表面流-垂直流复合湿地去除低碳氮比河水中氨氮

Removal of Ammonia Nitrogen from River Water with Low C/N Ratio Using Surface Flow-Vertical Flow Integrated Constructed Wetland

为了研究丹河人工湿地在不同温度下对低C/N值河水中氨氮的去除能力,于2015年1月—6月对丹河人工湿地各处理单元进、出水中NH_4^+-N和COD进行了逐日监测。结果显示,沉水植物型表面流-垂直流复合人工湿地对河水中NH_4^+-N的平均去除率随温度的升高从50.1%上升到80.2%,低温条件下,NH_4^+-N主要在垂直流湿地单元中被去除。温度<15℃时,复合系统中垂直流单元对NH_4^+-N的去除率介于50.6%~72.3%之间,显著高于单一垂直流人工湿地(27.5%~45.8%),说明表面流人工湿地有助于后续垂直流人工湿地对氨氮的去除。通过对湿地各单元进、出水中溶解氧含量的测定,推测表面流湿地单元的增氧作用可能是保证后续垂直流单元在低温条件下具有高氨氮去除能力的主要原因。

The removal of NH4^＋ - N from low C/N ratio river water under different temperature in the Danhe constructed wetland was investigated. The concentrations of NH4^＋ - N and COD in both influent and effluent of each unit were monitored from January to June, 2015. The results showed that the removal rate of NH4^＋ - N in the surface flow - vertical flow integrated constructed wetland increased from 50.1% to 80.2% as the temperature rose, and the NH4^＋ - N was mainly removed in the vertical flow constructed wetland under low temperature condition. When the temperature was below 15 ℃, the removal rate of NH4＋ - N in the vertical flow constructed wetland in the integrated system remained between 50.6% and 72.3% , and the removal rate in the vertical flow constructed wetland only system was from 27.5% to 45.8%, which suggested that the surface flow constructed wetland with submerged plant contributed to the removal of dissolved oxygen in of NH4 - N in the subsequent vertical flow constructed wetland. The measurement each unit indicated that the oxygen supply in surface flow constructed wetland was beneficial to the high removal efficiency of NH4 - N in vertical flow constructed wetland .