Now, trees can detect soil, water contaminants
Washington: Researchers at the University of Missouri-Rolla have proved that trees can really let you know about unseen degradation of their environment.
They have developed a method to detect the presence of soil and groundwater contamination without turning a shovel or touching the water.
The process, called ‘phytoforensics’, takes less time and costs much less than traditional detection methods, said Joel Burken, professor of civil and environmental engineering at Missouri S&T.
The process involves coring trunks of trees to gather small samples.
After previously relying on taking vials from tree samples to the lab for analysis, Burken and his team are now using a specially designed, less intrusive approach that uses a thin filament called a solid-phase microextraction fiber, or SPME, to detect traces of chemicals at minute levels in trees.
“The process of core-sampling plants has been around for a while. But we’re taking a new approach that will improve the process on multiple levels. Sampling is easy, fast and inexpensive for quickly identifying polluted areas or contamination patterns,” said Burken.
Tapping into several trees in an area suspected of contamination can help engineers better and more rapidly delineate contaminants in the subsurface.
The process removes just a small piece of the tree, compared to the traditional means of groundwater sampling through heavy-equipment drilling into the ground and creating sampling wells to extract water.
“The only damage to the site is taking a piece of the tree about the size of a pencil and just an inch long,” said Burken.
Berken said the tree sampling process allowed his team to provide more accurate data in one project that had first used 40 sampling wells drilled over 12 years to assess for the solvents perchloroethylene and trichloroethylene near an abandoned railroad in Sedalia, Mo.
By taking 114 tree samples during one day on site, the location and level of contamination was more accurately determined.
For most of the projects the samples were taken back to the lab for analysis. But Burken and his colleagues have been using mobile analytic equipment, a gas chromatography-mass spectrometer, more recently for on-site assessment.
Burken has filed to obtain a patent for his phytoforensic process.