Abstract

The application of Jatropha gossypiifolia for the remediation of impacted soils within the Niger Delta Zone of Nigeria was examined in this work. During the study, seeds of J. gossypiifolia were cultivated on different soils impacted with wastes from municipal dumpsite, automobile and, electronic workshops, and paint industry in Akwa Ibom State. Two kilograms each of the impacted soils in polyethene bags were amended with 20.0 mLday^-1 of mixed citric and ethylene diamine tetraacetatic acids. Plants and soil samples before and after remediation were assessed for the concentrations of Cd, Cu, Ni, and Pb. The concentrations (mg kg^-1) of metals in the impacted soils before remediation process were Cd (3.00±0.82), Cu (23.85±3.31), Ni (11.39±2.08), and Pb (36.10±2.27), respectively. Levels of the metals phytoextracted were 2.27±0.67 mg kg^-1, 2.51±3.27 mg kg^-1, 10.17±2.29 mg kg^-1, and 34.81±2.37 mg kg^-1 for Cd, Cu, Ni, and Pb, respectively. However, the concentrations of Cd, Cu, Ni, and Pb (mg kg^-1) were reduced to 0.68±0.18, 1.28±0.27, 1.19±0.25, and 1.14±0.13, correspondingly in soil after remediation. Higher values of all the environmental models were recorded for the metals during the pre than the post-remediation periods. The estimated daily exposure rates, non-carcinogenic and cancer risks for the adults and children were higher during the pre than the post remediation regimes however; the children class was more disposed to these hazards. The results revealed that the remediation of impacted soils by plants could sustain the soil environment and human life within the studied Region.