What Does Tuberculation Mean?
Tuberculation is the development of small mounds of corrosion products on the inside of iron pipes. These mounds are reddish brown and of various sizes.
This phenomenon generally happens in domestic water distribution systems where iron pipes are used for water supply. Tuberculation makes pipes rough inside, which can increase pumping costs and the pressure in the distribution system, while decreasing pump efficiency. In severe cases, it can cause pipelines to leak.
Corrosionpedia Explains Tuberculation
Tuberculation usually begins with a slime that may show signs of iron oxide precipitation. Iron bacteria attach themselves to the inside of the pipe and metabolize ferrous ions from the water as an energy source to create ferrous oxide. This creates an oxygen concentration cell, thus promoting dissolution of iron as Fe2+ under the deposit. As these ions move outward, they are oxidized to Fe3+ as they encounter higher oxygen concentrations. This creates a corrosion product of Fe(OH)3, which mixes with the biodeposit to create a growing tubercule.
Tuberculation can be prevented by proper chemical treatment of pipelines or by using a cement mortar lining.