Persistent organic pollutants(POPs) such as organochlorine pesticides are of global concern due to their widespread occurrence and persistence. This paper reports recent research studying the distribution and fate of ...Persistent organic pollutants(POPs) such as organochlorine pesticides are of global concern due to their widespread occurrence and persistence. This paper reports recent research studying the distribution and fate of organochlorine pesticides in the Jiulong River, the Minjiang River and the Pearl River estuaries in Southeast China. Eighteen organochlorine pesticides were extracted from water, pore water and sediment samples, followed by analysis by GC ECD. The results showed that the contamination levels were similar in these three estuaries. The levels of the total organochlorine pesticides in porewater were significantly higher than those in surface water, due to the high affinity of these hydrophobic compounds for sediment phase. Among the hexachlorocyclohexane(HCH) compounds, β HCH was found to be the most important isomer. The analysis of 1,1,1 trichloro 2,2 bis chlorophenyl ethane(DDT) and its metabolites showed that 1,1 dichloro 2[ o chlorophenyl] 2[ p chlorophenyl] ethylene(DDE) was dominant in the group.展开更多
The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nu...The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nutrient dynamics and fluxes under such a heavy background of anthropogenic perturbation,eight cruises were conducted from April 2008 to April 2011,covering both wet (May to September) and dry (October to April next year) seasons.Nutrient concentrations were very high for the freshwater end-member in the upper reach of the JRE (nitrate (NO 3-N):120-230 mol L-1 ;nitrite (NO 2-N):5-15 mol L-1 ;ammonium (NH 4-N):15-170 mol L-1 ;soluble reactive phosphorus (SRP):1.2-3.5 mol L-1 ;dissolved silicate (DSi):200-340 mol L-1).In dry seasons,concentrations of these nutrients were higher than in wet seasons.Nitrate was the dominant chemical species of dissolved inorganic nitrogen (DIN),with percentages of 67%-96% in wet seasons and 55%-72% in dry seasons.Distributions of NO 3-N and DSi against salinity were nearly constant during all cruises,and showed generally conservative mixing behaviors in the estuary (1<Salinity<32).The concentrations of SRP varied within a narrow range of 1.0-2.0 mol L-1 in low/middle salinity areas,and they were quickly diluted by relatively oligotrophic near-shore seawater in the high salinity region.Based on a temporally high-resolution water discharge dataset,riverine fluxes of DIN,SRP and DSi into the JRE were calculated at 34.3 10 3 t N a 1,0.63 10 3 t P a-1 and 72.7 10 3 t Si a-1,respectively.In comparison,estuarine export fluxes of DIN,SRP and DSi from the JRE to the TWS were estimated at 34.8 10 3 t N a-1,0.82 10 3 t P a-1 and 71.6 10 3 t Si a-1.The estuarine addition flux of SRP was independently estimated at 0.16 10 3 t P a-1.In comparison with major world rivers,the Jiulong River shows a very high areal yield rate of NO 3-N.In comparison with historical datasets from 1980s-1990s,concentrations of NO 3-N and SRP increased 2-3 times in upper/middle areas of the JRE,while DSi remai展开更多
文摘Persistent organic pollutants(POPs) such as organochlorine pesticides are of global concern due to their widespread occurrence and persistence. This paper reports recent research studying the distribution and fate of organochlorine pesticides in the Jiulong River, the Minjiang River and the Pearl River estuaries in Southeast China. Eighteen organochlorine pesticides were extracted from water, pore water and sediment samples, followed by analysis by GC ECD. The results showed that the contamination levels were similar in these three estuaries. The levels of the total organochlorine pesticides in porewater were significantly higher than those in surface water, due to the high affinity of these hydrophobic compounds for sediment phase. Among the hexachlorocyclohexane(HCH) compounds, β HCH was found to be the most important isomer. The analysis of 1,1,1 trichloro 2,2 bis chlorophenyl ethane(DDT) and its metabolites showed that 1,1 dichloro 2[ o chlorophenyl] 2[ p chlorophenyl] ethylene(DDE) was dominant in the group.
基金supported by the National Natural Science Founda-tion of China(NSFC)(40810069004)the National Basic Research Program of China(2009CB421204)+1 种基金Sampling cruises were partially supported by the State Oceanic Administration of China(contract DOMEP-MEA-01-10)the NSFC(40949901)
文摘The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nutrient dynamics and fluxes under such a heavy background of anthropogenic perturbation,eight cruises were conducted from April 2008 to April 2011,covering both wet (May to September) and dry (October to April next year) seasons.Nutrient concentrations were very high for the freshwater end-member in the upper reach of the JRE (nitrate (NO 3-N):120-230 mol L-1 ;nitrite (NO 2-N):5-15 mol L-1 ;ammonium (NH 4-N):15-170 mol L-1 ;soluble reactive phosphorus (SRP):1.2-3.5 mol L-1 ;dissolved silicate (DSi):200-340 mol L-1).In dry seasons,concentrations of these nutrients were higher than in wet seasons.Nitrate was the dominant chemical species of dissolved inorganic nitrogen (DIN),with percentages of 67%-96% in wet seasons and 55%-72% in dry seasons.Distributions of NO 3-N and DSi against salinity were nearly constant during all cruises,and showed generally conservative mixing behaviors in the estuary (1<Salinity<32).The concentrations of SRP varied within a narrow range of 1.0-2.0 mol L-1 in low/middle salinity areas,and they were quickly diluted by relatively oligotrophic near-shore seawater in the high salinity region.Based on a temporally high-resolution water discharge dataset,riverine fluxes of DIN,SRP and DSi into the JRE were calculated at 34.3 10 3 t N a 1,0.63 10 3 t P a-1 and 72.7 10 3 t Si a-1,respectively.In comparison,estuarine export fluxes of DIN,SRP and DSi from the JRE to the TWS were estimated at 34.8 10 3 t N a-1,0.82 10 3 t P a-1 and 71.6 10 3 t Si a-1.The estuarine addition flux of SRP was independently estimated at 0.16 10 3 t P a-1.In comparison with major world rivers,the Jiulong River shows a very high areal yield rate of NO 3-N.In comparison with historical datasets from 1980s-1990s,concentrations of NO 3-N and SRP increased 2-3 times in upper/middle areas of the JRE,while DSi remai
