Dry and Wet Deposition of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans on the Drinking Water Treatment Plant

Self Cite

Dry deposition is one of the major routes by which air pollutants enter the ecosystem, and thus this study investigated the dry deposition characteristics of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in the ambient air of industrial, urban, and rural areas in southern Taiwan from November 2010 to May 2011. Average dry deposition fluxes of total PCDD/Fs and PCBs in the ambient air of four sites were 157-544 pg/m 2 -day (8.30-27.5 pg I-TEQ/m 2 -day) and 289-1010 pg/m 2 -day (0.540-1.94 pg WHO-TEQ/m 2 -day), respectively. The results showed that particle phase depositions dominated the dry deposition processes for the removal of PCDD/Fs and PCBs from the atmosphere, and the atmospheric deposition flux in the cold season tended to be higher than that during the warm season. The dry deposition velocity of individual PCDD/Fs (0.031-0.546 cm/s) increased as the number of chlorinated substitutes increased, which were similar to those measured or predicted in other Asian countries. Similar patterns of dry deposition velocities were observed for individual PCBs (0.069-3.38 cm/s), due to the fact that low chlorinated PCBs are predominant in gas phase and have lower deposition velocities.

Section: Ambient Air Pcdd/f and Pcb Concentrationsmentioning

confidence: 99%

Section: Sampling and Analysismentioning

confidence: 99%

Atmospheric Dry Deposition of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in Southern Taiwan

Lin

et al. 2012

Self Cite

“…(1)- (3), based research by Pankow (1991), Pankow (1994), and Pankow and Bidleman, (1992) have been used to calculate the gas-particle partitioning of semivolatile organic compounds (especially for PAHs). Since PCDD/Fs and PAHs are all semivolatile organic compounds, equations which have been successfully used to describe gas-particle partitioning of PCDD/Fs by several researchers (Lohmann and Jones, 1998;Wu et al, 2009;Xu et al, 2009;Lin et al, 2010a;Wang et al, 2010).…”

Section: Gas-particle Partitioningmentioning

confidence: 99%

“…Results indicated that the dry deposition of PCDD/Fs is more important than the wet deposition of PCDD/Fs to the total PCDD/F distribution in the environment. In addition, significant influence of atmospheric deposition of PCDD/Fs on tap drinking water has been addressed (Lin et al, 2010a). Therefore, knowledge of the characteristics of PCDD/Fs deposition is essential for observing subsequent fate of PCDD/Fs in the environment.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Atmospheric Dry Deposition of Polychlorinated Dibenzo-p-dioxins/Dibenzofuran in a Rural Area of Taiwan

Huang

Chen

Lai

et al. 2011

Self Cite

The characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and the variation of the gas-particle partitioning of PCDD/Fs near two municipal solid waste incinerators (MSWIs) located in southern Taiwan were investigated. In order to better understand the mechanism of dry deposition, the atmospheric dry deposition flux and velocity of PCDD/Fs were calculated. It was found that the mean atmospheric PCDD/F concentrations (0.0386-0.106 pg I-TEQ/Nm 3 ) were comparable to those detected in the vicinity of MSWIs in Taiwan, but significantly lower than those in a highly industrialized urban area (0.15 pg I-TEQ/Nm 3 ) located in southern Taiwan. The relatively higher atmospheric PCDD/F concentrations was found in winter than in summer, probably because of several loss process including photolysis, chemical reactivity, wet and dry deposition, and scavenging by vegetation. The calculated total dry deposition flux of PCDD/Fs ranged from 0.0274-0.718 ng I-TEQ/m 2 -month, and the atmospheric deposition flux in winter tended to be higher than those in summer. The results also indicated that dry deposition velocities of atmospheric particles for each month ranged from 0.52-0.91 cm/s (mean = 0.63 cm/s) and 0.48-0.73 cm/s (mean = 0.55 cm/s) in sites A and B, respectively, which were similar to that for the ambient air near two MSWIs in Taiwan, but slightly higher than those in urban area of Korea. In addition, the dry deposition of PCDD/Fs was mainly contributed by particle-phase at both sampling areas during the estimated period. The above results demonstrated that the dominant mechanism of dry deposition was particle phase deposition.

“…It is well known that dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) generate toxicological effects and associated adverse health implications to organisms (U.S. EPA, 2003;Lin et al, 2010a;Ning and Sioutas, 2010). PCDD/Fs were first found in the fly ash of a municipal solid waste incinerator (MSWI) (Olie et al, 1977).…”

Section: Introductionmentioning

confidence: 99%

Identification the Content of the Windbox Dust Related to the Formation of PCDD/Fs during the Iron Ore Sintering Process

Kuo

Chen

Yang³

et al. 2011

This study measured the contents of the ionic and elemental constituents, and the chemical compounds containing in windbox (WB) dusts collected from a commercial iron ore sintering plant, then the results were used to identify possible PCDD/Fs formation pathways in the WB. We found that the abundance in both KCl and NaCl may provide a suitable condition for de novo synthesis of PCDD/Fs in the WB. Al, Fe, K, Ca, and Pb were the top five contents in WB16 dusts, but the co-existence of the above five metal contents warrants the need for further investigation on their roles in PCDD/F formation processes in the future. Although a low concentration of Cu was detected, it might be of importance to PCDD/Fs formation inside the WB. A total of 29 chemical compounds were identified. Among them, several oxygenated organic compound might be associated with PCDD/F formations at the beginning stage, but the roles of aromatic oxygenates on the formation of PCDD/Fs required further investigation. Finally, possible de novo synthesis pathways of PCDD/Fs were proposed based on the above findings. However, the above pathways are required further laboratory studies for validation before possible formation suppression approaches can be determined.