Going Green: Phytoremediation
Phytoremediation is a unique process that uses plants to clean up environmental contamination. Our Terry Ettinger has more on the process.
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These poplar trees are hard at work cleaning up landfill where chlorinated solvents are leaching out into a protected wetland. It is a process called phytoremediation.
"Phytoremediation is the use of plants to clean up environmental contamination. We can use plants to take up and sequester heavy metals or in the case of these poplar trees to take up organic compounds and break them down into non-toxic by-products," explained Dr. Lee Newman, ESF Environmental and Forest Biology.
Phytoremediation as a technology, has been around for about 20 years and offers a better alternative to the traditional landfill.
"If you put something in a landfill, you are keeping it safe and not letting anything come in contact with it, which means whatever you put in there, is staying in there," said Newman. "In these types of methods, we have the plants which are actually breaking down the contaminants so its no longer a toxic chemical in the environment."
In some cases, the trees can be harvested and safely turned into useful products.
"At one of our field sites in Oregon, we harvested some of the trees and we had paper made from the trees, and we tested them to make sure none of the contaminants that we were cleaning up, were in the paper. And it was perfectly useable," explained Newman.
On the other hand, if the contaminant is a heavy metal like lead or chromium, phytoremediation offers a recycling opportunity.
Newman said, "We can reclaim that metal by harvesting the plants and extracting the metals from them, so we're completely removing it from the environment, rather than just putting it someplace and keeping it there for future generations to have to deal with."
The plants could also be used to keep the contaminants right where they are.
"Alternatively, you can use the plants to sequester the metals in the soil, so rather than take it up, the plants are going to alter the soil chemistry and keep the metal in the soil in a non-biologically available form," noted Newman.
Through it all, the poplar tree is just doing what it does naturally.
"These plants have inherently, in their make up, the ability to do this type of clean up in the environment," said Newman.