Assessment of metal contamination of tiflet stream (Sidi Yahia Gharb city, Morocco)

Heavy metals are likely to cause micro nuisance even when they are released in very small quantities (developing toxicity through bioaccumulation). Moreover, small amounts are often offset by a volume effect due to the importance of water flows. The industry is responsible for almost all releases of heavy metals in water. Indeed, the water of rivers, streams, canals, seas has along been the "outlet" that allowed to evacuate wastes. This work focuses on the analysis and assessment of heavy metal contamination of raw sewage drained by four major collectors Tiflet river (Morocco) through Monitoring the spatio-temporal levels of some metal elements (Pb, Fe, Zn , Cd, Hg and Cr). Sampling was carried out twice a month over a period of three months(April, May and June) 2012. The Obtained results indicate the presence of contamination from metallic iron which exceeded the threshold of standards. Other metals trace elements exist in regular quantity, they could be classified in the order of abundance as follows: Fe> Zn> Pb> Cr> Hg> Cd, and the mean concentrations are respectively 10 mg/ l- 0.8mg /l -0.07 mg/l -0.037 mg/l -0.035 mg/l and 0.0038 mg/l.