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Table 1 Summary of experimental results of previous studies of Fe(II) reacted with Mn-oxides

From: Fe(II) reduction of pyrolusite (β-MnO2) and secondary mineral evolution

Mn-oxide substrate

Fe-oxide formed

Conditions

Notes

References

Birnessite [δ-MnO2]

FeOOH

pH 3–6

Fe(III) stays in solution for pH < 4 and XRD inconclusive

[18]

Birnessite [δ-MnO2]

Lepidocrocite and trace goethite

pH 4–6

Higher pH produces more goethite, noncrystalline Fe-oxide

[32]

Hexagonal birnessite

Lepidocrocite and goethite

pH 4–7

Less goethite under anoxic conditions compared to oxic

[48]

Cryptomelane [KMn8O16]

Akaganeite-FeOOH

pH 3–6

[20]

Hausmannite [Mn3O4]

Magnetite Fe3O4

pH 3–6

[20]

MnO2

Fe(OH)3

[15]

MnO2

Fe(OH)3; 6-line ferrihydrite

Column pH 2.5–6

Natural Mn-oxide coated sand

[19]

Pyrolusite [β-MnO2]

Fe-oxyhydroxide, lepidocrocite

pH 3–6

[20]

Pyrolusite coated silica sand

2-line ferrihydrite and jacobsite (MnFe2O4)

pH 3

Fe(III) precipitates inhibit reductive dissolution of pyrolusite by Fe(II)

[16]

Pyrolusite coated quartz

Schwertmannite or sulfate-substituted ferrihydrite

pH 3

[17]

Poorly crystalline MnO2 (similar to birnessite) and freshwater sediment

Amorphic Fe(III) oxide

pH 7

[49]

Vernadite [δ-MnO2]

Fe2O3

pH 7.4

Fe phase proposed in equation but not characterized

[50]