不同土壤生境下斑茅对重金属的富集特征

为了筛选Cu、Zn、Pb、Cd多重金属离子的富集植物,对不同土壤生境(铜铁矿、钨矿、铅锌矿和无矿场污染)的优势种斑茅(Saccharum arundinaceum(Retz.)Jeswiet)对Cu、Zn、Pb、Cd离子富集情况进行了调查。结果表明,斑茅对Cu、Zn、Pb、Cd离子有富集优势并以Cu富集显著,斑茅根系土壤与斑茅地上部Cu含量存在相关性(P<0.05),斑茅对Pb和Cd的富集与转运存在极显相关性(P<0.01);在强酸、多金属污染弃耕农田土壤中,斑茅不仅符合Cu超富集植物的特征,而且其对Zn、Pb和Cd3种重金属的富集系数和转运系数均>1。在Cd、Cu、Pb和Zn均低于国家土壤环境质量二级标准(GB15618-1995)的弃耕农田中,斑茅对Cu、Zn和Cd的富集系数均>1。研究表明,斑茅可以作为Cu、Zn、Pb、Cd多金属污染土壤的富集植物进行人工修复。

Enrichment of heavy metals in Saccharum arundinaceum ( Retz.) Jeswiet in different soil habitats

Metal ores mining and processing have caused serious pollution of different environmental compartments,and the soil heavy metal contamination around mining areas is of great concern because of its potential health risk to the local inhabitants.In order to screen the phytoaccumulators of heavy metals,an investigation was conducted on the enrichment of heavy metals(Cu,Zn,Pb and Cd) by the dominant species Saccharum arundinaceum(Retz.) Jeswiet growing on the different soil habitats in the vicinity of Dabaoshan copper ore mine,Ruyuan tungsten mine,and Renhua lead and zinc mine in Guangdong Province of South China,taking the Ruyuan non-polluted site as the control.By means of field sampling and chemical analysis,the concentrations of Cu,Zn,Pb and Cd in S.arundinaceum and soil were determined.The results showed that S.arundinaceum had the advantages in accumulating Cu,Zn,Pb and Cd,especially Cu.There was a significant correlation between the Cu concentrations in the sampling soils and sampling S.arundinaceum shoots(P<0.05),and between the enrichment and transportation of Pb and Cd by S.arundinaceum(P<0.01).In strong acidic and multi-metals contaminated soil environment,S.arundinaceum was featured with high enrichment capacity,which reflected the characteristics of S.arundinaceum as a Cu hyperaccumulator,and the enrichment factor and transport coefficients of Zn,Pb and Cd were greater than 1.For the S.arundinaceum growing on the abandoned farmland in which the concentrations of soil Cd,Cu,Pb and Zn were below the National Soil Environmental Quality Standards of Grade Ⅱ(GB 15618-1995),the enrichment factor of Cu,Zn and Cd was all greater than 1.This study showed that S.arundinaceum could be used as one of remediation plants for the abandoned farmlands contaminated by multi-metals Cu,Zn,Pb,and Cd.