Microplastics in Landfill Leachate: Sources, Potential Impacts, and Remediation Technologies

The modern lifestyle has significantly increased plastic usage, leading to a surge in plastic waste accumulation in landfills, where physical, chemical, and biological degradation generate microplastics (MPs). These MPs originate from diverse polymer types such as polypropylene, polyethylene, polystyrene, and polyethylene terephthalate, with their release strongly influenced by waste composition, landfill management practices, and aging processes. The highest reported concentration of MPs in landfill leachate was 33,213 items/L in Guangzhou, China, while the lowest ranging from 0.16 to 1.10 items/L, was observed in Lahti, Finland. MPs migrate into adjacent soil, groundwater, and adjacent surface water systems, thereby altering soil physicochemical properties, disrupting aquatic food webs, and acting as carrier of co-contaminants. Their environmental fate and toxicity are governed by MPs property and surface aging, which enhances sorption capacity and bioavailability across ecosystems. Remediation technologies, including physical separation, chemical, and biological treatment, have demonstrated removal efficiencies up to 99%. This review synthesizes the current knowledge on the source, types, and global distribution of MPs in landfill leachate, their environmental impacts, and emerging remediation approaches.