Microplastics in Landfill Leachate: Sources, Pathways, and Mitigation Approaches

Landfill leachate is increasingly recognized as a complex and hazardous waste stream, with microplastics (MPs) emerging as persistent contaminants of global concern. This review synthesizes current knowledge on the sources, transport pathways, and mitigation strategies of MPs in landfill leachate. From a global perspective, MP concentrations in landfill leachate span from 0.16 items/L to 33,213 items/L, highlighting the potential roles of waste composition, landfill management, and environmental conditions in shaping their distributions. Leachate acts as an important mobilization vector, facilitating the transfer of MPs from terrestrial environments to aquatic systems, with potential implications for food webs and human exposure. Existing mitigation strategies, including biological, physical, and chemical treatments, are evaluated, yet their effectiveness remains constrained by the complexity of leachate matrices. Future efforts should focus on establishing standardized analytical methods, particularly for smaller MPs and diverse polymer types, and developing advanced treatment technologies capable of efficiently removing MPs from landfill leachate systems.