Characteristics of PCDD/Fs in PM2.5 from emission stacks and the nearby ambient air in Taiwan

Abstract

This study aimed to find the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in fine particulate matter from different stationary emission sources (coal-fired boiler, CFB; municipal waste incinerator, MWI; electric arc furnace, EAF) in Taiwan and the relationship between PM2.5 and PM2.5-bound PCDD/Fs with Taiwanese mortality risk. PM2.5 was quantified using gravimetry and corresponding chemical analyses were done for PM2.5-bound chemicals. Mortality risks of PM2.5 exposure and PCDD/Fs exposure were calculated using Poisson regression. The highest concentration of PM2.5 (0.53 ± 0.39 mg/Nm3) and PCDD/Fs (0.206 ± 0.107 ng I-TEQ/Nm3) was found in CFB and EAF, respectively. Higher proportions of PCDDs over PCDFs were observed in the flue gases of CFB and MWI whereas it was reversed in EAF. For ambient air, PCDD/F congeners around the stationary sources were dominated by PCDFs in vapor phase. Positive matrix factorization (PMF) analysis found that the sources of atmosphere PCDD/Fs were 14.6% from EAF (r = 0.81), 52.6% from CFB (r = 0.74), 18.0% from traffic (r = 0.85) and 14.8% from MWI (r = 0.76). For the dioxin congener distribution, PCDDs were dominant in flue gases of CFB and MWI, PCDFs were dominant in EAF. It may be attributed to the different formation mechanisms among wastes incineration, steel-making, and coal-burning processes.

Optimizing the Elimination of Dioxin-Like Compounds (PCDD/Fs and PCBs) Through Effective Combustion Practices in the Flue Gas in the Medical Waste Incineration Facility

“…The lowest TEQ reading of 3.85 ng I-TEQ/m³ was obtained during SC3, whereas SC4 yielded the highest measurement at 20.04 ng I-TEQ/m³ . Higher proportions of PCDFs over PCDDs was observed in this study which was contradictory to Pan et al [62] who reported higher proportions of PCDDs over PCDFs in the flue gases from CFB and MWI. Formation of low-chlorinated PCDDs (1,2,3,7,8-PeCDD, 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD and 1,2,3,7,8,9-HxCDD) possessed strong correlation and the chlorophenols were the important precursors of low-chlorinated PCDDs which were generated within the low chlorinated content [62].…”

“…Higher proportions of PCDFs over PCDDs was observed in this study which was contradictory to Pan et al [62] who reported higher proportions of PCDDs over PCDFs in the flue gases from CFB and MWI. Formation of low-chlorinated PCDDs (1,2,3,7,8-PeCDD, 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD and 1,2,3,7,8,9-HxCDD) possessed strong correlation and the chlorophenols were the important precursors of low-chlorinated PCDDs which were generated within the low chlorinated content [62]. The stack emissions presented certain similarities with an increasing chlorinated level, the content of the 2,3,7,8-PCDD congener increased but the content of 2,3,7,8-PCDF congener showed irregularities.…”

Atmospheric emissions of hexachlorobutadiene in fine particulate matter from industrial sources

“…Among the EAFs, EAF-2 had a HCBD concentration of 441.6 ng/g, which was the next highest concentration after SCu. This high concentration of HCBD in EAF steelmaking could be caused by the presence of organic residues in scrap raw materials, such as rubber, cable wrapping, plastics, and polyvinyl chloride, which provide additional sources of chlorine for the unintentional formation and emission of HCBD 29 . Yang et al speculated that differences in the chlorine contents of raw materials and metal catalysts are important contributors to differences in the emissions of chlorinated organic pollutants 30 , 31 .…”

Air quality and health co-benefits of climate change mitigation and adaptation actions by 2030: an interdisciplinary modeling study in Ahmedabad, India

“…The application of ambient meteorology, emissions, and atmospheric chemistry datasets through WRF-Chem modeling at a high spatial-resolution of 4.2 km 2 provides more granular insights into local PM 2.5 levels. Air quality improves slightly in the vicinity of TPP even in 2030 BAU due to differences in meteorology inputs between 2018 and 2030 and meteorology effects on secondary PM 2.5 formation downwind of TPP (Pan et al 2021 ); eliminating emissions from TPP in 2030 M&A results in larger and more widespread PM 2.5 reductions than those attributed to changing meteorology.…”