| Abstract [eng] |
Landfills occupy extensive areas across Europe; however, landfill mining has uncovered their potential as valuable resource repositories. A significant portion of excavated material during landfill mining comprises a fine fraction (FF), which has been relatively underutilized for resource recovery. However, FF holds promise for biocover construction to address methane emissions. This study aimed to conduct a comprehensive and in-depth analysis of FF with a specific focus on identifying the optimal layer for biocover construction. Drilling operations were carried out at an ageing landfill in Lithuania up to 10.5 meters. FF samples were extracted at regular intervals of 1.5 meters. The characterisation included an extensive array of physical (moisture content, bulk density, water holding capacity, and particle size distribution) and chemical (organic content, pH, and conductivity) parameters, along with assessments of heavy metals and microplastics concentrations, considering their environmental significance. The study unveiled significant parameter variations across different depths, accompanied by medium-high correlations between specific parameters. Notably, a substantial correlation was observed between microplastics and mercury concentration. A comprehensive analysis, considering various depths and parameters, pinpointed the layer at a depth of 4.5–6 meters as the most suitable for biocover construction. However, this layer was characterized by the highest microplastics concentrations (30208±2728 particles kg-1 ), posing a potential challenge. Moreover, microplastics become finer with increasing depth, heightening associated risks. Consequently, FF can be used for biocover construction, but a detailed depth analysis is needed to determine the best layer of FF based on both physical-chemical parameters and pollutants concentrations. |
