不同种类浮萍对磷的去除及其体内磷的累积变化研究

以巢湖流域常见的3种浮萍——紫背浮萍（以下称紫萍）、稀脉浮萍萍和芜萍为对象，研究了三种浮萍对地表水浓度范围内（0．01mgP／L，0．05mgP／L，0．1mgP／L，0．2mgP／L，0．5mgP／L）的磷的去除作用，以及磷在三种浮萍体内的积累变化和三种浮萍对磷的吸收作用占总去除作用。探讨了浮萍处理含磷污水系统的去除磷途径。实验表明：植物体对磷的直接吸收是其净化作用的主要机制之一。三种浮萍对磷都有较高的去除效率。并且磷去除率紫萍〉稀脉浮萍〉芜萍，并且随浓度的降低而增加。三种浮萍对磷的利用率较高。紫萍对磷的利用率在60％～48．9％；稀脉浮萍在90％～47．2％；芜萍在90％～34．2％。三种浮萍对磷的吸收作用基本上占总去除作用的70％以上；并且不同品种，不同磷浓度之间存在差异，为浮萍进行巢湖流域的除磷生态修复提供了理论基础。

Study of Different Kinds of Duckweed in Different Low Concentration of Orthophosphate Culture Conditions on Phosphorus Removal and Float body Phosphorus Accumulation Change

Taking three common duckweed in the Chaohu Lake basin--Spirodela polyrrhiza, Lemna paucico- stata and wolffia arrhiza as the objects,this article studies the phosphorus removal function the three kinds of duckweed when the water is within the surface water concentration range （0.01 mgP/L,0. 05 mgP/L,0. 1 mgP/L,0.2 mgP/L,0.5 mgP/L）,and also analyzes the accumulation change of phosphorus in three kinds of duckweed. Moreover, it discusses the treatment of phosphorus wastewater system on remove phosphorus way, and provides theoretical basis for duckweed in Chaohu Lake basin dephosphorization ecological restora- tion. The experimental results show that the plant body on phosphorus direct absorption is one of the main mechanisms for clean--up effect; three kinds of duckweed respectviely have high removal efficiency, and phosphorus removal rate is Spirodela polyrrhiza 〉 Lemna paucicostata 〉 wolffia arrhiza, and three float right utilization rate increase as the concentration reduce;the phosphorus removal rate of Spirodela polyrrhiza is 60% -48.9%,Lemna paucicostata is 90% - 47.2%,wolffia arrhiza is 90% - 34.2%. The phosphorus absorption of three duckweed basically account for more than 70% of the remove function. And there are differences among different varieties and different phosphorus concentration.