DETOXIFICATION OF TOXIC HEAVY METALS IN CONTAMINATED SOIL USING SELECTED HYPERACCUMULATOR PLANTS

Phytoremediation is a method of bioremediation process which involves the application of biological processes for the removal of inorganic and organic pollutants from the contaminated environment. This technology has been getting attention due to of its low cost, efficient and eco-friendly nature. Phytoremediation is a promising approach for removal of contaminants from the environment by the use of hyperaccumulator plants. The basis of this technology is the natural ability of a green plant to accumulate chemical elements and transport them from the substrate to above the ground parts. Heavy metals like cadmium (Cd), copper (Cu) and zinc (Zn) when present in high concentrations in soil exert potential toxic effects on growth and metabolism of plants. Bioaccumulation of toxic metals in the plant poses a risk to human and animal health. In the present study a model field experiment was conducted using Talinum triangulare, Sansevieria roxburghiana and Plectranthus amboinicus plant species for their ability to absorb the heavy metals such as cadmium, copper and zinc from the contaminated soil. The metal uptake of Cd (7.61 mg/kg) and Cu (6.96 mg/kg) is observed in experimental field (F – I) and Cd (5.06 mg/kg) and Cu (3.95 mg/kg) in experimental field (F – II) by Water leaf (Talinum triangulare). Similarly, the metal uptake of Cu (7.3 mg/kg), Cd (6.54 mg/kg) and Cu (3.60 mg/kg), Zn (3.05 mg/kg) by Sansevieria roxburghiana and Cd (5.44 mg/kg) and Zn (3.86 mg/kg), Cd (3.35 mg/kg was noticed by Plectranthus amboinicus species in heavy metal contaminated soils. The results clearly suggested that, these plants can be used as potential bioindiators and metal scavengers for the removal of toxic heavy metals in contaminated soil.