Decontamination of heavy metals in polluted soil by phytoremediation using bryophyllum pinnatum

Abstract

Phytoremediation is the use of specially selected or engineered living green plants for in situ risk reduction and/or removal of pollutants from contaminated media. This process is one of the most rapidly developing components of environmentally friendly (green) and cost-effective technology to abate environmental pollution. The risk reduction could be through the process of removal, degradation, containment of a contaminant or a combination of any of these factors. Bryophyllum pinnatum a herbally-accepted plant in some parts of the world was cultivated in ten different plastic buckets containing heavy metal polluted soil and nurtured for 20 months. The plants were left in ambient conditions and watered periodically. After the first 2 weeks, the plant and soil samples were collected and analysed for total concentration of Cd, Cr, Cu, Ni, Pb V and Zn. Subsequently, the plant and soil samples were collected monthly and analysed for the total concentrations of these heavy metals, using Atomic Absorption Spectrophotometry. Maximum extracted heavy metals from soil by plant were Cd (3.12±1.03 mg/kg), Cr (32.48±3.21 mg/kg), Cu (81.01±2.3 mg/kg) Ni (11.91±2.32 mg/kg), Pb (399.90 ±4.32 mg/kg) V (5.81±0.08 mg/kg) and Zn (150.51± 0.33) and this occurred in the 4th month of study. This study confirms B. pinnatum as one of the plants that could be employed in phytoremediation of soil polluted by heavy metals.