间歇曝气潜流人工湿地的污水脱氮效果

采用间歇曝气运行方式,提升潜流人工湿地生活污水处理系统中的溶解氧浓度,强化脱氮效果。结果表明,间歇曝气运行方式有效提高了湿地内部溶解氧水平,曝气时溶解氧浓度可达6~9 mg/L,停止曝气后,溶解氧浓度迅速下降至0.5 mg/L以下,在湿地内部营造了一种交替的好氧和缺氧环境,分别促进好氧硝化和缺氧反硝化作用。在水力停留时间为3 d的情况下,间歇曝气潜流人工湿地系统对氨氮、总氮和COD的去除率分别可达到98.0%、87.6%和96.3%,较常规潜流人工湿地系统分别提高了74.1%、56.4%和18.1%,实现了氨氮、总氮和COD的同步高效去除。

Effect of intermittent aeration on performance of nitrogen removal in domestic wastewater treatment by subsurface constructed wetlands

The effect of intermittent artificial aeration on the performance of domestic wastewater treatment was investigated in subsurface constructed wetlands.Intermittent artificial aeration was used to increase dissolved oxygen conditions,and improve the nitrogen removal rates in the wetland reactors.The results showed that intermittent artificial aeration could greatly improve the dissolved oxygen level,the dissolved oxygen concentration could be as high as 6~9 mg/L during aeration time,and lower than 0.5 mg/L when aeration was turned off.It could create a favorable alternate aerobic and anaerobic wetland environment to promote nitrification and denitrification,respectively.The intermittently aerated constructed wetland could simultaneously obtain much higher removal rates of ammonia nitrogen,total nitrogen and COD under the hydraulic retention time of 3 d,which were 98.0%,87.6% and 96.3%,respectively.