Speciation of iron in the aquatic environment.

Iron is one of the basic metals occurring in the aquatic environment and it is considered a macroelement with regard to live organisms. This metal has a broad range of applications that, together with factors conditioning its chemical transitions, results in the occurrence of many iron species in water. Depending on water and land development type, as well as the use of water for household and industrial purposes, iron may be found in different forms, including solutions, colloids or suspensions, made up by both simple ions or particles and complex organic or inorganic compounds. Due to changing properties of the different iron forms and their varying influence, it is critical to gain information about its speciation. In this article we present information about iron species, including nano-iron forms, in various aquatic environments (i.e., marshland, ocean waters) as well as the exemplary methods for separating iron from iron-containing environmental samples.