Applicability of central composite design and response surface methodology for optimizing treatment of landfill leachate using coagulation-flocculation

Abstract

Without proper treatment, leachate can contaminate adjacent groundwater, soils, and streams, resulting in potential risks to public health, the environment, and surrounding biodiversity. This work aims to treat landfill leachate by coagulation-flocculation and optimize the results using the central composite design in combination with the response surface methodology in the Mohammedia-Benslimane landfill in Morocco. The optimization of the process allowed us to find optimal removal efficiencies of color, polyphenols, and nitrates, which reached 68.8%, 77.5%, and 81.0%, respectively. The optimum conditions in this study were pH 7.66, 9.5 g/L of coagulant dose, 9.1 ml/L of flocculant dose, and 10 min of agitation time. The models obtained for the 3 responses are reliable, reproducible, and well-fitted. By optimizing the leachate treatment at the Mohammedia-Benslimane landfill using coagulation-flocculation and the response surface methodology, our study offers an efficient and reliable approach to address the challenges of landfill leachate treatment. The results obtained from this research have significant implications for liquid waste management, particularly in the context of landfill leachate treatment.