Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbicula fluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three inter...Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbicula fluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three intertidal flat sites of the Changjiang (Yangtze) River estuary in China. The interface exchange flux of ammonium, nitrate and nitrite in the short experiment (6 h) was 46.4-40, 74.8-929.1 and 2.5-14.6 μmol/(m2·h), respectively. It was found that the burrowing activities of C. fluminea increased NH 4+ and NO 3-release from sediments to overlying water in the short-term experiment. During long-term incubation, NH +4 and NO 3-released in turn from the sediments. At the beginning of incubation, bioturbation by C. fluminea could accelerate NH +4 release from sediments 2-17 times in different sites, resulting in stronger nitrification and increased NO 3-concentrations in the overlying water. Sediment profile analysis post-incubation shows that organic matter mineralization and sediment-water NH +4 exchange had been stimulated by C. fluminea bioturbation and bioirrigation during the experiment. Therefore, C. fluminea activities such as excretion, burrowing, irrigation and turbation can effectively alter nitrogen dynamics and accelerate and stimulate nitrogen exchange and cycling at the sediment-water interface.展开更多
This study on the distribution features of petroleum hydrocarbon in water and sediment off the Fujian shore using data obtained from the baseline research on oceanic contamination in Fujian showed that: during the res...This study on the distribution features of petroleum hydrocarbon in water and sediment off the Fujian shore using data obtained from the baseline research on oceanic contamination in Fujian showed that: during the research period, petroleum hydrocarbon concentrations in water varied from 5.77 μg/L to 37.28 μg/L, averaged 14.48 μg/L; was lower in the wet season than in the dry season; and was highest in the Minjiang Estuary and Jiulong Estuary in both seasons. The petroleum hydrocarbon concentrations in shore sediment varied from 14.48 mg/kg to 784.36 mg/kg, averaged 133.3 mg/kg, and was closely related to sediment types (granularity).展开更多
基金NSFC(No40173030, 40701164)Science and Technology Committee of Shanghai (No 04DZ19301)
文摘Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbicula fluminea activity on sediment-water exchange of dissolved inorganic nitrogen (DIN) is studied. The areas included three intertidal flat sites of the Changjiang (Yangtze) River estuary in China. The interface exchange flux of ammonium, nitrate and nitrite in the short experiment (6 h) was 46.4-40, 74.8-929.1 and 2.5-14.6 μmol/(m2·h), respectively. It was found that the burrowing activities of C. fluminea increased NH 4+ and NO 3-release from sediments to overlying water in the short-term experiment. During long-term incubation, NH +4 and NO 3-released in turn from the sediments. At the beginning of incubation, bioturbation by C. fluminea could accelerate NH +4 release from sediments 2-17 times in different sites, resulting in stronger nitrification and increased NO 3-concentrations in the overlying water. Sediment profile analysis post-incubation shows that organic matter mineralization and sediment-water NH +4 exchange had been stimulated by C. fluminea bioturbation and bioirrigation during the experiment. Therefore, C. fluminea activities such as excretion, burrowing, irrigation and turbation can effectively alter nitrogen dynamics and accelerate and stimulate nitrogen exchange and cycling at the sediment-water interface.
文摘This study on the distribution features of petroleum hydrocarbon in water and sediment off the Fujian shore using data obtained from the baseline research on oceanic contamination in Fujian showed that: during the research period, petroleum hydrocarbon concentrations in water varied from 5.77 μg/L to 37.28 μg/L, averaged 14.48 μg/L; was lower in the wet season than in the dry season; and was highest in the Minjiang Estuary and Jiulong Estuary in both seasons. The petroleum hydrocarbon concentrations in shore sediment varied from 14.48 mg/kg to 784.36 mg/kg, averaged 133.3 mg/kg, and was closely related to sediment types (granularity).
