisai Wu A thesis in fulfilment of the requirements for the degree of Doctor of Philosophy School of Mining Engineering Faculty of Engineering July 2018 THE UNIVERSITY OF NEW SOUTH WALES Thesis/Dissertation Sheet Surname or Family name: Wu Other name/s: First name: Saisai Abbreviation for degree as given in the University calendar: PhD School: Mining Engineering Faculty: Engineering Title: Laboratory-Based Investigation of Stress Corrosion Cracking Of Cable Bolts Abstract 350 words maximum Premature failure of cable bolts due to stress corrosion cracking (SCC) in underground excavations is a worldwide problem with limited cost-effective solutions at present. To determine the cause and mechanism of SCC, identify potential technologies and eventually avoid catastrophic failure of cable bolts, a two-step methodology was implemented: (i) a long-term test using groundwater collected from underground mines, and (ii) an accelerated test using an acidified solution. Laboratory experimentation on both representative coupon and full-size cable bolt specimens was conducted. In the long-term tests, simulated underground environments were recreated in ‘corrosion cells’ which contained a newly designed cable bolt coupon together with a mixture of groundwater, coal and clay, to measure the potential for developing SCC. The incidence of SCC failures was not related to groundwater alone. Geomaterials in the corrosion cells accelerated the corrosion of cable bolts by increasing the concentrations of total dissolved solids and electrical conductivity of the water. Following this, an acidic solution containing sulphide, synthesised based on the chemical properties of groundwater from twelve Australian underground mines, was used as the testing solution for the accelerated tests.
    [Show full text]
  • Characterization of Sulfur Oxidizing Bacteria Related to Biogenic Sulfuric Acid Corrosion in Sludge Digesters Bettina Huber, Bastian Herzog, Jörg E
    Huber et al. BMC Microbiology (2016) 16:153 DOI 10.1186/s12866-016-0767-7 RESEARCH ARTICLE Open Access Characterization of sulfur oxidizing bacteria related to biogenic sulfuric acid corrosion in sludge digesters Bettina Huber, Bastian Herzog, Jörg E. Drewes*, Konrad Koch and Elisabeth Müller Abstract Background: Biogenic sulfuric acid (BSA) corrosion damages sewerage and wastewater treatment facilities but is not well investigated in sludge digesters. Sulfur/sulfide oxidizing bacteria (SOB) oxidize sulfur compounds to sulfuric acid, inducing BSA corrosion. To obtain more information on BSA corrosion in sludge digesters, microbial communities from six different, BSA-damaged, digesters were analyzed using culture dependent methods and subsequent polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). BSA production was determined in laboratory scale systems with mixed and pure cultures, and in-situ with concrete specimens from the digester headspace and sludge zones. Results: The SOB Acidithiobacillus thiooxidans, Thiomonas intermedia,andThiomonas perometabolis were cultivated and compared to PCR-DGGE results, revealing the presence of additional acidophilic and neutrophilic SOB. Sulfate concentrations of 10–87 mmol/L after 6–21 days of incubation (final pH 1.0–2.0)inmixedcultures,andupto 433 mmol/L after 42 days (final pH <1.0) in pure A. thiooxidans cultures showed huge sulfuric acid production potentials. Additionally, elevated sulfate concentrations in the corroded concrete of the digester headspace in contrast to the concrete of the sludge zone indicated biological sulfur/sulfide oxidation. Conclusions: The presence of SOB and confirmation of their sulfuric acid production under laboratory conditions reveal that these organisms might contribute to BSA corrosion within sludge digesters.
