A study of the water quality of the osun river: metal monitoring and geochemistry

Abstract

The concentrations and distributions of Cd, Cu, Ni, Pb, Cr and Zn in Osun river, selected rivers in the region and groundwaters have been studied, in order to establish the current levels of pollution. The metal concentration (mean plus or minus RSD in g dm-3) in the Osun river for the sampling periods of May, June and August, respectively, were: Cd, 1.45 plus or minus 0.65, 1.40 plus or minus 0.37, 1.25 plus or minus 0.52; Ni, 21.8 plus or minus 6.22, 10.6 plus or minus 3.68, 15.3 plus or minus 6.01; Pb, 7.16 plus or minus 3.30, 8.45 plus or minus 3.24, 4.86 plus or minus 1.98; Cu, 16.7 plus or minus 9.32, 11.9 plus or minus 4.81, 8.27 plus or minus 3.80; Cr, 250 plus or minus 118, 400 plus or minus 160, 150 plus or minus 72.9; Zn, 398 plus or minus 109, 289 plus or minus 113, 259 plus or minus 94.4. The correlation coefficient between metal pairs of river water and groundwater samples are calculated and possible sources of the polluting substances are discussed.