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Title: Metabolism-Induced CaCO 3 Biomineralization During Reactive Transport in a Micromodel: Implications for Porosity Alteration

We investigated the ability of Pseudomonas stutzeri strain DCP-Ps1 to drive CaCO 3 biomineralization in a microfluidic flowcell (i.e., micromodel) that simulates subsurface porous media. Results indicate that CaCO 3 precipitation occurs during NO 3 reduction with a maximum saturation index (SI calcite) of ~1.56, but not when NO 3 was removed, inactive biomass remained, and pH and alkalinity were adjusted to SI calcite ~ 1.56. CaCO 3 precipitation was promoted by metabolically active cultures of strain DCP-Ps1, which at similar values of SIcalcite, have a more negative surface charge than inactive strain DCP-Ps1. A two-stage NO 3 reduction (NO 3 → NO 2 → N 2) pore-scale reactive transport model was used to evaluate denitrification kinetics, which was observed in the micromodel as upper (NO 3 reduction) and lower (NO 2 reduction) horizontal zones of biomass growth with CaCO 3 precipitation exclusively in the lower zone. Our model results are consistent with two biomass growth regions and indicate that precipitation occurred in the lower zone because the largest increase in pH and alkalinity is associated with NO 2 reduction. CaCO 3 precipitates typically occupied the entire vertical depth of pores andmore » impacted porosity, permeability, and flow. This study provides a framework for incorporating microbial activity in biogeochemistry models, which often base biomineralization only on SI (caused by biotic or abiotic reactions) and, thereby, underpredict the extent of this complex process. Furthermore, these results have wide-ranging implications for understanding reactive transport in relevance to groundwater remediation, CO 2 sequestration, and enhanced oil recovery.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [4]
  1. Univ. of Illinois, Urbana-Champaign, IL (United States). Civil and Environmental Engineering and Inst. for Genomic Biology
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Geoscience Research and Applications
  3. Univ. of Illinois, Urbana-Champaign, IL (United States). Inst. for Genomic Biology and Dept. of Geology
  4. Univ. of Texas, Austin, TX (United States). Civil, Architectural and Environmental Engineering
Publication Date:
Report Number(s):
SAND2016-12592J
Journal ID: ISSN 0013-936X; 649898
Grant/Contract Number:
AC04-94AL85000; SC0001114; SCOC12504
Type:
Accepted Manuscript
Journal Name:
Environmental Science and Technology
Additional Journal Information:
Journal Volume: 49; Journal Issue: 20; Journal ID: ISSN 0013-936X
Publisher:
American Chemical Society (ACS)
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 59 BASIC BIOLOGICAL SCIENCES
OSTI Identifier:
1338390