Study On Aquatic Plant In Ecological Rehabilitation Of Waiqinhuai River

With the help of the integrated demonstrational project of the Waiqinhuai River, the treatment of eutrophicated water body was studied by the vegetation rehabilitation, according to the hydrology and water quality characteristics of the Waiqinhuai River. The investigation to hydrology and water quality of Waiqinhuai River and the preliminary selection of herbaceous plant, emerging plant and submerged plant; the filtration of revetment plants by the comparison of water resistance, adaptive ability and purifying effect between different herbaceous plant, emerging plant and submerged plant.The contents and conclusions of the study were summarized as follows:(1) TN exceeded the allowed figure in the whole Waiqinhuai River, partial water body pollution was still existing. The organic pollution of bottom sludge was serious, endogenous release was existing. The Waiqinhuai River was short of biodiversity.(2) Choosen herbaceous plant Festuca arundinacea and Zoysia japonica could both adapt to the riparian soil and water environment of Waiqinhuai River. They both had the adaptive ability to flooding and purifying ability to water body. And Festuca arundinacea was better than Zoysia japonica.(3) Choosen emerging plant Acorus gramineus and Typha latifolia L. could both adapt to the riparian soil and water environment of Waiqinhuai River. They both had the adaptive ability to flooding and purifying ability to water body. And Acorus gramineus was better than Typha latifolia L..(4) Choosen submerged plant Hydrilla verticillata and Ceratophyllum demersum Linn. both had the adaptive ability and purifying ability to the water quality of Waiqinhuai River. Their purifying ability to SS, COD_Mn and NH₃-N was almost same, The purifying ability to TN of Hydrilla verticillata wais better than Ceratophyllum demersum Linn., The purifying ability to TP of Ceratophyllum demersum Linn. was better than Hydrilla verticillata. The existence of bottom sludge had some effect to the removal of TN and NH3-N, had no effect to the removal of SS, COD_Mn and TP. (5) On the basis of ivestigation and experiment, the vegetation configure project was put forward. Icluding three areas: the area below ordinary water level , the area of changing water level and the area above flood stage.