Effect of Fe-based substance on Cr leaching behavior in hazardous waste incineration fly ash after thermal treatment

This study investigated the influence of the interaction between Fe-based substances and thermal treatment parameters on the leaching behavior of Cr in hazardous waste incineration fly ash (HWIFA) after thermal treatment. The results revealed that the interaction between the addition of Fe-based substance and the thermal treatment parameters and their effects on static and dynamic leaching behaviors of Cr had significant differences when Fe₂O₃, Fe₃O₄, and Fe were added, respectively. Specifically, when Fe₂O₃ or Fe was added, the thermal treatment temperature was the most significant factor affecting the static leaching of Cr in thermal treated HWIFA, and the interaction effect of other factors was not significant. The most important influence on the dynamic leaching behavior of Cr was the interaction between the thermal treatment temperature and the addition of Fe₂O₃. Different from the addition of Fe₂O₃, the effect of the addition of Fe₃O₄ on the static leaching of Cr in thermal treated HWIFA was more significant than that of thermal treatment temperature; meanwhile, the interaction between the thermal treatment temperature and the addition of Fe₃O₄ was also significant. However, when Fe₃O₄ was added, the effect of interaction between factors on the dynamic leaching of Cr in thermal treated HWIFA was consistent with that when Fe₂O₃ was added.