Restoration of Lead Contaminated Soil Using Arachis hypogaea
U. J. J. Ijah, S. A. Aransiola, and O. P. Abioye
Abstract
This study was designed to assess the potential of Arachis hypogaea (groundnut) to restore lead (Pb) contaminated soil. Pot experiment was conducted. Viable seeds were planted into five kilogram of the experimental soil placed in each plastic pot. Phytoremediation of soil contaminated with 0ppm (control), 5ppm, 10ppm, 15ppm, 20ppm and 25ppm heavy metal (Pb) were studied for a period of 12weeks under natural condition. The bacterial counts ranged from 32×106 cfu/g to 10×106 cfu/g in Pb polluted soil remediated with Arachis hypogaea (A. hypogaea) while the total fungi counts ranged from 25 × 102 cfu/g to 1 × 102 cfu/g. Microorganisms isolated from the rhizosphere were identified as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus flavus, Aspergillus niger, Mucor mucedo, Aspergillus fumigatus, Trichophytom mentagrophyte, Rhodotorula rubra and Candida albicans. Different compartments (leaf, stem, seeds and roots) of A. hypogaea were analyzed for heavy metal (Pb) uptake after 12 weeks. The plants mopped up substantial concentrations of Pb in the above biomass of the plant in the seeds (1.73ppm), stem (1.26ppm) and leaves (2.30ppm) compared to concentrations in the roots (1.27ppm). The phytoextraction ability of the plant was assessed in terms of its metal bioconcentration factor (BCF) and translocation factor (TF). It was observed that more of this element was translocated to leaves of the plant. The results obtained suggest that the plant (Arachis hypogaea) has phytoextraction potential and could be used in reclaiming soil polluted with Pb.
Keywords: Heavy metal, Lead, Phytoremediation, Arachis hypogaea