Fate of neptunium in an anaerobic, methanogenic microcosm

J. E. Banaszak, S. M. Webb, Bruce Rittmann, J. F. Gaillard, D. T. Reed

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)

Abstract

Neptunium is found predominantly as Np(IV) in reducing environments, but as Np(V) in aerobic environments. Currently, it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. To evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosm inoculated with anaerobic sediments from a metal-contaminated freshwater lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10 -5 M Np did not inhibit methane production. Total Np solubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbially produced Mn(II/III) and Fe(II) may serve as electron donors for Np reduction.

Original languageEnglish (US)
Title of host publicationMaterials Research Society Symposium - Proceedings
PublisherMaterials Research Society
Pages1141-1149
Number of pages9
Volume556
StatePublished - 1999
Externally publishedYes
EventProceedings of the 1998 MRS Fall Meeting - Symposium 'Scientific Basis for Nuclear Waste Management XXII' - Boston, MA, USA
Duration: Nov 30 1998Dec 4 1998

Other

OtherProceedings of the 1998 MRS Fall Meeting - Symposium 'Scientific Basis for Nuclear Waste Management XXII'
CityBoston, MA, USA
Period11/30/9812/4/98

Fingerprint

Neptunium
Sediments
Metals
Methane
Absorption spectroscopy
Microorganisms
Sulfates
Lakes
Acetates
Solubility
Oxidation
Electrons
Substrates

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Banaszak, J. E., Webb, S. M., Rittmann, B., Gaillard, J. F., & Reed, D. T. (1999). Fate of neptunium in an anaerobic, methanogenic microcosm. In Materials Research Society Symposium - Proceedings (Vol. 556, pp. 1141-1149). Materials Research Society.

Fate of neptunium in an anaerobic, methanogenic microcosm. / Banaszak, J. E.; Webb, S. M.; Rittmann, Bruce; Gaillard, J. F.; Reed, D. T.

Materials Research Society Symposium - Proceedings. Vol. 556 Materials Research Society, 1999. p. 1141-1149.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Banaszak, JE, Webb, SM, Rittmann, B, Gaillard, JF & Reed, DT 1999, Fate of neptunium in an anaerobic, methanogenic microcosm. in Materials Research Society Symposium - Proceedings. vol. 556, Materials Research Society, pp. 1141-1149, Proceedings of the 1998 MRS Fall Meeting - Symposium 'Scientific Basis for Nuclear Waste Management XXII', Boston, MA, USA, 11/30/98.
Banaszak JE, Webb SM, Rittmann B, Gaillard JF, Reed DT. Fate of neptunium in an anaerobic, methanogenic microcosm. In Materials Research Society Symposium - Proceedings. Vol. 556. Materials Research Society. 1999. p. 1141-1149
Banaszak, J. E. ; Webb, S. M. ; Rittmann, Bruce ; Gaillard, J. F. ; Reed, D. T. / Fate of neptunium in an anaerobic, methanogenic microcosm. Materials Research Society Symposium - Proceedings. Vol. 556 Materials Research Society, 1999. pp. 1141-1149
@inproceedings{ea44ace3ccf844aeb14c05c03f7b15f5,
title = "Fate of neptunium in an anaerobic, methanogenic microcosm",
abstract = "Neptunium is found predominantly as Np(IV) in reducing environments, but as Np(V) in aerobic environments. Currently, it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. To evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosm inoculated with anaerobic sediments from a metal-contaminated freshwater lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10 -5 M Np did not inhibit methane production. Total Np solubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbially produced Mn(II/III) and Fe(II) may serve as electron donors for Np reduction.",
author = "Banaszak, {J. E.} and Webb, {S. M.} and Bruce Rittmann and Gaillard, {J. F.} and Reed, {D. T.}",
year = "1999",
language = "English (US)",
volume = "556",
pages = "1141--1149",
booktitle = "Materials Research Society Symposium - Proceedings",
publisher = "Materials Research Society",

}

TY - GEN

T1 - Fate of neptunium in an anaerobic, methanogenic microcosm

AU - Banaszak, J. E.

AU - Webb, S. M.

AU - Rittmann, Bruce

AU - Gaillard, J. F.

AU - Reed, D. T.

PY - 1999

Y1 - 1999

N2 - Neptunium is found predominantly as Np(IV) in reducing environments, but as Np(V) in aerobic environments. Currently, it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. To evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosm inoculated with anaerobic sediments from a metal-contaminated freshwater lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10 -5 M Np did not inhibit methane production. Total Np solubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbially produced Mn(II/III) and Fe(II) may serve as electron donors for Np reduction.

AB - Neptunium is found predominantly as Np(IV) in reducing environments, but as Np(V) in aerobic environments. Currently, it is not known how the interplay between biotic and abiotic processes affects Np redox speciation in the environment. To evaluate the effect of anaerobic microbial activity on the fate of Np in natural systems, Np(V) was added to a microcosm inoculated with anaerobic sediments from a metal-contaminated freshwater lake. The consortium included metal-reducing, sulfate-reducing, and methanogenic microorganisms, and acetate was supplied as the only exogenous substrate. Addition of more than 10 -5 M Np did not inhibit methane production. Total Np solubility in the active microcosm, as well as in sterilized control samples, decreased by nearly two orders of magnitude. A combination of analytical techniques, including VIS-NIR absorption spectroscopy and XANES, identified Np(IV) as the oxidation state associated with the sediments. The similar results from the active microcosm and the abiotic controls suggest that microbially produced Mn(II/III) and Fe(II) may serve as electron donors for Np reduction.

UR - http://www.scopus.com/inward/record.url?scp=0033337208&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033337208&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:0033337208

VL - 556

SP - 1141

EP - 1149

BT - Materials Research Society Symposium - Proceedings

PB - Materials Research Society

ER -