Heavy metal enrichment in municipal solid waste incineration fly ash with various size ranges

Fly ash from a Hangzhou incinerator was characterized on the basis of the particle size distribution.Major elements,heavy metal distribution,and binding states of heavy metals with fly ash particles were studied in this paper.It was found that SiO2-CaO-Al2O3-metal-oxide was the carrier of heavy metals in fly ash.The contribution of Zn,Pb,Cu,Mn,Ni,Cr,Sb in 75—125 μm of the fly ash fraction is the highest,which reached about 52%.Zn,Cu and Cr contents increased with decreasing size of fly ash particles,but other heavy metals showed little increase.More heavy metals and higher distributions were detected on the crossing-section area of fly ash particles than their surface area.Our results suggest that the comprehensive method of applying XRF,ICP-MS,and SEM-EDX to analyze heavy metals in fly ash can provide better and deeper understanding on heavy metal distributions.