Abstract：Considering pollution control standards of municipal solid waste landfill (GB16889—2008) , the stabilized treatment of heavy metal in fly ash was studied, which aimed to finalizing the optimum addition ratio of chelating agent to meeting the requirements in GB16889—2008. The stabilized heavy metals efficiency was compared between cement solidification and two organic chelating agents in different proportions. The results show that the lead, nickel leaching concentrations exceed the standards in the fly ash leaching solution, in which lead exceeds 13.28 times and nickel exceeds 1.42 times. When the two chelating agent are added 2.0% and 2.5%, the concentrations of lead and nickel in leaching solution are below the standard limits in GB16889—2008to meet landfill admission requirements. Wherein the stabilized efficiency of lead and nickel are 93.42% and 59.11% with the first chelating agent, and the stabilized efficiency are 93.5% and60.02% when the second chelating agent is used.

Keywords: fly ash; leach; heavy metal; chelation; stabilization