Emission characteristics and potential toxicity of polycyclic aromatic hydrocarbons in particulate matter from the prebaked anode industry

The emission factors (EFs) and source profiles of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10 and PM2.5) from the prebaked anode industry were studied to fill the knowledge gap and provide data for emission inventory and source resolution. In 2018, three prebaked anode plants were selected in Central China, each having one calcining chimney as well as one baking chimney, and then 92 samples were collected from the stack gas of the six chimneys. The results of the study are as follows. (1) PM10 and PM2.5 from the prebaked anode industry contained 37-42% water-soluble ions, 16-20% elements, 11-17% organic carbon, and 9.2-14% elemental carbon. (2) The EFs for PAHs of PM10 and PM2.5 were 1146.1 +/- 899.7 and 866.2 +/- 1179.8mg/(t aluminum produced), respectively. The EF for BaP was seven times lower than that given by the European Environment Agency (EEA), whereas those of BbF, BkF, and IcdP were 2-13 times higher than those given by the EEA. (3) Seven diagnostic ratios for PAHs, including Ant/(Ant+Phe), Flua/(Flua+Pyr), BaA/(BaA+Chr), IcdP/(IcdP+BghiP), Flu/(Flu+Pyr), Phe/Ant and BaA/Chr were discussed. Just by diagnostic ratio, it is hard to precisely distinguish between calcining and baking in prebaked industry. (4) The toxic equivalence of PMs in the baking stack gas in the prebaked anode industrywas five times higher than that in the calcining stack gas, and PM2.5 showed higher potential toxicity risk than PM10. (C) 2020 Elsevier B.V. All rights reserved.