Mavakala Bienvenu K, Le Faucheur Séverine, Mulaji Crispin K, Laffite Amandine, Devarajan Naresh, Biey Emmanuel M, Giuliani Gregory, Otamonga Jean-Paul, Kabatusuila Prosper, Mpiana Pius T, Poté John
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.
Waste Manag. 2016 Sep;55:238-48. doi: 10.1016/j.wasman.2016.04.028. Epub 2016 May 10.
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.
许多国家的城市固体废物管理方式包括未经处理就将垃圾填埋，或者对包括塑料、纸张、玻璃、金属、电子垃圾和有机成分在内的固体废物进行选择性收集，这导致了众多生态系统，如空气、土壤、地表水和地下水受到污染的问题一直无法解决。了解渗滤液的成分对于评估垃圾填埋场对人类健康和环境的长期影响风险以及预防负面后果至关重要。本文所呈现的研究调查了刚果民主共和国金沙萨郊区姆帕萨一处接收垃圾填埋场渗滤液的泻湖盆地排水渗滤液成分的季节性变化及其产生的毒性，以及土壤/沉积物的污染状况。在旱季和雨季采集了样本，分析了其pH值、电导率、溶解氧、可溶性离子、有毒金属，然后进行了毒性测试。结果突出了渗滤液物理化学组成的显著季节性差异。受影响的土壤/沉积物中有毒金属含量高于渗滤液，这表明利用泻湖系统净化垃圾填埋场渗滤液，尤其是去除有机物和重金属沉淀是有可能的。然而生态毒性测试表明，渗滤液仍然是陆地和底栖生物毒性的重要来源。因此，垃圾填埋场渗滤液在未经预处理的情况下不应排放到环境（土壤或地表水）中。在泻湖系统中使用大型植物的兴趣与日俱增，未来需要对泻湖盆地接收系统中有毒金属的截留情况进行全面研究。本研究提供了评估泻湖系统中垃圾填埋场渗滤液质量和风险的有用工具，可应用于类似的环境区域。
