3种能源草在铅锌矿区土壤中的生长及其对重金属的富集特性

The Growth of Three Kinds of Energy Grass in Lead-Zinc Mining Area and Their Bioaccumulation Characteristics of Heavy Metals

采用土壤盆栽试验,研究紫色皇竹草、甜象草、柳枝稷3种能源草在铅锌矿区原状重金属污染土壤中的生长及其对Pb、Zn、Cd、Cu的吸收累积特性。结果表明,3种能源草在铅锌矿区重金属污染土壤中生长正常,外观均未表现出明显的受毒害症状,具有良好的适应性。在3种能源草中的重金属含量分别为Pb130.74~1 135.11mg/kg,Zn 88.51~269.07mg/kg,Cd 2.87~8.07mg/kg,Cu 6.64~55.45mg/kg。以转运系数（TF）和富集系数（BF）讨论3种能源草对重金属的转运富集能力,发现不同植物对不同重金属的TF和BF有较大差异。除柳枝稷对Zn的TF值为2.622,甜象草对Cd的BF值为1.021 4外,能源草对重金属的其余TF和BF值均小于1.0。根据植株的生长状况、重金属含量、富集能力和转运能力,说明3种能源草均能在铅锌矿区重金属复合污染土壤中正常生长,并可用于以Pb为主的重金属复合污染土壤的修复。

Pot experiments were carried out to investigate the influences of heavy metal stress on the growth of Pennisetum hydridum,Pennisetum purpureumand Panicum virgatumand the plants’ bioaccumulation of Pb,Zn,Cd and Cu in lead-zinc mine soil.The results showed that all of three energy grass could grow normally,and no apparent injuries could be observed.Three kinds of energy grass showed good tolerance to heavy metals.The content of Pb,Zn,Cd and Cu in different energy grass was 130.74~1 135.11mg/kg,88.51~269.07mg/kg,2.87~8.07mg/kg and 6.64~55.45mg/kg,respectively.Transport coefficient（TF）and enrichment coefficient（BF）were applied to estimate the plants’ bioaccumulation,and they were quite different for different heavy metals and for different energy grass.Except the TF value of Zn for Panicum virgatum（2.622）and the BF value of Cd for Pennisetum purpureum（1.021 4）,the rest of TF and BF values were less than 1.According to the growth conditions,content of heavy metals and TF and BF values,all the energy grass could grow normally in lead-zinc mining area and could be used to remediate Pb-based heavy metal contaminated soil.