博落回对不同化学形态铀的富集特征

为了研究陆生植物博落回（Macleaya Cordata）对不同化学形态铀的富集特征，采用Visual MINTEQ地球化学平衡软件设计了五种含不同化学形态铀UO₂2+、CaUO₂（CO₃）₃2-、UO₂Cit-、（UO₂）₂（EDTA）₂4-和UO₂HPO₄]的培养液，开展水培试验.博落回在这五种培养液中分别培养1、5、10、15、20和25 d后，测定其株高、根长和干质量，并用电感耦合等离子体质谱仪（ICP-MS）测定其地上部分和根部的w（铀）.结果表明:在不同化学形态铀胁迫下，博落回株高无显著差异，UO₂HPO₄可促进博落回根的生长，而（UO₂）₂（EDTA）₂4-降低了博落回的干质量.并且，博落回根部对不同化学形态铀的富集能力大小顺序为UO₂2+ > UO₂HPO₄ > CaUO₂（CO₃）₃2- > UO₂Cit- >（UO₂）₂（EDTA）₂4-，博落回地上部分对不同化学形态铀的富集能力大小顺序为UO₂Cit- >（UO₂）₂（EDTA）₂4- > UO₂2+ > CaUO₂（CO₃）₃2- > UO₂HPO₄.此外，博落回根部对UO₂2+的富集能力很高，但地上部分很低.添加柠檬酸，培养液中铀的主要化学形态为UO₂Cit-，并且在100 mg/L铀的胁迫下，博落回对UO₂Cit-的生物富集系数和转移系数分别达到0.09和8.53.因此，要提高博落回对铀污染土壤中铀的富集和转移，可添加柠檬酸，促使土壤中铀的形态以UO₂Cit-为主，同时要降低土壤中碳酸盐和磷酸盐的含量. 

Accumulation of Different Chemical Species of Uranium in Macleaya cordata

In order to investigate the accumulation of different chemical species of uranium (U) in Macleaya cordata, the geochemical equilibrium software Visual MINTEQ was used to design five nutrient solutions containing UO₂2+, CaUO₂(CO₃)₃2-, UO₂Cit-, (UO₂)₂(EDTA)₂4- and UO₂HPO₄, respectively, and hydroponic experiments on M.cordata were conducted in the nutrient solutions. The shoot heights, root lengths and dry weights of M.cordata were measured after it was cultured in the nutrient solutions for 1, 5, 10, 15, 20 and 25 days, respectively, and the U contents in its shoots and roots were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the chemical species of U did not have significant effects on the shoot height of M.cordata; UO₂HPO₄ promoted its root growth, and (UO₂)₂(EDTA)₂4- decreased its dry weight. The accumulation of different chemical species of U in the roots of M.cordata followed the order of UO₂2+ > UO₂HPO₄ > CaUO₂(CO₃)₃2- > UO₂Cit- > (UO₂)₂(EDTA)₂4-, and that in the shoots of M.cordata followed the order of UO₂Cit- > (UO₂)₂(EDTA)₂4- > UO2+ ₂ > CaUO₂(CO₃)₃2- > UO₂HPO₄. Besides, the accumulation of UO₂2+ in the roots of M.cordata was relatively high, but that in the shoots of M.cordata was relatively low. After application of citric acid, UO₂Cit- was the main chemical species of U in the nutrient solution. and the bioaccumulation factor and transfer factor of M.cordata for UO₂Cit- reached 0.09 and 8.53 after exposure to 100 mg/L U, respectively. Therefore, the accumulation and translocation of uranium from uranium contaminated soil by M.cordata can be increased by applying citric acid, which helps regulate the main species of uranium in soil to UO₂Cit-, and decrease the concentrations of carbonate and phosphate in soil.