Nitrogen and Phosphorus Uptake Capacity and Resource Use of Aquatic Vegetables Floating Bed in the Eutrophicated Lake

Ecological Floating Bed was the key technology to purify polluted water. In this study, three aquatic vegetables: Ipomoea aquatica, Zizania latifolia, and Oenanthe javanica were selected in Dianshan lake. Iris pseudacorus was selected as control. The results showed that: From April to October, the removal rate of TN and TP with Ipomoea aquatica were 82.3%, 72.6%, and with Zizania latifolia were 83.6%, 78.2%. With Oenanthe javanica, the removal rate of TN and TP were 89.1%, 90.4%. The removal rate of TN and TP with Ipomoea aquatica and Zizania latifolia showed no significant differences with Iris pseudacorus (P>;0.05). The removal rate of TN and TP with Oenanthe javanica was greater than other three aquatic plants (P<;0.01). This study suggested that Ipomoea aquatica, Zizania latifolia and Oenanthe javanica had not only strong uptake capacity of Nitrogen and Phosphorus, no accumulation of heavy metals in the stem and leaves, but also has good economical plant biomass productivity.