Microbiologically Influenced Corrosion (eBook)

Dr Reza Javaherdashti is a Senior Corrosion Engineer at Extrin Consultants, a specialist corrosion engineering consulting group based in Perth, Australia.

Preface 6
A Few Words About the Structure of This Book 6
Acknowledgements 10
Contents 12
A Short Journey to the Realm of Corrosion 16
1.1 Introduction 16
1.1.1 Definition of Corrosion 16
1.2 Electrochemical Corrosion: A Brief Introduction 17
1.3 When Does Corrosion Happen? 19
1.4 Corrosion Forecast 20
1.4.1 Anodic Polarisation (Anodic Polarisation Reaction) 21
1.4.2 Cathodic Polarisation (Cathodic Polarisation Reaction) 22
1.5 Summary and Conclusions 23
References 23
Further Reading 23
Technical Mitigation of Corrosion: Corrosion Management 24
2.1 Introduction 24
2.1.1 Corrosion Management: A Technical Approach 24
2.2 The Rationale for Using Coatings and Linings 24
2.3 The Rationale of Anodic and Cathodic Protection 25
2.3.1 Anodic Protection 25
2.3.2 Cathodic Protection (CP) 25
2.4 Use of Inhibitors 27
2.4.1 Anodic Inhibitors 27
2.4.2 Cathodic Inhibitors 28
2.4.3 Mixed Effect Inhibitors [2] 29
2.5 Material Selection and Design Improvement 29
2.6 Summary and Conclusions 30
References 31
Non-technical Mitigation of Corrosion: Corrosion Knowledge Management 32
3.1 Introduction 32
3.2 Corrosion (Knowledge) Management: A Managerial Approach 33
3.2.1 Importance of Defining “Resources” and “Targets” 33
3.2.2 Why Should We Care About Corrosion? 35
3.3 Components of Corrosion Knowledge Management as a Managerial Tool 37
3.4 Conclusion and Summary 41
References 41
Microbiologically Influenced Corrosion (MIC) 44
4.1 Introduction 44
4.2 Definition of MIC 45
4.3 Importance of MIC 46
4.4 Historical Profile of Advances in Understanding MIC 47
4.5 Categorising Bacteria 49
4.6 Biofilm Formation and Its Stages 51
4.7 How Biofilms Demonstrate Their Effects on Corrosion 57
4.8 Enhancing Corrosion 57
4.8.1 Biofilm Models 57
4.9 Corrosion Deceleration Effect of Biofilms 61
4.10 The Bacteria Involved in MIC 63
4.11 Sulphate-reducing Bacteria (SRB) 64
4.11.1 Mechanisms of MIC by SRB 66
4.11.2 Examples of Corrosion by SRB 69
4.11.3 Stress Corrosion Cracking (SCC) and SRB 70
4.12 Iron-reducing Bacteria 73
4.12.1 Why Is Microbial Reduction of Iron Important? 73
4.12.2 Contradicting Impacts of IRB on Corrosion 75
4.13 Magnetic Bacteria 78
4.14 Summary and Conclusions 80
References 81
How Does a System Become Vulnerable to MIC? 88
5.1 Introduction 88
5.2 General Points Regarding the Vulnerability of Industrial Systems 88
5.3 Important Systems/Working Conditions Leading to MIC 89
5.4 Physico-mechanical Factors and Their Effects on MIC 90
5.4.1 Chemical Factors 92
5.4.2 Water Treatment 92
5.4.3 Oxygen 92
5.4.4 Nutrients and the Ease of Reaching Them 92
5.4.5 Alloying Elements and Their Impacts 94
5.4.6 Welding 95
5.4.7 Impact of Hydrotesting 96
5.5 Some Points Regarding the Feasibility of Mitigation of Hydrotesting- assisted MIC 98
5.6 Summary and Conclusions 101
References 101
How Is MIC Detected and Recognised? 104
6.1 Introduction 104
6.2 Recognition Methods 105
6.2.1 Investigating Vulnerable Systems and Components 105
6.2.2 Pit Morphology 105
6.2.3 Mineralogical Finger Prints 106
6.2.4 Appearance and Colour of Corrosion Products 108
6.2.5 Characteristics of Microbial Attack 108
6.3 Detection Methods 111
6.3.1 Culturing and Its Alternatives 111
6.3.2 Quick (or Rapid) Check Tests 114
6.3.3 Electrochemical Recognition Methods and Their Application to MIC 116
6.4 Summary and Conclusions 118
References 120
Examples of Some Systems Vulnerable to MIC 124
7.1 Introduction 124
7.2 Buried Metallic Pipelines 125
7.3 Maritime Piled Structures (Jetty and Wharves) 128
7.4 Offshore Platforms 131
7.5 Firewater Lines 133
7.6 Summary and Conclusions 134
References 135
Examples of Some Materials Vulnerable to MIC 138
8.1 Introduction 138
8.1.1 Copper and Cupronickels 138
8.1.2 Duplex Stainless Steels 140
8.1.3 Concrete 141
8.2 Summary and Conclusions 145
References 145
How Is MIC Treated? 148
9.1 Introduction 148
9.2 Physical-mechanical Treatments 149
9.2.1 Pigging 149
9.2.2 Use of Ultraviolet Radiation 151
9.2.3 Ultrasonic Treatment 152
9.3 Chemical Treatments 152
9.3.1 Pros and Cons of Some Biocides 153
9.3.2 A Note on Dual Biocide Treatment 160
9.4 Electrochemical Methods 161
9.4.1 Cathodic Protection (CP) 161
9.4.2 Coating 167
9.5 Biological Methods 168
9.6 Summary and Conclusions 170
References 170
Glossary 174
Index 176