International Journal of Environmental Sciences

Volume 3 Issue 5 2013- March 2013    Pages: 1407-1415  <<Previous    Next>>

Heavy metal contamination in water and sediment downstream of municipal wastewater treatment plants, Dar es Salaam, Tanzania

Author Information:

Charles Kihampa

Department of Environmental Science and Management, Ardhi University, P. O. Box 35176, Dar es Salaam, Tanzania

ABSTRACT

The objective of this study was to determine concentrations of heavy metals leaving seven municipal wastewater treatment plants (MWWTPs), and reaching streams and rivers environment. Five metals including Cd, Pb, Cu, Zn and Cr, ranging from 0.01 to 0.27 mg/l and 0.17 to 225.83 mg/kg dw were detected in water and sediments, respectively. Industries and institutions wastewater were found to be the most important source for heavy metals in wastewater treatment plants (WWTPs). Concentrations of Pb, Cd and Cr in water were found to be higher than the maximum permissible limits as per Tanzania Bureau of Standard. High concentration in sediments beyond maximum limits for sediment quality guidelines (SQG) were detected for Pb, Zn and Cu. The results indicate that MWWTPs contribute to heavy metal pollution to Dar es Salaam environment. Acute health consequences in the investigated areas can be insignificant, but chronic adverse health effects due to prolonged pollution and long term exposure through vegetables consumption, washings, animal keeping and fishing can be inevitable.

Keywords: Environment, heavy metals, municipal wastewater, water, sediment.

DOI:10.6088/ijes.2013030500011

© 2013 Copyright by the authors, licensee Integrated Publishing Association.This is an open access article distributed under the Creative Commons Attribution License (3.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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