PHYTOREMEDIATION OF METALS: GREEN AND CLEAN

Ilya Raskin, Biotech Center, Foran Hall, 59 Dudley Rd., Cook College, Rutgers University., New Brunswick, N.J. 08901-8520.

Soils and waters contaminated with toxic metals pose a major environmental and human health problem, which may be partially solved by the emerging phytoremediation technology. Two subsets of phytoremediation are approaching commercialization. (I) Phytoextraction, in which high biomass metal-accumulating plants and appropriate soil amendments are used to transport and concentrate metals from the soil into above-ground shoots, which are harvested by conventional agricultural methods, (II) Rhizofiltration, in which plant roots grown in water, precipitate and concentrate toxic metals from polluted effluents. The metals targeted for phytoremediation include lead, cadmium, chromium, arsenic and various radionuclides. The market is estimated to be billions of dollars, with government and private responsible parties being major clients. Both phytoextraction and rhizofiltration have been tested successfully in the US and other countries. Effective use of phytoextraction technology requires a use of a specially selected plants in combination with uptake enhancing soil amendments and appropriate agronomic practices. Progress have been made in understanding the biological mechanisms of phytoremediation and metal uptake, accumulation and resistance in plants. Genetic approaches to improve phytoremediation of metals have also been developed. The data that summarize our findings will be presented.