Volume 11, No. 4, August 2011, Pages 448-459 PDF(5.83 MB)
Characterization of Atmospheric Dry Deposition of Polychlorinated Dibenzo-p-dioxins/Dibenzofuran in a Rural Area of Taiwan
Chun-Jen Huang1, Kang-Shin Chen1, Yi-Chieh Lai2, Lin-Chi Wang3, Guo-Ping Chang-Chien3
1 Institute of Environmental Engineering, National Sun Yat-Sen University, 70 Lienhai Road, Kaohsiung 80424, Taiwan
2 Department of Bioenvironmental Engineering, Chung Yuan Christian University, 200 Chung-Pei Road, Chung-Li 32023, Taiwan
3 Department of Chemical and Materials Engineering, Cheng Shiu University, 840 Chengcing Road, Niaosong Township, Kaohsiung County 833, Taiwan
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/Nm3) 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/Nm3) 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/m2-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.
Polychlorinated dibenzo-p-dioxins/Dibenzofurans (PCDD/Fs); Gas-Particle partitioning; Dry deposition; Velocity.