Lighting Up Dirty Water
Researchers may soon
be able to "see" into groundwater using a fiber optics instrument. With
the instrument, researchers will be able to detect chemical pollutants
more quickly than they can send samples to a laboratory.
Kate Leonard, assistant professor of civil and
environmental engineering at the University of Alabama, Huntsville,
is using a three-year, $50,000 NSF grant to develop a fiber optics testing
system that will check for contamination of water. Her proposed system
would allow researchers to document continual changes in the levels
of chemical contamination, identify dumping sites, and trace pollution
plumes as they move through the water system.
"Right now," Leonard told the Huntsville Times, "we
have to pull up samples and take them to the lab and have them analyzed,
which is a few days. The grab-sample method is OK if you only need limited
data." Leonard's new system, however, will provide essentially instantaneous
and continuous data analysis.
The system will work on the principle that chemicals
can be identified by their glow when struck by the correct color light.
Using optic fibers that transmit various colored lights, Leonard has
a spectrometer set up to analyze the glow reflected back by each chemical.
The device will work for many different chemicals,
but "we're going to have to go through them one at a time to get a database," she
told the Huntsville Times. So far, the system can spot xylene,
a carcinogen used in gasoline, and cyclohex-ane, a pollutant used in
cleaning solvents and paint removers.