重金属污染河流生态修复区挺水植物对重金属的吸收特性

为了分析比较滇东南选矿区重金属污染河流——小白河生态修复区所种植芦苇和香蒲对重金属的吸收及生态修复效果差异，于2015年4月在小白河西岸野生植物区及东岸生态修复区采集土壤及植物样品，对样品进行烘干、消解，使用电感耦合等离子体发射光谱法测定样品中铅（Pb）、锌（Zn）、铬（Cr）和镍（Ni）这4种重金属的含量，使用原子荧光光谱法测定样品中砷（As）的含量.结果表明:①小白河东岸生态修复区湿地底泥中As和Zn污染最为严重，但东岸底泥中各重金属含量已明显低于西岸，其中芦苇种植区底泥中w（As）和w（Ni）较西岸分别降低了38.82%和50.53%，香蒲种植区底泥中w（As）和w（Ni）较西岸分别降低了13.54%和21.95%.②芦苇对As、Pb、Zn和Pb、Cr以及Cr、Ni这3组重金属的吸收存在显著的协同作用，香蒲对重金属吸收的协同作用表现在As、Zn、Ni和Pb、Cr这2组重金属中，这种重金属吸收协同作用在芦苇中更明显.③芦苇对Cr的生物富集系数（BCF）较高，对Cr的转运系数（TF）为0.80，属于富集型耐受策略，芦苇对Zn和Ni属于根部囤积型耐受策略；香蒲对Pb、Zn、Ni、Cr这4种重金属的BCF较大，TF均接近1，属于富集型耐受策略，对As属于根部囤积型耐受策略.研究显示，芦苇可作为重金属污染河流生态修复区的先锋植物，香蒲的重金属生物富集效率较高，将重金属富集于地上部的能力较强，可考虑将植物分区种植的模式改为间作种植，并定期收割香蒲地上部，以使生态修复区具有更好的重金属修复效果. 

Absorption Characteristics of Heavy Metals by Emergent Plants from Polluted River in Ecological Restoration Areas

In order to analyze and compare the differences in heavy metal absorption and ecological restoration between Phragmites australis (the reed) and Typha angustifolia L. (the typha) in the Xiaobai River ecological restoration area, a river polluted by heavy metals in the mining area of Southeast Yunnan, we collected soil and plant samples on the west bank (wild plant area) and the east bank (ecological restoration area). The lead (Pb), zinc (Zn), chromium (Cr), nickel (Ni) in the soil and plant samples were analyzed by ICP-OES, and arsenic (As) was analyzed by AFS. The results showed that: (1) The w(As) and w(Ni) contents in the sediments of the reed planting area on the east bank were 38.82% and 50.53% lower than those in the west bank, while the contents of w(As) and w(Ni) in the sediment of the typha area were 13.54% and 21.95% lower than those in the west bank, and the wetland sediment in the ecological restoration area was seriously polluted by As and Zn. (2) There was a synergetic relationship among the enrichment of heavy metals by plants. This characteristics manifested among As-Pb-Zn, Pb-Cr and Cr-Ni in the reed, and in typha this characteristic was shown among As-Zn-Ni and Pb-Cr, being more pronounced in the reed than the typha. (3) The higher bioenrichment factor (BCF) of Cr and the transfer factor (TF) in the reed indicated that the characteristics of enrichment tolerance, while the tolerance strategy for Zn and Ni was root hoarding in reed. The results in the typha showed that higher BCF and the TF (about 1 ) in Pb, Zn, Ni and Cr, showing the characteristics of enrichment and tolerance, and the tolerance model for As was root hoarding. Based on our data, it could concluded that reed with large biomass and high coverage can be used as the pioneer plant in river ecological restoration area polluted by heavy metals. Moreover, the typha shows a high bioaccumulation factor and a strong ability to bioaccumulate heavy metals in the upper part of the ground, and therefore could be considered to change the planting mode of the two plants into intercropping, and harvest the upper part of typha regularly, in order to seek a better effect of heavy metals restoration in the ecological restoration area.