Research Of Eutrophic Water Treating By Constucted Wetlands And Aquatic-ecological Environmental Improvement By Bottom Areation Technology

Recently, the lake and river were eutrophicated, and the urban landscape water was deteriorated. In the view of these problems, it's take the principle in treating eutrophic water to 'pollution reduction and resource controll combined with ecological restoration '. The research of Constructed Wetland and Bottom Jet Aeration with Biofilm Technology had been carried out. The Constucted Wetland project was developed by national key research project of tenth five-year plan(No. 2002AA601013), which is 'Environmental dredging and ecological restoration for high pollution water'. The Bottom Jet Aeration with Biofilm Technology project was developed by National '863' Program (Mo. 2006AA06Z343), which is 'Aquatic-ecological improvement by The Bottom Jet Aeration with Biofilm Technology'.The research of Constructed Wetland impact factors including different wetland types, different substrate, different plants, with and without plants, batch flow, seasonal variation and bunch with wetlands, et al. The research of Bottom Jet Aeration with Biofilm Technology was N and P removal, increasing of transparency and improving of DO, pH, Eh and temperature. The aim of this article is to explore a efficiency way to treat eutrophicated water on a pilot or engineering scale.The research of Constructed Wetland indicated that: First, Vertical Flow Wetland (VFW) and Subsurface Flow Wetland (SFW) were better than Free Surface Wetland (FSW), such as the rates of TN and TP removal by VFW and SFW were ourdone 41.7 and 35.8 percents than FSW. Second, the otherness of removal rates among different substrates was small for long term. Third, the otherness of removal rates among different plants was small, but the removal rate of the system with plant was better than the blank system obviously, such as the rates of TN and TP removal by blank were less 17.9% and 25.1% than wetland with plants, especially the uptake by plant is crucal for TP removal. Forth, the removal efficiency had been increased under the condition of batch-flow, obviously. The oxygenation was increased about 51.06%, the rates of TN and NH₄⁺-N removal were increased about 28.6% and 51.5% under the condition of batch-flow. Fifth, bunch of the strengthened FSW and SFW had been prevented the jam, especially the strengthened FSW system trapped the Chl.a and TSS by 9222mg/m² and 3834g/m² per year, that could be prevented the jam of SFW efficiency. Sixth, the removal efficiencies of constructed wetlands decreased along with the summer, autumn, spring and winter. The FSW decreased mostly, next was SFW, the VFW decreased slightly.The research of Bottom Jet Aeration with Biofilm Technology indicated that: This technology has good spread application for scenic water quality improvement. The removal efficiencies of NH₄⁺-N, NO₃-N and TP were 86.6%,90% and 73.3%, when the concentrations of N and P were decrease, the algae bloom was controlled, so the transparency could be increased above 1 meter by the technology and would create a better environment for restorateion of submerged macrophytes.Above all, it was efficiency of the Constructed Wetland and Bottom Jet Aeration with Biofilm Technology to treat eutrophic water.