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Title: Final report for DOE Grant No. DE-SC0006609 - Persistence of Microbially Facilitated Calcite Precipitation as an in situ Treatment for Strontium-90

Abstract

Subsurface radionuclide and metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE's greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent ions, such as the short-lived radionuclide 90Sr, is co-precipitation in calcite. We have previously found that nutrient addition can stimulate microbial ureolytic activity, that this activity accelerates calcite precipitation and co-precipitation of Sr, and that higher calcite precipitation rates can result in increased Sr partitioning. We have conducted integrated field, laboratory, and computational research to evaluate the relationships between ureolysis and calcite precipitation rates and trace metal partitioning under environmentally relevant conditions, and investigated the coupling between flow/flux manipulations and precipitate distribution. A field experimental campaign conducted at the Integrated Field Research Challenge (IFRC) site located at Rifle, CO was based on a continuous recirculation design; water extracted from a down-gradient well was amended with urea and molasses (a carbon and electron donor) and re-injected into an up-gradient well. The goal of the recirculation design and simultaneous injection of urea and molasses was to uniformly accelerate the hydrolysis of urea and calcite precipitation over the entire inter-wellbore zone. The urea-molasses recirculation phase lasted, with brief interruptions for geophysical surveys, for 12 daysmore » and was followed by long-term monitoring which continued for 13 months. A post experiment core located within the inter-wellbore zone was collected on day 321 and characterized with respect to cation exchange capacity, mineral carbonate content, urease activity, ureC gene abundance, extractable ammonium (a urea hydrolysis product) content, and the 13C isotopic composition of solid carbonates. It was also subjected to selective extractions for strontium and uranium. Result of the core characterization suggest that urea hydrolysis occurred primarily within the upper portion of the inter-wellbore zone and that strontium was mobilized from cation exchange sites and subsequently co-precipitated with new calcium carbonate.« less

Authors:
 [1];  [2];  [3]
  1. Univ. of Idaho, Idaho Falls, ID (United States)
  2. Idaho National Lab. (INL), Idaho Falls, ID (United States)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Research Org.:
Univ. of Idaho, Moscow, ID (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
Contributing Org.:
University of Idaho, Center for Advanced Energy Studies, Idaho National Laboratory, Lawrence Berkeley National Laboratory
OSTI Identifier:
1107346
Report Number(s):
DOE-UIDAHO-SC-0006609-01
DOE Contract Number:  
SC0006609
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 58 GEOSCIENCES; bioremediation; strontium-90; Calcite; urea hydrolysis; ureC; urease

Citation Formats

Smith, Robert W., Fujita, Yoshiko, and Hubbard, Susan S. Final report for DOE Grant No. DE-SC0006609 - Persistence of Microbially Facilitated Calcite Precipitation as an in situ Treatment for Strontium-90. United States: N. p., 2013. Web. doi:10.2172/1107346.
Smith, Robert W., Fujita, Yoshiko, & Hubbard, Susan S. Final report for DOE Grant No. DE-SC0006609 - Persistence of Microbially Facilitated Calcite Precipitation as an in situ Treatment for Strontium-90. United States. https://doi.org/10.2172/1107346
Smith, Robert W., Fujita, Yoshiko, and Hubbard, Susan S. 2013. "Final report for DOE Grant No. DE-SC0006609 - Persistence of Microbially Facilitated Calcite Precipitation as an in situ Treatment for Strontium-90". United States. https://doi.org/10.2172/1107346. https://www.osti.gov/servlets/purl/1107346.
@article{osti_1107346,
title = {Final report for DOE Grant No. DE-SC0006609 - Persistence of Microbially Facilitated Calcite Precipitation as an in situ Treatment for Strontium-90},
author = {Smith, Robert W. and Fujita, Yoshiko and Hubbard, Susan S.},
abstractNote = {Subsurface radionuclide and metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE's greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent ions, such as the short-lived radionuclide 90Sr, is co-precipitation in calcite. We have previously found that nutrient addition can stimulate microbial ureolytic activity, that this activity accelerates calcite precipitation and co-precipitation of Sr, and that higher calcite precipitation rates can result in increased Sr partitioning. We have conducted integrated field, laboratory, and computational research to evaluate the relationships between ureolysis and calcite precipitation rates and trace metal partitioning under environmentally relevant conditions, and investigated the coupling between flow/flux manipulations and precipitate distribution. A field experimental campaign conducted at the Integrated Field Research Challenge (IFRC) site located at Rifle, CO was based on a continuous recirculation design; water extracted from a down-gradient well was amended with urea and molasses (a carbon and electron donor) and re-injected into an up-gradient well. The goal of the recirculation design and simultaneous injection of urea and molasses was to uniformly accelerate the hydrolysis of urea and calcite precipitation over the entire inter-wellbore zone. The urea-molasses recirculation phase lasted, with brief interruptions for geophysical surveys, for 12 days and was followed by long-term monitoring which continued for 13 months. A post experiment core located within the inter-wellbore zone was collected on day 321 and characterized with respect to cation exchange capacity, mineral carbonate content, urease activity, ureC gene abundance, extractable ammonium (a urea hydrolysis product) content, and the 13C isotopic composition of solid carbonates. It was also subjected to selective extractions for strontium and uranium. Result of the core characterization suggest that urea hydrolysis occurred primarily within the upper portion of the inter-wellbore zone and that strontium was mobilized from cation exchange sites and subsequently co-precipitated with new calcium carbonate.},
doi = {10.2172/1107346},
url = {https://www.osti.gov/biblio/1107346}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Nov 15 00:00:00 EST 2013},
month = {Fri Nov 15 00:00:00 EST 2013}
}