title: Leachates draining from controlled municipal solid waste landfill: Detailed geochemical characterization and toxicity tests.
abstract: Management of municipal solid wastes in many countries consists of waste disposal into landfill without treatment or selective collection of solid waste fractions including plastics, paper, glass, metals, electronic waste, and organic fraction leading to the unsolved problem of contamination of numerous ecosystems such as air, soil, surface, and ground water. Knowledge of leachate composition is critical in risk assessment of long-term impact of landfills on human health and the environment as well as for prevention of negative outcomes. The research presented in this paper investigates the seasonal variation of draining leachate composition and resulting toxicity as well as the contamination status of soil/sediment from lagoon basins receiving leachates from landfill in Mpasa, a suburb of Kinshasa in the Democratic Republic of the Congo. Samples were collected during the dry and rainy seasons and analyzed for pH, electrical conductivity, dissolved oxygen, soluble ions, toxic metals, and were then subjected to toxicity tests. Results highlight the significant seasonal difference in leachate physicochemical composition. Affected soil/sediment showed higher values for toxic metals than leachates, indicating the possibility of using lagoon system for the purification of landfill leachates, especially for organic matter and heavy metal sedimentation. However, the ecotoxicity tests demonstrated that leachates are still a significant source of toxicity for terrestrial and benthic organisms. Therefore, landfill leachates should not be discarded into the environment (soil or surface water) without prior treatment. Interest in the use of macrophytes in lagoon system is growing and toxic metal retention in lagoon basin receiving systems needs to be fully investigated in the future. This study presents useful tools for evaluating landfill leachate quality and risk in lagoon systems which can be applied to similar environmental compartments.
authors.affiliation: University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo.
authors.forename: Bienvenu K
authors.initials: BK
authors.lastname: Mavakala
authors.affiliation: Faculty of Science, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva, 66, Boulevard Carl-Vogt, CH - 1205 Geneva, Switzerland.
authors.forename: Séverine
authors.initials: S
authors.lastname: Le Faucheur
authors.affiliation: University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo.
authors.forename: Crispin K
authors.initials: CK
authors.lastname: Mulaji
authors.affiliation: Faculty of Science, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva, 66, Boulevard Carl-Vogt, CH - 1205 Geneva, Switzerland.
authors.forename: Amandine
authors.initials: A
authors.lastname: Laffite
authors.affiliation: Faculty of Science, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva, 66, Boulevard Carl-Vogt, CH - 1205 Geneva, Switzerland.
authors.forename: Naresh
authors.initials: N
authors.lastname: Devarajan
authors.affiliation: University of Kinshasa (UNIKIN), Faculty of Science, Department of Environmental Sciences, B.P. 190, Kinshasa XI, Democratic Republic of the Congo.
authors.forename: Emmanuel M
authors.initials: EM
authors.lastname: Biey
authors.affiliation: University of Geneva, Institute for Environmental Sciences, enviroSPACE Lab., Uni Carl-Vogt, 66 Boulevard Carl-Vogt, CH - 1205 Geneva, Switzerland.
authors.forename: Gregory
authors.initials: G
authors.lastname: Giuliani
authors.affiliation: Université Pédagogique Nationale (UPN), Croisement Route de Matadi et Avenue de la Libération, Quartier Binza/UPN, B.P. 8815, Kinshasa, Democratic Republic of the Congo.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Otamonga
authors.affiliation: Université Pédagogique Nationale (UPN), Croisement Route de Matadi et Avenue de la Libération, Quartier Binza/UPN, B.P. 8815, Kinshasa, Democratic Republic of the Congo.
authors.forename: Prosper
authors.initials: P
authors.lastname: Kabatusuila
authors.affiliation: University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo.
authors.forename: Pius T
authors.initials: PT
authors.lastname: Mpiana
authors.affiliation: University of Kinshasa (UNIKIN), Faculty of Science, Department of Chemistry, B.P. 190, Kinshasa XI, Democratic Republic of the Congo; Faculty of Science, F.-A. Forel Institute and Institute of Environmental Sciences, University of Geneva, 66, Boulevard Carl-Vogt, CH - 1205 Geneva, Switzerland; Université Pédagogique Nationale (UPN), Croisement Route de Matadi et Avenue de la Libération, Quartier Binza/UPN, B.P. 8815, Kinshasa, Democratic Republic of the Congo. Electronic address: john.pote@unige.ch.
authors.forename: John
authors.initials: J
authors.lastname: Poté
mesh_terms: D015023:Democratic Republic of the Congo; D059029:Electronic Waste; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D008670:Metals / Q000032:analysis; D012037:Refuse Disposal; D062611:Solid Waste / Q000032:analysis*; D018675:Toxicity Tests; D064091:Waste Disposal Facilities; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008670:Metals; D062611:Solid Waste; D014874:Water Pollutants, Chemical
keywords: Ecotoxicity test; Landfill leachate; Municipal solid waste; Risk assessment; Toxic metals; Tropical conditions