ETUDE PHYSICO-CHIMIQUE DES EAUX USEES DE L'UNITE INDUSTRIELLE PAPETIERE (CDM) A SIDI YAHIA EL GHARB (MAROC)

Abstract

The environmental impact of industrial effluents is now a reality and manifests a serious threat in the medium term for the quality of surface water and groundwater. Like other regions of Morocco, the region of Gharb knows multiple daily aggressions caused by industrialization, agriculture and urbanization. Indeed, the impact on the aquatic environment of the paper industry CDM planted in Sidi Yahia Gharb is mainly due to the use of water in the manufacturing process of the pulp by KRAFT process and the discharge of waste effluents in receiving waters: the Maâmora forest, the water table Maâmora and Sebu River. This study focuses on evaluating the efficiency of wastewater treatment of the CDM by the sewage lagoon anaerobic station.

This work has led to interpret the physicochemical parameters of raw and treated wastewater such as pH, temperature, Biological Oxygen Demand (BOD5), Chemical Oxygen Demand (COD) and Suspended Solids (SS). The physicochemical characterization of wastewater studied during the probationary period 2012/2013 was used to assess their properties and degree of pollution. Gross emissions are characterized by an average pH of 6.3 in summer and 7.9 in winter average temperature of 47°C in summer and 41°C in winter an average BOD5 of 334.3 mg/l in summer and 252.8 mg/l in winter, an average COD of 1072.2 mg/l in summer and 1567.5 mg/l in winter and average levels of MES 48.8 mg/l in summer and 86.6 mg/the winter. These liquid wastes are mixed character (COD/BOD5 is between 3 and 5).

During wastewater treatment, the purifying average yields reach 40.7% BOD5, 38.5% COD and 66.1% SS. This assessment that the WWTP of the CDM is inefficient and does not meet the standards of indirect discharges.