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Seasonal variations in atmospheric concentrations and gas–particle partitioning of PCDD/Fs and dioxin-like PCBs around industrial sites in Shanghai, China
Abstract Gas and particle phase air samples were collected in summer and winter around industrial sites in Shanghai, China, to allow the concentrations, profiles, and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) to be determined. The total 2,3,7,8-substituted PCDD/F and dl-PCB toxic equivalent (TEQ) concentrations were 14.2–182 fg TEQ/m3 (mean 56.8 fg TEQ/m3) in summer and 21.9–479 fg TEQ/m3 (mean 145 fg TEQ/m3) in winter. The PCDD/Fs tended to be predominantly in the particulate phase, while the dl-PCBs were predominantly found in the gas phase, and the proportions of all of the PCDD/F and dl-PCB congeners in the particle phase increased as the temperature decreased. The logarithms of the gas–particle partition coefficients correlated well with the subcooled liquid vapor pressures of the PCDD/Fs and dl-PCBs for most of the samples. Gas–particle partitioning of the PCDD/Fs deviated from equilibrium either in summer or winter close to local sources, and the Junge–Pankow model and predictions made using a model based on the octanol–air partition coefficient fitted the measured particulate PCDD/F fractions well, indicating that absorption and adsorption mechanism both contributed to the partitioning process. However, gas–particle equilibrium of the dl-PCBs was reached more easily in winter than in summer. The Junge–Pankow model predictions fitted the dl-PCB data better than did the predictions made using the model based on the octanol–air partition coefficient, indicating that adsorption mechanism made dominated contribution to the partitioning process.
Highlights PCDD/F and dl-PCB concentrations differed significantly in different seasons. Industrial sources affect PCDD/F and dl-PCB concentrations. Gas–particle equilibrium of dl-PCBs was more easily reached at higher TSP. Particle dl-PCBs near sources were predicted better by model than Koa model.
Seasonal variations in atmospheric concentrations and gas–particle partitioning of PCDD/Fs and dioxin-like PCBs around industrial sites in Shanghai, China
Abstract Gas and particle phase air samples were collected in summer and winter around industrial sites in Shanghai, China, to allow the concentrations, profiles, and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) to be determined. The total 2,3,7,8-substituted PCDD/F and dl-PCB toxic equivalent (TEQ) concentrations were 14.2–182 fg TEQ/m3 (mean 56.8 fg TEQ/m3) in summer and 21.9–479 fg TEQ/m3 (mean 145 fg TEQ/m3) in winter. The PCDD/Fs tended to be predominantly in the particulate phase, while the dl-PCBs were predominantly found in the gas phase, and the proportions of all of the PCDD/F and dl-PCB congeners in the particle phase increased as the temperature decreased. The logarithms of the gas–particle partition coefficients correlated well with the subcooled liquid vapor pressures of the PCDD/Fs and dl-PCBs for most of the samples. Gas–particle partitioning of the PCDD/Fs deviated from equilibrium either in summer or winter close to local sources, and the Junge–Pankow model and predictions made using a model based on the octanol–air partition coefficient fitted the measured particulate PCDD/F fractions well, indicating that absorption and adsorption mechanism both contributed to the partitioning process. However, gas–particle equilibrium of the dl-PCBs was reached more easily in winter than in summer. The Junge–Pankow model predictions fitted the dl-PCB data better than did the predictions made using the model based on the octanol–air partition coefficient, indicating that adsorption mechanism made dominated contribution to the partitioning process.
Highlights PCDD/F and dl-PCB concentrations differed significantly in different seasons. Industrial sources affect PCDD/F and dl-PCB concentrations. Gas–particle equilibrium of dl-PCBs was more easily reached at higher TSP. Particle dl-PCBs near sources were predicted better by model than Koa model.
Seasonal variations in atmospheric concentrations and gas–particle partitioning of PCDD/Fs and dioxin-like PCBs around industrial sites in Shanghai, China
Die, Qingqi (author) / Nie, Zhiqiang (author) / Liu, Feng (author) / Tian, Yajun (author) / Fang, Yanyan (author) / Gao, Hefeng (author) / Tian, Shulei (author) / He, Jie (author) / Huang, Qifei (author)
Atmospheric Environment ; 119 ; 220-227
2015-08-07
8 pages
Article (Journal)
Electronic Resource
English
Seasonal and particle size-dependent variations in gas/particle partitioning of PCDD/Fs
| Online Contents | 2008
Seasonal and particle size-dependent variations in gas-particle partitioning of PCDD-Fs
| Online Contents | 2008