湖南下水湾铅锌尾矿库优势植物重金属含量及富集特征

矿区废弃地优势植物调查与筛选是植物修复研究的重点.通过研究湖南下水湾铅锌尾矿库区土壤重金属含量,以及库区优势植物对Pb、Zn、Cd、Mn、Cu等重金属的富集能力与转移特征,筛选出适应该地区生态修复的先锋植物.结果表明,库区发现高等植物40种,40属22科,并筛选出15种优势植物.其中地枇杷地上部分Pb含量为正常含量上限值的4.01倍,转运系数达到3.91,富集系数达到14.4,可见地枇杷对Pb具有很强的转运能力与富集能力,因此地枇杷对库区污染土壤修复具有巨大潜力,需对其Pb富集能力作进一步研究.除地枇杷外,其余14种优势植物对尾矿库区重金属污染有较好的耐性,可作为下水湾尾矿库区生态修复的先锋植物.

Heavy Metal Contents and Enrichment Characteristics of Dominant Plants in a Lead-Zinc Tailings in Xiashuiwan of Hunan Province

The key of phytoremediation was researches and selecting of dominant species in the lead-zinc tailings. This assay analyzed the amount of heavy metals, and the enrichment and transporting features of heavy metals, such as Pb,Zn,Cu,Cd and Mn, in the dominant species in the district, and then we can select the pioneer plants for ecosystem restoration of the area. Results showed that there were 40 species of higher plants, which belonged to 40 chasses and 22 families in the area. And we selected 15 dominant species by heavy metals. Among these dominant species, the content of Pb in Ficus tikoua was 4.01 times higher than that in other plants, the transfer factor(TF) was 3.91, and bioaccumulation factor(BCF) was 14.4. The capability of TF and BCF of Ficus tikoua was high, so Ficus tikoua had potentials in phytoremediation of heavy metals in polluted area and its enrichment capability of Pb was worth for the further research. Apart from Ficus tikoua,other 14 kinds of dominant plants had a better tolerance in metal pollution in tailings,and they can be used as pioneer plants of ecological rehabilitation in lead-zinc tailings in Xiashuiwan.