潼湖平塘沉积物-水界面磷垂向分布及释放通量研究

Vertical distribution and release flux of phosphorus at the sediment-water interface of Tonghu Pingtang

研究了潼湖平塘10个样点沉积物磷污染空间分布,利用Peeper技术获取沉积物-水界面溶解性磷(SRP)垂向分布,并计算磷释放通量。结果发现:(1)潼湖平塘沉积物中总磷污染较严重(1.20~4.98 mg/g),西南部较高、东部较低。(2)沉积物孔隙水中SRP浓度均高于上覆水,表明沉积物是上覆水磷的潜在“源”。在垂向分布上,多数样点中磷在沉积物-水界面下0~3 cm快速增加到最大值,之后逐渐减小。(3)沉积物-水界面磷释放通量为1.33~10.96 mg/(d·m^(2)),由于水体扰动剧烈,位于出湖区域的样点(西部)磷释放通量明显高于东部和中部。对比国内其他湖库发现,潼湖平塘沉积物磷释放通量较高,沉积物内源磷释放是上覆水磷的重要来源。

The spatial distribution of phosphorus in Tonghu Pingtang sediments were studied from 10 sampling sites.The vertical distribution of soluble reactive phosphorus(SRP)at the sediment-water interface was measured by using Peeper technology,and the release flux of phosphorus was calculated.The results showed that:(1)serious pollution of total phosphorus(1.20-4.98 mg/g)in Tonghu Pingtang sediment was observed,with higher concentrations in the south-west lake area and lower in the east.(2)The concentrations of SRP in sediment interstitial water were higher than those in overlying water,indicating that sediment would be a potential source of phosphorus for overlying water.As for the vertical distribution,the concentration of SRP at most points increased rapidly to the maximum at about 0-3 cm,and then decreased gradually.(3)The release flux of phosphorus at the sediment-water interface ranged from 1.33 to 10.96 mg/(d·m^(2)).The sample points(in the west)located in the lake exit area were significantly higher than those in the east and middle due to the hydrodynamic disturbance.Compared with other lakes and reservoirs in China,the release flux of phosphorus in Tonghu Pingtang from sediment was relatively high,considering as a potential source of phosphorus to the overlying water.