Modeling biogeochemical dynamics in porous media: Practical considerations of pore scale variability, reaction networks, and microbial population dynamics in a sandy aquifer

King E. L., TUNCAY K., Ortoleva P., Meile C.

JOURNAL OF CONTAMINANT HYDROLOGY, cilt.112, ss.130-140, 2010 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 112
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1016/j.jconhyd.2009.12.002
  • Dergi Adı: JOURNAL OF CONTAMINANT HYDROLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.130-140
  • Anahtar Kelimeler: Reactive transport modeling, Pore scale heterogeneity, Biogeochemical reaction networks, Microbial population dynamics, COASTAL MARINE-SEDIMENTS, DEEP SANDSTONE AQUIFER, DRIVEN REDOX CHEMISTRY, NON-FICKIAN DISPERSION, GEOBACTER-SULFURREDUCENS, NATURAL ATTENUATION, SUBSURFACE ENVIRONMENTS, COUPLING TRANSPORT, PHENOLIC-COMPOUNDS, SULFATE REDUCTION
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Prediction of the fate and environmental impacts of groundwater contaminants requires the identification of relevant biogeochemical processes and necessitates the macroscopic representation of microbial activity occurring at the microscale. Using a well-studied sandy aquifer environment, we evaluate the importance of pore distribution on organic matter respiration in a porous medium environment by performing spatially explicit simulations of microbial metabolism at the sub-millimeter scale. Model results using an idealized porous medium under non-biofilm forming conditions indicate that while some heterogeneity is observed for flow rates, distributions of microbes and dissolved organic substrates remain relatively homogenous at the grain scale. At the macroscale in the same environment, we assess the impact of a comprehensive reaction network description for a phenolic contaminant plume, and compare the findings to a setting describing organic matter breakdown in a coastal marine sediment. This comparison reveals the importance of reactions recycling reduced metabolites at redox interfaces, leading to a competition for oxidants. When the spatio-temporal dynamics of microbial groups are accounted for, our simulations show the importance of reaction energetics and nutrient limitations such as microbial nitrogen demands. (C) 2009 Elsevier B.V. All rights reserved.