Leaching of copper, lead and zinc from municipal solid waste incineration bottom ash

Abstract

Municipal solid wastes incineration (MSWI) in modern waste-to-energy plants reduces the volume of MSW by up to 90%. Incineration process also produces two types of by-products – bottom ash (BA) and fly ash (FA). Municipal solid wastes incineration BA is rich in heavy metals and salts. The disposal of MSWI BA may cause serious environmental problems. The objective of this study is to assess fresh bottom ash chemical composition and heavy metals such as copper (Cu), lead (Pb) and zinc (Zn) leaching values. The chemical composition determination indicates that Cu (400–800 mg kg-1), Pb (680–1760 mg kg-1) and Zn (1330–2010 mg kg-1) are major heavy elements in MSWI bottom ash. The results showed that the concentrations of Cu were 0.1–2 mg kg-1, Pb – 0.2–12.2 mg kg-1, Zn – 0.4–5 mg kg-1. In order to reduce the leaching of heavy metals from bottom ash, they should be pre-treated. The most commonly used technologies are weathering, washing and metals separation.