Aljarafe_soilIron is the 5th most abundant element in the Earth’s crust. It occurs naturally as either ferrous or ferric iron and forms a wide variety of minerals, some of which are highly reactive towards environmental processes. Iron tends to coordinate with a large number of organic and inorganic ligands, and this in turn exerts a strong impact on its redox properties.

The relevance of these properties with respect to a wide range of (bio)geochemical processes in aquatic systems has been addressed by various disciplines within the environmental, geochemical and biogeochemical sciences. Such processes are generally related to the surface properties and transformation reactions of iron minerals.



It is impossible to detail here all the major processes in which iron plays a principal role, but some of the environmentally most significant ones, and that are of direct relevance to this programme, are listed below:

  • Iron is an important metal cofactor in many redox active and regulatory proteins required for a diverse range of metabolic processes.
  • Iron species serve as electron acceptors for heterotrophic bacterial growth (e. g. iron(III) (oxyhydr)oxides) and as electron donors for chemoautotrophic (e. g. pyrite) and photoautotrophic growth of bacteria and archaea.
  • Efficient iron metabolism is critical for life in many environments, where it is the limiting nutrient controlling many biogeochemical cycles.
  • Iron is of importance to those interested in the origin of life, with iron minerals potentially serving as templates for prototype metabolic reactions, and potential electron donors or acceptors for early respiratory processes.
  • Iron forms a wide number of minerals with varying surface reactivities that play a prominent role in environmental chemistry, including both natural processes (e.g. adsorption, abiotic reduction during sediment diagenesis) and anthropogenic activities such as water treatment and contaminant degradation in soils and ground water. Furthermore, weathering of iron minerals (particularly pyrite) may lead to severe environmental damage.
  • The redox chemistry of iron during sediment diagenesis is strongly linked to the global carbon and sulfur cycles and may drive CO2 storage in sediments. It has hence played an important role in governing the chemical state of the Earth’s surface in both the modern environment and throughout geological time.

Our understanding of the chemical and biological fundamentals of surface processes and iron mineral transformation reactions is, however, still incomplete. Improvement of our knowledge on the function of this abundant element in biogeochemical cycles is therefore a goal in many scientific disciplines. Moreover, it will significantly contribute to obtaining a better understanding of processes that are crucial to human and societal development such as the supply of clean water, remediation of contaminated sites or the regulation of CO2 emissions.

It therefore appears that the time is ripe to formulate a cross-disciplinary approach to understanding the role of iron in the environment and to make the ensuing knowledge, expertise and relevant instrumentation available to researchers throughout Europe. This Research Networking Programme addresses this need through an intensive training and education programme.

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last modified 2009-12-18