Monday, May 9, 2011

Trees Tapped to Shed Light on Soil Contamination

by Duane Craig

Trees link to soil contamination how?
One of the age old problems with identifying contaminants in the soil may be getting simplified, and much cheaper.

The current approach is to drill test wells and then extract water for analysis. This is a boon for drilling companies but it is also expensive, time consuming and invasive. Now, researchers at Missouri University of Science and Technology have developed a way to use trees as the sampling mechanism.

It’s an ingenious idea born to fruition by Dr. Joel Burken, professor of civil and environmental engineering, and his colleagues. Since trees uptake water through evapotranspiration they also uptake other elements in the water, including contaminants such as trichloroethylene (TCE) and perchloroethylene (PCE). The researchers devised a minimally invasive way to gather samples from the trees by tapping them, similar to the way maple trees are tapped for the sap that makes maple syrup. Then, using a gas chromatography-mass spectrometer the samples are analyzed right on the site.

This method of detecting contaminants is related to another method used to remediate soil contamination. Called phytoremediation, it is the use of plants to clean the soil of contaminants.

Burken’s process is already being marketed by an engineering firm in conjunction with Missouri S&T.

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