Assessment of the leachate quality from municipal solid waste landfill in Lebanon

Alternating degrees of solid waste management (SWM) are currently practiced in different parts of the 10,452 km2 Lebanese Middle Eastern country, with the exception of municipal solid waste, which constitutes about 90% of the total solid waste stream generated in Lebanon. Organic wastes (green wastes) are by far the largest component of the municipal solid wastes (55%), whereby only a minimal portion is recovered through composting (17%), and the remaining putrescible with the wastes rejects are baled and sent to the sanitary Naameh landfill for associated disposal. Overreliance on this landfill was the case where it operated for almost two decades and held 15 million tons of wastes. In order to adequately assess the contamination risks pertaining to the landfill, understanding the leachate characteristics is crucial. In the aim of achieving this purpose, chemical analysis was performed and the seasonal variation of the parameters was monitored, including pH, EC, BOD, COD, chloride, ammonia-N, orthophosphate, and sulfate. Also, metal parameters (Cd, Cr, Cu, Fe, Pb, Hg, and Ni) were tested for assessing the infiltration risk. The preliminary data obtained were statistically diagnosed through principal component analysis by Spadv55 software. Elevated levels of COD (6349 mg/L) and mercury (0.31 mg/L) were detected in comparison with the other tested parameters which were in conformity with the leachate characteristics of a 16-year-old landfill. However, the risks posed are minimal due to the domestic nature of the wastes. The results obtained indicated that the landfill is in its methanogenic phases and that the leachate produced needs treatment prior to discharge. Treatment will help in minimizing the negative effects on human health and the environment as well as in reducing the risk of groundwater and surface water contamination. © 2021, Saudi Society for Geosciences.