The physiochemical properties and heavy metal pollution of fly ash from municipal solid waste incineration

Abstract

Fly ash originating from municipal solid waste incineration (MSWI) is potentially hazardous waste and is harmful to the surrounding area once it enters the environment. In this study, we measured the physiochemical properties of fly ash derived from domestic waste incineration as well as the leaching toxicity of heavy metals in fly ash was contained. The results suggested that the porosity of fly ash is relatively high, and the leaching concentration of heavy metals can be greatly reduced through densification strategies in which fly ash is stabilized by chemical agents. The adsorption–desorption curve of fly ash had an obvious hysteresis loop that belongs to the H2-type hysteresis loop. Fly ash was typically mesoporous, and the silicate in fly ash was relatively stable. Its glass phase contents were higher—this allowed it to be used in ceramic tile decoration. In addition, Pb and Cd were the major heavy metals in fly ash. These heavy metals were mainly distributed in the residue. Heavy metals were easily leached out under strong acid or alkaline conditions.