Effect of flotation on the dioxin distribution in size-fractioned fly ash of hospital solid waste incineration

Characterization and stabilization of incineration fly ash from a new multi-source hazardous waste co-disposal system: field-scale study on solidification and stabilization

The multi-source hazardous waste co-disposal system, a recent innovation in the industry, offers an efficient approach for hazardous waste disposal. The incineration fly ash (HFA) produced by this system exhibits characteristics distinct from those of typical incineration fly ash, necessitating the use of adjusted disposal methods. This study examined the physicochemical properties, heavy metal content, heavy metal leaching concentration, and dioxin content of HFA generated by the new co-disposal system and compared them with those of conventional municipal waste incineration fly ash. This study investigated the solidification and stabilization of HFA disposal using the organic agent sodium diethyl dithiocarbamate combined with cement on a field scale. The findings revealed significant differences in the structure, composition, and dioxin content of HFA and FA; HFA contained substantially lower levels of dioxins than FA did. Concerning the heavy metal content and leaching; HFA exhibited an unusually high concentration of zinc, surpassing the permitted emission limits, making zinc content a critical consideration in HFA disposal. After stabilization and disposal, the heavy metal leaching and dioxin content of HFA can meet landfill disposal emission standards when a 1% concentration of 10% sodium diethyldithiocarbamate (DDTC) and 150% silicate cement were employed. These results offer valuable insights into the disposal of fly ash resulting from incineration of mixed hazardous waste.