Emission characterization of PeCB, HCB and their correlation in fly and bottom ashes from various thermal industrial processes in Northern Vietnam

Abstract

Pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) are unintentionally produced persistent organic pollutants. To date, control and management of PeCB and HCB emissions from residual ash in developing countries are lacked. In this study, the levels, emission of PeCB, HCB, and their correlation in bottom ash and fly ash from different thermal industrial facilities have been studies. The results indicated that the concentrations of PeCB, HCB and their emission factors (EFs) were different from investigated facilities, nevertheless, the highest concentrations and emission factors of PeCB, HCB were observed in residual ash from industrial waste incinerator and municipal waste incinerator. Using line regression and statistical analysis such as Pearson correlation, we found strongest correlation of EFs between PeCB and HCB in industrial waste incinerator (r 2 = 0.98, p < .001) and municipal waste incinerator (r 2 = 0.76, p < .001). The analyses of correlations of EFs between PeCB and HCB in fly ash and bottom ash indicated that emission of PeCB and HCB has similar formation mechanism in fly ash. Total exposure values for worker were much lower than the acceptable level. Our results can contribute the database on PeCB and HCB emissions in Vietnam, and could be used in the update data in the Toolkit for source categories and/or classes.