Bacteria Induced Corrosion

1
Bacteria Induced Corrosion

• Nathan, Shaun and Will
• March 29, 2001
• BY323

2
Introduction

• Ignorance of Bacterial Effects
• Various Corrosive Bacteria
• Corrosion of Steel
• Corrosive Method
• Solutions
• Corrosion of Concrete
• Corrosive Method
• Solutions

3
Bacteria Associated with Corrosion

• Sulfate Reducers (Desulfovibrio Desulfuricans)
• Sulfate Oxidizers (Thiobacillus)
• Slime Forming Bacteria (Pseudomonas)
• Filamentous Iron Bacteria (Sphaerofilus)
• Gallionella

4
Corrosion of Steel

• How it occurs
• What actually happens
• Budding of Corrosion Causing Organisms
• Stalk, Pili, Flagella
• Slime
• Industries Affected

5
Corrosive Method
6
Factors Affecting Corrosion

• pH
• Gallionella
• Leptothrix
• Temperature
• Availability of nutrients

7
Solutions

• What can be done
• Cost vs. Results

8
Corrosion of Concrete

• Industries affected
• Water and Waste Water Treatment
• Sewage Systems
• Sulfur bacteria
• Environmental influence

9
Oxidation of Hydrogen Sulfide

• Production of Hydrogen Sulfate
• Escape of Hydrogen Sulfate
• Oxidation of Hydrogen
• Decomposition of Concrete

10
Solutions

• Small diameter cases
• Larger cases
• System design

11
Conclusion

• Importance of understanding bacterial corrosion
• Type of bacteria is very dependant on the pH
• Most problems exist in
• Circulatory Systems
• Near Gaskets and Welds
• Low Flow Areas
• Countermeasures