Geochemistry and Distribution of Heavy Metals from Itakpe Iron-Ore Mine Tailings on Soils

Eight dry season soil samples were collected around the tailings dam in order to evaluate the impact of tailings on the soils. The mean concentrations of cations and heavy metals observed are: K(94.66)>Ca(75.92)>Na(18.47)>Mg(5.24) and Fe(29714.13)>Cd(1.51)>Cu(1.30)>Zn (1.20)>Ni (0.64)>Pb(0.55), respectively. Moderate to strong correlation relationship exist between cations and heavy metals. Among the heavy metals, fewer cases of moderate to strong correlations were observed. The factor and cluster analyses reveal both natural and anthropogenic influences on the variables. Three indices were used for heavy metal evaluation. Contamination factor (CF), enrichment factor (EF) and index of geo-accumulation (Igeo). The degrees of heavy metal impact were also evaluated using pollution load index (PLI). Among the three indices, CF and EF recorded this order: Fe>Pb>Cu>Zn>Ni>Cd and Igeo recorded this order: Fe>Pb>Cu>Zn>Cd>Ni among the heavy metals. The pollution load index suggests that all sites have experienced various degrees of deterioration with locations ITK12, ITK21, ITK23, ITK11 and ITK22 severely deteriorated. This study has revealed the need for statistical and quantitative data evaluation and presentation. From these indices used, Fe, Pb, Cu and Zn are the most impacted of the heavy metals. While long term treatment methods such as phytostabilization, phytoextraction and rhizofiltration are recommended, there is also the need to treat the soil and put monitoring measures in place to forestall further contamination.