浮萍对富营养化水体中磷的去除规律

磷是藻类增殖的限制因子，引起水体富营养化的关键营养物质。修复富营养化水体的重点在于磷的去除。通过对三种浮萍的磷吸收动力学特征和动态吸收特点研究，选择适合不同富营养化程度水体的修复植物。吸收试验结果表明，浮萍吸收磷的动力学特征可用Michaelis-Menten方程来描述。青萍对磷有较大的亲和力，适宜修复轻度富营养化水体；紫萍对磷有较大的最大吸收速率，适宜修复重度富营养化水体；而少根紫萍由于吸收速率小，生长速度慢，不适宜作为水体生态修复植物使用。

Phosphorus removal rules of duckweed plants in eutrophication water

Phosphorus, the cause of most eutrophication cases, is often the limiting factor of algae proliferation. The key point toward restoration of eutrophicated water body is phosphorus removal. Based on studies of phosphorus-absorption kinetics and dynamic absorption characteristics among three kinds of duckweed, the suitable one was identified for water bodies with various eutrophic levels. Experiment results indicated that kinetic characteristics of phosphorus-absorption of certain duckweed plants can be described by the Michaelis-Menten equation.? In addition, it was found that Lemna minor has the highest value of 1/Km and is suitable for restoring water bodies slightly eutrophicacted. Spirodela polyrhiza, with the highest value of Vmax among the three, which can be used for restoration of the heavily eutrophicated water bodies. While Spirodela oligorrhiza, with low absorption rate and slow growth, is therefore unqualified for purification purpose.