Performance Evaluation of the Wastewater Treatment Plant of Sfax City (Tunisia): Influence of Intrinsic and Extrinsic Factors

This study detailed the effect of simultaneous multiple intrinsic and extrinsic factors on the characteristics of an aerated lagoon, located in a semi-arid Mediterranean region (Sfax city, Tunisia). The plant performance was evaluated through descriptive and statistical analysis of quantity and quality data of both raw wastewaters and treated effluents over a period of six years (1991-1996). Poor performance was shown to be attributed to raw wastewaters quality, expansion of the population and its activities, rainwater, bad functioning of the grit chamber and ventilation conditions. Furthermore, the influence of other factors related to the industrial atmospheric contribution appeared to be non-negligible.