Heavy metal pollution assessment in the sediments of lake Chad, Nigerian sector

Abstract

Sediments were collected from Dumba and KwataYobe of Lake Chad, Nigerian Sector.The aim was to assess the pollution statusof the sediments of the lake. The concentration of heavy metals, Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni), lead (Pb), Z (Zn) and Arsenic (As) were analysed using energy dispersive x-ray fluorescence (EDXRF). The mean concentration of heavy metals varies between 0.01 to 80877.06 ±10.12mg/kg, were compared with standard average shale to assess the pollution status of the pollution in Dumba and KwataYobe sediments for Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and As was assessed using geo-accumulation index (Igeo). The results indicated that the sediments have been polluted with Cd, Cr, Fe, Mn, Pb, Zn and As.The Igeo values for Cd, Cr, Cu, Fe, Mn, Ni and Zn at KwataYobevaries between 0.007 to 0.630, indicating unpolluted sediments, while Igeo values for Cd at Dumba and Pb in both sites varies between 1.002 + 01.550 indicating moderately polluted sediments.Igeo values for As varies between 10. 411 to 13.20 in both sites indicating very highly polluted sediments. The Igeo values for Cd at Dumba, Pb and As in both sites indicated that the sediments were polluted.

Keywords: Assessment,Average shale, Geo-accumulation index, Heavy metal pollution, Sediments.