贵州牛角塘铅锌矿区优势植物的重金属富集特征

Heavy metal enrichment of dominant plants in Niujiaotang mining area of Guizhou Province

关键词:  牛角塘铅锌矿区, 富集植物, 矿区复垦, 根部囤积型植物, 规避型植物

Key words:  Niujiaotang lead-zinc mining area, enrichment, heavy metal, root-hoarding plant, evading plant

摘要:

为筛选适合贵州喀斯特地区重金属污染土壤修复治理以及矿区生态复垦的植物材料,该研究在贵州牛角塘铅锌矿区采集30种优势植物及其根系土壤,测定其地上部、地下部和根系土壤的Cd、Cu、Ni、Pb、Zn含量,计算植物对重金属的富集和转运系数,并通过聚类分析综合评估植物的应用潜力。结果表明:(1)千里光、鬼针草地上部Cd含量高达40.33、43.26 mg·kg^-1,富集系数(地上部分)分别为0.20和0.37,转运系数分别为1.35和1.16,有较强富集Cd的能力,对Cd污染土壤有一定的修复潜力。(2)头花蓼地上部Cd、Zn含量分别为77.49、3 557.96 mg·kg^-1,均为本次调查30种植物中的最大值,是一种修复Cd、Zn复合污染土壤的潜在植物材料。(3)醉鱼草地上部Ni含量为0.62 mg·kg^-1,富集系数(地上部分)和转运系数高达6.16和1.37,醉鱼草是否是Ni的一种富集植物,还需进一步研究加以验证。(4)紫茉莉、节节草根部Cd、Cu、Pb和Zn含量远大于地上部,属于根部囤积型植物; 河北木蓝地上部、地下部Cd、Cu和Zn等重金属含量都较低,属于规避型植物。因此,千里光、鬼针草和头花蓼可用于修复土壤重金属污染,紫茉莉、节节草、河北木蓝可用于矿区复垦。

Abstract:

To select suitable materials for remediation of heavy metal pollution in karst areas of Guizhou Province and ecological reclamation of mining area. A total of 30 dominant plants and their root soils were collected in Niujiaotang lead-zinc mining area of Guizhou Province for testing of the contents of Cd, Cu, Ni, Pb and Zn in aboveground, underground and root soils. The enrichment and transport coefficients of heavy metals by plants were calculated, and the application potential of plants was comprehensively evaluated by cluster analysis. The results were as follows:(1)Cd contents in the aerial part of Senecio scandens and Bidens Pilosa were respetively 40.33 mg·kg^-1and 43.26 mg·kg^-1, the enrichment coefficients(aboveground part)were respectively 0.20 and 0.37, and the transport coefficients were respectively 1.35 and 1.16, and they had strong ability to enrich Cd and had certain remediation potential for Cd contaminated soil.(2)The contents of Cd and Zn in aboveground of Polygonum capitatum were 77.49 mg·kg^-1 and 3 557.96 mg·kg^-1 respectively, which were the maximum values among the 30 plants investigated in this survey. It is a potential plant material for remediation of Cd and Zn contaminated soil.(3)The content of Ni in aboveground of Buddleja lindleyana was 0.62 mg·kg^-1, and the enrichment coefficient(aerial part)and transport coefficient were 6.16 and 1.37 respectively. However, a further study need to be done to test whether the plant for Ni enrichment.(4)The contents of Cd, Cu, Pb and Zn in the roots of Mirabilis jalapa and Equisetum ramosissimum were much higher than those in aboveground, which were root-hoarding plants. The contents of Cd, Cu, Zn and other heavy metals in aboveground and underground parts of Indigofera bungeana were relatively low, which belonged to evading plant. Therefore, Senecio scandens, Bidens pilosa, and Polygonum capitatum can be used to remediate heavy metal pollution in soil, and Mirabilis jalapa, Equisetum ramosissimum, and Indigofera bungeana can be used for reclamation of mining area.