Heavy metals concentrations in coal and sediments from River Ekulu in Enugu, Coal City of Nigeria

Abstract

The levels of some heavy metals such as; Mn, Cr, Cd, As, Ni, and Pb were analysed in coal and sediment samples from River Ekulu in Enugu, Coal City using Atomic Absorption Spectrophotometer (AAS) model Spectra-AA-10 variant. Mean concentrations of Mn (0.256-0.389mg/kg) and Cr (0.214-0.267 mg/kg) are high relative to concentrations of Cd (0.036-0.043 mg/kg), As (0.016-0.018 mg/kg), Ni, (0.064-0.067 mg/kg) and Pb (0.013-0.017 mg/kg). Except for Mn, there is a steady decrease in the concentration of all metals from November to March corresponding to decreasing run-off. Metal concentrations are generally higher in the coal samples than in the sediments. Selectiveleaching of these metals is suspected from the trends of their concentration. Seasonal fluctuations are higher in the sediments than the coal samples. Correlation coefficients show that all the metals are positively correlated with each other implying that they are from the same source or origin. The presence of toxic metals in the area is established, calling for the assessment of their impact on the health of human and aquatic lives around the area Journal of Applied Sciences and Environmental Management Vol. 9(3) 2005: 5-8