白洋淀表层沉积物氮磷分布、储量及污染评价

Distribution,reserves and pollution evaluation of nitrogen and phosphorus in surface sediments of Baiyangdian Lake

白洋淀是雄安新区核心生态功能区,为查明白洋淀表层沉积物氮磷分布特征、储量及污染程度,系统开展了氮磷营养盐调查及污染评价。结果表明:白洋淀底泥层总氮含量为528.5~10566.5 mg/kg,均值为2859.91 mg/kg,总磷含量为425.7~2446.0 mg/kg,均值为789.22 mg/kg;过渡层总氮含量为318.5~4662.0 mg/kg,均值为1706.7 mg/kg,总磷含量为315.05~976.30 mg/kg,均值为598.97 mg/kg;表层沉积物总氮总储量为15.86×10^(4)t,其中底泥层总氮储量为3.76×10^(4)t,过渡层总氮储量为12.10×10^(4)t;总磷总储量为5.54×10^(4)t,其中底泥层总磷储量为1.02×10^(4)t,过渡层总磷储量为4.52×10^(4)t。根据综合污染指数法评价结果,白洋淀湿地底泥层氮磷污染程度均为重度,过渡层除烧车淀为重度外,其余各淀泊均为中度或轻度。

Baiyangdian Lake is the main ecological function area of Xiong'an New Area.In order to find out the distribution characteristics of nitrogen and phosphorus in the surface sediments of Baiyangdian Lake and evaluate the pollution degree of nitrogen and phosphorus,we carried out the investigation and pollution assessment of nitrogen and phosphorus in Baiyangdian Lake.The results indicate that the total nitrogen(TN)content of sludge layer of surface sediments are 528.5~10566.5 mg/kg,and the average is 2859.91 mg/kg.The total phosphorus(TP)content of sludge layer is 425.7~2446.0 mg/kg,and the average is 789.22 mg/kg.The TN content of transition layer is 318.5~4662.0 mg/kg,and the average is 1706.7 mg/kg.The TP content of transition layer is 315.05~976.30 mg/kg,and the average is 598.97 mg/kg.The total TN reserves of surface sediments are 15.86×10^(4)t,among which the TN reserves of sludge layer are 3.76×10^(4)t and the TN reserves of transition layer are 12.10×10^(4)t.The total TP reserves of surface sediments are 5.54×10^(4)t,among which the TP reserves of sludge layer are 1.02×10^(4)t and that of transition layer are 4.52×10^(4)t.According to the evaluation result of comprehensive pollution index method,the sludge layer of surface sediments in Baiyangdian Lake have been heavily polluted.As for the transition layer,except Shaoche Lake,which is severely polluted,the other lakes are all moderately polluted or slightly polluted.