TITLE:
Speciation of Trace Metals Pb, Zn, Cu and Cd in Surficial Sediment from Makupa Creek Mombasa, Coastal Kenya
AUTHORS:
Philip K. Maritim, A. N. Gachanja, T. M. Munyao
KEYWORDS:
Speciation, Sequence Extraction Procedure, Bioavailability, Trace Metals, Sediment
JOURNAL NAME:
Open Access Library Journal,
Vol.3 No.7,
July
28,
2016
ABSTRACT: Trace metals (Zn, Pb, Cu, Cd) speciation of surface sediments from Makupa
creek, coastal Kenya were determined by sequential extraction procedure. The
procedure was used to extract the trace metals in sediments geochemical phases
(exchangeable, carbonates, Fe-Mn oxides, organic matter/sulphide, and residual).
Trace metals analysis was done using ICP/MS. The trace metal speciation results
indicated that Pb, Zn, and Cd were mainly associated with the exchangeable, carbonates
and Fe-Mn oxides in most of the sampling sites. The highest concentration of
the trace metals were associated with Fe-Mn oxides with Zn concentration at
362.5 μg/g, Pb, 31.5 μg/g. Copper was mostly associated with the organic matter/sulphide
and carbonate at concentration of 117.5 μg/g and 69.9 μg/g respectively.
Generally, trace metals in sediment from Makupa creek were mainly associated
with the bioavailable fractions (BAF) and their ranges were: Pb (60%-98%), Zn
(90%-99%), Cu (70%-91%). It was found therefore, that there was trace
metals enrichment in sediments from Makupa from anthropogenic sources and
bioavailable to biota.