Heavy metals in municipal waste: the content and leaching ability by waste fraction

Today, heavy metals remain crucial pollutants in municipal waste due to their danger and leaching behavior. The purpose of this study is to analyze the sources of heavy metals in mixed municipal waste, including from recently introduced products, and to identify their composition and leaching properties in various fractions. The author has measured the concentration of four heavy metals (lead, cadmium, nickel, and chromium) in various fractions sampled from an operational municipal waste facility in the town of Pirna (Saxony, Germany). Batteries and waste electrical and electronic equipment (WEEE) were found to be the main sources of heavy metals in municipal waste, while a relatively high metals' content was also detected in the rubber fraction. To assess leaching behavior, landfill simulation reactors were used to simulate conditions over several decades. The metals' weight in the input and output waste was compared. The lowest leaching rate was found for lead, while the highest was found for cadmium and chromium. In addition, it was confirmed that the degree of leaching depended on the humidity and organic matter in the landfill: the higher the moisture and organic matter, the more heavy metals are leached from the waste.