Simultaneous removal of SO2 and PAHs by adding calcium-based additives during sewage sludge incineration in a fluidized bed incinerator

Abstract

In this paper, the simultaneous removal of sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs) by adding calcium-based additives [CaO, Ca(OH)2, and CaCO3] during sewage sludge incineration was investigated in a fluidized bed incinerator. The effects of the types, CaO/S (mole ratio) and particle size of calcium-based additives on PAHs or PAHs Toxic Equivalent Quantity concentrations (TEQs) were also considered. The experimental results indicated that CaO had a better performance of reducing SO2 and PAHs emission, and the removal efficiencies of SO2, PAHs and PAHs TEQs at 850 °C were 86.89, 38.88 and 75.19%, respectively. Meanwhile, the increase of CaO/S and decrease of particle size were beneficial for suppressing PAHs formation and capturing SO2. Moreover, the adsorption and catalytic effect of calcium-based additives were regarded as inhibiting PAHs formation.