Evaluation of Wastewater Quality Treated by the Step of the City of Errachidia (Morocco)

Abstract

The objective of this study is the physico-chemical and bacteriological characterisation of raw and purified wastewater from the WWTP of the city of Errachidia, Morocco, during the year 2020, in order to evaluate the effectiveness of wastewater treatment. of the wastewater treatment plant, of the aerated lagoon type, and see their reuse in irrigation. The average monthly results of the physico-chemical analyses of treated wastewater carried out from January to December 2020 are as follows: BOD5 = 94.45 mgo2/l; COD = 339.32 mgo2/l; SS = 87.67 mg/L. The results show compliance with the general limit values for the discharge of Moroccan surface water, which protects the environment. Thus, the bacteriological results show the presence of various germs with average annual values where faecal coliforms (CF) are 680 CFU/100 ml; total coliforms (CT) are 2810 UFC/100 and faecal streptococci are 46 UFC/100 ml, which remain below the limit values recommended by Moroccan irrigation standards (CF < 1000 UFC/100 ml), which allows their exploitation and their reuse in irrigation.