Office of
Biological and Environmental Research Weekly Report
December 1,
2008
Superior Stainless Steel Coatings for Solid
Oxide Fuel Cells. Extreme high
temperature and corrosive conditions inside operating solid oxide fuel cells
(SOFC) have led researchers to investigate a variety of metallic alloys with
oxidation-resistant coatings over the last few years. A research team from Montana State University;
Arcomac Surface Engineering, LLC; and the Pacific Northwest National Laboratory
recently created and examined three types of stainless steel surfaces with and
without multilayer coatings for their high temperature oxidation resistance and
surface electrical conductivity. Two of the coatings were found to have
superior characteristics. The article describing these research findings is
ranked first on Elsevier’s ScienceDirect list of the 25 hottest papers in
physics and astronomy and seventh on the materials sciences list. This
research was funded by the Department of the Interior and a DOE subcontract
from PNNL. Portions of the research were performed in the Environmental
Molecular Sciences Laboratory, a DOE scientific user facility located at PNNL. Additional details are
available at: http://www.emsl.pnl.gov/news/highlights/stainless20081120.pdf.
Reference: Surface and
Coatings Technology, 2004, vol
188-189: 55-61.
Media Interest: No
Contact:
Paul Bayer, SC-23.1, (301) 903-5324
Long-Term Bioimmobilization of Chromium in
Groundwater Demonstrated at the Hanford
Site. As a result of past nuclear processing activities, chromium is a
common contaminant in the soils and groundwater at most DOE sites. Chromium in
groundwater most commonly exists either as hexavalent chromium, Cr(VI), or
trivalent chromium, Cr(III). While Cr(VI) is quite mobile and toxic in
groundwater, Cr(III) complexes are much less toxic, and form insoluble and
stable precipitates. A multi-institutional research team led by scientists from
Lawrence Berkeley National Laboratory (LBNL) conducted field experiments in the
100-H area at the Hanford Site to test the effectiveness of a slow-release
glycerol polylactate, or hydrogen release compound (HRC), to see if it would
stimulate the existing microbial community to transform Cr(VI) moving in the
groundwater into non toxic and insoluble Cr(III). The microbial community
initially changed dramatically and then appeared to stabilize to a community
with a new composition. In addition, Cr(VI) levels in wells down gradient from the
HRC injection wells dropped from more than 150 micrograms/liter to an
undetectable level and remained at that level for more than three years.
Additional HRC and tracer injection tests are planned to further assess the
biogeochemical process changes that occur as a result of HRC injection, to
investigate reoxidation of Cr(III) to Cr(VI), and to develop a reactive
transport model. For further information on this project: http://esd.lbl.gov/ERT/hanford100h/index.html.
Reference:
Environmental Science & Technology,
2008, vol 42(22):8478-8485.
Media Interest:
No
Contact: Paul E. Bayer, SC-23.1, (301)
903-5324