Partitioning of Trace Metals in Sediments from the Mediterranean Coastal Zone of Ajdabia to Benghazi, Libya: Case Study

Surface sediment samples were collected from different sites along the Libyan coasts of the Mediterranean Sea from Ajdabia to Benghazi during the period January – April 2012. Collected samples were sequentially extracted using modified BCR procedure and analyzed by FAAS for Cd, Cu, Pb, Fe, Co, Ni, Mn, Zn and Cr. Average total concentrations were 4.49, 5.57, 68.24, 690.40, 17.44, 29.01, 57.97, 32.00 and 18.84 mg/kg for Cd, Cu, Pb, Fe, Co, Ni, Mn, Zn and Cr, respectively. Enrichment factor calculations indicated that Mn, Fe and Cu didn’t show any enrichment, while Cr and Zn showed minor enrichment. High enrichments were observed for Cd, Pb, Ni and Co. The results of sequential extraction showed that significant fractions of Cd, Ni, Cr, Pb, Co, and Cu were present in the exchangeable/carbonate phase (20% - 35%). Fe was mainly contained in the residual fraction (58%), while Mn was mainly contained in the Fe-Mn oxide phase. Cu and Zn were predominantly contained in the organic phase followed by the Fe- Mn oxide phase. Co, Ni, Cr and Pb were mainly contained in the Fe-Mn oxide phase (32% - 41%).