| Autor: |
Druhan JL; Department of Earth and Planetary Science, University of California Berkeley, Berkeley, California 94720, United States. jennydruhan@berkeley.edu, Steefel CI, Molins S, Williams KH, Conrad ME, DePaolo DJ |
| Jazyk: |
angličtina |
| Zdroj: |
Environmental science & technology [Environ Sci Technol] 2012 Aug 21; Vol. 46 (16), pp. 8895-902. Date of Electronic Publication: 2012 Aug 10. |
| DOI: |
10.1021/es302016p |
| Abstrakt: |
Stable isotope fractionations of sulfur are reported for three consecutive years of acetate-enabled uranium bioremediation at the US Department of Energy's Rifle Integrated Field Research Challenge (IFRC) site. The data show a previously undocumented decrease in the time between acetate addition and the onset of sulfate reducing conditions over subsequent amendments, from 20 days in the 2007 experiment to 4 days in the 2009 experiment. Increased sulfide concentrations were observed at the same time as δ(34)S of sulfate enrichment in the first year, but in subsequent years elevated sulfide was detected up to 15 days after increased δ(34)S of sulfate. A biogeochemical reactive transport model is developed which explicitly incorporates the stable isotopes of sulfur to simulate fractionation during the 2007 and 2008 amendments. A model based on an initially low, uniformly distributed population of sulfate reducing bacteria that grow and become spatially variable with time reproduces measured trends in solute concentration and δ(34)S, capturing the change in onset of sulfate reduction in subsequent years. Our results demonstrate a previously unrecognized hysteretic effect in the spatial distribution of biomass growth during stimulated subsurface bioremediation. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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