Characterization of the Leachate from the Municipal Landfill of Akouédo (Abidjan, Côte d´Ivoire)

Abstract

Municipal solid waste in developing countries especially in Africa are commonly managed by discharging in uncontrolled landfill. This leads to the generation of huge amounts of leachate that are rejected in the nature without any treatment. This study consisted in characterizing the leachate from the Landfill of Akouédo in the District of Abidjan (Côte d’Ivoire) despite the completion of filling operations in 2019. The physico-chemical composition of raw leachate suggested a stabilized landfill, with alkaline pH (i.e. ~ 8.85±0.03). However, the concentrations of nutrients and organics such as NH₄⁺ (212.5±0.31 mg.L^-1), NO^-₂ (257.5±0.42 mg.L^-1), NO^-₃ (301.85±0.16 mg.L^-1), BOD₅ (1015±0.12 mg O₂ L^-1) et COD (9640±0.4 mg O₂ L^-1) obtained in Landfill of Akouédo were slightly weak, compared to the FEPA’s standard (1991). This could confirm the stabilization of the leachate, with a BOD₅ / COD ratio of around 0.1 ± 0.05. In addition, most of the metallic trace element contents (i.e. Iron, Copper, Nickel, Zinc and Lead) were below FEPA’s standard (1991). To further investigate, humic acid (HA), fulvic acid (FA) and humin were extracted from the humic substance of this leachate. Thus, about 91 % and 9 % were obtained for humic acid and fulvic acid + humin, respectively. For better understanding, synthetic humic acid (SHA) was used as the reference material. The DRIFT analysis helped determine some difference between the LHAs of the leachate and SHA. However, the characteristics of the functional groups of the LHA and SHA molecules were essentially similar. The data on the characteristics of the HS shown in the results of the landfill leachate can be used in several related research areas, such as the optimization of leachate treatment processes and the remediation of groundwater contaminated with leachate.

Keywords: Municipal solid waste, Landfill, Leachate, humic substance, humic and fulvic acid.

DOI: 10.7176/JEES/10-4-03

Publication date: April 30^th 2020