    [Show full text]
  • Investigation of Sulfate-Reducing Bacteria
    INVESTIGATION OF SULFATE-REDUCING BACTERIA GROWTH BEHAVIOR FOR THE MITIGATION OF MICROBIOLOGICALLY INFLUENCED CORROSlON (MIC) A Thesis Presented to The Faculty of the Fritz. J. and Dolores H. Russ College of Engineering and Technology Ohio University In Partial Fulfillment of the Requirement for the Degee Master of Science November, 2004 Acknowledgements I would like to express my sincere gratitude and deep appreciation to my academic advisor, Dr. Tingyue Gu for his expert guidance, continuous encouragement and patience. I would also like to specially thank Dr. Srdjan Nesic, director of Institute for Corrosion and Multiphase Flow Technology of Ohio University, for his help, guidance and support. I would also like to thank Dr. Peter Coschigano for his suggestions while serving as my committee members. Under their help and supervision, I was able to turn my Master's study into a hlfilling, intellectually challenging and enjoyable journey. I would also like to extend my gratitude to the technical staff at the Institute for their expertise in designing, troubleshooting the equipment. I would also like to thank all the ~y-aduatestudents at the Institute. Special thanks go to my fellow graduate student Mr. Chintan Jhobalia for sharing his experiences and having helpful discussjons with me. I would also like to thank Mr. Kaili Zhao and Mr. Jie Wen for their help during the busiest days in my work. Table of Contents ... Acknowledgements ...........................................................................................................
    [Show full text]
  • Understanding and Addressing Microbiologically Influenced Corrosion (MIC) Laura L
    REVIEW PAPER Understanding and Addressing Microbiologically Influenced Corrosion (MIC) Laura L. Machuca OVERVIEW corrosion on underground pipelines [5]. We know MIC involves the interaction Microbial life is everywhere. The formation of biofilms on metals of electrochemical, environmental, Microorganisms have been found and alloys can result in corrosion rates operational, and biological factors inhabiting iced-covered lakes in in excess of 10 mm per year (mm/y) that often result in substantial Antarctica at -13°C and hydrothermal leading to equipment failure before increases in corrosion rates to metals vents at the bottom of the ocean their expected lifetime and serious in specific environments. However, at 120°C [1]. Microorganisms have environmental damage [6, 7]. The the complex and dynamic nature of inhabited our planet for billions 2006 trans-Alaskan pipeline failure, these interactions have made detailed of years before plants and animals which was attributed to microbial mechanisms elusive, i.e. the precise appeared. It was through their corrosion where 200,000 gallons of mechanism(s) of MIC is still being activities that higher forms of life crude oil leaked resulted in significant debated among corrosion specialists. could appear and thrive [2]. However, environmental pollution, lost The most challenging aspects of MIC microorganisms can also be harmful production of two million barrels and is its lack of predictability and the fact and their activities can result, under a worldwide impact on oil price [7] is a that it does not produce a distinct type certain conditions, in detrimental prime example of such issues. Incidents of corrosion or a unique morphology effects such as disease and damage like these have resulted in increased of corrosion damage, or any sort of to infrastructure.
    [Show full text]
  • Types of Corrosion Damage of Tubing in the Oilfield
    E3S Web of Conferences 121, 03001 (2019) https://doi.org/10.1051/e3sconf/201912103001 Corrosion in the Oil & Gas Industry 2019 Types of corrosion damage of tubing in the oilfield Natalya Devyaterikova*,1, Marianna Nurmukhametova1, Aleksandr Kharlashin 2, Yegor Popov 2 1 JSC Pervouralsk New Pipe Plant, Pervouralsk, Russian Federation 2 Ural State University named after the First President of Russia B.N.Yeltsin, Yekaterinburg, Russian Federation Abstract. The accumulated research data of tubing fragments after operation made it possible to generalize and systematize information on the prevailing type of corrosion damage and operating conditions that determine the mechanism of their development. Understanding basic laws of the development of corrosion processes in specific operating conditions, allows to select the optimal type of tubing for these conditions more accurately. 1 Introduction − hydrogen sulphide corrosion; − fretting corrosion; During the development of the Material Selection System − stress corrosion cracking; for specific conditions of oil production, at JSC "PNTZ" − microbial corrosion. studies were conducted for the tubing operating The regularities of the corrosion process in a complex conditions, and evaluation of their impact on the nature of system, which is formed during oil production, are corrosion damages was done. The accumulated research determined by many factors, the main ones of which are data of more than 100 tubing fragments made it possible the content of carbon dioxide and hydrogen sulphide (both to generalize and systematize information on the primary and secondary which is bacterial). The mineral prevailing type of corrosion damage and operating composition of accompanying waters, temperature and conditions that determine the mechanism of their pressure conditions in the well, salt formation processes, development.
