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作 者 ：沈佳;纪桂琴;许文;周兴龙;石福臣*

期 刊 ：植物研究 2009年 29卷 5期 页码：585-591

关键词：菹草；重金属；伪二级动力学方程；Freundlich吸附等温线；去除率；

Keywords:Potamogeton crispus L., heavy metal, pseudo second order kinetics equation, Freundlich sorption isotherm, removal ratio, bioaccumulation,

摘 要 ：在10℃的较低温度条件下，研究了冬春季节生长旺盛的沉水植物菹草(Potamogeton crispus L.)对重金属离子Cu²⁺，Pb²⁺，Zn²⁺的生物吸附特征及解吸情况，对不同初始浓度重金属水体中的重金属离子去除率情况，以及在此过程中菹草各器官(叶、茎、根茎、根)对重金属离子的富集情况。结果表明，菹草对Cu²⁺，Zn²⁺的吸附在20 min内达到平衡，对Pb²⁺的吸附在50 min内达到平衡，吸附动力学结果符合伪二级动力学方程，决定系数分别达1，1，0.997 8。Freundlich等温线可较好地拟合菹草吸附Cu²⁺，Pb²⁺，Zn²⁺的过程，Cu²⁺，Pb²⁺，Zn²⁺的吸附容量分别达到66.900 6，26.543 0，30.371 8 mg·L^-1。以去离子水作洗脱剂，解吸液中3种重金属离子浓度均低于仪器检出限(0.01 mg·L^-1)，解吸程度微弱。投放菹草后，随着初始处理浓度的升高，水体Cu²⁺的去除率先降低后升高，Pb²⁺的去除率的变化趋势与Cu²⁺类似。Zn²⁺去除率则随水体Zn²⁺初始浓度的升高而逐渐升高。菹草各器官对水体3种重金属离子的富集能力不同，排序为Cu²⁺＞Zn²⁺＞Pb²⁺。不同器官对同一种重金属离子的富集量差异显著，叶是富集重金属离子的主要器官。水体重金属离子的初始浓度会影响菹草各器官富集重金属离子的能力，一般随水体重金属初始浓度升高，菹草各器官的重金属离子富集量虽有不同程度的增加但富集系数持续减小。

Abstract:Experiments were conducted to study the biosorption properties of heavy metals (copper，lead and zinc) by Potamogeton crispus which flourishes in winter and spring at relatively low temperature(10℃).Removal ratio of heavy metals in water with different initial heavy metal concentrations by P.crispus was studied as well. We also studied heavy metal bioaccumulation by different organs (leaf, stem, rhizome and root) of P.crispus. The results showed that Cu²⁺ and Zn²⁺ sorption by P.crispus reached balance within 20 min whereas Pb²⁺ sorption reached balance within 50 min. The results of sorption kinetics conformed to the pseudo second order kinetics equation with correlativity coefficient reaching 1, 1, 0.997 8, respectively. Freundlich sorption isotherm was well fit for Cu²⁺, Pb²⁺, Zn²⁺ sorption process by P.crispus. Sorption capability for Cu²⁺, Pb²⁺, Zn²⁺ were 66.900 6, 26.543 0, 30.371 8 mg·L^-1, respectively. In the desorption test, the desorption ratios of all Cu²⁺， Pb²⁺，Zn²⁺ initial concentration were nearly zero. Removal ratio of heavy metals from water was high after planting P.crispus. With the initial heavy metal concentration increased, removal ratio of Cu²⁺ and Pb²⁺ firstly declinced and then increased whereas removal ratio of Zn²⁺ was gradually increased. Bioaccumulation capability of different organs was distinguishing. Bioaccumulation capability was Cu²⁺＞Zn²⁺＞Pb²⁺. The same heavy metal content in different organs had marked difference. Leaf was the main heavy metal bioaccumulation organ. The initial heavy metal concentration of water may affect heavy metal bioaccumulation capability of every organ. Generally, with increasing initial heavy metal concentration, content of heavy metals in organs increased differently but bioaccumulation concentration of organs of P.crispus decreased.

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