U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


How Sulfur Affects Chemistry of Iron in the Environment
Published: May 30, 2014
Posted: January 06, 2017

Substantial amounts of iron are present in many subsurface environments. This element has a significant effect on both the biogeochemical cycling of carbon and the fate and transport of trace environmental contaminants, because it is readily transformed among several reactive species. The interactions of subsurface iron with various naturally occurring bacteria have a major influence on its environmental impacts, but these interactions are not well understood. Scientists at Argonne National Laboratory and three partner universities have identified a key role for sulfur in how bacteria affect the speciation of subsurface iron. They determined that bacteria unable to reduce ferric iron directly under alkaline conditions can do so indirectly. The bacteria do this by reducing elemental sulfur to sulfide ion, which then reduces the ferric iron in the goethite to ferrous iron. In addition, this ferrous iron can reduce other metal species such as uranyl ion, thus affecting their solubility. The researchers determined that this process is common in alkaline environments such aquifers, especially those in arid regions. This new understanding of this environmental role of iron will enable progress in a wide range of areas, from modeling of potential carbon capture systems to understanding speciation of contaminants such as uranium and arsenic.

References: Flynn, T. M., E. J. O’Loughlin, B. Mishra, T. J. DiChristina, and K. M. Kemner. 2014. “Sulfur-Mediated Electron Shuttling During Bacterial Iron Reduction,”, Science 344, 1039-42. DOI: 10.1126/science.1252066. (Reference link)

Friedrich, M. W., and K. W. Finster. 2014. “How Sulfur Beats Iron,” Science 344, 974-75. DOI: 10.1126/science.1255442. (Reference link)

Contact: Roland F. Hirsch, SC-23.2, roland.hirsch@science.doe.gov, 301-903-9009.

Topic Areas:

  • Research Area: Subsurface Biogeochemical Research
  • Research Area: Carbon Cycle, Nutrient Cycling
  • Research Area: Microbes and Communities

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)