Réutilisation des eaux épurées en agriculture, Cas d’étude : La station d’épuration des eaux usées de la commune de Sidi Ali, Wilaya de Mostaganem

Abstract

The reuse of treated wastewater in agriculture has proven to be a promising solution to address the challenges associated with the scarcity of freshwater resources, particularly in Algeria. When carried out rigorously and in compliance with quality standards, this practice offers multiple benefits: preservation of potable water resources, improvement of agricultural productivity, and reduction of production costs. This study is conducted within the context of the reuse of wastewater from the wastewater treatment plant of Sidi Ali commune. Its primary objective is to assess the efficiency of the biological treatment using activated sludge. This thesis focuses on evaluating the performance of this plant with a detailed description of the processes implemented. A measurement campaign was carried out to assess the physico-chemical and bacteriological parameters of the effluents. The results obtained show that the plant meets the regulatory standards for most parameters, except for an excess of orthophosphates caused by the absence of chemical treatment in the wastewater treatment plant. The presence of various germs can be explained by the absence of disinfection treatment. The results have shown the suitability of these waters for irrigation without major negative impacts on the environment, provided that the crops grown are not intended for raw consumption. Improvements have been proposed, such as the use of tertiary treatment to reduce the level of microorganisms and to completely eliminate nitrites, nitrates, and phosphorus in order to use the treated water for irrigation with periodic monitoring to determine the sanitary quality level of the treated wastewater at the outlet of the station.