Heavy metals in residues from hospital solid waste incineration

Abstract

Solid residues of the combustion of hospital solid waste were characterized. Hospital solid wastes are generated as a heterogeneous product whose composition can fluctuate significantly from day to day to such an extent that a representative sample of solid residues of the combustion of a given load cannot be expected. However, if temperature is kept constant, as was done in this study, a representative analysis of the heavy metal content in the solid residues of the combustion can be carried out. Bottom ashes and fly ashes were collected from the incinerator; the samples collected are representative of an average weekly production. The heavy metal content was determined for samples obtained applying the “quartering” sampling approach and analyzed by AAS. Such analytical measures allowed the toxicity of residues of hospital solid waste incineration to be pinpointed with regard to the concentration of Cd, Cr, Cu, Ni, Pb, and Zn. Replicate digestion of a reference material (BCR 176 City Waste Incineration Ash) showed a good degree of accuracy in the determination of all the elements investigated.