Removals of nitrogen and phosphorus in the water by submerged hydrophytes

Through static simulation test,three kinds of submerged plant including Elodea densa(Planch.)Casp.,Ceratophyllum demersum L,Cabomba Fanwort were studied.They were highly efficient in removing total nitrogen(TN),total phosphor(TP).The change of the biomass at the different nutritional levels was also investigated.The nutritional levels were described by mesotrophic concentration,eutrophic concentration,hyperbolic concentration and stress concentration.The research results indicate that three kinds of submerged hydrophytes are capable of removing nitrogen and phosphorus effectively at the different nutritional levels in the water.At mesotrophic concentration,eutrophic concentration and hyperbolic concentration,Ceratophyllum demersum L showed well TN removal efficiency in the water,Elodea densa(Planch.)Casp.showed well removal efficiency on both TN and TP in the water at the different nutritional levels.At hyperbolic concentration and stress concentration nutritional levels,the removal efficiency of Elodea densa(Planch.)Casp.is higher than Ceratophyllum demersum L,and Cabomba Fanwort.