Etude des performances épuratoires de la technique de Lagunage naturel de la station d'épuration des eaux usées domestique de la ville d'Azilal -MAROC- [ Study of the treatment performance of the technique of Natural lagoons of the treatment plant for domestic wastewater of the city Azilal -MAROC- ]

In Morocco, like in all developing countries, sanitation and sewage treatment are one of the biggest environmental problems. The lack of public network for waste water treatment, the absence of control and of environmental sensitivity contribute to spreading diseases, degrading landscapes and contaminating surface as well as underground water. Wastewater is considered their main polluting factor. In Morocco, the treatment of wastewater by the natural lagoon is probably the most efficient solution both in economic terms and in terms of performance. The objective of this work is to study the physical, chemical and bacteriological parameters of raw and treated water from the station. For this, we opted carried out a series of measures: For the physicochemical parameters as temperature, pH, salinity, turbidity, the redox potential, electrical conductivity (EC), biochemical oxygen demand BOD^sub 5^, chemical oxygen demand (COD), suspended solids SS, and O^sub 2^ dissolved oxygen and bacteriological parameters as fecal coliforms (FC) and total coliforms (CT). Data analysis showed that the treatment efficiency of the station reached respectively 15,86%, 55,34%, 55,58% of the SS, COD and BOD^sub 5^ which does not meet the discharge standards. The bacteriological analysis showed faecal pollution of human origin and performance of abatement of fecal germs can be deduced that the treatment adopted by facultative ponds far beyond the values required by Moroccan or European standards.