Potential of <I>Ricinus communis </I>L. For Removal of Heavy Metal in Contaminated Soil

Abstract

Heavy metal contamination has become a serious ecological problem due to its toxic effects on soils, plants and human. Experimental study was conducted on dumpsite soil to assess the potential of Ricinus communis to accumulate heavy metals from the soil using bioconcentration (BCF) and tanslocation factors (TF). Heavy metals concentration (mg/kg) in dumpsite and control soil before planting were Mn (50.68- 220.08); Zn(29.01- 135.56); Cu (8.92- 86.88), Pb (5.88-48.86), Ni (3.01-7.99) and Co (1.78-6.88) while the concentration in soils after planting were Mn(29.89- 135.21); Zn (15.11-88.21); Cu (3.89-50.22), pb (3.68-31.56), Ni (1.22-3.56) and Co (0.67-2.68) in Mg/kg. Ricinus communis showed BCF greater than 1 for Ni and Co and less than 1 for Mn, Cu, Zn and Pb while TF is greater than 1 for all the determined heavy metals. The dumpsite soils have higher heavy metal concentration than the control soil. The levels of heavy metals concentration in soils and plants are in the order of Mn> Zn> Cu> Pb> Ni. Significant reduction (P<0.05) was observed in the heavy metal concentrations in the soils before and after planting indicating their accumulation in the plants. Results of this study indicate the accumulation of heavy metals in Ricinus communis plants and its potential for effective removal of Cu, Zn, Pb, Ni, Co and Mn from the dumpsite soils.

Keywords: Heavy metal accumulation, Ricinus communis, Dumpsite soil, Translocation factor, Remediation