Survey of heavy metals in sediments of Kolo creek in the Niger Delta, Nigeria
Concentrations of Fe, Pb, Cr, Ni and V were measured in sediments taken from eight (8) sampling stations along a section of Kolo creek which traverses an oil flow station and a point in Epie creek which receive effluent discharges from human and industrial activities. The study was conducted in four seasons (Dry, Late Dry, Rainy and Late Rainy Seasons). Vanadium was less than 0.001 mg/Kg in all the samples analysed. Fe, Pd, Cr and Ni had annual means of 5109.85, 1.60, 14.22 and 10.18 mg/Kg respectively. One way ANOVA at 95% confidence limit showed no significant difference in the nine (9) sampling stations. However, there was significant difference in the four (4) seasons that the study was conducted. Cluster analysis of the data further classified the four seasons into two groups. Geoaccumulation indices showed that the Creek is not polluted by Pb, Cr and Ni, however, it is highly polluted with Fe. The highest positive correlation was between Pb and Cr while the highest negative correlation was between Fe and Ni. Compared to DPR intervention values, Kolo creek is free from pollution by Pb, Cr and Ni.
Key words: Heavy metals, sediment, Kolo creek, cluster analysis, geoaccumulation index.