Phytoremediation of Heavy Metals Using Spinach (Amarantus spinosa) Grown on Contaminated Soils

This work was designed to assess the phytoremediation ability of Spinach (Amarantus spinosa) grown on two different soils (contaminated soil obtained from Chalawa Industrial Estate, Kano, and control soil obtained from Biological Garden of Umaru Musa Yar’adua University, Katsina). Concentrations (mg/Kg) of Cr, Fe, Mn, Ni, Pb, and Zn were determined using atomic absorption spectrophotometry (AAS). Biological concentration factors (BCFs) and translocation factors (TFs) were calculated. The mean levels of metals obtained ranged widely from 0.23 mg/kg Ni to 1971.37 mg/kg Fe. Highest mean levels of Cr (97.74 mg/kg), Fe (1971.37 mg/kg), Mn (78.22 mg/kg), Zn (170.60 mg/kg) were contained in the leaf of the spinach samples, whereas Ni (1.98 mg/kg) and Pb (14.24 mg/kg) were contained in the root of the spinach samples. The results showed a significant level (p<0.05) of all the metals analysed in the spinach samples grown on the polluted soil compared with those grown on the control soils. Amongst the metals, Ni and Pb were found to have the lowest (0.50) and highest (7.57) BCF values respectively. The lowest and highest TF values were found to be on Cr (0.32) and Zn (1.17) respectively. Consequently, Higher BCF and TF values were found for Pb and Zn and this resulted in greater extraction ability of Pb and Zn. The spinach ability to extract Fe and Ni was found to be poor.