螯合剂诱导五节芒强化修复铀污染土壤

以典型铀矿山周边铀污染土壤为研究对象，采用盆栽试验，以五节芒为试验材料，研究乙二胺四乙酸(EDTA)、柠檬酸(CA)、乙二胺二琥珀酸(EDDS)等不同浓度螯合剂(0、2.5、5.0、7.5 mmol/kg)对五节芒修复铀污染土壤的影响。结果表明，五节芒的生长及富集吸收铀与螯合剂浓度及种类有关。EDTA对五节芒有明显的毒害作用，随浓度的提高消极影响越大，修复效果不理想；2.5 mmol/kg和5.0 mmol/kg的CA与EDDS均可促进五节芒的生长和富集吸收铀的效果，但CA效果优于EDDS,CA在5.0 mmol/kg处理组时，地上、根部生物量分别增加27.06%、12.88%,铀富集量分别提高68.05%、43.21%,且根部的铀含量远远大于地上部，说明螯合剂促进土壤溶液中残渣态铀逐渐向活性态铀转换，促进了植物的吸收富集。

Remediation of Uranium Contaminated Soil by Chelating Agent Induced Miscanthus Floridulus

Taking the uranium-contaminated soil from uranium mines as the research object, the effects of different concentrations of chelating agents (0, 2.5, 5.0, 7.5 mmol/kg) such as ethylene diamine tetraacetic acid (EDTA), citric acid (CA) and ethylenediaminedisuccinic acid (EDDS) on remediation of uranium-contaminated soil by miscanthus floridulus were studied in pot experiment. The results show that the growth, enrichment and absorption of uranium by miscanthus floridulus are related to the concentration and type of chelating agent. EDTA has an obvious toxic effect on the pseudomonas sinensis. With the increase of the concentration of EDTA, the negative effect is greater, and the repair effect is not ideal. However, both CA and EDDS at 2.5 mmol/kg and 5.0 mmol/kg can promote the growth and enrichment of uranium, but the effect of CA is better than that of EDDS. When CA is treated at 5.0 mmol/kg, the above ground and root biomass increase by 27.06% and 12.88% respectively, and the enrichment of uranium increases by 68.05% and 43.21%, respectively, and uranium content in the roots is much higher than that in aboveground part, which indicating that addition of chelating agent promotes the conversion of residual uranium to active uranium in soil solution gradually, and promotes the absorption and enrichment of plants.