Feasibility Study on Solidification of Pb from MSWI Fly Ash with Cementitious Materials Based upon Industrial Waste

摘要

Physical and chemical characteristics of municipal solid waste incinerator (MSWI) fly ash were systematically investigated and the teachability of heavy metals was analysed. The results show that the concentration of Pb from the leaching liquid of the fly ash is 23.41mg/L, while the limit value in the National Identification Standard for Hazardous Wastes is 5mg/L. In this study, MSWI fly ash was solidified by four different cementitious materials (H1, H2, H3, H4) which are composed of industrial waste and the content of Hx is 15%. The leachability of Pd decreased to 1.81mg/L when H2 was added after 3 days. Furthermore the dual stabilization with different admixture (C, D) and H2 were discussed. The results show that the concentration of Pb is 0.22mg/L when 10% H2 and 0.2% admixture C added after 3 days. XRD and SEM methods were applied to identify the hydraulic products and the mechanism of the heavy metals stabilization is also summarized.