Particle Size Distribution of Materials and Chemical Element Composition in Mixed Commercial Waste

Abstract

In processing mixed commercial waste (MCW), particle size distribution is as critical as material composition. Detailed knowledge of particle size distribution unlocks the recycling potential of specific material groups and facilitates the efficient conversion of these materials into secondary fuels. Additionally, understanding particle size-dependent element distribution in waste is crucial, particularly given potential legal limits on several heavy metals. While two studies carried out in 2019 have addressed these issues, the inherent variability in MCW composition necessitates further investigation to validate and expand upon these findings. In this study, ten representative samples of MCW were collected and screened with eight screen cuts (200 mm, 100 mm, 80 mm, 60 mm, 40 mm, 20 mm, 10 mm, 5 mm). Six of these fractions (>20 mm) were sorted into 37 material classes, combined again by particle size, and subjected to chemical analyses. These analyses included essential fuel parameters, such as lower heating value and biogenic carbon content, and the concentration of 35 elements across all particle size fractions. A Mann–Whitney U test was conducted to identify correlations in element concentrations between the present study and the study carried out in 2019. Although the results confirm considerable variability in MCW composition, they also reveal trends in element concentrations related to calorific value.

Keywords

• waste analysis
• element concentration
• heavy metals
• fuel parameters
• biogenic content
• waste screening