Leachate characterization and pollution index as a tool for landfill management: The case of Nsumia Waste Facility in Accra, Ghana

Abstract

Landfills are most countries' primary structures by which solid wastes are disposed of. However, most landfills are not properly engineered and therefore tend to pose a threat to health and the environment, especially through the leachate they produce. The leachates are difficult to treat and, in most cases, are either not adequately treated or not treated at all before release into the environment. This study was conducted to identify the dominant pollutants, assess leachate pollution potential, and identify a suitable treatment approach to leachate from an active municipal solid waste landfill site in Accra, Ghana. Physico-chemical and biological results from leachate analyses indicated the landfill site was in its methanogenic phase. The overall leachate pollution index (LPI) of 12.55, LPI organic (LPI_org = 19.08), and LPI inorganic (LPI_in = 16.00) were much higher than the standard values for treated leachates before disposal into the environment. Individual pollution ratings show that TDS, Hg, COD, and BOD were the major pollutants influencing the leachate pollution indices. Based on the fact that the organics and the inorganics are the major influencers of leachate toxicity, the tandem operation of co-treatment with wastewater and membrane bioreactor treatment of leachate is recommended.