Trace pollutant in MSW incinerator fly ash: Heavy metals and dioxins

Municipal solid waste incinerator (MSWI) fly ash contains leachable heavy metals and toxic equivalents (TEQ) dioxins of high level, and is usually classified as a hazardous waste. Thus further detoxification and stabilization treatment must be applied to MSWI fly ash before disposing. The trace pollutants such as heavy metal and dioxins of MSWI fly ash have an important influence on selection of treatment technology. Dioxin and heavy metal in fly ashes collected from several MSW incinerators in China and France were studied. A comparative analysis with previous studies is performed. The results show that the content of each heavy metal is different. The contents of Cu, Pb and Zn are usually more than those of Cr, Ni and Cd in fly ash. The content of dioxins varies in the range of 1.36-31.54 ng/g. The results indicate that trace pollutant (such as heavy metal and dioxins) in MSWI fly ash is significantly affected by raw material, tape of furnace, incineration temperature and residence time.