Fatima-Zahra EL MADANI
Abstract
In recent years, the quality of surface water in the city of Fez has deteriorated day after day due to the development of various anthropogenic activities, reckless human action, the discharge of wastewater in an unregulated manner and waste. solid. This poses a worrying threat to man and the environment. Upstream treatment of this water would be desirable. The objective of this study is to contribute to the treatment of metallic pollutants from surface water discharged into the most polluted wadis identified in the city of Fez: wadi Tghat and Zhoun, by coagulation-flocculation. The results of the treatment of these surface waters discharged into wadis Tghat and Zhoun which downstream wadi Fez by coagulation-flocculation under optimal conditions, from pH to 6.5, a dose of Aluminum Sulphate coagulant equal to 0, 15 gL-1 and Praestol flocculant equal to 1 mg.L-1, in a time of rapid coagulation and slow flocculation of 3min at 150 rpm-1 of coagulation and 20 min at 20 rpm-1 of flocculation made it possible to reduce their overall metallic load by approximately between 90% and 94, ie: almost 94.26% Cr; 93.76% of As; 92.98% of Pb and 92.24% of Cd at wadi Tghat and 93.34% of Cr; 90.71% of As; 92.11%; from Pb and 92.94% from Cd to oued Zhoun