Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1071/EN10125
Title (Primary) FeII oxidation by molecular O2 during HCl extraction
Author Porsch, K.; Kappler, A.
Source Titel Environmental Chemistry
Year 2011
Department BIOENERGIE
Volume 8
Issue 2
Page From 190
Page To 197
Language englisch
Keywords abiotic oxidation; biogeochemistry; geomicrobiology; iron minerals; soil extraction
Abstract HCl is commonly used to stabilise FeII under oxic conditions and is often included in Fe extractions. Although FeII oxidation by molecular O2 in HCl is described in the field of hydrometallurgy, this phenomenon has not been systematically studied in environmentally relevant systems. The extent of FeII oxidation by O2 during extraction of soils and magnetite by HCl and in HCl/FeCl2 solutions was therefore quantified. FeII was stable in 1 M HCl at room temperature for several days, whereas in 6 M HCl at 70°C, 90% of the FeII was oxidised within 24 h. In the absence of O2, no FeII oxidation occurred. Experiments at low pH with increasing H+ or Cl concentration alone and geochemical modelling suggested that the formation of complexes of FeII and HCl may be responsible for the observed FeII oxidation. The use of strictly anoxic conditions for Fe extraction by HCl to obtain reliable Fe redox speciation data is therefore recommended.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=14763
Porsch, K., Kappler, A. (2011):
FeII oxidation by molecular O2 during HCl extraction
Environ. Chem. 8 (2), 190 - 197 10.1071/EN10125