Abstract: The harmless disposal of waste incineration fly ash is the key link in the pollution control of waste incineration. Fly ash and its solidification/stabilization products from typical waste incineration plants were selected to compare and analyze the changes of heavy metal content, morphology, leaching characteristics and micro-morphology of fly ash before and after solidification/stabilization. Meanwhile, the potential risk evaluation method and environmental risk index method were used to evaluate the pollution risk differences of heavy metals before and after solidification/stabilization treatment. The results showed that the content of Zn， Pb and Cu in fly ash from waste incineration in Chongqing was high, especially the leaching toxicity of Pb reached 80.8 times of the standard limit value, and the migration of Pb, Cu, Zn, As and Hg was strong. Solidification/stabilization treatment significantly reduced the leaching toxicity and mobility of heavy metals, but the leaching toxicity of Pb still exceeded the standard. The results of the environmental pollution risk suggested that the environmental pollution risk of fly ash after solidification/stabilization treatment was significantly reduced, but the treatment effect of Pb and Cd still needs to be improved. The research results could provided crucial data support for the optimization of fly ash disposal technology.

Key words: 　waste incineration, fly ash, heavy metals, solidification/stabilization, environmental risk assessment