Accumulation of heavy metals on bed sediments of Nairobi dam, Kenya
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Date
2017-03
Authors
Ndeda, L. A.
Manohar, S.
Macharia, G. M.
Journal Title
Journal ISSN
Volume Title
Publisher
Academic Journals
Abstract
Globally heavy metals pollutants in aquatic systems are increasing and creating major ecological
disturbance(s) and direct health problems. The study on accumulation of Copper (Cu), Cadmium (Cd),
Lead (Pb) and Nickel (Ni) on the bottom surface sediments of Nairobi dam was conducted between
November 2012 to April 2013. Seven sampling sites were selected within the dam and sediment
samples were collected once in a month during the wet and dry season. Standard methods for
sampling, storage and analysing according to APHA were used; statistical analysis in form of means,
independent T-test and ANOVA were used to summarize the findings. (Mean±SE) (ppm) concentrations
of Pb, Cd, Cu and Ni in the dam during the dry season are: 38.01±0.26, 30.86±0.21, 21.7±0.22, 8.44± 0.15,
and in wet season are: 33.73±0.22, 26.60±0.19, 19.11±0.14 and 5.94±0.12, respectively. The levels of
heavy metals in the sediments at the outlet are lower compared to the other sites within the dam. These
metals accumulated in the order: Pb> Cd> Cu> Ni with higher concentration during the dry than wet
season. It is concluded Nairobi dam sediments are contaminated with heavy metals that are
significantly higher during the dry compared to wet season (P<0.0001). Therefore it is recommended
that sediments of this dam are not suitable for cultivation and or any agricultural activities
Description
Research Article
Keywords
Accumulation, Heavy metals, Sediments, Nairobi dam
Citation
Journal of Environmental Chemistry and Ecotoxicology Vol. 9(1), pp. 1-7, March, 2017; DOI:10.5897/JECE2015.0353