多重金属富集植物李氏禾体内铜的化学形态研究

为了探明李氏禾对铜的吸收和解毒两个关键过程机理,采取逐级提取法对李氏禾中的铜的赋存形态以及其不同组织部位中的总铜进行了分析测定,研究结果表明:李氏禾对铜以根系吸收为主,其滞留率平均为91.47%。李氏禾根细胞组分中,乙醇提取态(F_1)和醋酸提取态(F_4)中的铜含量占大多数,占总量的60%~80%;李氏禾叶片中,乙醇提取态的Cu作为主要存在形态,所占比例最低的为水溶态铜含量(F_2)。此外,与李氏禾富集Cr相比,由于Cr的低生物利用导致李氏禾根细胞中Cr的赋存形态不同,其高浓度的Cr存在于李氏禾根残留态(F_6)当中。因此,李氏禾对铜虽不具备超富集能力,但其具备把铜大量吸附和积累到李氏禾根系的能力,搭配上其生长迅速,分布广泛的特点,使其在重金属修复上有着广阔的应用前景。

Chemical Forms of Cu in Co -accumulator Leersia Hexandra Swartz

In order to explore the two key processes ,the adsorption and detoxification of the Leersia Hexandra Swartz on Cu ,the sequential chemical extraction process is applied to analyze and measure the occurrence form of copper in the Leer-sia Hexandra Swartz ,as well as the total Cu in different parts and the results show that most of Cu in Leersia Hexandra Swartz is deposited in the root with the average retention rate of 91 .47% .Moreover ,the content of Cu extracted by ethanol (F1) and acetic acid(F4) in the root is largest ,accounting 60% ~80% of the total;meanwhile ,the content of Cu ex-tracted by ethanol in the leaf is dominant and that extracted by water is the lowest in the leaf relatively .Compared to Cr ac-cumulation in the Leersia Hexandra Swartz ,the occurrence form of Cr in the root is different because of its low bioavailability and the high concentration of Cr exists in root residue ( F6 ) .Therefore ,Leersia Hexandra Swartz is not the Cu hyperaccu-mulator ,but it has the ability to absorb and accumulate the large amount Cu to Leersia Hexandra Swartz root ,with the ad-vantages of growing rapidly and widely distributing ,so it can be widely applied in heavy metals contamination remediation .