COMPARATIVE ANALYSIS ON HEAVY METALS COMPOSITION OF THE SEDIMENT AND OVERLAYING WATER OF NWANIIBA

Nwaniba river system could be influenced by different activities going on in and around the river system. To determine levels of Co, Cu, Pb, Cd, Cr and Ni in sediment and its overlaying water, digestion process and application of Atomic Absorption Spectrophotometer was applied. No value exceeded the maximum permissible limit set by WHO. But for Cu, all sediment values were higher than those obtained for water, while Pb was not detected in both samples. Ni (0.87±0.01mg/kg) was highest among all the metals analysed in sediment, while Cu (1.00±0.02mg/kg) was highest in overlaying water. Sediment having higher values compared to its overlaying water portrays sediments as a sink for contaminants introduced into the water, and the contaminant can be released back into water through mineralization and resuspension process. Zero value for Pb suggests absence of Pb generating factor into the river system. The results obtained in the work suggest a safe status of sediments and water from Nwaniba river for aquatic life.