Statistical Approach of Assessing Horizontal Mobility of Heavy Metals in the Soil of Akouedo Landfill Nearby Ebrie Lagoon (Abidjan-Cote D'Ivoire)

Abstract

The present study aim to quantify heavy metals in the Akouedo landfill soil and evaluate the extent of their contamination, to better understand the horizontal migration of these pollutants towards the Ebrie lagoon located downstream. Horizontal mobility of heavy metals in soil was performed by the Kruskal-Wallis test which was used to evaluate the heavy metals concentrations according to the upstream downstream disposition of soil sample sites. Then the Mann-Whitney test was applied to find if variances between upgradient and downgradient parameters concentrations in the soil sample sites were homogenous. The results show that the soil is rich in organic matter (organic carbon and organic nitrogen) with a basic pH (7.94 <pH <8.7), characteristic of the landfill leachate. Metals such as lead (Pb) and zinc (Zn) are retained by the organic matter while the other metals (Cd, Cr, Cu, Fe) relative to migrate upstream to downstream. Thus, the flow of infiltration water into the soil of the Akouedo landfill drains more easily iron, cadmium, copper, chromium towards the lagoon Ebrie located downstream, increasing the risk of pollution by heavy metals.

Keywords

• landfill
• heavy metals
• soil
• horizontal mobility
• Ebrie lagoon
• Abidjan
• Côte d'Ivoire