Phytoremediation
Mr.Intel writes "Wired has an article up about an 18 year old biology whiz who has done some very interesting research on phytoremediation (plants used to clean contaminated soil). This type of soil remediation is very eco-friendly compared to traditional methods but requires about 10 to 20 years to be effective. Marc Burell (the kid who did the experiments) used wheat to remove lead from soil in Mississippi."
Overall, very cool stuff. Check out this site. It's great if you're into mushrooms (no, not those kind!).
Method of processing duck feet
then what do you do with the wheat? You can't eat it, and if you bury it you are back to square one.
#include "disclaim.h"
"All the best people in life seem to like LINUX." - Steve Wozniak
From the article:
{snip}
Burrell used wheat for his experiments, planting the crop in lead-contaminated soil. The roots accumulated the metal, which moved to the shoots -- the portion of the plant above the ground. The plants were then harvested.
{/snip}
So I'm assuming the basis of this is to have plants "soak" up the metals as they grow. The plants would then be smelted or dumped somewhere else.
What happens to the critters that eat the plants? Wouldn't it be just as bad for the animals to eat toxic metals as them live in them? Biological magnification would still take place.
The technology behind the process is nothing new. I worked for a bio-tech startup in the mid nineties that pioneered and first commercialized the process of phytoextraction. Of course, that company is long gone, but another company bought the technology and is trying it again. http://www.edenspace.com
seriouslyexcited.net
One of the things that phytoremediation does is soak up metals and organic compound.
It also can have the effect of converting either the metal or organic chemical to a different form.
Say converting lead from its soluble Pb2+. To its reduced mettalic form Pb which isn't as toxic.
Or in organic chemical say PCBs, ploychlorinated biphenols, the plant may break off a few clorines off the phenol chain, again making it less toxic (or at least easier to break down).
So with the correct choice of organisms this should be a safe way of cleaning up things.
Veramocor
This sort of stuff is pretty interesting. At my old university, there was a Prof. who was looking at taking up gold from the soil. You just need to add a simple chemical to the soil, then grow your plants (making sure that you get the species right), and get ready to harvest and extract the gold. While it isn't as cheap as some gold extration methods, it can be used in areas where the gold concentration is too low for other means of extration. Plus you don't have to go pouring tonnes of cyanide into the soil.
Warning: Some ideologies on the Net are smaller than they appear.
Note that plants are just part of the process, someone else here mentioned Fungi as well as other treatments.