Influence of depth on running effect of surface-flow constructed wetland treating polluted river water
水深对表面流人工湿地污染河水处理系统运行效果的影响

Based on one year continuous operation monitoring of pilot system,the influence of depth on Phragmites australis surface-flow constructed wetland treating polluted river water was studied.The results showed that depth had a great impact on the treatment performance of constructed wetland.When COD,ammonia nitrogen,total nitrogen(TN),total phosphorus(TP) of influent were 36±4.46 mg/L,0.92±0.47 mg/L,6.27±2.01 mg/L,0.13±0.05 mg/L,respectively,the depth of 50 cm had the best treatment performance: COD,ammonia nitrogen,TN,TP removal rates reached 42.75%,58.42%,56.94%,43.24%,respectively.Considering pollutants removal and constructed wetland construction project quantity,surface-flow constructed wetland should adopt the depth of 50 cm.The study of the plant photosynthetic physiology and dissolved oxygen condition showed that depth affected water purifying ability by influencing the plant photosynthetic physiology and dissolved oxygen condition,etc.