Fig. 7. Chromium oxidation by four Mn oxides in 12 h at pH 4 and 7. The four Mn oxides are abbreviated as follows: todorokite (T), birnessite (B), lithiophorite (L), and pyrolusite (P).
Fig. 7. Chromium oxidation by four Mn oxides in 12 h at pH 4 and 7. The four Mn oxides are abbreviated as follows: todorokite (T), birnessite (B), lithiophorite (L), and pyrolusite (P).