Heavy metal concentrations in Bottom Sediments of Ikpoba River, Edo State, Nigeria

The concentrations of fe, mn, zn, cu, pb, cr, ni and v were investigated. samples were collected fortnightly from five (5) stations for four months (july to september, 2009) using ekman grab operated by hand in shallow water. station 1 is upstream (old capitol bridge) and stations 2, 3, 4 and 5 are downstream. the main concentrations (ppm) in stations 1, 2, 3, 4 and 5 are: 931, 117, 812, 679 and 619.7 (fe); 12.11, 21.08, 9.58, 8.64 and 7.89 (mn); 9.90, 12.5, 9.64, 7.07 and 6.62 (zn); 7.88, 8.04, 5.81, 4.34 and 3.88 (cu); 0.48, 0.61, 0.36, 0.26, and 0.28 (pb); 0.19, 0.26, 0.13, 0.12 and 0.11 (cr); 0.12, 0.16, 0.08, 0.08 and 0.08 (cd); 0.13, 0.19, 0.13, 0.11 and 0.11 (ni) and 0.10, 0.15, 0.10, 0.09 and 0.09 (v). analysis of variance (anova) showed that fe (stations 1 and 2), cr (stations 1 and 2) and cd (station 2) were significantly different (p<0.05) between stations. all parameters studied were below fepa limits. the heavy metal concentrations in bottom sediments of ikpoba river showed a seasonal pattern of variation. this investigation in comparison with earlier study based on data from jimoh, 2006; show that fe and mn concentration increased overtime while cd, pb, and cu did not