Strength and leaching characteristics of CGF solidification/stabilization heavy metal contaminated soil
Contaminated soils with different soil types(different proportions of clay,silt and sand)and different composite heavy metals(Cu,Ni,Pb and Zn)content were solidified/stabilized by CGF(a solid waste based binder composed of calcium carbide residue(CCR),ground granulated blastfurnace slag(GGBS)and fly ash(FA)),macro and micro tests were conducted to study the strength characteristics,heavy metal leaching characteristics and solidification/stabilization mechanism of the solidified/stabilized contaminated soil.The results show that the strength and leaching concentration of heavy metal contaminated soil solidified/stabilized by CGF were mainly determined by curing time,heavy metal content and soil type;With the increase of curing time,the strength of solidified/stabilized contaminated soil gradually increased,leaching concentration was negatively correlated with curing time,there is a"critical content"of heavy metal,which was controlled by the type of heavy metal ions and the type of soil.The"critical content"of solidified/stabilized Clay contaminated soil at 7,28 and 90d were respectively 200,300 and 600mg/kg;the"critical content"of solidified/stabilized Clay,CSSM511 and CSSM111 contaminated soil at 28d were respectively 300,200 and 200mg/kg,solidified/stabilized CSSM011 contaminated soil didn't exist"critical content".The mechanism of CGF solidification/stabilization heavy metal contaminated soil includes the stabilization of heavy metal ions by chemical precipitation,encapsulation,adsorption and ion exchange of the and the stabilization of heavy metal ions by clay mineral in the soil.
solidification/stabilizationcomposite heavy metalunconfined compressive strengthleaching concentrationcritical contentfunction mechanism
万方数据
维普
