Hussein Kehinde Okoro*1, 2, Julius Oluwafunso Ige1, Catherine J. Ngila2
1Material and Environmental-Analytical Research Group, Department of Industrial Chemistry University of Ilorin, P.M.B. 1515. Ilorin 24003, Nigeria.
2Analytical-Environmental and Membrane Nanotechnology Research Group, Department of Applied chemistry, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, Johannesburg, Republic of South Africa
Corresponding Author e-mail : hkoadeola@gmail.com
Abstract
Geochemistry, pollution load index (PLI) contamination factor (CF), geoaccumulation index (Igeo) and anthropogenic factors (AF) of sediment samples collected from Olonkoro river, South West, Nigeria has been conducted. Atomic absorption spectrometry (AAS), Xray diffraction (XRD) and Fourier Transform infrared (FTIR) techniques were explored for sample analyses. Metals concentrations were varied therefore, the presences of these metals were entirely from non-crustal materials. The enrichment factor EF values in this site are in the decreasing order Cu > Pb> Mn> Zn >Cd. High Igeo was recorded for most of the metals; Zn belong to strongly contaminated while Pd was predominately extremely contaminated. Igeo values for Cu ranged from 5.44 to 6.98 with a mean value of 6.17 and most of the samples fell into class 6 of very strongly contaminated. This high index is caused mainly by industrial activities and agricultural activities taking place within the area. The PLI values from location P1 to P10 suggest deterioration of site sediment quality. The mineral phases were extracted from the XRD data. All the samples exhibited similar diffractographs, it is confirmed that the most dominant of all the minerals present is quartz. its absorption band appears around 455 to 450, 798 to 800. Pyrites are principally present at locations 1, 5, 7 and 10 its absorption frequency ranges from 700 to 800. This could be connected to the presence of iron (Fe) Thus, an immediate intervention to ameliorate pollution at sites is needed. The average AF of >1 was recorded for Fe, this suggest that it’s enrichment was through anthropogenic source. Fe in the entire ten locations exhibit this characteristic while Mn, Cu, Zn, Pb, Cd reflect geogenic sources of these metals. Thus, the order of degrees of anthropogenic contamination in the sediment samples is: Fe > Cu > Zn > Pb > Mn> Cd. Geomineral analyses confirmed the presence of pyrite, quartz, Felspar, Goethite, chromites, calcite, and Kaolin as part of the sediment compositions.
Keywords:
Geoaccumulation index; pollution index, contamination factor, anthropogenic factors, sediments, pollution
