摘要
香根草是一种能在极端环境中生长的草本植物。对安徽铜陵冬瓜山铜矿水木冲尾矿库生态修复植物香根草及其根际尾矿砂中重金属Cu、Zn、Mo和Cd进行了赋存形态分析。香根草根际尾矿砂中四种元素形态绝大部分是残渣态,但Cu和Cd的有效态含量远高于香根草正常生长所需,是主要胁迫元素。香根草的生物富集系数(BCF)和转运系数(TF)均小于1,表明它严格限制这四种重金属元素在根-茎叶中的迁移。乙醇提取态和去离子水提取态是植物体中活性较高的重金属形态。香根草地下部分Cu、Zn、Mo和Cd的乙醇提取态和去离子水提取态之和占各形态总和的比例分别为10%、23%、51%和16%;地上部分相应的比例为24%、26%、47%和12%。不同重金属元素表现出不同形态分布特征,这与香根草对它们的吸收和转运方式有关。香根草根际尾矿砂及其体内重金属形态决定了它对重金属的耐受性,表明香根草是有色金属矿山尾矿库理想的生态修复植物。
Vetiver （Vetiveria zizanioides （L.） Nash） is a specific herbaceous plant that can grow in extreme environment. The vetiver grass planted in Shuimuchong mine tailings of Dongguashan Copper Mine in Tongling City, Anhui Province was selected to study the geochemical fractions of heavy metals Cu, Zn, Mo and Cd in the vetiver and its rhizosphereic tailings. The major fraction of these four metals in the rhizospheric tailings was the residual fraction. With respect to the high total concentrations of Cu and Cd, their bioavailable concentrations were far above the amounts necessary for vetiver growth, and presented as the primary threatening metals. Both bioconcentration factors and translocation factors of vetiver were less than one, which sug- gested that the four metals were limited strictly from root to stem. Ethanol- and water-extractable heavy metals have higher toxicity in plants. The proportion of ethanol- and water-extractable Cu, Zn, Mo and Cd in the underground part of vetiver were 10%, 23%, 51%and 16%, respectively, whereas the aboveground part were 24%,26%,47%,12%, respectively. Different heavy metals show various distributions of geochemical fractions, which were related to their specific absorption and transportation by vetiveria. The geochemical fractions of heavy metals in vetiver and its rhizospheric tailings constrained its tolerance to heavy metals, which proved that vetiver is an ideal plant used for mine site restoration.
出处
《地球与环境》
CAS
CSCD
北大核心
2010年第3期280-285,共6页
Earth and Environment
基金
国家科技支撑计划项目(2006BAC09B04)
国家重点基础研究发展计划(2009CB426307)
关键词
香根草
尾矿砂
重金属
形态
vetiver
tailings
heavy metals
geochemical fractions
