1Department of Geology, University of Dar es Salaam, PO Box 35060, Dar es Salaam, Tanzania
2Department of Chemistry, University of Missouri - Columbia, 125 Chemistry Building, 601 S. College Avenue-Columbia, MO-65211, USA
3Department of Chemistry and Chemical Biology, University of New Mexico
4University of New Mexico, Albuquerque, NM-87131, USA
*Email: agnesmrutu@gmail.com
Online published on 6 December, 2013.
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.
Dar es Salaam, heavy metals, mangroves, Msimbazi River, sediments
