复合垂直流人工湿地氧化还原特征及不同功能区净化作用研究

研究了复合垂直流人工湿地系统氧化还原电位（Eh）的时空变化规律及不同功能区中污染物的净化效果。结果表明：湿地系统下行流池表层、两池底层、上行流池表层Eh的变化范围分别为402～585、-87～-130、308～432 mV，沿水流方向依次形成了好氧A区/缺氧、厌氧区/好氧B区3个功能区。好氧A区是污染物去除的主要区域，BOD₅、COD_Cr、NH⁺_4- N的去除率分别为430%、484%、541%，特别是NH+4 N去除率占总去除率的79%；缺氧、厌氧区主要是进行反硝化反应和有机物的厌氧分解；好氧B区则主要是去除厌氧分解后的有机物以及进一步脱氮。另外，NH+4 N的去除率与系统各功能区Eh呈显著相关关系（〖WTBX〗p〖WTBZ〗＜001），而BOD₅、COD_Cr、NO^-_3-N的去除率与系统各功能区Eh相关性不显著。

REDOX CHARACTER AND PURIFICATION OF DIFFERENT FUNCTIONUNITS IN INTEGRATED VERTICAL-FLOW CONSTRUCTED WETLAND

Spatio temporal variation of redox potential (Eh) in the integrated vertical flow constructed wetland (IVCW) and purification efficiency of pollutants in different function units have been studied.The results showed that the Eh of down flow surface strata,bottom strata and up flow surface strata in IVCW were 402～585 mV,-87～-130 mV and 308～432 mV,respectively.The IVCW system could be divided into three function units along the water flow direction—oxic A unit,anaerobic unit and oxic B unit.Oxic A unit is the predominant area for pollutants removing,of which the removal efficiency of BOD5、CODCr、NH+4 N were 430%,484%,541%,respectively,especially the NH+4 N,accounting for 79% of the total removal efficiency.Denitrification and anaerobic decomposition of organic matters primarily occurred in anaerobic unit.The further removal of organic matters after anaerobic decomposing and further nitrogen removal occurred in oxic B unit.It was also observed that there was significant correlation between the removal efficiency of NH⁺₄-N and Eh of different function units in the system（p＜001）,but the correlation between the removal efficiency of BOD₅、COD_Cr、NO^-₃-N and Eh of different function units were not significant.