Preferential elimination of Ba through irreversible biogenic manganese oxide sequestration

Tani, Yukinori*; Kakinuma, Satomi*; Chang, J.*; Tanaka, Kazuya  ; Miyata, Naoyuki*

In this study, we examined the Ba sequestration potential of enzymatically active biogenic Mn oxides (BMOs) with and without exogenous Mn. The BMOs readily oxidized exogenous Mn to produce another BMO phase, and subsequently sequestered Ba at a pH of 7.0, with irreversible Ba sequestration as the dominant pathway. Extended X-ray absorption fine structure spectroscopy and X-ray diffraction analyses demonstrated alteration from turbostratic to tightly stacked birnessite through possible Ba incorporation into the interlayer.