白洋淀铁锰的分布水平及迁移特征

为确定白洋淀的铁锰分布水平,在白洋淀国控点采集上覆水和沉积物进行监测分析,并通过潜在迁移指数评价了铁锰的潜在风险。结果表明:白洋淀上覆水中铁锰含量平均值分别为0.10mg/L、0.41mg/L,其中铁能够达到地表水水质标准,锰超标。沉积物中铁含量平均值为2.49mg/kg;锰含量在府河入淀口南刘庄浓度达到2260mg/kg,明显高于其他采样点,其余几个采样点的平均值为95mg/kg。铁的存在形态浓度从大到小依次为:残渣态酸溶态可还原态可氧化态;锰的存在形态浓度顺序为:酸溶态残渣态可还原态可氧化态。沉积物中铁、锰的潜在迁移指数平均值分别为46.95%、62.23%。说明锰的潜在迁移可能性大于铁,更易形成二次污染。

The Distribution and Transference Characteristics of Iron and Manganese in Lake Baiyangdian

The total content and species of iron and manganese in Lake Baiyangdian were investigated in this paper. Overlying water and sediment samples were collected and determined. Potential migration indices (PMI) were calculated to show the potential risk. The determined results showed that the average contents of iron and manganese in the overlying water were 0.10 and 0.41 mg/L, respectively. The content of manganese in the overlying water exceeded the national water quality standard. The average content of iron in the sediments was 2.49 mg/kg. The highest content of manganese in Nanliuzhuang reached 2260 mg/kg, while the average content in the other sites was 95 mg/kg. The results of speciation analysis of iron in the sediments gave the following order:residual fraction > acid soluble fraction > reducible fraction > oxidable fraction. Manganese species were in the following order:acid soluble fraction > residual fraction > reducible fraction > oxidable fraction. The average PMI values of iron and manganese in the sediments were 46.95% and 62.23%, respectively, suggesting manganese was easier to transfer from sediments to overlying water.