黄铁矿强化人工湿地反硝化处理含氮废水的研究

Enhancement of denitrification by pyrite in constructed wetland for the treatment of nitrogen containing wastewater

通过构建黄铁矿垂直流人工湿地(PCW)和对照组湿地(CW0),考察黄铁矿强化人工湿地对含氮废水的处理效果,分析最佳脱氮条件下不同形态氮的沿程变化,探索氮转化去除途径。结果表明:PCW的脱氮效率优于对照组,NO_(2)^(-)-N、NH_(4)^(+)-N和SO_(4)^(2-)积累显著降低。碳氮比为6、HRT为12 h时PCW脱氮效果最好,对NO_(3)^(-)-N、TN和COD的去除率分别为95.6%,92.1%、83.0%,比CW0提高了7.5%、14.1%、5.5%。沿程变化表明NO_(3)^(-)-N、TN浓度沿水流方向明显降低。湿地上部10~30 cm处COD大部分得到去除,底部NO_(2)^(-)-N、NH_(4)^(+)-N维持在较低水平。

Pyrite vertical-flow constructed wetland(PCW)and control constructed wetland(CW0)were established.The effects of strengthen constructed wetland of pyrite for treatment of nitrogen containing wastewater was investigat-ed.The change of different forms of nitrogen along the path under the optimal conditions was analyzed,and the ways to remove nitrogen was explored.The results showed that the nitrogen removal effect of PCW was higher than that of CW0,and the accumulation of NO_(2)^(-)N,NH_(4)^(+)-N and SO_(4)^(2-)was significantly lower than that of CW0.When carbonnitrogen ratio 6 and HRT=12 h,the average removal efficiency of NO_(3)^(-)-N,TN and COD of PCW were 95.6%,92.1%and 83.0%,respectively,which was 7.5%,14.1%and 5.5%higher than that in CW0.The variation along the path indicated that NO_(3)^(-)-N,TN decreased significantly in the flow direction.A majority of COD were removed at 10-30 cm depth,and the accumulation of NO_(2)^(-)N,NH_(4)^(+)-N maintained at a low level.