Removal of organic matter and nitrogen from wastewater by integrated vertical flow constructed wetland
复合人工湿地去除生活污水中的有机物和氮

To improve the sewage treatment capacity of constructed wetland, the traditional single vertical flow wetland was improved and optimized to two linked vertical flow constructed wetland. Aeration was increased in the aerobic wetland and the dissolved oxygen within the aerobic wetlands remained in 2~2.5 mg/L, and then the recirculation was added. The results showed that the removal rate of effluent COD and NH3-N was significantly improved with increasing aeration, but the TN removal efficiency still could not reach the standard. With the increasing of reflux ratio, the removal rate of NH3-N increased slightly and gradually kept stable, while the removal rate of TN increased significantly. When the recirculation ratio got too large, the removal rate of TN would decrease.