摘要
Three typical constructed wetlands(CWs)including Vertical Flow(VF),Free Water Surface(FWS),and Subsurface Flow(SF),and combined VF-SF-FWS constructed wetlands were investigated for the treatment of domestic wastewater with low C/N ratio.The performance of nutrient removal and the characteristics of greenhouse gas emissions,such as CH4 and N2O,from these CWs were compared.The results indicated that the four types of CWs had high removal efficiencies for organic matter and suspended solid(SS).The combined wetland also showed a comparatively good performance for nitrogen and phosphorus removal,and the removal efficiencies for total nitrogen(TN)and total phosphorus(TP)were 81.3%and 84.5%,respectively.The combined CWs had a comparative lower global warming potential.The FWS CW had the highest tendency to emit CH4 and led to a higher global warming potential among the four types of CWs,which was about 586 mg CO_(2)/m^(2)·h.
