三明铅锌矿区植物对重金属的富集特征

采用野外调查与室内分析相结合的方法,对福建三明典型矿区尤溪铅锌矿、大田铅锌矿以及尤溪铅锌矿冶炼厂等进行了调查,研究这些矿区重金属含量较高的区域如采矿区、尾砂库、洗矿排水沟以及铅锌矿冶炼厂厂区和排水沟冲积扇区域土壤中的Pb、Zn和Cd的含量,在此基础上,对在这些区域自然定居的16种优势植物体内的三种重金属元素的耐性、富集特性进行了分析。结果表明:该矿区的主要优势物种为禾本科和菊科植物,其中笔管草(Equisetum ramosissimum)、一年蓬(Erigeron annuus)和五节芒(Miscanthus floridulus)的地上部重金属富集量较大,对矿区周边污染土壤修复有潜在应用价值;乌蕨(Stenoloma chusana)、千金子(Bochloe dactyloides)、二歧飘拂草(Fimbristylis dichotoma)、柔枝莠竹(Microctegium Vimineum)、短叶水蜈蚣(Kyllinga brevifolia)、狗娃花(Heteropappus hispidus)适用于污染程度较高且植物萃取技术难以实施的重金属污染矿业废弃地。矿区植物地上部Zn含量平均值最高,为1225.74mg·kg-1,植物地上部Pb含量范围在52.78～2137.11mg·kg-1,平均为521.39mg·kg-1;一年蓬地上部Cd含量达到了119.51mg·kg-1,超过了超富集植物的临界值100mg·kg-1,转运系数为1.3,是潜在的Cd超富集植物。

Heavy metal enrichment of plants at lead-zinc mines in south China

A field investigation was carried out on the heavy metal concentrations of soils and plants growing in the tailing dumps and smelter areas of the Sanming lead-zinc mines. The concentration of Cd, Pb and Zn in roots and shoots of 16 dominant species were analyzed. The dominant species were Gramineae and Compositae on the investigated field. The concentration of heavy metal in Equisetum ramosissimum, Miscanthus floridulus, Erigeron annuus (Linn.)Pers. were much higher than those of other plant species The mean concentration of Zn in shoots reached 1 225.7 mg·kg~(-1), and the Pb concentration in shoots was from 52.78 mg·kg~(-1) to 2 137.1 mg·kg~(-1), and the mean value was 521.4 mg·kg~(-1). The Cd concentration in shoots orE. annuus reached 119.51 mg·kg~(-1), and the transfer coefficient was 1.3, which exceeded the threshold of Cd hyperaccumulator. The investigation results indicated that E. ramosissimum, M. floridulus ,E. annuus could be applied for phytoextraction technique, and Stenoloma chusana, Bochloe dactyloides, Fimbristylis dichotoma, Microctegium Vimineum, Kyllinga brevifolia, Heteropappus hispidus for phytostablization technology.