Emission of polycyclic aromatic hydrocarbons from animal carcass incinerators

This study investigated two batch-type animal carcass waste incinerators, one in a hog farm (HOWI) and the other in a livestock disease control centre (LIWI). Additionally, a medical waste incinerator (MEWI) with a fixed grate for the disposal of biological medical waste was also examined. A GC/MS technique was applied to analyze the concentrations of 21 polycyclic aromatic hydrocarbons (PAHs) species in the stack flue gas, bottom ash and wet scrubber (WSB) effluent. The analytical results indicated that total-PAHs in the stack flue gas for HOWI, LIWI and MEWI were mainly in the gaseous phase. Moreover, the mean total-PAHs concentrations of the stack flue gas for HOWI and LIWI were 1.5 and 1.4 times higher than for MEWI (=391 μg/m3), respectively. At the most carcinogenic potencies, the results revealed that the mean BaP+BbF+DBA concentrations in the stack flue gas for HOWI and LIWI were 7.6 and 4.6 times higher than those of MEWI (=1.18 μg/m3), respectively. Moreover, during the outbreak of foot-and-mouth disease among pigs in southern Taiwan in 1997, emissions of total-PAHs and BaP+BbF+DBA exceeded 226.2 and 2.3 kg/day, respectively.