Caracterisation Physico-Chimique Du Lixiviat De La Decharge Sauvage De Meknes

Abstract

Solid and urban waste produced by the municipality of Meknes amounts to more than 185.103 tons annually. Since 2002 they have been transported to a landfill controlled, wild of an area of 23 hectares on the outskirts of the Commune. This discharge is unfortunately devoid of a leachate treatment device (brownish liquid effluent, produced under the combined action of rainwater and fermentation of buried waste). This study aims to make a physico-chemical characterization and evaluate the states mineral and organic of this leachate. It should be noted that this physicochemical characterization is arbitrary because this discharge will soon be equipped with a waste disposal and recovery center (CEV) using Evalixm as a treatment method. Since 2014, the company '' SUEZ ''Environment began to put in place under control this discharge. For the realization of this characterization, we carried out a series of sampling leachate from June 2014 to June 2015. During this period, the physico-chemical analyzes carried out on these samples, revealed: - low levels of nitrates (NO3 - max = 18,1 mg / L) and phosphates (PO4 3- max = 0,38mg / L) - high levels of ammonium (NH4 + max = 54,13 mg / L) and nitrites (NO 2 - , max = 27,67mg / L). This mineral concentration is translated by a high electrical conductivity which has reached a maximum value of 7.35 10 3 μS / cm. Organic pollution estimated by the pollutant load is important; the values of the Calculated DCO from 1205 to 9207 mg O2 / L with an average of 4808 mg O2 / L, those of DBO are between 53 and 386 mg O2/ L for an average of 157 mg O2 / L. The values of the ratio DBO5 / DCO oscillate between 0.01 and 0.08 with an average of 0.04. This which testifies to the anaerobic character that prevails at the level of the discharge and a probable contamination of the water table. The hydrogen variant (pH) between 6,42 and 8,99 is an annual average of 8,42 which shows that the leachate produced by the landfill is basic. The pH value shows a stagnation (8.42 and 8.23) from one year to the next, reflecting its stability and aging