Abiotic oxidation of Mn(II) induced oxidation and mobilization of As(III) in the presence of magnetite and hematite

- Abiotic oxidation of Mn(II) to amorphous Mn(III, IV) (hydr)oxides (MnOx) occurred on magnetite and hematite.
- MnOx formed through abiotic oxidation of Mn(II) on iron oxides oxidized either dissolved or adsorbed As(III) to As(V).
- A fraction of the oxidized As(V) was released back into solution.
- MnOx formed on iron oxides could take up the sorption sites previously occupied by As(III) and make TAs released.