Cd/Sb/Pb复合污染对竺麻生长及吸收富集特征的影响

通过盆栽试验,分析了不同浓度Cd/Sb/Pb复合作用下苎麻的生长响应及重金属吸收、富集和迁移特征变化。结果表明,低浓度Cd/Sb/Pb复合处理对苎麻生长及生物量没有产生明显影响,而高浓度条件下则产生明显抑制效应,株高变矮,茎粗变细及生物量明显减少。苎麻体内Cd、Pb和Sb吸收量与污染土壤具有直接相关性,随复合处理浓度增加明显增大。至最高污染浓度处理时,苎麻体内重金属吸收量以Cd>Sb>Pb,地上部含量分别达335.74 mg/kg、157.55 mg/kg和92.31 mg/kg。复合处理下苎麻地上部对Cd、Sb和Pb的富集系数分别在0.67~0.88、0.13~0.17和0.05~0.06之间,均表现为随复合处理浓度增加而减少变化。苎麻Cd、Sb和Pb的转运系数分别为0.81~0.92、0.38~0.46和0.53~0.73,其中Cd、Sb的转运系数随复合处理浓度增加而增大,Pb则随复合处理浓度增加而减少。苎麻对重金属Cd/Sb/Pb复合污染具有较好吸收累积及转运能力,相比生物量小的植物而言,是目前修复重金属Cd/Sb/Pb复合污染的理想植物。

Growth and Absorption Enrichment Responses of Ramie to Cd/Pb/Sb Stress

A pot experiment was done to observe the growth responses,accumulation and transfer characteristics of ramie(Boehmeria nivea) in different concentrations of Cd/Pb/Sb.Results showed that there was not significant influence on growth and biomass of ramie under low concentrations of Cd/Sb/Pb combined treatment,while had significant inhibitory effect under high concentrations,with the shorter plant height,thinning stem diameter and decreasing biomass.Cd,Pb and Sb absorption content of ramie had a direct correlation with contaminated soil,which increased significantly with the combined treatment concentration raising.To the highest pollution levels,heavy metals absorption by ramie was ranked as Cd,Sb and Pb,with their content of shoots up to 335.74 mg/kg,157.55 mg/kg and 92.31 mg/kg respectively.Bioaccumulation factor of Cd,Sb and Pb of ramie shoot was at 0.67~0.88,0.13~0.17 and 0.05~0.06 under the combined treatment,and showed changes of decrease with the combined treatment concentration increased.Transfer coefficients of Cd,Sb,Pb were 0.81~0.92,0.38~0.46 and 0.53~0.73,with Cd and Sb showing increase and Pb reducing with increasing concentration respectively.Ramie has good capacity of absorption,accumulation and transfer under Cd/Sb/Pb combined pollution.Compared to the small biomass plants,ramie is the ideal plant to repair composite pollution of heavy metals Cd/Sb/Pb.