This study evaluates the feasibility of using the aerated lagoon method as a pre-treatment stage for young and old landfill leachates within a comprehensive multi-stage treatment system. Experimental results demonstrated that the method alone is insufficient to achieve final purification standards. However, its application as a pre-treatment step offers significant advantages, including cost-effectiveness and accessibility. The aerated lagoon method achieved notable reductions in contaminant concentrations, including ammonium nitrogen (70% for old leachates and 99% for young leachates), COD (31% for old leachates and 26% for young leachates), and phosphates (93% for old leachates and 81% for young leachates). These reductions effectively alleviate the load on subsequent treatment stages, such as reverse osmosis, municipal wastewater treatment plants, or constructed wetlands. The findings highlight the potential of the aerated lagoon method to serve as an economical and efficient pre-treatment strategy in landfill leachate management systems.