An updated review on landfill leachate treatment methods

This review article analyses the landfill leachate treatment technologies with a focus on their environmental footprint, removal efficiencies, and economic viability. Current reviews do not seem to have an integrated comparison across technical, environmental, and economic aspects. Herein, for the first time, life cycle assessment, cost, and pollutant removal data are combined to compare both conventional and hybrid technologies. The hybrid processes like powdered activated carbon with Fenton (99% removal of colour and COD) and Fenton with activated sludge (removal of more than 78% of COD, BOD₅, DOC, NH₄ + –N, and TP) showed the highest removal efficiencies. The least environment penetrating treatments are biological, and the most energy-efficient were pipe freeze crystallization (171 kWh/ton ice) and activated sludge (as low as $0.082/m 3 and 0.3–65 kWh/m 3 ). The integration of advanced oxidation with biological treatment offers the most economical method ($0.47/m 3 ). The originality of this review is its quantitative life cycle, economic, and technical comparison with a holistic view and take-home advice for sustainable landfill leachate management.