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Title: Microbial Methylation of Iodide in Unconfined Aquifer Sediments at the Hanford Site, USA

Abstract

Incomplete knowledge of environmental transformation reactions limits our ability to accurately inventory and predictably model the fate of radioiodine. The most prevalent chemical species of iodine include iodate (IO3-), iodide (I-), and organo-iodine. The emission of gaseous species could be significant loss or flux term but these processes have not been investigated at radioiodine impacted sites. We examined iodide methylation and volatilization for Hanford Site sediments from 3 different locations under native and organic substrate amended conditions at 3 iodide concentrations. Aqueous and gaseous sampling revealed methyl-iodide to be the only iodinated compound produced under biotic conditions. No abiotic transformations of iodide were measured. Methyl-iodide was produced by 52 out of 54 microcosms, regardless of prior exposure to iodine contamination or the experimental concentration. Interestingly, iodide volatilization activity was consistently higher under native (oligotrophic) Hanford sediment conditions. Carbon and nutrients were not only unnecessary for microbial activation, but supplementation resulted in > 3 fold reduction in methyl-iodide formation. This investigation not only demonstrates the potential for iodine volatilization in deep, oligotrophic subsurface sediments at a nuclear waste site, but also emphasizes an important role for biotic methylation pathways to the long-term management and monitoring of radioiodine in the environment.

Authors:
 [1];  [1];  [1];  [1]; ORCiD logo [1]
  1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States). Earth Systems Science Div.
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1574898
Report Number(s):
PNNL-SA-143910
Journal ID: ISSN 1664-302X; TRN: US2001180
Grant/Contract Number:  
AC05-76RL01830
Resource Type:
Accepted Manuscript
Journal Name:
Frontiers in Microbiology
Additional Journal Information:
Journal Volume: 10; Journal ID: ISSN 1664-302X
Publisher:
Frontiers Research Foundation
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Bagwell, Christopher E., Zhong, Lirong, Wells, Jacqueline R., Mitroshkov, Alexandre V., and Qafoku, Nikolla P. Microbial Methylation of Iodide in Unconfined Aquifer Sediments at the Hanford Site, USA. United States: N. p., 2019. Web. doi:10.3389/fmicb.2019.02460.
Bagwell, Christopher E., Zhong, Lirong, Wells, Jacqueline R., Mitroshkov, Alexandre V., & Qafoku, Nikolla P. Microbial Methylation of Iodide in Unconfined Aquifer Sediments at the Hanford Site, USA. United States. doi:https://doi.org/10.3389/fmicb.2019.02460
Bagwell, Christopher E., Zhong, Lirong, Wells, Jacqueline R., Mitroshkov, Alexandre V., and Qafoku, Nikolla P. Thu . "Microbial Methylation of Iodide in Unconfined Aquifer Sediments at the Hanford Site, USA". United States. doi:https://doi.org/10.3389/fmicb.2019.02460. https://www.osti.gov/servlets/purl/1574898.
@article{osti_1574898,
title = {Microbial Methylation of Iodide in Unconfined Aquifer Sediments at the Hanford Site, USA},
author = {Bagwell, Christopher E. and Zhong, Lirong and Wells, Jacqueline R. and Mitroshkov, Alexandre V. and Qafoku, Nikolla P.},
abstractNote = {Incomplete knowledge of environmental transformation reactions limits our ability to accurately inventory and predictably model the fate of radioiodine. The most prevalent chemical species of iodine include iodate (IO3-), iodide (I-), and organo-iodine. The emission of gaseous species could be significant loss or flux term but these processes have not been investigated at radioiodine impacted sites. We examined iodide methylation and volatilization for Hanford Site sediments from 3 different locations under native and organic substrate amended conditions at 3 iodide concentrations. Aqueous and gaseous sampling revealed methyl-iodide to be the only iodinated compound produced under biotic conditions. No abiotic transformations of iodide were measured. Methyl-iodide was produced by 52 out of 54 microcosms, regardless of prior exposure to iodine contamination or the experimental concentration. Interestingly, iodide volatilization activity was consistently higher under native (oligotrophic) Hanford sediment conditions. Carbon and nutrients were not only unnecessary for microbial activation, but supplementation resulted in > 3 fold reduction in methyl-iodide formation. This investigation not only demonstrates the potential for iodine volatilization in deep, oligotrophic subsurface sediments at a nuclear waste site, but also emphasizes an important role for biotic methylation pathways to the long-term management and monitoring of radioiodine in the environment.},
doi = {10.3389/fmicb.2019.02460},
journal = {Frontiers in Microbiology},
number = ,
volume = 10,
place = {United States},
year = {2019},
month = {10}
}

