SRB Corrossion

[chiefeng]

Has anyone had any experience with Sulphate Reducing Bacterial Corrosssion? We have a ship that has extensive pitting in the ballast tanks on the flat bottom area. How can we nuetralize it? After plate replacement and blasting how would you suggest we treat the minor effected areas after blasting? The classification society has put a condition of class on the vessel to be drydocked in 2 months and we would like to prepare the tanks before then.

 

[Metalguy]

Ah, SRB's one of my favorite subjects. They thrive where the oxygen is low, sometimes developing under other oxygen-dependent bacteria and slimes.

One way to prevent attack would be to epoxy coat the newly sand-blasted areas. Since you have ballast tanks, I wouldn't think that water treatment is practical.

Cleanliness is really the key. If you can keep the tank bottoms clean, you shouldn't have a problem.

 

[Hossem]

Hi,
The SRB are anaerobic bacteria which grows in water, they reduct sulphates SO4= to sulphides S=, their activity leads to pitting corrosion. it is absolutely necessary to avoid the water stagnation at tanks bottom. The recommended treatment is effective biocide use, sometimes it is necessary to proceed to surfaces pigging before treatment. One can also use two different biocides in order to avoid the habituation phenomenon.