Several
iron sulfide polymorphs have been identified within oil and gas pipelines.
Moreover, it was reported that the formation of gold NPs by Plectonema boryanum UTEX 485 occurred by three possible mechanisms involving
iron sulfide, localized reducing conditions, and metabolism [148].
These naturally occurring, marine-derived soils are characterised by a highly acidic (pH <3.5) oxidised horizon, overlying a neutral to alkaline (pH >6.5) reduced horizon rich in
iron sulfides. These soils are stable under reducing conditions.
The main conclusions obtained from these studies have been: i) both abiotic and biotic
iron sulfide films ate related to the formation of tubercles on the steel surface.
It can be found on quartz, dolomite,
iron sulfide minerals and chalcopyrite.
Bush RT (2000)
Iron sulfide micromorphology and mineralogy in acid sulfate soils: their formation and behaviour.
"When you bring this
iron sulfide to the surface, what you're doing is exposing these metal sulfides to oxygen and water," Chapin says.
Region 3 contains high levels of ferrous iron in the first meter of sediment, where a black precipitate of
iron sulfide exists just beneath the sediment surface.
Pyrite is
iron sulfide. When this chemical is exposed to air or water it forms sulfuric acid.
Another possible mechanism could be
iron sulfide and residual unreacted iron in the return activated sludge flow.
Characteristic of the mixed regime is the formation of scales of iron carbonate and
iron sulfide. The application of a sweet corrosion model for the mixed regime appears justified, though it maybe conservative [4].
The EPS attracts the paraffin crystals, asphaltenes and
iron sulfide to form a deposit on any surface.