A list of super plants that help return the ecosystem to a less toxic state by absorbing toxic metals from the soil. by Maki Naro via popsci
There’s a common saying that “Nature finds a way.”
And it’s true. During our short stint here on Earth, humans have tested nature’s ingenuity time and time again. We have also learned to reap the benefits of natures odder evolutionary adaptations to environmental messes (both man-made and natural).
The process of phytoremediation uses a plant’s ability to remove contaminants from the soil in situations where other methods would be too infeasible. If the term sounds familiar, you may remember it from the tumbleweed comic a while back, where scientists had suggested using the invasive shrub’s propensity for absorbing uranium as a way to clean up contaminated military firing ranges. While all plants absorb nutrients and minerals, some species of plants, dubbed hyperaccumulators, absorb far more dangerous metals at a much greater quantity than others.
…phytoremediation and phytomining, two of the ways that special hyperaccumulator plants can be used to clean the environment, and maybe make a little money. The above are just a few of these robust plants that not only thrive in toxic soil, but actually help make it more suitable for less hardy organisms. Organizations such as the USDA and the EPA are studying ways to not only use hyperaccumulator plants in soil clean-up, but how to help make it easier for plants to absorb the pollutants. For example, it was found that ammonium ion was effective in dissolving cesium-137 in order for it to be better taken in by plants.
So some of you asked, what happens to the plants now that they’re full of toxic metals? Well, I hope you’re ready for some more phyto-words. Most of the time, the plants are harvested, incinerated, and replanted. Much easier than trying to sift through the soil for the pollutants. But sometimes, in cases of phytodegradation (AKA phytotransformation) the pollutants are broken down the by plant and used as nutrients, and require no further action by people. In phytovolatilization, the pollutant is absorbed by the plant, and a modified version of the contaminant transpires into the air in low concentrations.
Hyperaccumulators can also be used to prevent pollutants from getting into water supplies through phytostabilization. This is where certain plant species are used to immobilize contaminants in the soil through absorption and accumulation in their roots. These plants can be used to create a vegetative cover over a contaminated area which prevents the spread of pollutants by wind erosion or leaching. Thanks, plants!
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