生态浮床对千岛湖水体氮磷净化效果研究

为探索生态浮床对较清洁型湖水的氮磷去除效果，以华东地区最大深水水库千岛湖为例，选取浮叶植物黄花水龙(Jussiaea stipulacea Ohwi.)、沉水植物绿色狐尾藻(Myriophyllum aquaticum)、挺水植物菖蒲(Acorus calamus)为材料，采用氮磷浓度相对较高的库尾湖湾湖水进行生态浮床静态模拟试验，测定浮床植物生长及水体氮磷浓度变化，并利用膜接口质谱仪测定水体溶解性氮气(N₂)含量，研究浮床植物体内吸收、反硝化脱氮等综合脱氮除磷能力. 结果表明:①浮床植物的氮磷净化能力存在明显的季节性差异，春季浮床植物长势、氮磷去除效果、反硝化脱氮能力均高于秋季；②不同水生植物间的氮磷去除能力差异显著，试验水体中黄花水龙和绿色狐尾藻的总氮(TN)、总磷(TP)去除效率分别为2.22、0.07和2.89、0.08 mg/(kg·d)，绿色狐尾藻体内吸收氮、磷最多，植物干质量的氮、磷含量分别为12.44~15.57和0.96~1.95 g/kg；③植物的生长大大增强了水体的反硝化脱氮能力，黄花水龙、绿色狐尾藻、菖蒲与空白对照组溶解性N₂差值（净脱氮差）分别为0.16~22.35、?4.14~24.63、?0.26~15.74 μmol/L，水生植物生物量是影响浮床系统反硝化作用的最关键因素. 研究显示，生态浮床是较清洁型湖水氮磷削减的一种可行技术，浮床植物组合方案设计应充分考虑不同植物的季节生长特性和反硝化脱氮能力. 

Nitrogen and Phosphorus Purification Effects of Ecological Floating Bed in Qiandao Lake

In order to explore the nitrogen and phosphorus removal effect of ecological floating bed in lake with clean water quality, taking Qiandao Lake, the largest deep-water reservoir in East China, as an example, the floating leaf plant (Jussiaea stipulacea Ohwi.), submerged plant (Myriophyllum aquaticum) and emergent plant (Acorus calamus) were selected to carry out the nitrogen and phosphorus purification static simulation experiment using ecological floating bed technology. The experimental lake water was collected from reservoir tail bay with relatively high nitrogen and phosphorus concentration. The growth parameters of floating bed plants and nitrogen and phosphorus concentrations in the water were measured, the content of dissolved N₂ in water was also determined by Membrane Interface Mass Spectrometer, and the comprehensive nitrogen and phosphorus removal abilities of floating bed plants were investigated. The results showed that: (1) There were significant seasonal differences in the nitrogen and phosphorus purification capacity of floating bed plants. The growth rates, nitrogen and phosphorus removal efficiency and denitrification capacity of floating bed plants in spring were higher than those in autumn. (2) There were significant differences in nitrogen and phosphorus removal capacity among different aquatic plants. In the experimental water, the TN and TP degradation rates of ecological floating bed with Jussiaea stipulacea Ohwi. and Myriophyllum aquaticum were 2.22, 0.07 and 2.89, 0.08 mg/(kg·d), respectively. Myriophyllum aquaticum absorbed the most nitrogen and phosphorus, and the nitrogen and phosphorus contents of plant dry weight were 12.44-15.57 and 0.96-1.95 g/kg, respectively. (3) The growth of plants also greatly enhanced the denitrification of ecological floating bed system. The variation range of net nitrogen removal by denitrification of Jussiaea stipulacea Ohwi., Myriophyllum aquaticum and Acorus calamus were 0.16-22.35, ?4.14-24.63, ?0.26-15.74 μmol/L, respectively. The aquatic plant biomass is the most key factor affecting the denitrification of aquatic plants. This study shows that ecological floating bed is a feasible technology for nitrogen and phosphorus removal in slightly clean lake. The seasonal growth characteristics and denitrification capacity of different plants should be fully considered in the design of floating bed plant combination scheme. The research results can provide theoretical support for the in-depth treatment of nitrogen and phosphorus pollution in slightly clean reservoir.