Micropollutants and organic carbon concentrations in surface and deep sediments in the Tunisian coast near the city of Sousse.

A radioactive tracer was used to map the plume of the effluent of a municipal water treatment plant located on the Tunisian coast, close to the city of Sousse. A sampling campaign was programmed on the basis of the radioactivity distribution. The extent of sediment contamination was investigated to determine the impact of the plant effluent. Organic carbon and organic micropollutants (PCBs and chlorinated pesticides) were analysed on resuspendable particulate matter, on grab and core sediments. The area distributions of different compounds analysed were studied and relationships were investigated between radioactivity and organic carbon and micropollutant data. The study shows that sludge particles are deposited and accumulate in the zone south of the effluent outlet, contaminating sediments. Good correlations were found which demonstrate the efficiency of the technique used to plan the sampling and the link between organic carbon and organic micropollutants.