5 Microbiologically Induced Corrosion (MIC)

Question 1

A form of corrosion caused by living organisms such as bacteria, algae or fungi. It is often associated with
the presence of tubercles or slimy organic substances.

Answer 1

Micro biologically Induced Corrosion (MIC)

Question 2

MIC is usually found in ,,,,,

Answer 2

• aqueous environments or
• services where water is present
• stagnant or low-flow conditions

Question 3

MIC is usually causes due to conditions such as,,,,,

Answer 3

• lack of oxygen,
• light or dark,
• high salinity,
• pH range of 0 to 12, and
• temperatures from 0°F to 235°F

Question 4

MIC affected systems may become,,,,,,by the introduction of organisms that multiply and spread unless controlled.

Answer 4

“inoculated”

Question 5

Different organisms thrive on different nutrients including,,,,,

Answer 5

• Inorganic substances (sulfur, ammonia, H2S,

hydrocarbons, organic acids)

Question 6

All MIC organisms require a source of ,,,,,,, for growth.

Answer 6

• Carbon,
• Nitrogen and
• Phosphorous

Question 7

MIC corrosion is usually observed as ,,,,, under deposits or tubercles that shield the organisms

Answer 7

localized pitting

Question 8

MIC - Damage is often characterized by ,,,,,in carbon steel or ,,,,,,in stainless steel

Answer 8

• Cup-shaped pits within pits

- Subsurface cavities

Question 9

MIC corrosion can be prevented by treating system water with,,,,,,

Answer 9

biocides such as,
chlorine, bromine, ozone, ultraviolet light or proprietary
compounds.

Question 10

Proper application of biocides will control but ,,,,,,microbes so that continued treatment is necessary

Answer 10

not eliminate