复合垂直流人工湿地氧调控条件优化研究

STUDY ON OPTIMIZATION OF AERATION CONDITION IN INTEGRATED VERTICAL-FLOW CONSTRUCTED WETLAND

溶解氧是制约人工湿地净化空间的重要影响因素之一,调控与优化湿地内的氧状态分布,对提高人工湿地的去污效果十分重要。为此,利用复合垂直流人工湿地(IVCW)特有的通气管进行氧调控,选择曝气位置、曝气速率、曝气机运行/停止时间、开始曝气时刻进行正交试验,开展了IVCW氧调控的操作条件优化研究。结果表明,各因素的影响力依次为:曝气机运行/停止时间>曝气位置>曝气速率>开始曝气时刻;较佳的操作条件为:曝气位置为下行池底部,曝气速率0.25m·3h-1,曝气机运行/停止时间为8h/16h,开始曝气时刻为进水时刻。另外,TN负荷削减量与供氧量呈显著相关,当供氧量为2m·3d-1时,IVCW对COD、TN、TP负荷削减量可分别达到16、1.6、0.20g·m-·2d-1。

Oxygen is an important limited factorof purification space in constructed wetlands, so it is very important forimproving pollutants removal efficiencyofconstructedwetlands that the optimization of oxygen distribution within wetlands. Therefore, artificial aeration was added to integrated vertical-flow constructed wetland （IVCW） through its unique aeration pipe. Four aeration parameters such as aeration position （S）, aeration rate （Q 气）, aeration and stop time of the pump （tR/tS）, time of starting aeration （T） were chosen to undertake the orthogonal experiment in orderto get optimum aeration condition of IVCW.The results showed that the comparison of four aeration parameters influencing pollutants removal efficiency are as followed： （tR/tS）SQ 气T. The optimum aeration conditions are obtained as follows： aeration location is at the bottom of down-flow chamberof IVCW, Q 气 = 0.25 m3·h-1, tR/tS = 8 h/16 h, T is the time of influent. It is also observed that there was significant correlation between TN mass removal and the amount of oxygen supply.When the amount of oxygen supply is 2 m3·d-1,COD、TN and TP mass removal in IVCW are 16 g·m-2·d-1,1.6 g·m-2·d-1 and 0.20 g·m-2·d-1, respectively.