The cement solidification of municipal solid waste incineration fly ash

Abstract

The chemical composition, the content and the leachability of heavy metals in municipal solid waste incineration (MSWI) fly ash were tested and analyzed. It is shown that the leachability of Pb and Cr exceeds the leaching toxicity standard, and so the MSWI fly ash is considered as hazardous waste and must be solidified. The effect of solidifying the MSWI fly ash by cement was studied, and it is indicated that the heavy metals can be well immobilized if the mass fraction of the fly ash is appropriate. The heavy metals were immobilized within cement hydration products through either physical fixation substitution, deposition or adsorption mechanisms.

Keywords

MSWI fly ash / heavy metals / leaching toxicity / cement / solidification

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