某铀尾矿区植物组成及其对铀的积累作用研究

分析研究了某铀尾矿区植物资源，并对这些植物的铀积累作用进行了研究。结果显示，该尾矿区污染土壤上植物群落较简单，共有高等植物31种，隶属12科，其中：禾本科最多，12种；其次是菊科植物，5种；凤尾蕨科和莎草科植物各3种；其他科各1种。1年生或多年生草本植物有28种，占总数的90.3%，其他3种为灌木或小乔木。对这31种植物进行了铀含量测定，结果发现，铀富集量在200 mg/kg以上的植物有14种，占总数的45%，其中富集量在600 mg/kg以上的有3种，分别是水莎草、牧草、小飞蓬。植物体内铀迁移系数大于1的有9种，其中燕麦、牧草、鼠曲草、青蒿中铀的迁移系数较大。这31种植物中，可考虑将水莎草、牧草作为超富集植物应用于铀污染土壤的修复，小飞蓬、盐肤木、枸骨、燕麦、鼠曲草、碎米莎草、龙葵等对铀污染土壤的修复具有潜在应用价值，可进一步研究。

Plant Composition in Certain Uranium Tailings Area in China and Their Accumulation on Uranium

In this study, the plant resources and their accumulation of uranium element were analyzed in certain uranium tailings area, in China. The results show that the plant community are relatively simple in the soils polluted by uranium tailings, in which there are only 31 species of higher plants, belonging to 12 families, including 12 species of gramineae plants, 5 species of compositae plants, 3 species of pteridaceae plants, 3 species of cyperaceae plants, and 1 specie in every other family. There are 28 species of annual or perennial herbs, accounting for 90.3%, and 3 species of shrubs or small trees in this flora. The uranium contents in these 31 plants were also determined. Uranium contents in 14 species of plants, accounting for 45%, are above 200 mg/kg. Of note, uranium content is more than 600 mg/kg in 3 species of plants, which are the water sedge, phleum alpinum and conyza canadensis, respectively. The TF of uranium is more than 1 in 9 species of plants, among which the TF of uranium of toats, phleum alpinum, gnaphalium and southernwood is higher than that of the others. In these 31 species, water sedge and phleum alpinum can be used as hyperaccumulating plants in phytoremediation of uranium contaminated soils. The conyza canadensis, rhus chinensis, ilex cornuta, oats, gnaphalium, cyperus iria, and solanum nigrum, as the potential plant species for phytoremediation of uranium contamination in soils, are necessary for the further study.