Effect of artificial aeration on the performance of vertical-flow constructed wetland treating heavily polluted river water.
Three lab-scale vertical-flow constructed wetlands (VFCWs), including the non-aerated (NA), intermittently aerated (IA) and continuously aerated (CA) ones, were operated at different hydraulic loading rates (HLRs) to evaluate the effect of artificial aeration on the treatment efficiency of heavily polluted river water. Results indicated that artificial aeration increased the dissolved oxygen (DO) concentrations in IA and CA, which significantly favored the removal of organic matter and NH(4+)-N. The DO grads caused by intermittent aeration formed aerobic and anoxic regions in IA and thus promoted the removal of total nitrogen (TN). Although the removal efficiencies of COD(Cr), NH(4+)-N and TN in the three VFCWs all decreased with an increase in HLR, artificial aeration enhanced the reactor resistance to the fluctuation of pollutant loadings. The maximal removal efficiencies of COD(Cr), NH(4+)-N and total phosphorus (TP) (i.e., 81%, 87% and 37%, respectively) were observed in CA at 19 cm/day HLR, while the maximal TN removal (i.e., 57%) was achieved in IA. Although the improvement of artificial aeration on TP removal was limited, this study has demonstrated the feasibility of applying artificial aeration to VFCWs treating polluted river water, particularly at a high HLR.
State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. hydong_st@rcees.ac.cn
Huiyu
H
Dong
Zhimin
Z
Qiang
Tinggang
T
Li
Hui
H
Jin
Weidong
W
Chen
D057919:Biological Oxygen Demand Analysis; D009566:Nitrates / Q000302:isolation & purification; D009584:Nitrogen / Q000302:isolation & purification; D010100:Oxygen / Q000737:chemistry*; D010758:Phosphorus / Q000302:isolation & purification; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D012212:Rheology; D045483:Rivers / Q000737:chemistry*; D012995:Solubility; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014876:Water Pollution / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen; D010100:Oxygen