Content of trace metals in surface sediments of Lac Sud de Tunis before development; Teneurs en metaux traces des sediments de surface du Lac Sud de Tunis avant restauration

The analysis of metal (Hg, Cd, Pb, Cu, Cr, Ni, Mn, Zn, Fe) concentrations in the surface sediments of the South Lake of Tunis before its restoration showed a high level of contamination. The values for mercury, cadmium and lead oscillate respectively between (0,17 and 2,6 {mu}g/g d.w), (0,13 and 13,3 {mu}g/g d. w); (3,97 and 698 {mu}g/g d. w). This pollution is generated by the intensive industrial activity situated on south banks of the Lake. This environment constitutes since more of the millennium a outfall of urban used waters and since one century an outfall of industrial waste waters strongly charged with nutrients and heavy metals. (author) 14 refs, 6 figs, 1 tab