Effect of Different Hydrophytes＇ Wetland Systems on Removal of Nitrogen and Phosphorus

Abstract：In order to study the removal effects of nitrogen and phosphorus pollutants drainaged from farmland by different hydrophytes,an outdoor in-suit experiment was conducted in Jiangxi Central Irrigation Experimental Station.The main goal of the experiment is to determine the best hydrophytes in nitrogen and phosphorus control,seven selected plants lotus root,white lotus,Artemisia selengensis,Water Dropwort,Acorus calamus,Aponogeton lakhonensis and two compared treatments weeds and blank,totally 9 treatments were held in constructed wetlands.Results show that： wetlands with selected plants have much better effects on TN and TP control while compared with weeds and blank control.At the hydraulic retention time of 9 days,TN and TP removal rate in constructed wetlands increased 10.0% to 34.9% and 8.7% to 18.4% compared with blank treatment,respectively.Hydrophytes like lotus root,white lotus,calamus and weeds,those has higher biomass,has greater removal effects on TN and TP control.Among the 7 selected plants,White Lotus and Calamus performs best purification ability in TN,which is 33.4% and 34.9% higher than blank treatment.Consider economy and biology comprehensively,Lotus,White Lotus and Calamus are the ＂best practice＂ plants in local area on nitrogen and phosphorous control.