Multiple organic substrates support Mn(II) removal with enrichment of Mn(II)-oxidizing bacteria

Shoiful Ahmad

Ohta Taiki

Kambara Hiromi

Matsushita Shuji

Kindaichi Tomonori

Ozaki Noriatsu

Aoi Yoshiteru

Imachi Hiroyuki

Ohashi Akiyoshi

Journal of Environmental Management

Journal of Environmental Management

Three different organic substrates, K-medium, sterilized activated sludge (SAS), and methanol, were examined for utility as substrates for enriching manganese-oxidizing bacteria (MnOB) in an open bioreactor. The differences in Mn(II) oxidation performance between the substrates were investigated using three down-flow hanging sponge (DHS) reactors continuously treating artificial Mn(II)-containing water over 131 days. The results revealed that all three substrates were useful for enriching MnOB. Surprisingly, we observed only slight differences in Mn(II) removal between the substrates. The highest Mn(II) removal rate for the SAS-supplied reactor was 0.41 kg Mn⋅m−3⋅d−1, which was greater than that of K-medium, although the SAS performance was unstable. In contrast, the methanol-supplied reactor had more stable performance and the highest Mn(II) removal rate. We conclude that multiple genera of Comamonas, Pseudomonas, Mycobacterium, Nocardia and Hyphomicrobium play a role in Mn(II) oxidation and that their relative predominance was dependent on the substrate. Moreover, the initial inclusion of abiotic-MnO2 in the reactors promoted early MnOB enrichment.

Biological manganese oxidation

Down-flow hanging sponge reactor

K-medium

Manganese-oxidizing bacteria

Methanol

Sterilized activated sludge

eng

Elsevier

© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

This is not the published version. Please cite only the published version. この論文は出版社版ではありません。引用の際には出版社版をご確認、ご利用ください。

[ISSN] 0301-4797

[DOI] 10.1016/j.jenvman.2019.109771

[PMID] 32072950

[DOI] https://doi.org/10.1016/j.jenvman.2019.109771