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Works referenced in this record:

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journal, August 2013

  • Zhang, Saijin; Xu, Chen; Creeley, Danielle
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Formation of methyl iodide on a natural manganese oxide
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Iodine-129 and Caesium-137 in Chernobyl contaminated soil and their chemical fractionation
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Combining 16S rRNA gene variable regions enables high-resolution microbial community profiling
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Biogenic fluxes of halomethanes from Irish peatland ecosystems
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Abiotic formation of organoiodine compounds by manganese dioxide induced iodination of dissolved organic matter
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Incorporation Modes of Iodate in Calcite
journal, April 2018

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Sorption and speciation of iodine in groundwater system: The roles of organic matter and organic-mineral complexes
journal, June 2017


Sequestration and Remobilization of Radioiodine ( 129 I) by Soil Organic Matter and Possible Consequences of the Remedial Action at Savannah River Site
journal, December 2011

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Microbial Participation in Iodine Volatilization from Soils
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The geochemistry of iodine — a review
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Bacteria Mediate Methylation of Iodine in Marine and Terrestrial Environments
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Radioiodine Biogeochemistry and Prevalence in Groundwater
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Technetium and iodine aqueous species immobilization and transformations in the presence of strong reductants and calcite-forming solutions: Remedial action implications
journal, September 2018


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Ectomycorrhizal fungi: A new source of atmospheric methyl halides?
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Comparison of Iodide and Iodate Accumulation and Volatilization by Filamentous Fungi during Static Cultivation
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Sorption and transport of iodine species in sediments from the Savannah River and Hanford Sites
journal, July 2005


Reduction of TcO4− by sediment-associated biogenic Fe(II)
journal, August 2004

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Geochemical Processes Controlling Migration of Tank Wastes in Hanford's Vadose Zone
journal, January 2007

  • Zachara, John M.; Serne, Jeff; Freshley, Mark
  • Vadose Zone Journal, Vol. 6, Issue 4
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Methyl iodide distribution in the ocean and fluxes to the atmosphere
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  • Moore, Robert M.; Groszko, Wayne
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  • DOI: 10.1029/1998JC900073

    Works referencing / citing this record:

    Combining 16S rRNA gene variable regions enables high-resolution microbial community profiling
    journal, January 2018


    Incorporation Modes of Iodate in Calcite
    journal, April 2018

    • Kerisit, Sebastien N.; Smith, Frances N.; Saslow, Sarah A.
    • Environmental Science & Technology, Vol. 52, Issue 10
    • DOI: 10.1021/acs.est.8b00339

    Tracing the History of Nuclear Releases:  Determination of 129 I in Tree Rings
    journal, March 2002

    • Rao, Usha; Fehn, Udo; Muramatsu, Yasuyuki
    • Environmental Science & Technology, Vol. 36, Issue 6
    • DOI: 10.1021/es011045i

    Sorption and speciation of iodine in groundwater system: The roles of organic matter and organic-mineral complexes
    journal, June 2017


    Microbial Participation in Iodine Volatilization from Soils
    journal, September 2003

    • Amachi, Seigo; Kasahara, Mizuyo; Hanada, Satoshi
    • Environmental Science & Technology, Vol. 37, Issue 17
    • DOI: 10.1021/es0210751

    Ectomycorrhizal fungi: A new source of atmospheric methyl halides?
    journal, June 2004


    Geochemical Processes Controlling Migration of Tank Wastes in Hanford's Vadose Zone
    journal, January 2007

    • Zachara, John M.; Serne, Jeff; Freshley, Mark
    • Vadose Zone Journal, Vol. 6, Issue 4
    • DOI: 10.2136/vzj2006.0180

    Methyl iodide distribution in the ocean and fluxes to the atmosphere
    journal, May 1999

    • Moore, Robert M.; Groszko, Wayne
    • Journal of Geophysical Research: Oceans, Vol. 104, Issue C5
    • DOI: 10.1029/1998jc900073

    Formation of volatile iodinated alkanes in soil: results from laboratory studies
    journal, July 2003


    Determination of organic, inorganic and particulate iodine in the coastal atmosphere of Japan
    journal, October 1995

