垂直潜流人工湿地由于自身构造的限制,传氧能力较差,内部溶解氧(DO)浓度较低,若在湿地内部曝气则会限制反硝化的进行,不利于TN的去除。为解决这一问题,对垂直潜流人工湿地进行起端曝气,考察不同曝气强度下人工湿地内DO沿程变化以及污染物沿程去除规律,通过对曝气强度进行优化,以实现对湿地内部DO环境的有效调控。结果表明,随曝气强度的增加,湿地的好氧环境从表层区域逐渐扩大到40cm深度,且起端曝气人工湿地对COD、氨氮和TP的降解为垂直方向分层降解;当曝气强度达到0.86m~3/d时,COD、氨氮、TP去除率均高达80%以上,分别为85.8%、80.9%、82.7%。
Due to the limit of the vertical flow constructed wetland structure,the oxygen transfer capacity of vertical flow constructed wetland was weak and internal dissolved oxygen(DO)concentration was low.Continuous aeration in the constructed wetland would restrict the denitrification,which was not conducive to the removal of TN.To solve the problem,front aeration vertical flow constructed wetlands were proposed to investigate the variation of DO and removal of pollutants in constructed wetland under different aeration intensity.By optimizing the aeration intensity,effective control of DO within the constructed wetland environment could be realized.Results showed that with increasing of aeration intensity,aerobic environment in the constructed wetland gradually expanded from the surface area to 40 cm depth.In the aeration system,the degradation of COD,ammonia nitrogen and TP showed layered degradation in the vertical direction.When the aeration intensity reached 0.86m3/d,the removal efficiencies of COD,ammonia nitrogen and TP were all up to 80%,which were 85.8%,80.9% and 82.7%,respectively.