Numerical Modeling of Heavy Metals in Riverine Systems in Eldoret, Uasin Gishu County, Kenya
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Date
2018
Authors
Munene, Emily Naitore
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
Heavy metals are gradually being added into water resources due to the rise in
Municipal, industrial and agricultural activities. The fate of heavy metals being in
water systems is mainly controlled by transport processes. Transportation of heavy
metals by rivers can be both as metal in solution and adsorbed to suspended solids. A
one dimension environmental model has been developed in this work to simulate the
transport of heavy metals discharged into a riverine system. The model has been
developed by solving a mass transport equation. The governing equation describing
the mathematical model is discretized implicitly by integral finite difference method
(IFDM). Heavy metal samples were collected along river Sosiani as it passes
through Eldoret town. The concentration levels of copper, zinc and lead metals was
analysed. The concentration values obtained from the heavy metal analysis were
above WHO standards of 0.2mg/l and 0.05mg/l for copper and lead respectively for
drinking water. The model developed in this study was validated for spatial variation
of heavy metal concentration. The model considered multiple sources of pollutants.
During validation, field parameters like flow rate and dispersion coefficient were
varied so as to reduce the differences between simulated and measured values. There
was close agreement between the measured and the simulated values. Correlation
coefficients of 0.8879, 0.7907 and 0.8644 for zinc, copper and lead were
respectively obtained. The results of the dissolved heavy metal concentrations agree
well with the measured data. The results obtained in this study show that the model
demonstrated good capabilities for describing spatial characteristics of heavy metals
in riverine systems. It can be concluded that by using mass balance model it is
possible to simulate heavy metal transport in surface waters for risk assessment
purposes and is shown to be a useful management tool in monitoring water quality
in the River Sosiani.
Description
A Thesis Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science (Physics) In the School of Pure And Applied Sciences of Kenyatta University, May 2018