International Journal of Environmental Sciences

Volume 3 Issue 5 2013- March 2013    Pages: 1641-1655   <<Previous    Next>>

Spatial distribution of heavy metals in Msimbazi River mangrove sediments in Dar es Salaam coastal zone, Tanzania

Author Information:

Agnes MRUTU1,2, Hudson H. NKOTAGU1, Gebhard B. LUILO3

1- Department of Geology, University of Dar es Salaam, PO Box 35060, Dar es Salaam, Tanzania

2- Department of Chemistry, University of Missouri-Columbia, 125 Chemistry Building, 601 S. College Avenue, Columbia, MO 65211, USA

3- Department of Chemistry and Chemical Biology, University of New Mexico

1- University of New Mexico, Albuquerque, NM 87131, USA

ABSTRACT

This paper reports on distribution of heavy metals in sediments of the Msimbazi River mangrove forest. The levels of heavy metal decreased with increasing depth as well as with increasing distance from mangrove to the Indian Ocean shoreline. The total metal levels of heavy metals ranged from 1000 to 27000 ppm (iron, Fe), 16 to 173 ppm (zinc, Zn), 3.1 to 76 ppm (lead, Pb), 13.2 to 71.2 ppm (chromium, Cr), 6.9 to 22.5 ppm (nickel. Ni), 4.1 to 17.4 ppm (cobalt, Co) and 0.03 to 3.90 ppm (cadmium, Cd). These observations indicate that Msimbazi River sediments have high metal retention. This is attributed, among other factors, to clay contents at 0 - 50 cm core that ranged from 15.78 to 85.04 % and its content decreased with increasing depth. Thus, the Msimbazi River sediments play a role in filtering heavy metals from the wastewater flowing through it prior to its discharge into Indian Ocean.

Keywords:  Dar es Salaam, heavy metals, mangroves, Msimbazi River, sediments.

DOI:10.6088/ijes.2013030500033

© 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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