辽宁兴城松北铅锌矿化区土壤-植物系统中重金属分布和迁移特征

Distribution and Migration Characteristics of Heavy Metals in Soil-plant System in Songbei Pb-Zn Mining Area,Xingcheng,Liaoning Province

研究辽宁兴城松北铅锌矿化区玉米和艾草两种植物及其根系土壤系统中Cu、Mn、Pb、Zn和Ni的分布、富集和迁移特征,并采用单因子污染指数法、内梅罗指数法、生物富集系数法和迁移系数法对该地区的重金属污染、富集和迁移情况做出了评价。结果表明,该地区土壤受到了Cu和Zn两种重金属污染。重金属在植物的各个器官中分布不均匀,Cu在两种植物的叶片中富集明显,其他重金属在两种植物各器官中的富集均不明显。两种植物对重金属的迁移特征相差较大,玉米中重金属的迁移能力为Cu>Mn>Zn>Pb>Ni,其中Cu的迁移能力最强,迁移系数达到了2.8,Mn的迁移系数都在1左右,Zn、Pb和Ni的迁移系数均小于1。艾草中各重金属的迁移系数较为接近,均为2左右,其中Pb的迁移能力最强,迁移系数达到了2.5,Ni的迁移系数最小,为1.9。虽然艾草对土壤重金属具有一定的迁移能力,但其对重金属的富集能力相对较弱,与玉米相近,因此推断两种植物对研究区土壤重金属污染无明显改善作用。

To understand pollution/remediation in soil of Songbei Pb-Zn mining area,the distribution,enrichment,and migration of Cu,Mn,Pb,Zn,and Ni in soil-plant systems of corn and wormwood in Songbei Pb-Zn mining area,Xingcheng,Liaoning,NE China were investigated.The single-factor pollution index,Nemerow index,bioconcentration factor,and transfer factor were employed to evaluate the heavy metal pollution,enrichment,and migration in this area.The results show that soil in this area was contaminated by Cu and Zn.Heavy metals distributed unevenly among different plant organs.Cu was enriched in leaves of the two plants,and the enrichment of other heavy metals was not obvious.On the other hand,migration of heavy metals in the two plants was very different.The transfer ability of heavy metals in the corns was Cu>Mn>Zn>Pb>Ni.Among them,Cu had the largest transfer factor of 2.8,that of Mn about 1,and those of Zn,Pb,and Ni below 1.In the wormwood,the transfer factors of all the heavy metals were close to 2,and the largest one was 2.5 for Pb,and the smallest one was 1.9 for Ni.Therefore,although wormwood has a certain ability to transport heavy metals in soil,its ability of absorbing heavy metals was relatively weak,which is similar to that of corn.It was shown that the two plants could not be able to remediate soil from heavy metal pollution in the study area remarkably.