Office of Biological and Environmental Research Weekly Report

May 12, 2008

 

Successful Completion to the Department of Energy’s International Polar Year (IPY) Study:  Office of Science’s Atmospheric Radiation Measurement (ARM) International Polar Year study, Indirect and Semi-Direct Aerosol Campaign (ISDAC), ended its month-long mission on April 30, 2008.  All of the campaign’s objectives were met and will help answer some of the key scientific questions about Arctic cloud and aerosol interactions.  Results from the ISDAC study will be presented at the 4th PAN-Global Water and Energy Experiment (GEWEX) Cloud System Study meeting, June 2-6, 2008, in Toulouse, France.  The study involved the use of research aircraft containing state-of-the-art instruments that measured cloud microphysics, aerosol chemistry and optical properties, particularly for ice and mixed-phase clouds, which are key regulators of Arctic climate.  The suite of instruments used included the Single Particle Laser Ablation Time-of-flight mass spectrometer (SPLAT) which measures in-situ the size and composition of individual aerosols.  SPLAT-II was designed, constructed and operated by EMSL.  Cooperation across BER programs enabled SPLATT-II to be compatible with an airborne platform (weight, size and power consumption reductions; and shock absorbance).  Measurements collected during the ISDAC study included layers of organic and black carbon from Siberian fires, dust from China, and sulfate from fossil fuel combustion.  Sampling was also conducted of low level ice/mixed phase and water clouds, and high level cirrus clouds.  

Media Interest:  No

Contact:  Rick Petty, SC-23.3, (301) 903-5548, Wanda Ferrell, SC-23.3, (301) 903- 0043

 

Three Publications in the April Issue of Environmental Science & Technology Highlight the Complex Physical, Chemical and Biological Processes that Influence Contaminant Transport. To more accurately predict the mobility of contaminants in the environment and to devise new remediation techniques, DOE site managers need to understand the complex physical, chemical and biological processes that influence the mobility of metal and radionuclide contaminants in the subsurface. Three Office of Science, BER research activities, reported in the April 15, 2008, issue of ES&T, highlight the factors affecting the fate of radionuclide contaminants in subsurface environments. The articles highlight results obtained from three different DOE sites and demonstrate the importance of understanding complex biogeochemical processes influencing the mobility of radionuclide contaminants in the subsurface. In one article, researchers from the Lawrence Berkeley National Laboratory used a variety of synchrotron-based techniques to evaluate the potential of persistent iron (III) oxides present under reducing-conditions in sediment columns to reoxidize uranium to a more mobile phase. In a second article, researchers from the University of Massachusetts and the Pacific Northwest National Laboratory examined the sorption of oxidized uranium on cell surfaces in uranium-contaminated sediments during biostimulation as a contributing mechanism to immobilizing uranium in situ. In a third article, researchers from the Idaho National Laboratory examined a biological mechanism for stimulating calcite precipitation in subsurface sediments as means to facilitate precipitation, and therefore immobilization, of Sr-90 in subsurface environments.

 

Tokunaga, TK; Wan, JM; Kim, YM; et al. , Real-time X-ray absorption spectroscopy of uranium, iron, and manganese in contaminated sediments during bioreduction. ENVIRON. SCI. & TECHNOL., 42 (8): 2839-2844 APR 15 2008

 

N'Guessan, AL; Vrionis, HA; Resch, CT; et al., Sustained removal of uranium from contaminated groundwater following stimulation of dissimilatory metal reduction. ENVIRON. SCI. & TECHNOL., 42 (8): 2999-3004 APR 15 2008

 

Fujita, Y; Taylor, JL; Gresham, TLT; et al. , Stimulation of microbial urea hydrolysis in groundwater to enhance calcite precipitation. ENVIRON. SCI. & TECHNOL., 42 (8): 3025-3032

 

Media Interest: No

Contact: Robert T. Anderson, SC-23.4, (301) 903-5549