    • Yoshida, S.; Muramatsu, Y.
    • Journal of Radioanalytical and Nuclear Chemistry Articles, Vol. 196, Issue 2
    • DOI: 10.1007/bf02038047

    Iodine-129 and Iodine-127 Speciation in Groundwater at the Hanford Site, U.S.: Iodate Incorporation into Calcite
    journal, August 2013

    • Zhang, Saijin; Xu, Chen; Creeley, Danielle
    • Environmental Science & Technology, Vol. 47, Issue 17
    • DOI: 10.1021/es401816e

    Emissions of Methyl Halides and Methane from Rice Paddies
    journal, November 2000


    Analysis of 129I and its Application as Environmental Tracer
    journal, September 2012

    • Hou, Xiaolin; Hou, Yingkun
    • Journal of Analytical Science & Technology, Vol. 3, Issue 2
    • DOI: 10.5355/jast.2012.135

    Radioiodine Biogeochemistry and Prevalence in Groundwater
    journal, August 2014

    • Kaplan, D. I.; Denham, M. E.; Zhang, S.
    • Critical Reviews in Environmental Science and Technology, Vol. 44, Issue 20
    • DOI: 10.1080/10643389.2013.828273

    Comparison of Iodide and Iodate Accumulation and Volatilization by Filamentous Fungi during Static Cultivation
    journal, June 2017

    • Duborská, Eva; Urík, Martin; Bujdoš, Marek
    • Water, Air, & Soil Pollution, Vol. 228, Issue 6
    • DOI: 10.1007/s11270-017-3407-4

    Iodine-129 and Caesium-137 in Chernobyl contaminated soil and their chemical fractionation
    journal, June 2003


    Biogenic fluxes of halomethanes from Irish peatland ecosystems
    journal, January 2001


    Radioiodine sorption/desorption and speciation transformation by subsurface sediments from the Hanford Site
    journal, January 2015


    The geochemistry of iodine — a review
    journal, June 1986

    • Fuge, Ronald; Johnson, Christopher C.
    • Environmental Geochemistry and Health, Vol. 8, Issue 2
    • DOI: 10.1007/bf02311063

    Halocarbons produced by natural oxidation processes during degradation of organic matter
    journal, January 2000

    • Keppler, F.; Eiden, R.; Niedan, V.
    • Nature, Vol. 403, Issue 6767
    • DOI: 10.1038/35002055

    Sorption and transport of iodine species in sediments from the Savannah River and Hanford Sites
    journal, July 2005


    Reduction of TcO4− by sediment-associated biogenic Fe(II)
    journal, August 2004

    • Fredrickson, James K.; Zachara, John M.; Kennedy, David W.
    • Geochimica et Cosmochimica Acta, Vol. 68, Issue 15
    • DOI: 10.1016/j.gca.2003.10.024

    The distribution and transformations of iodine in the environment
    journal, January 1984


    Bacteria Mediate Methylation of Iodine in Marine and Terrestrial Environments
    journal, June 2001


    Sequestration and Remobilization of Radioiodine ( 129 I) by Soil Organic Matter and Possible Consequences of the Remedial Action at Savannah River Site
    journal, December 2011

    • Xu, Chen; Miller, Eric J.; Zhang, Saijin
    • Environmental Science & Technology, Vol. 45, Issue 23
    • DOI: 10.1021/es201343d

    Hanford Site Vadose Zone Studies: An Overview
    journal, January 2007

    • Gee, G. W.; Oostrom, M.; Freshley, M. D.
    • Vadose Zone Journal, Vol. 6, Issue 4
    • DOI: 10.2136/vzj2006.0179

    Formation of methyl iodide on a natural manganese oxide
    journal, August 2010


    Technetium and iodine aqueous species immobilization and transformations in the presence of strong reductants and calcite-forming solutions: Remedial action implications
    journal, September 2018


    Biospheric 129I Concentrations in the Pre-nuclear and Nuclear Age
    journal, January 1993


    A study on the association of two iodine isotopes, of natural127I and of the fission product129I, with soil components using a sequential extraction procedure
    journal, November 1995

    • Schmitz, K.; Aumann, D. C.
    • Journal of Radioanalytical and Nuclear Chemistry Articles, Vol. 198, Issue 1
    • DOI: 10.1007/bf02038260

    Abiotic formation of organoiodine compounds by manganese dioxide induced iodination of dissolved organic matter
    journal, May 2018


    Iodine-129 and iodine-127 in environmental samples collected from Tokaimura/Ibaraki, Japan
    journal, January 1986