4种植物对133Cs和88Sr污染土壤的修复研究

以露地盆栽的苏丹草、向日葵、芥菜、萝卜4种植物为对象,研究它们对土壤中不同浓度(0、2.5、5.0、10.0、20.0、40.0mg/kg)133Cs、88Sr的吸收积累状况,并比较它们对133Cs、88Sr污染土壤的修复效率。结果显示:(1)4种植物单株生物量在各浓度处理下均表现为向日葵>萝卜>芥菜>苏丹草,但它们对133Cs的吸收能力为萝卜>苏丹草>向日葵>芥菜,单株133Cs累积量为向日葵>萝卜>苏丹草>芥菜,单株88Sr累积量表现为萝卜、向日葵>苏丹草>芥菜,而且4种植物对88Sr的吸收能力均强于133Cs。(2)萝卜在除10.0mg/kg133Cs外的各处理中富集系数均大于1,对土壤中133Cs的吸收能力较强;苏丹草在除5.0mg/kg133Cs处理外的转运系数均大于1,其余3种植物在各处理中的转运系数均低于1;88Sr在萝卜体内从根系向上转运到地上部分的能力明显高于其它3种植物,芥菜、向日葵次之。(3)4种植物对88Sr在体内向上的迁移转运能力均大于133Cs。研究表明,向日葵单株对133Cs、88Sr污染土壤的修复效率最高,萝卜次之,且向日葵和萝卜分别因其生物量和吸收能力优势而对被污染土壤中的133Cs和88Sr具有更强的提取能力。

Phytoremediation of Four Plant Species in 133Cs and 88Sr Contaminated Soil

The absorption and accumulation of 133Cs and 88Sr in four plant species,such as Sudan grass(Sorghum sudanense),sunflower(Helianthus annuus),radish(Raphanus sativus L.) and leaf mustard(Brassica juncea) in different 133Cs and 88Sr concentration contaminated soils(0,2.5,5.0,10.0,20.0,40.0 mg/kg)was studied and their phytoremediation efficiency was compared.The result showed that:(1)The biomass order of the individual plant in different 133Cs and 88Sr concentration contaminated soil ranked as:sunflower>radish>leaf mustard>Sudan grass,the order of 133Cs absorption capacity of the root from the soils:radish>Sudan grass>sunflower>leaf mustard,the total concentration of 133Cs and 88Sr individual plant ranked:sunflower>radish>Sudan grass>leaf mustard and radish,sunflower>Sudan grass>leaf mustard,respectively.Four plant species revealed stronger 88Sr absorption capacities than that of 133Cs.(2)The bioaccumulation factor(BCF) of radish was greater than 1 in different treatments except in the 10.0 mg/kg 133Cs treatment and it performed stronger 133Cs bioaccumulation ability.The translocation factors(TF) of four plant species in different treatments were less than 1 except in the 5.0 mg/kg 133Cs treatment.The translocation ability of 88Sr from the roots up to the upper ground part of the radish was relatively higher than that of other three species.Leaf mustard and sunflower ranked the second.(3)The translocation ability of 88Sr from the roots up to the upper ground part of the plants was stronger than that of 133Cs in four plant species.The result revealed that the plant species of the highest phytoremediation efficiency was sunflower and the second radish.They had stronger phytoextraction ability from 133Cs and 88Sr contaminated soil because of their advantages in the highest individual plant biomass of sunflower and the more 133Cs and 88Sr uptake capacity of radish,respectively.