Assessment of Urban Wastewater Pollutiondischarged by the Moroccan City of Kenitra at Thesebou River Estuary

Abstract

The dangerous chemical contamination of the Sebou River Estuary by the untreated urban wastewater from the city of Kenitra has been the subject of an extensive and comprehensive characterization through the study of the physico-chemical qualities of effluent samples from eight different municipal wastewater collectors (A, B, C, D, E, F, G and H) using standard methods. The evaluated physico-chemical parameters include: flow rate, pH, temperature (T °), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended matter (SM) and electrical conductivity (EC). The characterization of the examined parameters displayed a moderately neutral pH level in the domestic wastewater collectors (B to H), nonetheless, collector (A) showcased an exceptionally alkaline pH that arrays from 8.1 to 9.6, which in turn impacts the electrical conductivity and temperature, to the point of occasionally reaching up to 30.3 °C in the collectorin question. Pertaining to the collected (COD) and (BOD5) results, their values significantly exceeded the Moroccan standards, especially in collectors A, G and F, exhibiting thus low biodegradability with a COD / BOD5 ratio exceeding 3. The characterization of municipal wastewater and the measurement of its flow made the estimation of the pollution quantity discharged at the level of the Sebou river estuary achievable, these data will subsequently be used in favor of modeling and monitoring the fate of pollution in the receiving environment.

Water Quality Modelling of the Sebou River Estuary (Morocco) Before and After the Installation of the Kenitra City’s Wastewater Treatment Plant

“…The results demonstrated that the physicochemical quality of Sebou River estuary does not meet the national standards for discharges into the natural environment, similar results were found by (Nizar & Igouzal, 2022a;Nizar et al, 2022c) which also demonstrated the good impact of the treatment plant on the attenuation of BOD 5 in the river, analogous results were obtained by (Nizar et al, 2022b). The simulations provided other answers such as the release dispersion and the residence time in the estuary.…”

“…A signifi cant amount of wastewater heads from Kenitra (about 17 km from the mouth) to Sebou estuary, and this amount is increasing because of the demographic growth, as well as the agricultural and industrial effl uent discharges which are loaded with a variety of contaminants susceptible to temporarily damage the quality of Sebou estuary waters at concentration levels exceeding their standards values in an aquatic environment. Before 2020, water was discharged without prior treatment through six collectors into Sebou estuary (Nizar & Igouzal, 2022a). Therefore, the main aim of constructing the wastewater treatment plant (WWTP) in Kenitra was to convey the wastewaters and to put them under treatment, thus making WWTP the only discharge point for Sebou estuary (Nizar et al, 2022b).…”

“…Early studies on water quality of Sebou estuary have been carried out since 1966 (S. Haddout, 2016;Mergaoui et al, 2003;Nizar & Igouzal, 2022a;Combe, 1996;Nizar et al,, 2022b;Nizar et al, 2022c;Haddout, et al, 2019) showed that the physico-chemical quality of Sebou River estuary does not meet the WHO standards for discharges into the natural environment. All of these studies recommended the construction of a WWTP to treat urban wastewaters of Kenitra.…”