Abhatoo - Centre Nationale de Documentation

Casablanca (Central West Morocco, Atlantic coast) is the economic and industrial capital of Morocco, where water is consumed in large quantities. Therefore, water is a major challenge for the sustainable development of the city due to the climatic and hydrological conditions that characterizes the region which are an arid climate, modest water resources, very irregular rainfall and often poor quality of surface and ground water. The supply of drinking water, more than 170 Million m3 (Lydec, 2008) is provided to 98% by water catchments outside of the city district : the watershed of Bouregreg in the north and Oum Er Rbia in the south.
In this context, the possibility of treatment of domestic and industrial wastewater by new successful technologies to a quality that can be used for internal recycling or reuse in agriculture is examined. The proposed study is part of an action-research project on Urban Agriculture for sustainable urban development of Casablanca. It examines an aerobic membrane bioreactor (MBR) system for a tertiary treatment of wastewater of a food processing company who has already implemented a secondary wastewater treatment plant as a sequencing batch reactor (SBR).
The results obtained after a trial period of 6 months (February-July 2011), show rates of degradation of 50 to 60% for COD and 85 to 90% for BOD5 compared to the effluent of the secondary treatment. The quality of treated water complies with the regulations for agricultural reuse or the irrigation of green spaces. For the internal reuse of the water at the company, for example for cooling in an evaporation tower, the use of activated carbon was tested. This resulted in a further reduction of COD and a total BOD elimination. Such an operation will enable the company to enhance its environmental profile and allows savings of water costs.