Heavy Metal Speciation Study of Water and Bottom Sediments from River Wujam in Chip District of Pankshin Local Government Area, Plateau State, Nigeria

Abstract

Heavy metal species of water and bottom sediment samples from River Wujam in Chip district of Pankshin L.G.A. were investigated in the dry and wet seasons. The analysis was done using standard procedures. The results for the total metal concentration of the water samples ranges, thus, 0.02 -0.03 mg/L for copper, 0.01 – 0.11 mg/L for lead, 0.02 - 0.07 mg/L for manganese, 0.01 – 0.06 mg/L for cadmium. But nickel and zinc were not detected within the limits used. The total metal concentration of metals analysed (Cu, Pb, Mn, Cd, Zn, and Ni) in the sediments revealed a generally higher concentration in the dry season except for cadmium which revealed a higher concentration in the wet season. Speciation of the metals was also carried out on the sediments using Tessier method to determine their distribution in the sediment of the river. The percentage ranges of the fractions for the dry season are, 12.24 – 46.09%, 15.80 – 24.01%, 11.47 – 21.91%, 10.83 – 22.80%, and 7.61 – 75.00% for exchangeable, carbonate, Fe-Mn oxide, organic, and residual fractions respectively. Ni was not detected within the limits used in the carbonate, Fe-Mn oxide and organic fractions. The range of fractions for the wet season are, 4.25 – 33.77%, 10.82 – 24.21%, 15.91-38.35%, 10.65 – 51.06%, and 19.01 – 26.77% for exchangeable, carbonate, Fe-Mn oxide, organic, and residual fractions respectively. Ni was not detected within the limits used in the carbonate and organic fractions. With change in the environmental conditions Cadmium and lead bound to such labile phases in both the dry and wet season, can easily remobilize in the water system. A moderate positive correlation existed in the total metal concentration of water samples between dry and wet seasons. A strong positive correlation existed in the total metal concentration in the sediments samples between dry and wet seasons. T-test results indicated that there is no significant variation in the concentrations between the seasons in both cases.<div><br></div>