Evaluation of the impact from the discharge of treated sewage on the south-east Saronicos Gulf through mathematical water quality modelling

Abstract

The paper presents the results of a study of the impact caused by the discharge of treated sewage from the south-west Attiki area to the south-east coast of the Saronicos Gulf. The study involved the application of a eutrophication-dissolved oxygen model which, following validation on the basis of field measurements, was applied to predict the impact of three different biological treatment configurations, with and without nutrients removal, as well as three alternative disposal sites on the quality of the receiving waters. The simulation results show that nitrogen is the limiting nutrient and that its removal during treatment results in a substantial improvement of the quality of the recipient. The disposal site is a critical factor in the case of a biological treatment scheme exhibiting carbon removal, but it is of limited importance in the case of treatment systems with nitrogen removal.