Phytoremediation of cyanide

Abstract

Free cyanide and complex cyanide, including HCN and CN- is the most reactive and toxic substance of all industrial and anthropogenic pollutants. Many studies till date have proved that cyanide can be efficiently removed by plants. From the economic point of view, phytoremediation could be an attractive and useful technology in dealing with this dangerous pollutant. Phytoremediation of complex and free cyanide include removal of cyanide by terrestrial and aquatic plants. Experiments using free and complex cyanide have shown that many terrestrial and aquatic plants including willow, sorghum, cassava and water hyacinth can remove free cyanide from the hydroponic media. Cyanide uptake in plants can be associated with very complex physiological mechanisms which include transport and assimilation of cyanide within the plants for catering plant's nitrogen needs. Transport and metabolism of different chemical species of cyanide differ in various plant species including trees, grasses and aquatic plants. Again uptake of cyanide by roots is depending on its form and condition. A detailed insight of uptake, transport and assimilation of cyanide compounds in plants is discussed here. In this chapter, chemical nature of cyanide, possible industrial pollutant sources, various phytoremediation approaches, mechanism of cyanide assimilation in plants, and genomics of cyanide remedy are evaluated.