Study on purification effects by three floating-bed plant systems in eutrophic water bodies
3种浮床植物系统对富营养化水体净化效果研究

The purification effects by floating-bed plant systems of Cyperus alternifolius ,Acorus calamus and Dracaena sanderiana in eutrophic water bodies were investigated. The experiment lasted 35 days. Results indicated that Cyperus alternifolius and Acorus calamus could grow well under the conditions of water temperature 24～ 301 , but Dracaena sanderiana could not grow well. The removal rates of NH_4~+ -N, TN, TP, and PO_4~(3-) by these three plants were 76.8% , 85.5% and 56.3% , 69.1% , 66.2% and 54.4% , 76.91% , 84.6% and 61.5% , and 91.7% , 91.7% and 75% respecctively. Three plants had good removal effects on the true color. The removal effects of the floating-bed systems in nitrogen, phosphorus and true color were significantly different ( P < 0.05 ) from three plants and the control. Turbidity removal releated to natural sedimentation. NH_4~+ -N removal was through plant adsorption. Dissolved phosphorus removal concerned with dissolved phosphorus adsorbed by plant. Based on their good effect on nitrogen, phosphorus and true color removal, Cyperus alternifolius and Acorus calamus are recommended as species of aquatic vegetation in eutrophic water bodies.