| Compared to the traditional two stage activated sludge process, artificial wetland system because of its low investment and operation cost, convenient maintenance and management, good ecological landscape resistance shock load capacity strong, have good nitrogen and phosphorus removal effect and other advantages, gradually by the people's attention. But due to the limitations of the traditional artificial wetland structure itself, the wetlands purification effect is vulnerable to the effects of dissolved oxygen, temperature, wetland plants, pollution load and hydraulic load factors, these problems is becoming restricted the popularization and promotion of artificial wetland is an important factor.The to intermittent aeration vertical flow constructed wetland based, research different hydraulic residence time, flow mode, aeration mode, aeration rate, reflux ratio, wetland plants, water quality and other factors of artificial wetland sewage purification effect of determined optimum operation parameters, provide reference to the construction of artificial wetland for the future. The main conclusions of this study are as follows:(1)Through the investigation of the upstream and downstream in HRT for 1-5 days time intermittent aeration constructed wetland system for ordinary life sewage purification performance study shows, the best HRT for 4 days, and the upward flow of pollutants removal is superior to the down stream; the COD, TP and NH3-N removal rate with the extension of hydraulic retention time increased, and TN removal rate is increased first and then decreased, and reached a 4D in the HRT was the highest, and NO3-N with hydraulic retention time increased gradually accumulated. Compared to the hydraulic retention time of 1D, the removal rate of NH3-N, TP, TN and COD in the two groups of wetland systems can be increased by about 21, 23, 30 and 46 percentage points respectively, when the hydraulic retention time is 4D.(2)By changing the position of the aeration, the purification effect of the middle aeration of the wetland system is better than that of the middle and the back. Compared with the dual reactor aeration, SLR should aerator under the condition of two groups of wetland system of COD, NH3-N and TP removal rate increase is not obvious, but single reactor aeration can effectively reduce wetland system water NO3-N concentrations, the TN removal efficiency can improve about(4 ~ 5) of a percentage point.(3)The aeration gas water ratio was 0.25:1, 0.5:1, 1:1, 2:1, 4:1 of pollutants removal effect, found that the water gas ratio 4:1 wetland purification effect is the best; and gas water ratio was 0.25:1 compared, in the gas water ratio is 4:1 wetland system on COD, TP, TN and NH3-N removal rate were increased by about 5, 3, 40 and 42 percent.(4)The of effluent recycling can significantly improve the of pollutants removal efficiency, optimum reflux ratio is 1.5; in reflux ratio is 1.5, of COD, TN and NH3-N removal effect is best; in return ratio is 1, of TP removal effect is best; compared with reflux, reflux of COD, TP, TN and NH3-N removal rate can were increased about 7, 5, 18, 18 percent.(5)Intermittent aeration wetland system in the treatment of micro polluted water, the best aeration rate for the gas water ratio was 1:1. Wetland system of COD and NH3-N removal rate with the gas water ratio increases, while for TN and TP removal rate showed the trend of first increased and then decreased, and in the gas water ratio is 1:1 reached highest; wetland system the concentration of NO3-N in the water with the increase of aeration rate and increased.(6)In ordinary living sewage treatment, Cyperus alternifolius and yellow iris of the wetland purification performance impact, there was a significant difference, which iris pseudacorus on wetland purification effect to better than Cyperus alternifolius group; ordinary living sewage treatment, yellow iris group wetland system for each pollutant removal rate increased about(1 ~ 4) percentage points compared to the windmill grass group; low concentration sewage treatment, iris pseudacorus group wetland system on COD, TP, TN and NH3-N removal rate than Cyperus alternifolius group were increased by approximately 3, 10, 2, 3 percent. |
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