33 research outputs found

    Particulate and Dissolved Black Carbon in Coastal China Seas: Spatiotemporal Variations, Dynamics, and Potential Implications

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    Elaborating the spatiotemporal variations and dynamic mechanisms of black carbon (BC) in coastal seas, the geographically pivotal intermediate zones that link the terrestrial and open oceanic ecosystems, will contribute significantly to refine the regional and global BC geochemistry. In this study, we implemented a large spatial-scale and multiseason and -layer seawater sampling campaign in high BC emission influenced coastal China seas (Bohai Sea and Northern Yellow Sea) and quantified the thermal/optical reflectance-based particulate BC (PBC) and benzene polycarboxylic acids-based dissolved BC (DBC). We found that the climate and its associated hydrological effects (including the intensive resuspension and coastal current transport) largely regulate both PBC and DBC spatiotemporal variations and dynamics. In combination with previous work on upstream rivers and downstream open ocean, a significant and continuous decrease in the DBC aromatic condensation was observed along the river-to-ocean continuum, probably due to the increment of the photochemical degradation during the waterborne transport. Based on our DBC methodological development, i.e., the determination and subsequent inclusion of the nitrated BC molecular markers, the magnitudes of the current global DBC fluxes and pools were updated. After the update, the DBC fluxes from atmospheric deposition and riverine delivery were estimated at rates of 4.3 and 66.3 Tg yr(-1), respectively, and the global oceanic DBC pool was approximately 36 Gt. This update will greatly assist in constructing a more robust regional and global DBC and BC cycling and budgets

    Antibiotics pollution in Jiulong River estuary: Source, distribution and bacterial resistance

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    SOA [200805064, 200805065, 200905011, 201005016]; Natural Sciences Foundation of China [40706042]To gain insight into the antibiotic pollution in the Jiulong River estuary and the pollutant sources, we analyzed the concentration of 22 widely-used antibiotics in water samples collected from the river and estuary, 17 and 18 sampling sites, respectively. Contamination with sulfonamides, quinolones and chloramphenicols was frequently detected and the distribution pattern of antibiotics suggested that most of the pollutants are from the Jiulong River, especially from the downstream watersheds. To reveal the ecological effects, we isolated 35 bacterial strains from the estuary and analyzed their antibiotic resistance to the eight most frequently detected antibiotics. The bacteria were subsequently classified into seven different genera by 16SrDNA sequencing. Up to 97.1% of the bacteria showed resistance and 70.6% of strains showed multi-resistance to these antibiotics, especially to sulfonamides. This study demonstrated a pattern of antibiotic contamination in the Jiulong River and its estuary and illustrated high bacterial antibiotic resistance which was significantly correlated with the average antibiotics concentrations and detected frequencies in the estuary. (C) 2011 Elsevier Ltd. All rights reserved
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