Distribution and assessment of trace metal contamination in the surface sediments of the Meliane River and the Coast of the Gulf of Tunis (Tunisia, Mediterranean Sea)

The Meliane River, the second longest and most important river in Tunisia, is one of major rivers that flow into Gulf Tunis. However, it known by its significant discharges urban industrial activities have seriously affected quality aquatic ecosystem. highest amounts Cadmium (Cd), Copper (Cu), Lead (Pb), Zinc (Zn), Nickel (Ni), Chromium (Cr) Manganese (Mn) surface sediments River indicate downstream part polluted area. chemical speciation shows majority trace metals are bound to a reducible fraction (Zn, Mn, Cr Ni) Pb Cu oxidizable fraction. Cd linked exchangeable fraction, which indicates high mobility toxicity. Both contamination enrichment factors values some elevated River. percentage risk assessment code 59.8%, presents very environmental risk. Therefore, spatial distribution elements characterized concentration These concentrations decrease as function change physicochemical parameters from freshwater-saltwater mixing zone marine stations.