    [Show full text]
  • Review of Microbially Influenced Corrosion of High-Level Waste
    CNWRA 93-014 A S S. l ' -S I& 0X- 0,,,, al-s~~~~~~~~~~~ _ Prepared for Nuclear Regulatory Commission Contract NRC-02-88-005 Prepared by Center for Nuclear Waste Regulatory Analyses San Antonio, Texas June 1993 CNWRA 93-014 A REVIEW OF THE POTENTIAL FOR MICROBIALLY INFLUENCED CORROSION OF HIGH-LEVEL NUCLEAR WASTE CONTAINERS Prepared for Nuclear Regulatory Commission Contract NRC-02-88-005 Prepared by Gill Geesey Department of Microbiology Montana State University Bozeman, Montana Edited by Gustavo A. Cragnolino Center for Nuclear Waste Regulatory Analyses San Antonio, Texas June 1993 RECEIVED JUN 281993 CNWRA-WO PREVIOUS REPORTS IN SERIES Number Name Date Issued CNWRA 91-004 A Review of Localized Corrosion of High-Level Nuclear Waste Container Materials - I April 1991 CNWRA 91-008 Hydrogen Embrittlement of Candidate Container Materials June 1991 CNWRA 92-021 A Review of Stress Corrosion Cracking of High-Level Nuclear Waste Container Materials - I August 1992 CNWRA 93-003 Long-Term Stability of High-Level Nuclear Waste Container Materials: I - Thermal Stability of Alloy 825 February 1993 CNWRA 93-004 Experimental Investigations of Localized Corrosion of High-Level Waste Container Materials February 1993 ii ABSTRACT The potential for microbially influenced corrosion (MIC) of the candidate and alternate container materials for the proposed Yucca Mountain repository site is examined on the basis of an extensive review of the literature. A brief description of the environmental conditions expected outside the waste packages, in terms of the geology, hydrology, water chemistry, radiation, temperature, and moisture content, is followed by a detailed discussion regarding the characteristics of microbial life in subsurface environments.
    [Show full text]
  • Microbiologically Influenced Corrosion and Its Mitigation: (A Review)
    Material Science Research India Vol. 7(2), 407-412 (2010) Microbiologically influenced corrosion and its mitigation: (A review) RAHUL BHOLA*, SHAILY M. BHOLA, BRAJENDRA MISHRA and DAVID L. OLSON Department of Metallurgical & Materials Engineering, Colorado School of Mines, Golden, Colorado - 804 01 (USA). Email: [email protected] (Received: October 08, 2010; Accepted: November 17, 2010) ABSTRACT The microbiologically influenced corrosion (MIC) is one of the most common forms of corrosion that results from the presence and activity of microorganisms. The presence of microorganism aids in the formation of a biofilm and constitutes various bacterial cells, extracellular polymeric substrates (EPS) and corrosion products. In this paper, a review on the importance of MIC and various ways to mitigate has been introduced; a brief description of the physical, chemical, electrochemical and biological mitigation methods for MIC has been included and EPS formation mechanism, chemical composition, properties and its influence on corrosion has been discussed. Key words: Microorganisms, MIC, EPS, corrosion. INTRODUCTION the bulk of life on the planet is still composed of microbial organisms from the Bacteria and Archaea Microbiologically Influenced Corrosion (MIC) domains. Even the majority of Eucarya are microbial Microbiologically induced corrosion (MIC) - for instance, Giardia a well-known protozoan has been reported in several papers and journals microbial Eukaryote3. in the literature. It is quite clear that the microorganisms affect the corrosion of metals and alloys immersed in aqueous environments1. Microbes adhere to the metal surfaces forming biofilms, which can alter the surface chemistry at the interface. Biofilms or the microbial coverings form complex ecosystems in the presence of the four prerequisite of life, i.e., a small amount of water; an electron donor; an electron acceptor and a carbon source2.
