Analysis On The Constructed Wetlands’ Purification For Urban Lakes

In recent years, with faster urbanization the urban lakes water quality has became a measure of a city living environment an important reference standard. But many of our city lakes are subject to a certain degree of pollution,There is an urgent need to find a method of purification of urban lake water.The main purpose of this experiment is the application of artificial wetland technology purifying polluted water, hoping to seek out a city lake can maintain the original environment, but also to deal with sewage purification process. The experimental take a combination of traditional techniques for removing the influence of the matrix packing on the experiment, the individual units are using the same matrix filler combination. The experimental site for a open-air water conservancy Pavilion, so you can more fully simulated wetland purification treatment effect in the natural state of the lake water.Take two different processes combined, compared, a combination of two different removal processes. The results showed that the overall effect is ideal for removing, CODMn、TP、TN、NH4+-N、NO3--N、chlorophyll a、BGA removal rates were 75%, 83%, 35%, 36%, 87%, 48%, 31%. Their respective effluent concentrations is 1.5mg/L、0.02mg/L、3.44mg/L、2.36mg/L、0.017mg/L、2.8ug/L、2.6×104cell/L. Where the water quality index COD, TP treated after most obvious effect, to GB3838-2002 the class Ⅰ water standards. Compare the two groups showed that the overall results of a second set of TP and NO3--N removal is better than the first group, the first group of other water quality indicators better.In different seasons, The effect of wetland treatment of urban water bodies for analysis, to explore its effects on wetland water treatment, the results showed that the overall performance is better than removal summer in spring and autumn. But the degree of removal of the affected TP minimal overall range between 85% and 89%. The highest removal efficiency of summer, and the lowest in spring. Like this purification performance effect on other water quality indicators, including the removal of the more obvious effects of changes in TN. But the overall effect is not very satisfactory removal, including removal of the best summer but only reached 38 percent, the worst spring still is 30%.Under different hydraulic load condition, the treatment effect on the hydraulic load on the wetlands is also very significant, the hydraulic load range of the experiment is between 0.27 m3/m2·d and 0.84 m3/m2·d. Which is more ideal TP and COD removal were at a lower hydraulic loading conditions. Experimental results show that the optimal removal of both occurred in this experiment a minimum of 0.27 m3/m2·d.The other indicators show that is too high or too low hydraulic loading can not hit the best treatment effect. TN optimum handling hydraulic loading is 0.46 m3 / m2 ? d. And the NH4+-N is 0.33 m3/m2·d, Experimental results show continued its decline with other indicators after different maximum, there will be a trough at 0.46 m3 / m2 · d.In the analysis results for each wetland unit showed that the treatment effect canna undercurrent units are very good, canna plants purfying effect is very good. Different wetlands of comparative experiments show: subsurface >vertical Flow> General sag>emergent plants Unit> floating plants units.