Microplastics in Landfill Bodies: Abundance, Spatial Distribution and Effect of Landfill Age

Abstract

Almost a quarter of the plastic produced in Europe still ends up in landfills. In addition to the loss of valuable resources, this leads to the generation and accumulation of microplastics in landfills. The microplastics abundance in the refuse and their spatial distribution in the landfill body have not been practically studied. In the current work, changes in the abundance and characteristics of microplastics in landfill refuse from 3 age sections of the Lapės regional landfill, Lithuania, to a depth of 10–20 m were studied. A microplastics abundance of up to 55 particles/g or 52.8 g/kg was found. The lowest microplastics abundance was found in the old section, while the highest in the young (numerical) and the middle-aged (mass) sections. Moreover, microplastics abundance increased with the age of landfilled waste and depth, which may reflect the fragmentation of microplastics and their transport. Polyethylene and polypropylene were the dominant polymer types in all sections, while films were the dominant shape. The carbonyl index of PE microplastics was calculated to monitor microplastics oxidation. The analysis showed an increase of carbonyl index with landfill depth and landfill age, proving the intensive degradation of microplastics. Thus, landfills are large reservoirs of microplastics and their potential sources.