Experimental Research on Purification of Different Aquatic Plants in the Urban River's

Using the water hyacinth、Hydrilla verticillata and Hydrilla verticillata - water hyacinth combination to conduct the purification research,which simulates the urban river water , the experimental study discovery, under the move water condition which the velocity of flow is 1.74cm/s, the water hyacinth group has obvious superiority to TN, TP,COD and Turbidity purifies, the average elimination rate of TN ,TP and COD achieves 74.92% ,87.8%,and 78.19% respectively.With NH3-N elimination and DO density maintain the Hydrilla verticillata group has good effect, the average elimination rate of NH3-N achieves 87.79%,At the entire experimental process, the Hydrilla verticillata - water hyacinth combination group has not show obvious advantage compared with others, The elimination of NH3-N is slightly inferior to the Hydrilla verticillata group, the average elimination rate achieves 85.40%, and the average elimination rate of TP achieves 82.5%.