Problem Solving Forum
September 20 - September 26, 2015
What generic types of coating materials best resist microbiologically induced corrosion (MIC)?
William Slama of International Paint/Ceilcote Products on
September 30, 2015:
MIC activity has also been found in some power pla ...read more MIC activity has also been found in some power plant flue gas desulfurization systems in the large absorber vessels. It, as expected, caused accelerated steel corrosion but had no effect on the coated/lined surfaces. It caused a distinct hydrogen sulfide odor. In one instance, the solution was use of some antibacterial additives.
Chris Lloyd of Flexcrete Technologies Ltd on
September 29, 2015:
We have some successful experience in the use of&n ...read more We have some successful experience in the use of cementitious coating to combat Accelerated Low Water Corrosion (ALWC), a form of microbiologically induced corrosion that can occur on sheet piling and other marine structures at or around the low water level. Unheard of in the UK until the 1990’s, this is a phenomenon which has been described as a ‘steel-eating bug epidemic’ and is characterised by localised areas of soft orange corrosion products, overlaying a black organic sludge containing colonies of several types of bacteria. It is a concern to many port authorities and engineers worldwide as it can pose unexpected engineering and financial challenges. Cases of ALWC have been found on structures within just 20 years of operation, thereby requiring extensive and costly repair work on structures which would have otherwise been expected to have an effective life of 60-120 years. The problem is not just associated with salt water; it has also been found on structures exposed to fresh water. The most economical solution is to provide protection from accelerated corrosion at an early stage, thus maximising the design life and avoiding the risk of catastrophic, sudden failure with all the associated expense of repairs, lost business and risks to health and safety. A waterborne cementitious coating offers an effective defence strategy to ALWC as it cures to form a dense coating with high levels of protection from water, oxygen and chloride ion penetration