Occurrence And Distribution Of Semi-volatile Organic Pollutants And Perfluorochemicals In The Yangtze Estuary

The Yangtze Estuary is the largest estuary in China. It brings together amounts of organic pollutants from Yangtze River basin, which probably poses threats to the aquatic environment of the estuary and adjacent area and human health. In this study, the Yangtze Estuary as the study area, we undertook an extensive screening for the semi-volatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and perfluorochemicals (PFCs) in water samples collected in August2012(wet season) and March2013(dry season), respectively, and systematically analyzed the overall ogranic pollution profile in water of the Yangtze Estuary. In this study, solid-phase extraction (SPE) was used to pretreat the water samples, GC-MS and automated identification and quantification system with a database (AIQS-DB) were combined to screen943SVOCs in samples. Meanwhile, GC-MS/MS was used to analyze the18target PCBs and10target OCPs, and LC-MS/MS was used to analyze16target PFCs.The results showed that SVOCs, PCBs, OCPs and PFCs were found in water in both seasons. In water samples from wet season,103SVOCs of12classes,10PCBs,9OCPs and8PFCs were detected. And the total concentrations of SVOCs (∑SVOCs), PCBs (∑PCBs), OCPs (∑OCPs) and PFCs (∑PFCs) were in the range of0.866-10.581μg/L,0.06-0.38ng/L,0.87-2.65ng/L and2.07-6.19ng/L, respectively. In dry season,98SVOCs of12classes,15PCBs,8OCPs and6PFCs were detected. And∑SVOCs,∑PCBs,∑OCPs and∑PFCs were in the range of0.862-7.416μg/L, nd-0.15ng/L,0.30-1.08ng/L and14.52-21.05ng/L, respectively. In the Huangpu River estuary (HP), the concentrations of alcohols (9.307μg/L) and perflurooctanoic acid (PFOA,86.08ng/L) are much higher than other sampling points in Yangte Estuary, which indicates that the Huangpu River is an important pollution source of some organic pollutants to Yangtze Estuary.In general, the organic pollution in the Yangtze Estuary showed notable seasonal variation:the pollution of SVOCs is more serious in wet season, while the pollution of PFCs is the other way around. Moreover, the distribution of PFCs showed significant regional differences, in both seasons, the total concentrations of perfluorinated alkyl substances (∑PFSAs) in the North Bay are higher than the South Bay. On the contrary, the higher total concentrations of perlluorocarboxylic acid (∑PFCAs) appeared in the South Bay. It illustrated that the sources of PFCs in South Bay and North Bay are different. Apart from benzo(a)pyrene, the concentrations of other compounds in the Chinese national environmental quality standards for surface water (GB3838-2002) didn’t exceed the limits of the standards. Compared with the organic pollution in other areas, the organic pollution level of Yangtze Estuary in this study is relatively low.