CHEMICAL POLLUTION FROM URBAN AND INDUSTRIAL SEWAGES IN AUGUSTA-BAY (SICILY)

The Augusta Bay is a complex area where heavy industrialization and de nse urbanization have promoted a very high state of degradation. This basin has already been studied for several years because of various eu trophication phenomena which induced a massive fish mortality. In orde r to deepen our knowledge on the state of chemical pollution due to Di ssolved/Dispersed Petroleum Hydrocarbons (DDPH), detergents and N- and P-salts as well as on the eutrophication of the bay, three campaigns have been carried out. The results (from 0.0 to 96.6 mu g/l in chrysen e equivalents) have indicated that the distribution of DDPH is charact erized by an extreme spatial and temporal variability linked to occasi onal localized spills and to the wind's action which influences the su rface water circulation in the bay. The concentration of non ionic (Bi AS) and ionic (ABS) detergents averages respectively 63 and 55 mu g/l with a predominance of BiAS in the waters affected by the urban discha rges, while high ABS values have been also measured in correspondence of a cooling water effluent. Finally, the PO4 (maw 0.3 mu/l) and NO2 NO3 (max 4 mu l) levels were relatively low and constant in compariso n with previous results, while NH4 remains ata high level (max 14.6 mu /l) with supplies located in the urban discharge as well as in the ind ustrial ones, indicating that both types of effluents are equally resp onsible for eutrophication and the distrophic crisis observed in the b ay.