By Laura Briscoe, Leanna Feder

Sep 25 2019

Phytoremediation is the process in which living plants are used to remove toxins, such as heavy metals, from soil and water. It is often a more cost-effective option compared to traditional remediation techniques such as soil excavation or ground water removal and treatment.

There are different soil types all over the world that have naturally occurring high levels of heavy metals. Plants that have evolved in these places often have the ability to accumulate levels of heavy metals that would be fatal to most other plants, and are called hyperaccumulators. A good example is Pycnandra acuminata, a tree native to New Caledonia. P. acuminata is a hyperaccumulator of naturally occurring nickel, which turns its latex blue green.

Hyperaccumulators may be used to sequester contaminants in plant tissue (phytoextraction), reduce the bioavailability of contaminants (phytostabilization), or convert contaminants into volatile compounds that can be released through the above ground plant tissue (phytovolatilization). Scientists can look to hyperaccumulators to understand the processes that allow plants to accumulate dangerous substances, and understand which plants may be useful for cleaning brownfields and other polluted sites.