Pervasiveness and classification of microplastics in Landfill Leachate: Impacts, risks, and treatment efficiency

Abstract

Microplastics (MPs) in surface and groundwater in Bangladesh are a significant issue. The purpose of this research was to assess the possibility of landfill leachate acting as a potential origin of MPs and to determine if the surrounding surface water (SW) and groundwater (GW) act as recipients. Furthermore, this research assessed the leachate treatment plant MP removal efficacy and MP risk assessment. The findings show that discharge leachate from the Matuail landfill contributes 3.5 × 10⁸ particles per hour to the surrounding aquatic environment, with an average of 350 ± 10 MPs/L. MPs were found highly in SW and then in GW with an average of 1683 ± 70 and 614 ± 40 MPs/L, respectively, with 48.9% of MPs ranging from 0.1 mm to 0 .5mm. The dominant shapes were fibers and fragments. The Fourier transform infrared spectroscopy (FTIR) analysis revealed low density polyethylene (LDPE), high density polyethylene (HDPE), and Polypropylene (PP) were the most common, and Polyurethane (PUR), Polymethyl methacrylate (PMMA), and Polyacrylonitrile (PAN) posed the greatest threat to the environment. The inefficient treatment method resulted in the release of 83.33% of MPs, indicating a low removal efficiency in the leachate. The inefficient removal rate leads to the highest pollutant load index for SW (2.18). Ultimately, the analysis of the nemerow pollution index (NPI), contamination factor (CF), pollution load index (PLI), polymer hazard index (PHI), and potential ecological risk (Ei), revealed a minimal to extremely high range of contaminations. A clear link was obsevered between the particles shape and size throught the principal component analysis (PCA). Moreover, it highlights the need for ongoing national surveillance of MPs considering the gravity of this contamination and indicates the importance of proactive management of landfill sites.