Microbially formed Mn(IV) oxide as a novel adsorbent for removal of Radium

被引：0

作者：

Tanaka K. ^{[1
,6
]}

Yamaji K. ^{[2
]}

Masuya H. ^{[3
]}

Tomita J. ^{[4
]}

Ozawa M. ^{[4
]}

Yamasaki S. ^{[5
]}

Tokunaga K. ^{[6
]}

Fukuyama K. ^{[6
]}

Ohara Y. ^{[6
]}

Maamoun I. ^{[1
]}

Yamaguchi A. ^{[1
,7
,8
]}

Takahashi Y. ^{[8
]}

Kozai N. ^{[1
,6
]}

Grambow B. ^{[1
,9
]}

机构：

[1] Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki

[2] Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki

[3] Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki

[4] Department of Radiation Protection, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki

[5] Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki

[6] Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency, Kagamino, Tomata, Okayama

[7] Center for Computational Science and e-Systems, Japan Atomic Energy Agency, 178-4 Wakashiba, Chiba, Kashiwa

[8] Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo

[9] Subatech, UMR 6457 IMT-Atlantique, Université de Nantes CNRS/IN2P3, Nantes

来源：

Chemosphere | 2024年 / 355卷

基金：

日本学术振兴会;

关键词：

Mn(II) oxidizing fungus; Mn(IV) oxide; Radium; 226; Uranium mill tailings pond;

D O I：

10.1016/j.chemosphere.2024.141837

中图分类号：

学科分类号：

摘要：

Radioactivity of Ra isotopes in natural waters is of serious concern. Control of 226Ra concentrations in tailings ponds, which store waste from U ore extraction processes, is an important issue in mill tailings management. In this study, we tested microbially formed Mn(IV) oxide as an adsorbent for removal of Ra in water treatment. Biogenic Mn(IV) oxide (BMO) was prepared using a Mn(II)-oxidizing fungus, Coprinopsis urticicola strain Mn-2. First, adsorption experiments of Sr and Ba, as surrogates for Ra, onto BMO were conducted in aqueous NaCl solution at pH 7. Distribution coefficients for Ba and Sr were estimated to be ∼106.5 and ∼104.3 mL/g, respectively. EXAFS analysis indicated that both Sr and Ba adsorbed in inner-sphere complexes on BMO, suggesting that Ra would adsorb in a similar way. From these findings, we expected that BMO would work effectively in removal of Ra from water. Then, BMO was applied to remove Ra from mine water collected from a U mill tailings pond. Just 7.6 mg of BMO removed >98% of the 226Ra from 3 L of mine water, corresponding to a distribution coefficient of 107.4 mL/g for Ra at pH ∼7. The obtained value was convincingly high for practical application of BMO in water treatment. At the same time, the high distribution coefficient indicates that Mn(IV) oxide can be an important carrier and host phase of Ra in the environment. © 2024 Elsevier Ltd

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