The Research About Taking Advanced Removal Of Nitrogen By Making Use Of Constructed Wetland To Treat Tailwater In Sewage Treatment Plants Of Town

Taking advanced treatment to the tailwater in sewage treatment plants of town can help natural water to relieve stress of depurating, after advanced treatment, recycling of the sewage also means developing the new water resource, therefore it's very significant. Against a high index of total nitrogen on tailwater in one sewage treatment plant of Tailake, I did experiment about the advanced removal of nitrogen by using constructed wetlands, the research was about depurating ecologically on tailwater, the main study results are as follows:1,In the unloading phase of the experiment(no plants), the removal of pollutants in hybrid constructed wetlands mainly depend on the substrate, the system has certain handing ability to COD; each kinds of substrate has a high removal efficiency to NH4+-N and TP; the removal efficiency of TN is low, and zeolite has best removal efficiency of TN.2,In the study phase of the experiment with plants), hybrid constructed wetlands has certain processing power and impact resistance towards COD, the influent hydraulic loading and temperature have little effect on the removal of COD; the kind of plants have a big effect on the removal of TN, Canna lily is the best, the hydraulic retention time and the removal efficiency of TN are positive, so do the removal rate of TN and influent hydraulic loading, with the temperature increased, the removal rate of TN firstly increased and then decreased, the most suitable temperature for the remove of nitrogen is 22-28℃; the systems of hybrid constructed wetlands have a powerful removal capacity of NH4+-N, and the removal mainly occurred in vertical subsurface flow wetland, the hydraulic retention time and the removal efficiency of NH4+-N have a positive correlation, so do the removal rate of NH4+-N and influent hydraulic loading, with the same hydraulic retention time, the removal rate of NH4+-N fluctuated with the increase of temperature; gravel has best removal efficiency of TP, the removal rate of TP and influent hydraulic loading have the positive correlation, by effecting the plants,the growth of the microbes and the physiological property, temperature can effect the removal efficiency of TP.3,In the strengthened phase, under aeration in hybrid constructed wetlands,only the removal of NH4+-N are effected greatly; under aeration in vertical subsurface flow wetlands, the removal efficiency of COD,NH4+-N,TN all increase.