Removal effects on phosphorus and nitrogen in eutrophic water with different kinds of hydrophytes

Hydroponic experiments were designed to investigate removal effect on nitrogen and phosphorus in eutrophic water with ten hydrophytes in late July 2012,including Oenanthe javanica,Acorus gramineus,Eichhornia crassipes,Pistia stratiotes,Lemna minor,Limnanthemun nymphoides,Ceratophyllum demersum,Hydrilla verticillata,Vallisneria natans,Potamogeton malainus.Results indicated that all of the ten species grew well in the constructed wetlands,and showed excellent nitrogen and phosphorus removal capacities.Among the ten hydrophytes,Oenanthe javanica had the best TN removal capacities,increased the average TN removal rates by 91.5 %.Vallisneria natans had the best TP removal capacities,making the removal rate by 94.2%.Comprehensive analysis of aquatic plants had a strong uptake of nitrogen and phosphorus and water purification capacity.The average nitrogen and phosphorus removal rate reached more than 70% respectively.