中国南方某铀尾矿库周缘土壤重金属污染研究

选择中国南方某铀尾矿库周边2条背景剖面（B1、B2）和3条潜在污染剖面土壤剖面（S1、S2、S3），通过比较各剖面中重金属元素分布，讨论铀尾矿库土壤中外源重金属元素的污染特征、迁移行为.研究表明：（1）相较于背景剖面，邻近铀尾矿库周缘土壤主、微量组分呈显著外源输入特征.（2）应用主成分法分析铀尾矿库周缘土壤外源重金属元素来源，发现尾矿库是该地区土壤重金属污染的直接来源，并向周缘土壤输送As、Pb、Sb、Cd、U等重金属污染元素.（3）分析铀尾矿库周缘土壤中尾矿库源重金属元素（As、Pb、Sb、Cd、U）同主、微量组分与理化参数的关系，发现潜在污染土壤中各金属元素与LOI（烧失量）、K、P呈较密切相关，与Na、Ca、Mn、pH、Fe存在次等相关性；由重金属淋溶迁移程度可知，重金属在潜在污染剖面（S1、S2）呈显著富集特征；各重金属横向迁出特征表明，其迁移至铀尾矿库周缘土壤具有不同的迁移方式.（4）铀尾矿库周缘近源土壤（距尾矿库30m左右）As、Pb、Sb、Cd、U呈显著污染，含量远大于国家农用地土壤环境质量评价标准和所在省份土壤元素背景值，应对该尾矿库潜在风险进行及时管控.

Heavy metal pollution in a uranium mining and metallurgy area in South China

Two background profiles (B1, B2) and three potentially polluted profiles (S1, S2, S3) around a uranium tailings pond in South China were selected. The characteristics and behaviors of exogenous heavy metal pollution in the soil of uranium tailings pond were discussed by comparing the distributions of heavy metal elements in each profile. Results showed that:(1) Compared with the background profile, the main and minor components in the soil adjacent to the uranium tailings reservoir were significantly input. (2) The tailings pond was the direct source of soil heavy metal pollution in the area, and the heavy metals such as As, Pb, Sb, Cd and U were transported to the peripheral soil, as shown in PCA. (3) The metal elements in potential polluted soil were closely related to LOI (loss on ignition), K and P, and have secondary correlation with Na, CA, Mn, pH and Fe. Heavy metals were significantly enriched in potential polluted profile (S1 and S2) according to the leaching and migration degree of heavy metals. From the tailings pond to its surrounding soil, the lateral migration characteristics of the heavy metals were different. (4) The potential risks of the tailings pond should be controlled because from tailings pond to its surrounding soil 30m, As, Pb, Sb, Cd and U were significantly polluted, and their contents exceed much larger than the agricultural land soil pollution risk control standards and the background value of the soil elements specified in the provincial level.