Atmospheric concentration characteristics and gas/particle partitioning of PCBs from the North Pacific to the Arctic Oce
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Atmospheric concentration characteristics and gas/particle partitioning of PCBs from the North Pacific to the Arctic Ocean WANG Zhen1, NA Guangshui1, GAO Hui1, WANG Yanjie1, YAO Ziwei1* 1
National Marine Environmental Monitoring Center, Dalian 116023, China
Received 1 March 2014; accepted 8 July 2014 ©The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2014
Abstract Polychlorinated biphenyls (PCBs) were measured in atmospheric samples collected from the North Pacific to the Arctic Ocean between July and September 2012 to study the atmospheric concentration characteristics of PCBs and their gas/particle partitioning. The mean concentration of 26 PCBs (vapor plus particulate phase) (ƩPCBs) was 19.116 pg/m3 with a standard deviation of 13.833 pg/m3. Three most abundant congeners were CB-28, -52 and -77, accounting for 43.0% to ƩPCBs. The predominance of vapor PCBs (79.0% to ƩPCBs) in the atmosphere was observed. ƩPCBs were negative correlated with the latitudes and inverse of the absolute temperature (1/T). The significant correlation for most congeners was also observed between the logarithm of gas/particle partition coefficient (logKP) and 1/T. Shallower slopes (from −0.15 to −0.46, average −0.27) were measured from the regression of the logarithm of sub-cooled liquid vapor pressures (logpºL) and logKP for all samples. The difference of the slopes and intercepts among samples was insignificant (p>0.1), implying adsorption and/or absorption processes and the aerosol composition did not differ significantly among different samples. By comparing three models, the J-P adsorption model, the octanol/ air partition coefficient (KOA) based model and the soot-air model, the gas/particle partitioning of PCBs in the Arctic atmosphere was simulated more precisely by the soot-air model, and the adsorption onto elemental carbon is more sensitive than the absorption into organic matters of aerosols, especially for lowchlorinated PCB congeners. Key words: PCBs, gas/particle partitioning, Arctic Ocean, soot-air model, semi-volatile organic compounds Citation: Wang Zhen, Na Guangshui, Gao Hui, Wang Yanjie, Yao Ziwei. 2014. Atmospheric concentration characteristics and gas/ particle partitioning of PCBs from the North Pacific to the Arctic Ocean. Acta Oceanologica Sinica, 33(12): 32–39, doi: 10.1007/ s13131-014-0531-5
1 Introduction Polychlorinated biphenyls (PCBs) are a group of ubiquitous semi-volatile organic compounds (SVOCs) characterized by high lipophilicity, extreme toxicity and high persistence. Although PCBs have been banned for over 20 years, they are still detected in all environmental media, even in the Arctic and Antarctic (Helma and Bidleman, 2005; Galbán-Malagón et al., 2013; Newton et al., 2013). Researchers considered that these chemicals are still released into the atmosphere by primary (e.g., vaporization or burning of products containing PCBs) and secondary sources (e.g., air/sea and air/soil exchange) (Hung et al., 2001; Breivik et al., 2002). The wide range of sub-cooled liquid vapor pre
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