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Vediment samples were collected during summer, 2004 from Lake ^Manzala to determine the chemical association of trace metals (Fe, Mn, Cu, Zn, Pb, Cd, Co, Ni and Cr) in the lake sediments. Five fractions were extracted using sequential extraction techniques, which represent the major sedimentary phases including the exchangeable, carbonate, Fe-Mn oxides, organic fraction and residual metal. The results of metals speciation indicated that, the high proportion of trace metals were presented in the residual fraction which represents 50% of the total metals for Mn, Cu, Pb and reached to 73% of the total for Zn. The geochemical analysis of metal forms reflected the lithogenic origin of these metals in the study area. The results also showed high percentage of Fe, Co, Ni and Cr in the organic fractions (40% of the total metal). High percentage of Cd was found in the carbonate fraction (32%). However, few percentages were recorded in the exchangeable fraction of Fe, Cu and Zn (< 1% of total content), while increased from 2 to 6% of total Mn, Cr, Co, Ni and reached to 6% for Pb and 12% for Cd. It is evident from the results that the sediments of Lake Manzala are highly polluted with Cd, Cr, Ni and Co, and the greater amount of these were found in the non-lithogeous origin (exchangeable, carbonate, oxides and organic materials). Multivariate techniques of statistical analysis have been applied to a set of chemical forms of metals obtained by the analysis of Lake Manzala sediments. The correlation matrix and principal component analysis were performed to show the behavior of the nine metals in each fraction.

TRACE METALS SPECIATION IN SEDIMENTS OF LAKE MANZALA, EGYPT