Characterization of heavy metals migration from leachate-leaching municipal solid waste incineration bottom ash

Following the research idea of waste treatment with waste, to investigate the effects of leaching temperature (50—90℃) and leaching time (5—15min) on the migration characteristics of heavy metals (Zn, Ni, Cu, Pb, Ba and Cr), the test of leaching municipal solid waste incineration bottom ash (MSWI-BA) by leachate was conducted, and leaching toxicity of the bottom slag formed after leaching was analyzed to determine the best condition. It was found that MSWI-BA captured Ni, Zn, Pb, Cr and Ba within the leachate, while Cu was released from the MSWI-BA into the leachate. With the increase of leaching temperature, except Pb and Cr, the content of heavy metals in MSWI-BA tended to increase first and then decrease. With the increase of leaching time, each heavy metal showed different changing trends due to the changes of precipitation, adsorption, complexation, precipitation dissolution and other factors. Meanwhile, based on the results of leaching concentration and leaching rate of heavy metals, the toxicity of the bottom slag formed under different treatment conditions was relatively low, with leaching temperature of 70℃ and leaching time of 10min being the optimal operating condition. This paper provided a valuable reference on heavy metal migration control during the contact of MSWI-BA and leachate in real industrial processes. © 2024 Chemical Industry Press Co., Ltd.. All rights reserved.