8种植物对铀和镉的富集特性

研究8种植物在铀镉复合污染土壤条件下的吸收、富集和转运特性具有重要意义。在每千克土中施用铀、镉的浓度分别为150、15 mg·kg-1，采用主成分分析法对植物富集特性进行综合性评价。结果表明：白皮菜铀镉综合评价值最高，地上部、地下部、单株铀镉总含量、单株铀镉总积累量均最大，分别为90.03 mg·kg-1DW（干质量）、477.00 mg·kg-1DW、150.26 mg·kg-1DW和1 168.52 μg；花椰菜铀综合评价值最高，地上部、地下部铀含量分别为42.16、444.83 mg·kg-1DW，单株铀积累量达到255.42 μg；南瓜综合评价最低，单株铀镉积累量仅为58.47 μg；供试植物地上部铀含量均显著小于地下部铀含量，转运系数均小于1，根系是植物富集铀镉的主要器官。

Enrichment characteristics of eight plants to uranium and cadmium

Studies on the absorption, accumulation, and transportation abilities of eight kinds of plants regarding uranium (U) and cadmium (Cd) have important influences on U-Cd contaminated soil. The concentrations of U and Cd in the contaminated soil were 150 and 15 mg·kg-1, respectively. Principal component analysis was used to evaluate the plant enrichments of U and Cd. The results are as follows. Comprehensive evaluation of Beta vulgaris L.var. cicla L.showed it had the highest enrichment, with contents of U plus Cd in the shoots and roots and concentration and accumulation of U plus Cd per plant of 90.03 mg·kg-1DW(dry weight), 477.00 mg·kg-1DW, 150.26 mg·kg-1 DW, and 1 168.52 μg, respectively. Comprehensive evaluation of Brassica oleracea L. var. botrytis L. showed it had the highest enrichment for U, with contents of U in the shoots and roots and per plant accumulation of U at 42.16 mg·kg-1 DW, 444.83 mg·kg-1DW, and 255.42 μg, respectively. Comprehensive evaluation of Cucurbita moschata (Duch. ex Lam.) Duch. ex Poiret showed it had the lowest enrichment, with a per plant accumulation amount for U plus Cd of only 58.47 μg. The content of U in the plants showed that the shoots were smaller than the roots and the transfer factors for U were smaller than 1, as U and Cd were located mainly in the roots.