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

AbstractAfter flotation of hospital solid waste incinerator (HSWI) fly ash, two types of solid products, froths and tailings, are produced. This paper reports the effect of flotation on the dioxins distribution patterns in different particle size fractions (-25, -38+25, -75 + 38, -106 + 75, and +106 µm) of fly ash. The results showed that the froths had a higher small-size particle distribution than that of the raw fly ash. The dioxin content with particle size in the flotation products depended on the partition behavior of powder-activated carbon (PAC). The dioxin content in the fine particles of the froths was higher than that in the coarse particles, and the highest content is in the finest particles (-25 µm). The dominant PCDD/F congeners in the froths and tailings were similar to those in the raw fly ash. A positive correlation between carbon removal and PCDD/F removal with different size fractions was observed. The carbon removal efficiencies of the fractions of -25 and -38 + 25 µm were evidently hi...