Modelling of heavy metal pollution potential for different components of the Lake Victoria aquatic ecosystem

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Date
2008
Journal Title
Journal ISSN
Volume Title
Publisher
University of Dar es Salaam
Abstract
Pollution is the most serious of all environmental problems and poses a major threat to the health and the well-being of people and ecosystems. The introduction of heavy metals and their compounds in the Lake Victoria primarily presents a potential threat to the public health. The study established the distribution of Cu, Zn, Fe Hg and Pb in water sediments and plants in Nungwe bay and its surrounding wetlands. Analysis of heavy metal was done by atomic absorption spectrophotometer. Mathematical models are applied to predict the levels of concentrations in various components of the aquatic system from the estimation of the anthropogenic sources. Results from laboratory analysis show that sediments had high concentrations heavy metal ranging from trace amount to 960µg/kg for Pb, 14824-17432 µg/kg for Fe, 4-32 µg/kg for Cu, 24-68 µg/kg for Zn and from trace to 1.13 µg/kg for Hg. From speciation analysis the heavy metal retention can be ranked in the following order: Organic/sulfide bound> Residual> Fe & Mn oxides>Exchangeable portion > Carbonates bound. Total metal concentration of water in Nungwe Bay was low for Zn, Cu, with average of 0.065 and 0.105 [tg/1 for Zn and Cu respectively while the levels was high for Hg, Fe and Pb with an average of 15.6iug/1, 2.49 and 10.61 nil for Hg, Fe and Pb respectively. Mathematical model application predicted concentration of the dissolved Cu with reasonably good agreement to the measured values in most of the sampling points.
Description
Available in print copy
Keywords
Modelling, heavy metal pollution, Lake Victoria, aquatic ecosystem, Pollution
Citation
Mkumbo, S.(2008) Modelling of heavy metal pollution potential for different components of the Lake Victoria aquatic ecosystem, Master dissertation, University of Dar es Salaam. Dar es Salaam.