The removal effect of 12 aquatic plants on nitrogen and phosphorus in the return flow of farmland
[Objective]Exploring the removal effects of nitrogen and phosphorus in the return flow of farmland by different aquatic plants,providing scientific basis for the use of aquatic plants in the remediation and prevention of water pollution.[Method]Using hydroponic experiments to determine the changes of biomass,content and absorption of nitrogen and phosphorus in roots,stems and leaves of 12 aquatic plants,as well as removal rate of nitrogen and phosphorus in water.Cluster analysis was conducted on the nitrogen and phosphorus removal ability of 12 aquatic plants using the average membership function values of screening indicators.[Result]Among the emergent plants,the net increase biomasses of Scirpusvalidus,Phragmitesaustralis and Typhaorientalis were higher.Phragmitesaustralis had the highest nitrogen absorption,reaching 201.22 mg·m-2,and Typhaorientalis had the highest phosphorus absorption,reaching 26.64 mg·m-2.Phragmitesaustralis had the highest removal rates for ammonia nitrogen,nitrate nitrogen,total nitrogen,and total phosphorus,reaching 98.56%,78.93%,80.22%,and 81.36%,respectively.Among floating plants,the net increase biomass of Eichhorniacrassipes was the highest.Eichhorniacrassipes had the highest nitrogen absorption,reaching 156.14 mg·m-2,and Nymphaea tetragona had the highest phosphorus absorption,reaching 23.48 mg·m-2.Eichhorniacrassipes had the highest removal rates for ammonia nitrogen,nitrate nitrogen,total nitrogen,and total phosphorus,reaching 95.63%,76.01%,71.66%,and 80.58%,respectively.Among submerged plants,the net increase biomass of Myriophyllumverticillatum was the highest.Myriophyllumverticillatum had the highest nitrogen absorption,reaching 230.75 mg·m-2,and Vallisnerianatans had the highest phosphorus absorption,reaching 26.11 mg·m-2.Myriophyllumverticillatum had the highest removal rate of ammonia nitrogen and total nitrogen,reaching 97.94%and 84.93%,respectively;and Vallisnerianatans had the highest removal rates of nitrate nitrogen and total phosphorus,reaching 76.32%and 79.09%,respectively.Phragmitesaustralis,Scirpusvalidus and Nymphaea tetragona mainly absorbed nitrogen and phosphorus through their roots,while the other 9 aquatic plants mainly absorbed nitrogen and phosphorus through their stems and leaves,thereby increasing biomass and removing nitrogen and phosphorus from the water.The removal rate of nitrogen and phosphorus in water was significantly positively correlated with the absorbed quantities of nitrogen and phosphorus by plants.Phragmitesaustralis,Typhaorientalis and Myriophyllumverticillatum were highly efficient purification plants,while Vallisnerianatans,Scirpusvalidus,Eichhorniacrassipes,Nymphaea tetragona,and Lythrumsalicaria were relatively efficient purification plants.[Conclusion]In Ningxia Yellow River irrigation region,the emergent plants such as Phragmitesaustralis,Typhaorientalis,Scirpusvalidus,and Lythrumsalicaria,as well as the floating plants such as Nymphaea tetragona,and the submerged plants such as Myriophyllumverticillatum and Vallisnerianatans,had a good removal effect on nitrogen and phosphorus.
emergent plantsfloating plantssubmerged plantsreturn flow of farmlandremoval rateYellow River irrigation region
万方数据
维普
