Pollution emission characteristics, distribution of heavy metals, and particle morphologies in a hazardous waste incinerator processing phenolic waste

Secondary pollution emitted from hazardous waste incinerators (HWIs) can pose potential risks to the surrounding populations and environment. An investigation was conducted on pollutant emission status in a HWI combusting homogenized phenolic waste, woodchips, and electroplating sludge during the sampling period. Morphologies and elemental compositions of particles in flue gas and indoor air of the incinerator were characterized by TEM-EDS. Eight types of single particles were classified, as organic, soot, K-rich, S-rich, Na-rich, Ferich, mineral and fly ash particles. In the indoor air near the fly ash collector, organic and S-rich particles were the two most observed particles, taking 56 % and 30 %, respectively. While near the bottom ash collector, Ferich particles took approximately 30 %. Besides, the partitioning behavior of heavy metals in the incinerating process were investigated. Hg, Cd and Pb were mainly enriched in fly ash through evaporation, condensation, and adsorption; while Cr, Cu, Mn, and Ni were mostly remained in the bottom ash due to their low volatilities. This study provides information for regional air pollution source apportionment, but also helps understand the partitioning behavior of heavy metals for the secondary pollution control. Meanwhile, the visualized microcompositions of indoor particles pave a way for occupational exposure risk assessment.