Owor M., Hartwig T., Muwanga A., Zachmann D., Pohl W.
Department of Geology, Makerere University, P.O. Box 7062, Kampala, Uganda; Institute of Environmental Geology, Technical University, P.O. Box 3329, Braunschweig 38023, Germany
Owor, M., Department of Geology, Makerere University, P.O. Box 7062, Kampala, Uganda; Hartwig, T., Institute of Environmental Geology, Technical University, P.O. Box 3329, Braunschweig 38023, Germany; Muwanga, A., Department of Geology, Makerere University, P.O. Box 7062, Kampala, Uganda; Zachmann, D., Institute of Environmental Geology, Technical University, P.O. Box 3329, Braunschweig 38023, Germany; Pohl, W., Institute of Environmental Geology, Technical University, P.O. Box 3329, Braunschweig 38023, Germany
The abandoned Kilembe copper mine in western Uganda is a source of contaminants, mobilised from mine tailings into R. Rukoki flowing through a belt of wetlands into Lake George. Water and sediments were investigated on the lakeshore and the lakebed. Metal associations in the sediments reflect the Kilembe sulphide mineralisation. Enrichment of metals was compared between lakebed sediments, both for wet and dry seasons. Total C in a lakebed core shows a general increment, while Cu and Co decrease with depth. The contaminants are predominant (> 65%) in the ≤ 63 μm sediment size range with elevated Cu and Zn (> 28%), while Ni, Pb and Co are low (< 18%) in all the fractions. Sequential extraction of Fe for lakeshore sediment samples reveals low Fe mobility. Relatively higher mobility and biological availability is seen for Co, Cu and S. Heavy metal contents in lake waters are not an immediate risk to the aquatic environment. © 2006 Springer-Verlag.
Copper mines; Environmental impact; Impurities; Sediments; Wetlands; Aqueous geochemistry; Copper mining; Lake George; Uganda; Tailings; abandoned mine; copper; enrichment; heavy metal; lacustrine deposit; lake pollution; pollutant source; tailings; Africa; East Africa; East African Lakes; Lake George [Western Province]; Sub-Saharan Africa; Uganda; Western Province [Uganda]