雀稗-博落回间作强化修复铀污染土壤的研究

采用铀富集植物博落回与雀稗进行间作,开展了强化修复铀污染土壤的试验,对各植物富集铀的性能以及根际土壤中可交换态铀的浓度、酶的活性及微生物群落结构的变化进行了研究。结果表明,与雀稗、博落回单作相比,雀稗-博落回间作下,它们的铀富集总量分别达到了0.25 mg/株、1.2 mg/株,铀的富集总量分别提高了38.89%、34.83%,转移系数分别提高了40.00%、43.48%;根际土壤中Acidobateria等耐受菌比例升高,提高了植物对铀的耐受性,根际土壤酶活性增强,间接提高了植物的生物量,根际土壤中Aspergillus等真菌分泌的有机酸与铀形成螯合物,增加了生物可利用态铀的比例。这些可能是雀稗-博落回间作能强化修复铀污染土壤的主要机理。

Enhanced Phytoremediation of Uranium Contaminated Soils with Paspalum Scrobiculatum-Macleaya Cordata Intercrop

The uranium accumulators including Macleaya cordata and Paspalum scrobiculatum linn were planted in intercropping patterns to enhance the phytoremediation of the uranium contaminated soils.The bioaccumulation capabilities of the plants for uranium,the exchangeable uranium concentration,the enzyme activity,and the change of microbial community structure in their rhizosphere soils were investigated.It is found that compared with the monoculture,the bioaccumulation amounts of uranium by Paspalum scrobiculatum linn and Macleaya cordata amounted to 0.25 and 1.2 mg/plant,respectively,increasing by 38.89% and 34.83%,respectively,and their transfer coefficients increased by 40.00% and 43.48%,respectively.The increase of Acidobateria in rhizosphere soil increased the tolerance of plants to uranium,and the increase of soil enzyme activity indirectly increased the biomass of plants.Organic acid secreted by Aspergillus formed a chelate with uranium,which increased the bioavailability of uranium in soil.These may be the mechanisms by which the phytoremediation of the uranium contaminated soils was enhanced by the Paspalum scrobiculatum linn and Macleaya cordata intercropping.