Study on the Migration Characteristics of As, Pb, and Ni during Oily Sludge Incineration with CaO Additive

Adding CaO during oily sludge (OS) incineration is viewed as an efficient approach to treat high-sulfur-containing OS on a large scale. It can effectively reduce the content of SO2 and affect the migration and transformation of heavy metals. To explore the effect of CaO on the migration characteristics of As, Pb, and Ni during OS incineration, incineration experiments of OS with and without CaO were carried out respectively in a horizontal tube furnace at temperatures ranging from 800 to 1000 °C. The total amount and leachability of As, Pb, and Ni in samples were presented in this paper. The results showed that the migration characteristics of As, Pb, and Ni during OS incineration were affected by incineration temperature and CaO. As temperature increases, the residue ratios of As and Pb in bottom ash decreased, but Ni increased first and then decreased. CaO played an important role in promoting the residue of As and Pb in bottom ash. Moreover, when adding CaO, the leachability of As and Pb in bottom ash was significantly reduced. The results will supply essential data and theoretical support for the innocuous treatment of OS.