Study of Physicochemical and Bacteriological Quality of Treated Wastewater by the New Aourir Plant (Southwestern of Morocco) Using Activated Sludge Technology in a Semi-Arid Region

In order to use the purified wastewater for the irrigation of a golf course in the Taghazout area (Southwestern of Morocco), this study was conducted to evaluate the physicochemical and bacteriological quality of the treated wastewater in the new Aourir plant (Activated Sludge technology). In order to achieve these objectives, three types of water were analyzed: raw water (RW), biologically treated water (BTW) and water treated by ultraviolet radiation (UV-TW). The physicochemical parameters analyzed were Temperature, pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), Chemical Oxygen Demand (COD), five-day Biological Oxygen Demand (BOD 5 ), Total Suspended Solids (SS), Nitrate (NO 3 ), and Orthophosphates (PO 4 ). Otherwise, the analyzed biological parameters are Total Coliforms (TC), Fecal Coliforms (FC), Escherichia coli (E. coli), and Fecal Streptococci (FS). The physicochemical parameters showed that temperature is always lower than 30C, the pH is close to neutrality and a strong fluctuation of the high electrical conductivity (2700 S/cm) occurs in UV-TW. At all stages of wastewater treatment, COD, BOD 5 , SS, NO 3 and PO 4 were below the limit values recommended by Moroccan standards. The bacteriological results showed a high level of bacterial contamination in RW and BTW, but in UV-TW the loads did not exceed 3 log10. The average loads of TC, FC, E. coli and FC in UV-TW were 2.13, 1.67, 1.77, and 2 (log10 CFU/100ml) respectively. Activated sludge treatment combined with UV has demonstrated sufficient quality to reuse treated water in irrigation; however, the UV treatment requires control to avoid any effect on the microbiological and physicochemical quality of green spaces and groundwater.