Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Temporal trends of polychlorinated biphenyls in precipitation in Beijing, China
Abstract Temporal trend of polychlorinated biphenyls (PCBs) was determined in precipitation and monthly depositional fluxes were calculated in Beijing for the first time from February 2009 to March 2011. Total PCBs concentrations ranged from 7.00 to 993 ng L−1 in dissolved phase and from 1.00 to 133 ng L−1 in particulate phase, with a two orders of magnitude variation. Concentrations of PCBs were dominated by dissolved phase, which accounted for 82.5% of the total PCBs in precipitation, implying PCBs enrichment in rainwater due to efficient scavenging of highly contaminated gas phase and nonfilterable submicron particles which easily adsorbed organic contaminants in urban atmosphere. Highest concentrations of PCBs were measured in snow, which were about two times higher than those in rainwater, demonstrating more efficient scavenging of PCBs by snow. The sum of bi-, tri- and tetrachlorinated congeners accounted for 70.5% of total PCBs in precipitation, suggesting that PCBs mainly come from the historical usage of domestic PCB product, e.g., trichlorobiphenyl. PCBs concentrations in both dissolved and particulate phases showed slow rate of decline, with a half-life of 16.9 years in precipitation, suggesting that the atmospheric concentrations of PCBs were decreasing slowly in Beijing. The wet deposition flux of ∑PCBs ranged from 0.240 to 6.55 μg m−2 month−1 (mean: 1.41 μg m−2 month−1), indicating a relatively high level of PCBs contamination in Beijing atmosphere.
Highlights ► We determine the characters of PCBs in precipitation in Beijing from February 2009 to March 2011. ► Wide concentration variations in both phases are found. ► High portions of dissolved phase in precipitation are exhibited. ► The sum of low weighted congeners accounts for 70.5%. ► The wet deposition flux of ∑PCBs is 16.9 μg m−2 yr−1.
Temporal trends of polychlorinated biphenyls in precipitation in Beijing, China
Abstract Temporal trend of polychlorinated biphenyls (PCBs) was determined in precipitation and monthly depositional fluxes were calculated in Beijing for the first time from February 2009 to March 2011. Total PCBs concentrations ranged from 7.00 to 993 ng L−1 in dissolved phase and from 1.00 to 133 ng L−1 in particulate phase, with a two orders of magnitude variation. Concentrations of PCBs were dominated by dissolved phase, which accounted for 82.5% of the total PCBs in precipitation, implying PCBs enrichment in rainwater due to efficient scavenging of highly contaminated gas phase and nonfilterable submicron particles which easily adsorbed organic contaminants in urban atmosphere. Highest concentrations of PCBs were measured in snow, which were about two times higher than those in rainwater, demonstrating more efficient scavenging of PCBs by snow. The sum of bi-, tri- and tetrachlorinated congeners accounted for 70.5% of total PCBs in precipitation, suggesting that PCBs mainly come from the historical usage of domestic PCB product, e.g., trichlorobiphenyl. PCBs concentrations in both dissolved and particulate phases showed slow rate of decline, with a half-life of 16.9 years in precipitation, suggesting that the atmospheric concentrations of PCBs were decreasing slowly in Beijing. The wet deposition flux of ∑PCBs ranged from 0.240 to 6.55 μg m−2 month−1 (mean: 1.41 μg m−2 month−1), indicating a relatively high level of PCBs contamination in Beijing atmosphere.
Highlights ► We determine the characters of PCBs in precipitation in Beijing from February 2009 to March 2011. ► Wide concentration variations in both phases are found. ► High portions of dissolved phase in precipitation are exhibited. ► The sum of low weighted congeners accounts for 70.5%. ► The wet deposition flux of ∑PCBs is 16.9 μg m−2 yr−1.
Temporal trends of polychlorinated biphenyls in precipitation in Beijing, China
Yang, Guosheng (Autor:in) / Ma, Lingling (Autor:in) / Xu, Diandou (Autor:in) / Liu, Liyan (Autor:in) / Jia, Hongliang (Autor:in) / Chen, Yang (Autor:in) / Zhang, Yongbao (Autor:in) / Chai, Zhifang (Autor:in)
Atmospheric Environment ; 56 ; 222-227
26.03.2012
6 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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