Phytoremediation is a technique for environmental repair
. It utilizes living organism
s (in particular, trees
, hence phyto
) to help break down and bind environmental contaminant
s. As such, it is a form of bioremediation
One pioneering firm in this area has developed a technique for utilizing Poplar trees to anchor the 'caps' over landfills. In addition to increasing soil integrity, the Poplar increases the water and oxygen flow through the landfill (both required for breakdown of many toxins to occur) and, in addition, is capable of 'binding' some toxins within the wood when they do leach into the groundwater and are absorbed. Once bound, the toxins are relatively harmless.
The trees used are Poplar because (sorry) not only do they have the aforementioned capabilities, but they grow fast, are easily planted, and the wood gleaned from them is commercially viable. White Poplar is used for paneling and furniture construction. It is not recommended for fuel if in fact it has been used in phytoremediation, as combustion may release bound contaminants into the atmosphere. However, usually the trees don't end up having to bind toxins if the landfill is properly constructed; the increased water and air flow through the fill mass that the trees provide is enough of a decomposition accelerant that the water reaching the tree root systems is relatively clean.
Phytoremediation is a technology that offers enormous potential advantages in dealing with environmental difficulties. With proper bioengineering, species might be augmented or even developed that are capable of attacking, neutralizing or simply binding even more dangerous contaminants. Finally, a phytoremediation installation is aesthetically pleasing (it's trees!), cheap compared to mechanical processing of stored waste, and mostly self-repairing/self-renewing (again, it's trees).