They dig up the dirt, mix in cement, and haul the gloop to a hazardous waste landfill. It would be easier some scientists say to grow metal-munching plants in the lab and transfer them to a toxic site. There, plant roots would soak up soil metal, translocating it to shoots. After harvest, the plants might be ashed or composted to recycle the metal. After several plant croppings, phytoremediation proponents say, the site should be clean.
Plants decontaminate land without ruining the soil.
And recycling makes it a true cost-saving effort. The stars of phytoremediation are plants called hyperaccumulators. They can be herbs, shrubs, and even trees. Hyperaccumulators concentrate trace elements, heavy metals, or radio nuclides at levels 100-fold or greater than normal. Despite having this useful trait, nothing was known about these plants until this century.