伊乐藻对CuCd污染底泥修复的应用研究

在自然条件下，采用人工模拟水缸培养方法，研究了湖泊底泥不同Cu、Cd处理对沉水植物伊乐藻生长、叶绿素含量以及Cu、Cd吸收和积累的影响。结果表明，较低浓度Cu刺激伊乐藻的生长（生物量、叶绿素），高浓度抑制伊乐藻的生长；随着Cd处理浓度的增加，伊乐藻的生物量、叶绿素含量均一直降低，在底泥Cd含量为168．69mg·kg^-1 DW（含背景值）时，植株出现死亡。随着Cu处理浓度的增加，伊乐藻体内的Cu含量一直增加，在底泥cu含量为414mg·kg^-1DW（含背景值）时，根部、叶部的富集系数均达到最大（0．21和0．17）；伊乐藻体内的Cd含量随Cd处理浓度的增加先增后减，底泥Cd含量为88．69mg·kg^-1 DW时，根部、叶部的富集系数均达到最大（0．07和0．09）。以上结果说明，伊乐藻对Cu、Cd具有很强的耐受性，可以作为原位修复Cu和Cd污染底泥的植物种类应用。

In situ Remediation of Cu and Cd Polluted Sediment by Elodea nuttallii

Macrophytes show great potential to remedy heavy metals contaminated water bodies. Nevertheless, there is still lack of knowledge concerning phytoextraction of heavy metals from sediment by submerged macrophyte in situ. In the present study, remediation of copper （Cu） and cadmium（ Cd ） polluted sediment by Elodea nuttallii were studied in pot experiment. The growth and physiological activities of E. nuttallii, and the metal accumulation in plant were investigated under different Cu, Cd treatment levels. The growth of E. nuttallii was stimulated under low concentration Cu treatment, but was inhibited under higher concentration Cu treatment with Cu concentration of 1 014 mg .kg^-1 DW. The biomass and chlorophyll content of E.nuttallii decreased significantly with the increasing of Cd concentration in treatments, moreover a few ofE. nuttallii seedlings died when the Cd concentration in sediment reached 168.69 mg.kg^-1 DW. The concentrations of Cu in both roots and leaves of E. nuttallii increased significantly with the increasing of Cu concentration in treatments, the bioconcentration factors （BCF） in root and leaf were reached the highest values with 0.21 and 0.17, respectively, under the treatment of Cu concentration was 414 mg.kg^-1 DW in sediment. The concentrations of Cd in both roots and leaves of E. nuttallii increased slowly at lower Cd level but decreased dramatically when Cd concentration was higher than 88.69 mg.kg^-1 DW in the treatment, and the BCFs of root and leaf reached the highest values with 0.07 and 0.09 under the treatment of Cd was 88.69 mg.kg^-1 DW, respectively. Conclusionly, E. nuttallii could be suitable pioneer sepcies for phytoremediation of sediment contaminated by Cu and Cd due to its strong reproduce and tolerance ability.