Iron Chemistry
Introduction of Iron Chemistry
The redox reaction of iron chemistry are involved in several important phenomena accouring in natural waters and water treatment systems. The oxidation of reduced iron minerals, such as pyrite (FeS2), produces acidic waters and the problem of acid mine drainage. The oxidation/reduction of iron in soil adn groundwaters determines the iron content of these waters.
Redox reaction are intimately involved in the removal of iron from waters. As we know that the oxidation of metallic iron is an important corrosion reaction. The purpose of this article is to expand the discussion on the chemistry of iron and to use it as an example of redox reactions in natural waters. The reaction kinetics of redox reactions will be discussed using ferrous iron oxidation as an example.
Iron in Groundwaters
Iron equilibria in groundwaters can be nicely modeled with a pH diagram that includes the interaction of iron species with sulfide and bicarbonate. Two more solids are evident: ferrous carbonate (FeCO3) and ferrous disulfide (FeS2). The iron content of waters from this region is very low because at pH 6, for example, only a fraction of Fe3+/liter is in solution at equilibrium. They produce waters with a low pH because they are often in the biologically active zone of the soil where considerable CO2 production take place.
The redox reaction of iron chemistry are involved in several important phenomena accouring in natural waters and water treatment systems. The oxidation of reduced iron minerals, such as pyrite (FeS2), produces acidic waters and the problem of acid mine drainage. The oxidation/reduction of iron in soil adn groundwaters determines the iron content of these waters.
Redox reaction are intimately involved in the removal of iron from waters. As we know that the oxidation of metallic iron is an important corrosion reaction. The purpose of this article is to expand the discussion on the chemistry of iron and to use it as an example of redox reactions in natural waters. The reaction kinetics of redox reactions will be discussed using ferrous iron oxidation as an example.
Iron in Groundwaters
Iron equilibria in groundwaters can be nicely modeled with a pH diagram that includes the interaction of iron species with sulfide and bicarbonate. Two more solids are evident: ferrous carbonate (FeCO3) and ferrous disulfide (FeS2). The iron content of waters from this region is very low because at pH 6, for example, only a fraction of Fe3+/liter is in solution at equilibrium. They produce waters with a low pH because they are often in the biologically active zone of the soil where considerable CO2 production take place.
