Chemical pollution from urban and industrial sewages in Augusta Bay (Sicily)

Abstract

The Augusta Bay is a complex area where heavy industrialization and dense urbanization have promoted a very high state of degradation. This basin has already been studied for several years because of various eutrophication phenomena which induced a massive fish mortality.In order to deepen our knowledge on the state of chemical pollution due to Dissolved/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 μg/l in chrysene equivalents) have indicated that the distribution of DDPH is characterized by an extreme spatial and temporal variability linked to occasional localized spills and to the wind's action which influences the surface water circulation in the bay.The concentration of non ionic (BiAS) and ionic (ABS) detergents averages respectively 63 and 55 μg/l with a predominance of BiAS in the waters affected by the urban discharges, while high ABS values have been also measured in correspondence of a cooling water effluent.Finally, the PO4 (max 0.3 μ/l) and NO2 + NO3 (max 4 μl) levels were relatively low and constant in comparison with previous results, while NH4 remains at a high level (max 14.6 μ/l) with supplies located in the urban discharge as well as in the industrial ones, indicating that both types of effluents are equally responsible for eutrophication and the distrophic crisis observed in the bay.