Testing of Remediation Technologies
||Massachusetts Military Reservation, Cape Cod, MA
of Civil and Environmental Engineering, Virginia Polytechnic Institute
and State University
contamination is one of our Nation's most ubiquitous ground-water
contamination problems. USGS microbiologists and their colleagues
have used a two-phase approach to developing remediation strategies
for nitrate contamination in ground water. In the field, USGS scientists
have been investigating the potential for enhancing denitrification
(the reduction of nitrate to nitrogen gas) by injecting sodium formate
into the aquifer. Denitrifying bacteria are native to the subsurface,
but are usually electron
donor-limited. The addition of formate, which can serve as an
electron donor for denitrification, overcomes that limitation, thus
increasing the extent to which nitrate can be consumed. In the laboratory,
USGS scientists are testing a bench-scale model that uses hydrogen
in a bioreactor to enhance denitrification. Hydrogen can also serve
as an electron donor for special types of denitrifying bacteria.
These microorganisms are autotrophs, requiring only carbon dioxide
as a carbon source and producing innocuous products (nitrogen gas
and water) from the nitrate and hydrogen. A patent application has
been filed for the hydrogen bioreactor. The hydrogen bioreactor
has many applications. Many drinking-water suppliers are faced with
high nitrate concentrations in their source waters and the hydrogen
bioreactor could be an effective tool for them to supply safe drinking
water to their customers. The reactor could also be used to treat
the discharge from confined animal feeding operations.
- Richard L. Smith, USGS, National Research Program, Boulder,
- Denis LeBlanc, USGS, Massachusetts Water Science Center, Northborough, MA,
- Smith, R.L., 2005, Small-scale hydrogen-oxidizing-denitrifying bioreactor: Washington, D.C., U.S. Government Patent and Trademark Office, United States Patent No. 6,863,815 B1.
- Smith, R.L., Buckwalter, S.P., Repert, D.A., and Miller, D.N., 2005, Small-scale, hydrogen-oxidizing-denitrifying bioreactor for treatment of nitrate-contaminated drinking water: Water Research, v, 39, p. 2014-2023.
- Smith, R.L., Miller, D.N., Brooks, M.H., Widdowson, M.A., and
Killingstad, M.W., 2001, In
situ stimulation of groundwater denitrification with formate to
remediate nitrate contamination: Environmental Science and
Technology, v. 35, no. 1, p. 196-203.
- Killingstad, M.W., Widdowson, M.A., and Smith, R.L., 2002, Modeling enhanced in situ denitrification in groundwater: Journal of Environmental Engineering, v. 128, no. 6, p. 491-504.
Other Toxics Remediation Studies on Cape Cod
Information on Sewage-Contaminated Ground Water
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