Chemical speciation and mobility of heavy metals in municipal solid waste incinerator fly ash.
Chemical speciation is a significant factor that governs the toxicity and mobility of heavy metals in municipal solid waste incinerator fly ash. Sequential extraction procedure is applied to fractionate heavy metals (Pb, Zn, Cd, Cu, and Cr) into five defined groups: exchangeable, carbonate, Fe-Mn oxide, organic, and residual fractions. The mobility of heavy metals is also investigated with the aid of toxicity characteristic leaching procedure. In the fly ash sample, Pb is primarily presented in the carbonate (51%) and exchangeable (20%) fractions; Cd and Zn mainly exist as the exchangeable(83% and 49% respectively); Cu is mostly contained in the last three fractions (totally 87%); and Cr is mainly contained in the residual fraction (62%). Pb, Zn and Cd showed the high mobility in the investigation, thus might be of risk to the natural environment when municipal solid waste incinerator fly ash is landfilled or reutilized.
Liu
Feng
F
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. Liufeng@tsinghua.org.cn
Liu
Jian-Guo
JG
Yu
Qian-Feng
QF
Nie
Yong-Feng
YF
D002244:Carbon / Q000737:chemistry*; D060729:Coal Ash; D006256:Hazardous Waste; D017745:Incineration; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry*; D052638:Particulate Matter; D012037:Refuse Disposal; D018570:Risk Assessment
D060729:Coal Ash; D006256:Hazardous Waste; D019216:Metals, Heavy; D052638:Particulate Matter; D002244:Carbon