We investigated the microbial community that developed at an iron seep where anoxic groundwater containing up to 250 muM Fe flowed out of a rock wall and dense, mat-like aggregations of ferric hydroxides formed at the oxic-anoxic interface. In situ analysis with oxygen microelectrodes revealed that the oxygen concentrations in the mat were rarely more than 50% of air saturation and that the oxy...

Mining-impacted sediments of Lake Coeur d'Alene, Idaho, contain more than 10% metals on a dry weight basis, approximately 80% of which is iron. Since iron (hydr)oxides adsorb toxic, ore-associated elements, such as arsenic, iron (hydr)oxide reduction may in part control the mobility and bioavailability of these elements. Geochemical and microbiological data were collected to examine the ecologi...

The difference in the standard Gibbs free energy for the formation of any two oxides or sulfides is the chemical potential for selective reduction of metals from complex minerals. The magnitude of the Gibbs free energy difference is shown by plotting the univariant relationships for relevant sulfides and oxides. In this investigation, three examples of mineral sulfides are considered, and the e...

Biogeochemical transformation (inclusive of dissolution) of iron (hydr)oxides resulting from dissimilatory reduction has a pronounced impact on the fate and transport of nutrients and contaminants in subsurface environments. Despite the reactivity noted for pristine (unreacted) minerals, iron (hydr)oxides within native environments will likely have a different reactivity owing in part to change...

Mobilization of contaminant Pb and other cations from a weathered andesite was examined by conducting water–rock leaching experiments to measure release rates of the major and minor elements found in the bulk rock. Experiments were conducted for over 600 h, at pH 3 and 6.5, as a function of grain size, and in the presence and absence of a common subsurface bacterial species, Bacillus subtilis. ...

We have developed an efficient conversion of amino iron oxides to carbohydrate and protein derived nanoparticles with highly conserved bioactivity through a combination of diazo transfer and azide-alkyne click technology.

Benzohydroxamic acid is shown to be an unexpectedly good ligand for iron(iii) oxides, favouring surface attachment to the formation of trisbenzohydroxamato complexes, which are known to have very high thermodynamic stability in solution.

CORROSION is a natural process. Just like water flows to the lowest level, all natural processes tend toward the lowest possible energy states. Thus, for example, iron and steel have a natural tendency to combine with other chemical elements to return to their lowest energy states. In order to return to lower energy states, iron and steel frequently combine with oxygen and water, both of which ...