    [Show full text]
  • Microbiologically Influenced Corrosion of a Pipeline in a Petrochemical
    metals Article Microbiologically Influenced Corrosion of a Pipeline in a Petrochemical Plant Mahdi Kiani Khouzani 1 , Abbas Bahrami 1, Afrouzossadat Hosseini-Abari 2, Meysam Khandouzi 1 and Peyman Taheri 3,* 1 Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran; [email protected] (M.K.K.); [email protected] (A.B.); [email protected] (M.K.) 2 Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan 817463441, Iran; [email protected] 3 Delft University of Technology, Department of Materials Science and Engineering, Mekelweg 2, 2628 CD Delft, The Netherlands * Correspondence: [email protected]; Tel.: +31-15-278-2275 Received: 1 March 2019; Accepted: 16 April 2019; Published: 19 April 2019 Abstract: This paper investigates a severe microbiologically influenced failure in the elbows of a buried amine pipeline in a petrochemical plant. Pipelines can experience different corrosion mechanisms, including microbiologically influenced corrosion (MIC). MIC, a form of biodeterioration initiated by microorganisms, can have a devastating impact on the reliability and lifetime of buried installations. This paper provides a systematic investigation of a severe MIC-related failure in a buried amine pipeline and includes a detailed microstructural analysis, corrosion products/biofilm analyses, and monitoring of the presence of causative microorganisms. Conclusions were drawn based on experimental data, obtained from visual observations, optical/electron microscopy, and Energy-dispersive X-ray spectroscopy (EDS)/X-Ray Diffraction (XRD) analyses. Additionally, monitoring the presence of causative microorganisms, especially sulfate-reducing bacteria which play the main role in corrosion, was performed. The results confirmed that the failure, in this case, is attributable to sulfate-reducing bacteria (SRB), which is a long-known key group of microorganisms when it comes to microbial corrosion.
    [Show full text]
  • Microbiological Corrosion
    CORROSION CONTROL Microbiological Corrosion-What Causes It and How It Can Be Controlled Downloaded from http://onepetro.org/jpt/article-pdf/14/10/1074/2213691/spe-391-pa.pdf by guest on 01 October 2021 A. W. BAUMGARTNER BRADFORD LABORATORIES, DIV. OF HAGAN CHEMICALS & CONTROLS, INC. ASSOCIATE MEMBER AIME ABILENE, TEX. Abstract ism as an electrochemical process.'" For this process to take place, three requirements must be fulfilled. A synopsis of conditions that must be present for corro­ sion of ferrous metals to occur is presented. These criteria 1. An electromotive force or potential difference must are discussed as they are encountered in oil producing and be present. Before a metal can corrode it must have an gathering systems and in water-storage, transfer, treating anode or area that has a positive potential which attracts and injecting equipment. negatively charged particles or ions (anions), and a cath­ ode or area that has a negative charge or potential to The role of bacteria in corrosion is described in detail. which positively charged particles or ions (cations) are Special emphasis is placed on sulfate-reducing "Desulfo­ attracted. vibrio" bacteria, since these microorganisms are directly responsible jar practically all corrosion attributable to bac­ 2. There must be an electrical circuit or couple estab­ teria in the oil-producing industry. Typical situations that lished between the anode and the cathode. should lead operating personnel to suspect the presence oj 3. The anode and cathode, electrically connected, must these microbes, as well as more specific methods for their be in contact with a solution that will conduct a current detection, are given.
    [Show full text]