河口滨岸潮滩沉积物-水界面N、P的扩散通量

Nitrogen and phosphorus diffusion fluxes across sediment-water interface in estuarine and coastal tidal flats

选择了长江河口及上海滨岸作为研究对象 ,分析了潮滩上覆水、沉积物孔隙水中营养物质N、P的含量 ,并初步估算了潮滩沉积物 水界面间N、P的扩散通量。上覆水中NH4 + N含量分布在 0 .0 0 82～ 2 .5 6mg/L ,NO2 - N为 0 .0 3～ 0 .5 8mg/L ,NO3- N为 0 .6 9～ 5 .38mg/L之间 ,溶解态磷 (DP)的含量为 0 .0 35～ 0 .5 3mg/L之间 ;表层沉积物孔隙水中NH4 + N的含量为 0 .0 0 2 5～ 1.35mg/L ,NO2 - N的含量为 0 .0 0 5 5～ 0 .2 0mg/L ,NO3- N的含量为 0 .6 1～ 1.14mg/L ,DP的含量为 0 .11～ 0 .5 3mg/L ;计算表明 ,沉积物 水界面间NH4 + N、NO2 - N、NO3- N和DP的扩散通量分布范围分别在 - 0 .0 2 4～ 0 .99、- 0 .39～ 0 .0 0 19、- 3 .0 9～ - 0 .12和 - 0 .48～ 0 .12 μg/ (cm2 ·d)之间。研究揭示 。

Nitrogen and phosphorus contents were analyzed in the overlying waters and pore waters taken from the Changjiang Estuary and Shanghai coast tidal flats in this study. In addition, the diffusion fluxes of nitrogen and phosphorus across sediment water interface in tidal flats were estimated according to the nutrient concentration gradients at the interface. It has been indicated that the concentrtions of ammonium, nitrite, nitrate and dissolved phosphorus in overlying waters ranged from 0.008 2～2.56,0.03～ 0.58, 0.69～5.38 and 0.035～0.53 mg/L, respectively, while 0.002 5～1.35 mg/L for NH 4 + N, 0.005 5～0.20 mg/L for NO 2 - N, 0.61～1.14 mg/L for NO 3 - N and 0.11～0.53 mg/L for DP in surface pore waters. The findings have revealed that ammonium, nitrite, nitrate and dissolved phosphorus diffusion fluxes across sediment water interface were from -0.024～0.99?-0.39～-0.001 9?-3.09～-0.12 and -0.48～0.12 μg/(cm 2·d) respectively, and that the sediment in tidal flats was the source of phosphorus and an important sink for nitrogen in the waters.