Title : Reducing environmental impact of landfills: Treatability tests of leachates
Abstract:
Land filling of municipal waste, is originally a technical waste disposal, easy to implement and relatively inexpensive, and widely used in the world. However, without proper management, it can cause various problems, both for hygienic and health aspects and environmental constraints. In recent years, in Algeria, land filling of household and similar waste remains the most preferred method because of excessive moisture they contain. In landfills leachates (LL) at the deposition phase, the waste is subject to degradation processes related to biological and complex chemical reactions. Water seeps and produces leachates and biogas containing organic or inorganic substances which cause pollution primarily organic and metallic type.
The major objective of this work was to evaluate the treatability of landfill leachate collected from a disposal site located on the western outskirts of Algiers. The leachate was characterized by high concentrations of biodegradable organic matter (maximum COD = 8045.6 mg/L; maximum BOD₅ = 1100 mg/L), mineral content (maximum conductivity = 50.47 mS/cm), and suspended solids (maximum TSS = 4800 mg/L). The results obtained after physicochemical treatment using FeCl₃ showed an overall COD removal efficiency of 47.04%. When biological treatment was combined with coagulation–flocculation, COD removal increased to 68.84%. In addition, a BOD₅ reduction of 87% was achieved. A significant decrease in Ni concentration was also observed after treatment.
Keywords: landfill leachates, COD, physical-chemical treatment.
