Characterizing polycyclic aromatic hydrocarbon emissions from hog fuel boilers

The results of 29 stack tests on 10 hog fuel boilers operating at pulp and paper mills across Canada are summarized. Total PAH emissions ranged from 0 .65 to 151 mu g / m(3). Inclusion of only the PAH compounds that are on the ARET (Accelerated Reduction / Elimination of Toxics) list reduced total PA H emissions; ARET FAH emissions ranged from less than 0.001 to 115 mu g / m (3). Expressed as toxicity equivalents (TEQs), PAH emissions ranged from le ss than 0.001 to 2.53 pg / m(3). Benzo(a)pyrene was found to be a good surr ogate for TEQs. Higher PAH emissions were generally associated with poor co mbustion conditions and correspondingly high CO emission rates.