No abstract

The chemical mass balance model was applied to estimate the major sources of atmospheric polycyclic aromatic hydrocarbons (PAHs) at an Industrial Region in Kaohsiung, Taiwan. The gaseous and particulate phases of 16 individual compounds were analyzed between March 2012 and August 2012. The mean total concentrations and total BaP eq were higher during the cold season and lower during the warm summer, with gaseous PAHs predominant at all sites. Low weight-PAHs and median weight-PAHs were found predominantly in the gaseous phase, while high weight-PAHs were predominant in the particle phase. Results from the receptor model revealed that the average contributions were 38.2%, 27.2%, 20.7%, 6.8%, 5.2%, and 2.0% from vehicles, heavy oil combustion, natural gas combustion, incinerator, tetrabromobisphenol A production, and diesel combustion at the seven receptors, respectively. Vehicle emissions appear to be the significant source of PAHs in the investigated area, although other industrial sources, as described above, also have an impact on the total PAHs.

Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/Fs) in the ambient air of five sampling sites around central Taiwan were investigated. Principal components analysis (PCA), cluster analysis (CA) and the chemical mass balance (CMB) model were adopted to assess possible PCDD/F sources and their effects on the air quality levels. Field experimental results showed that the mean PCDD/F concentrations in the ambient air were 0.0526, 0.0591, 0.0339 and 0.0727 pg I-TEQ/Nm 3 in winter, spring, summer and autumn, respectively. Analysis of atmospheric isopleths for five sampling sites displayed that high PCDD/F concentrations were mostly close to electric arc furnace plants (EAF). Through PCA and CA, the congener profiles of ambient air sampling sites were close to medical waste incinerators (MWI), secondary aluminum smelters (ALS), EAF, waste open burning (OB) and crematories (CM). By using the CMB model, the dominant sources of PCDD/Fs in ambient air were EAF, medical waste incinerator/municipal solid waste incinerators (MWI/MSWI) and unleaded gasoline fuel vehicle/diesel fuel vehicle (UGFV/DFV), which contributed 22-23%, 17-31% and 9-22%, respectively. The above results revealed that ambient air was affected by surrounding PCDD/F sources (MWI, ALS, EAF, CM and OB). However, due to high stack height and low emission concentration, the impact of coal-fired power plant on the PCDD/F levels of ambient air was insignificant.

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This study investigated Hg emissions from a coal-fired power plant (CFPP) and their impact on the nearby environment. Atmospheric Hg concentrations were measured at sampling sites near a CFPP located in central Taiwan from November 2008 to March 2011. The mean gaseous and particulate Hg concentrations were 2.59-4.12 ng/m 3 and 105-182 pg/m 3 , respectively, with gaseous Hg predominant at all sites (approximately 96% of the total atmospheric Hg). The seasonal variations of both gaseous and particle Hg concentrations in the atmosphere showed a similar pattern, with the highest concentrations in the cold season and the lowest in warm season. The mean emission factor of 13.1 mg/ton was found for the CFPP burning bituminous coal, with an electrostatic precipitator (ESP), flue gas desulfurization (FGD), and selective catalytic reduction (SCR) in series as air pollution control devices (APCDs). This figure was significantly lower than that measured at various power facilities, probably due to different fuel type, APCDs configuration, and flue gas condition. The modeling of the Industrial Source Complex Short Term (ISCST) revealed that the contribution of the CFPP to ambient atmospheric Hg was minimal (less than 1%).