| This paper investigated the characteristics of hazardous waste incineration residues (HWIR) from four typical disposal centers in Zhejiang Province, explored the effects of magnetic pretreatment, studied the stabilization effects of fulvic acid (FA) and humic acid (HA), and tested the long-term stability of solidified sample. It was found that the Cu content and Cu2+ leaching concentration of the HWIR can amount to 7227.7 mg/kg and 131.00±1.57 mg/L, respectively, which is significantly higher than the landfill permission control standard (75 mg/L), while those of Pb and Cd were close to the standard that indicating potential environmental risks. Magnetic pretreatment can enrich Cu but still lower than the demand of smelting. At the same time, magnetic pretreatment also can change the ratio of available and residual form of the heavy metals, thereby increasing the environmental risk. It meant that the residues weren’t suitable for the reutilization.7% of FA added to the residues could decrease the TCLP concentration of Cu1+ to 72.42±0.77 mg/L, which is below the landfill admission control standard. Ca2+ can strengthen the stabilization of Cu, while the HA was opposite. The best addition of FA, HA and CaCl2 was 10%,0.7% and 0.35%, respectively. The compressive strength of all of the solidified samples can meet the USA EPA standard (0.35MPa). The leaching of Cu2+, Pb2+ and Cd2+ decreased gradually with the increasing of cement and curing time, and 10% cement, 7 days’ conserving or 5% cement 14 days’conserving can meet the standards. The simulated acid rain leaching test found even if the leaching concentrations of heavy metals by HA stabilization meet the standard, the follow-up solidified was necessary, otherwise the solidified samples collapse easilily. Rainfall test showed that the acid buffering capacity of solidified samples were steady, heavy metals slowly released. To evalute the long-term releasing behavior of heavy metals, a longer test needed. |
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