Speciation of Metallic Elements in Tannery Waste Water Case Study: Mohammedia Tannery Morocco

Tanneries discharge wastes without any treatment on the vast areas. Untreated effluents contain toxic materials like heavy metals which accumulate in soils and cause many hazards health. The tannery wastewaters samples were collected from tannery in Mohamedia Morocco. The metallic speciation is referred to physical fractionation (particulate, colloidal, dissolved). This study describes the physical speciation of Cr, Cd, Pb, Zn, Cu, Fe, Ni and Hg in tannery wastewaters. Five important steps of process were selected for sampling process wastes and seven hourly samples from collection basin were collected in order to evaluate total metallic pollution along the process. After Mineralization of Samples, this one was analyzed by ICP-AES. The results indicate that most of the metals have high abundance in particulate forms. Hence, small amounts of Cr, Cu, Pb, Hg and Ni were found in dissolved form: (Cr: 0.05 8 % ; Cu: 7.1 - 47.2 %; Pb: 4.4 - 50 %; Hg: 2 11 %, Ni: 0 14 %). While high quantities of Cd were present in dissolved forms (60 100 %). The average of presence in particulate forms for the metals giving the following order: Crgreater than Ni greater than Hg greater than Cu greater than Fe greater than Pb greater thanZn greater than Cd.