SPECIATION OF HEAVY METALS IN SEDIMENTS OF A POLLUTED TROPICAL STREAM USING THE BCR SEQUENTIAL EXTRACTION TECHNIQUE
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Date
2007-10
Authors
Oyeyiola, A. O.
Olayinka, K. O.
Alo, B. I.
Journal Title
Journal ISSN
Volume Title
Publisher
The Nigerian environmental society
Abstract
The Physico-chemical parameters and heavy metal (Pb, Cd, Cr, Cu, Zn) content of water and the concentration of heavy metals (Pb, Cd, Cr, Ni, Zn) in sediment, and the species which these metals occur were determined, using the Sequential Extraction Procedure proposed by the BCR in Odo-iyaalaro stream
The water was found to have a low DO (0-2.2mgO2/l ), high BOD (36-72.8mgO2/l ) and COD (52.6-108.0mgO2/l )values. The results of the speciation studies indicated that Pb was predominant in the organic matter/sulphide bound fraction(51.3%), and is distributed between the residual(26.8%) and Fe-Mn oxide bound fraction(19.7%), while a smaller proportion was found in the water soluble, exchangeable/carbonate bound fraction (0.4%). Cd followed a similar pattern to that of lead, i.e 42.6% organic matter/sulphide bound, 22.5% residual, 18.9% Fe-Mn oxide bound and 15.9% water soluble, exchangeable/carbonate bound. Cr was mainly associated with the organic matter and sulphide bound fraction(47.1%), while Ni was predominantly associated with the residual fraction,((48.1%). Zn was found to be predominant in the water soluble, exchangeable and carbonate bound fraction (39.0%).
Zn was found to be the most mobile and bioavailable heavy metal determined. Ni was found to be more in the residual fraction (33.6%-51.8%). Generally, much of the metals were found in the organic matter/sulphide bound fraction. This is probably due to the generally high organic carbon content of the sediment.
Description
Staff publications
Keywords
Research Subject Categories::NATURAL SCIENCES::Chemistry::Analytical chemistry::Separation methods , Physico-chemical , heavy metal , Sequential Extraction Procedure , speciation studies , organic matter
Citation
Oyeyiola, A. O., Olayinka, K.O. and Alo, B. I. (2007). Speciation Of Heavy Metals In Sediments Of A Polluted Tropical Stream Using The Bcr Sequential Extraction Technique. Journal of Nigerian Environmental society, 7(1), 139-150pp.