Plants That Decontaminate Soil And Extract Toxic & Useful Metals

Scarce but potentially valuable plants exist on the landscape left after at least a thousand years of mining for lead in Darley Dale, England.

The last lead mine in the area closed in 1939 after over a thousand years of mining and the remains left are the invisible waste deposits in the soils, and the visible above-ground scars on the landscape caused by man made underground tunnels, and plants of which some can tolerate high levels of metals in soils that other plants cannot.

These plants are called Metallophytes and there are four species in the area:

In addition to tolerating metallic elements in the soil, the plants actually extract metals such as lead, zinc, cadmium and copper through their roots and are able to store the metals in their stems and leaves.

The use these metallophytes either to remove remove metals from contaminated substances, or to make the metals safer for the environment, is called Phytoremediation.

Professor Alan Baker, who has worked in the fields of Botany and environmentally friendly methods for mine decontamination, has said that there are three types of  Phytoremediation:

• Phytoextraction – cleaning up metals from polluted soils.
• Phytostabilization – immobilising metals in soils or in metal rich mine waste.
• Rhozofiltration – extraction metals from water and industrial waste waters.

In addition, to their amazing properties with metals, the plants produce nectar for invertebrates such as flies and beetles, and also seeds for mammals and birds.

The existence and research of these plants needs to be seriously considered.

The above is a summary of articles from aboutderbyshire.co.uk and there is also a more recent article on The New Scientist.