Appraisal of heavy metal contents in soils using different digestion methods

Abstract The concentration of some heavy metals (Fe, Cu, Zn, Cr, Pb, Ni, Cd) were analysed in soils in and around Keteren-Gwari Mechanic village, Minna metropolis, Niger State, North-central Nigeria using Atomic Absorption Spectroscopy (AAS) (Buck Scientific 210VGB). Two digestion methods were used to concentrate the metals. Mean concentration for Fe was 6548±72.94µg/g; 24.57±16.74µg/g Cu; 24.57±16.74µg/g Zn; 11.64±9.02µg/g Cr and BDL for Pb, Ni and Cd using aqua-regia digestion while mean concentrations using HClO4, HNO3 and H2SO4 mixture digestion were 5175±29.99µg/g Fe; 27.07±17.43 µg/g Cu; 126.57±97.29 µg/g Zn; 18.14±12.45 µg/g Cr; 128±22.22 µg/g Pb and BDL for Ni and Cd. The contamination factor (CF) calculated was shown to be Fe ˃ Zn ˃ Cu ˃ Cr for surrounding soil samples and Fe ˃ Pb ˃ Zn ˃ Cu ˃ Cr in the mechanic village work area. It is recommended that laws are formulated and enforced that prevent any form of farming in the area, mechanic villages be relocated out of the city and other environmental protection regulations to stop the build-up of these metals in similar locations be implemented.

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Updated: April 26, 2017 — 4:46 pm