Partitioning of heavy metals in residues of a clinical and industrial waste incineration plant

Abstract

This study focuses on the partitioning of heavy metals (Pb, Cd, Cr, As, Cu) between bottom ash and fly ash in a waste incineration plant. For the plant that incinerate clinical waste and industrial waste (incineration amount is about 50 tons per day), the heavy metal content in the bottom ash and the fly ash were measured. Then the partitioning ratio was calculated from the heavy metal content and the amount of the ashes generated. The result showed that 2.1 kg of Pb was discharged per day, and about 50% of the Pb was partitioned into fly ash. Nearly 90% of Cd was partitioned into fly ash (although its concentration is low and uncertainty is high). Almost all part of Cr (2.6 kg per day) and Cu (39 kg per day) remained in the bottom ash. Although the content of As was too low to consider the partitioning ratio, most of As seemed to remain in the bottom ash. A weak correlation was found between the contents of Pb and Cu in fly ash, suggesting that the origins of the two may be the same.