Advanced treatment of secondary aerobic unit effluent by combined constructed wetlands [组合型人工湿地对二级好氧单元出水的深度处理]

作者：Zhang L.; Yang Y.^*; Zhang Q.; Sun X.; Wu S.; Chen F.

来源：Chinese Journal of Environmental Engineering, 2019, 13(7): 1592-1601.

DOI：10.12030/j.cjee.201811083

• Advanced nitrogen removal
• Canna indica
• Domestic sewage
• Subsurface flow constructed wetland
• Tidal flow

After aerobic treatment, organic carbon is normally depleted which limits the subsequent denitrification. Therefore, three new type constructed wetlands (CWs) named as CW1, CW2 and CW3, combining tidal flow constructed wetland (TFCW) and subsurface flow constructed wetland (SSFCW), were constructed to treat effluent from aerobic unit with raw sewage as organic carbon source. In these three CWs, Canna indica was planted on the top surface of CW2 and CW3, down-up compound flow was used in CW1 and CW3, while one-way flow was used in CW2. At hydraulic loading rate of 30 cm?d-1, COD removal efficiencies by all CWs were about 70%. The average removal efficiencies of NH_4^+-N, TN and TP by CW1 were 71.2%, 51.7% and 35.9%, respectively. CW2 had the best performance on NH_4^+-N removal (91.5%) and the worst performance on TN removal (38.3%). Comparably, CW3 could remove 69.9% of TN and 62.2% of TP in average, which were higher than CW1 and CW2. Consequently, better comprehensive removal efficiencies of pollutants were achieved in CW3 with compound flow and Canna indica, which could provide useful information for optimizing the design of constructed wetlands and the advanced treatment of domestic sewage with low C/N ratio.

• 单位
  中国科学院大学