Microbiological contribution to accelerated low water corrosion of support piles

Dr. Reza Javaherdashti, Senior Corrosion Engineer, Extrin Consultants, Perth, Australia, (on behalf of Nace International)

View in full: Microbiological contribution to accelerated low water corrosion of support piles
Read the full article

Introduction
Accelerated low water corrosion (ALWC) is a complex type of corrosion as it not only involves purely electrochemical factors, it also is greatly affected by microbiologically influenced corrosion (MIC). While some definitions of ALWC do consider MIC as an integral part of the definition, emphasising the importance of the role played by corrosion-enhancing bacteria, it is still open to discussion how MIC can enhance severity of this type of corrosion.

ALWC has been reported to cause severe corrosion of mainly steel piles in ports and jetty structures all around the world such as USA, Europe and Australia. In many cases of ALWC, microbial corrosion manifest itself as an orange mass known as ‘orange bloom’ that schematically can be shown in Figure 1. Figures 2a to 2d show real life examples of the orange blooms. Figures 3a and 3b show two more examples of orange blooms as appearing under-water with the deteriorating effects of orange blooms on the steel material of the piles. The metal underneath the orange blooms can be highly deteriorated. Figures 4a and 4b show such instances.

It has been suggested that some groups of corrosion-enhancing bacteria such as sulphate reducing bacteria (SRB) and Iron reducing bacteria (IRB) may play an important role in ALWC problems, Figure 5.

However, there are some issues that when taken to consideration, may further increase the complexity that MIC can induce to ALWC. Of these issues is possible involvement of other types of corrosion-enhancing bacteria such as iron bacteria (IB) as their growth and corrosion activity can be supported by biochemical nature of seawater. The other issue is the rather false reputation that routine laboratory-based methods for investigation of numbers and intensities of corrosion-enhancing bacteria have created among professionals who have little hands-on experience on MIC-assisted issues.

This ‘over-relying’ on these methods may br ing about technical misunderstandings and ‘myths’ that would result in misinterpretations and thus wrong synopsis of the corrosion-case...

 


  Edition 29      Mooring & Berthing

I already have a Free Member Account

   Remember Me

Lost password?

Free Members Account Registration

Please register for a free members account to access all free content.
Once registered, you will not have to re-enter your details to download free papers.
Please note: You will receive an activation code via email. If you do not receive this email straight away, please check your spam folder.

I would like to:

 
 I consent to Port Technology International collecting and storing my data from this form.
By submitting your details, you are accepting these Terms & Conditions and agreeing to our Privacy and Cookies policies. You can opt out of these communications at any time.

Register for a Full Paid Members Account

Click here to choose from 3 membership packages and access over 1,700 technical papers.

Purchase a Premium Membership


Edition 29

PTI EDITION 29

In edition 29, DP World talk about constructing gateways to open up Asia; plus we look at new detection technologies for WMD and radiation detection, and yard automation.